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Fixes i2c_bcm2708: Write to FIFO correctly - v2 #1574

Merged
merged 2 commits into from Aug 29, 2016
Merged

Fixes i2c_bcm2708: Write to FIFO correctly - v2 #1574

merged 2 commits into from Aug 29, 2016

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SimonMaes
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Check if FIFO can accept data before writing.

@SimonMaes
i2c: fix i2c_bcm2708: Clear FIFO before sending data
3a46cfd 
Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).
@popcornmix
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Can you describe the use case that this fixes?
Looks sane to me. @pelwell ?
Anyone else who cares about I2C? @DFyson perhaps?

@pelwell
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pelwell commented Aug 23, 2016

Can you explain your logic a bit more?

  • Why is it necessary and safe to clear the FIFO?
  • Unless I've missed something, you don't seem to handle the FIFO filling in the combined case. Yes you bail out early, but then you zero the pos field, losing any indication that the transfer wasn't completed.

@SimonMaes
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Hi all, hi @pelwell,

  • During debugging the combined mode I noticed that in case data from master (rPi) to slave doesn't get ACK'ed by the slave, the remaining bytes resides in the FIFO register. In case we try to send additional data in combined mode, part of this new data get lost, since the FIFO is already partly filled while the remaining bytes from the previous message are getting clocked out first. Therefor its necessary to clear the FIFO every time before we fill the FIFO for writing.
  • FIFO filling in combined mode is done at line 164, unless I don't understand your question correctly :-). FIFO filling without combined mode is done using the "bcm2708_bsc_fifo_fill" function.

Thx for reviewing,
In case of remarks/questions, plz don't hesitate to ask,

@pelwell
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pelwell commented Aug 23, 2016

  • For the FIFO clearing, does this only affect the combined case? Why don't we always clear the FIFO before writing, or only clear it after an error?
  • My question was badly worded - what I meant was that the code doesn't seem to cope if the FIFO becomes full during the write. The extra condition you've added causes us to exit early from the write loop, but nowhere is that failure recorded or acted upon.

@SimonMaes
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  • Due to this commit we always clear the FIFO before writing, before the FIFO only got cleared in normal mode, see line 131 in combination with line 187.
  • The hardware ignores writes to a full FIFO, the extra condition I've added was to describe the hardware's behavior and align with "bcm2708_bsc_fifo_drain" and "bcm2708_bsc_fifo_fill" functions. I agree that it would be a necessary to log/report this "failure". I suggest to add a check in the "bcm2708_i2c_master_xfer" function to detect whether the length of each i2c_msg exceeds the maximum of 16bytes, in that case we still continue with writing the data but log, using dev_err, that the driver currently doesn't support writing packages which contain more than 16bytes.
    If we want to support writing packages with more than 16bytes, we will need to poll the hardware to check if the FIFO is ready to accept new bytes. I would suggest we do this in a different patch?

Plz. Let me know what you think.
Kr,

@pelwell
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pelwell commented Aug 24, 2016

OK - the clear makes sense. I'm still not convinced on the need for checking for fullness in the combined write case - if over-long messages are an error (which ought to be trapped earlier - a separate patch would make sense), and the hardware ignores extra writes, I don't see any value in slowing down the filling by checking for a condition that shouldn't occur and we don't do anything about when we've found it.

@SimonMaes
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OK. I follow your reasoning. For now, I'll leave the check out until we have a solution which act upon the failure. Is it OK if I remove the second commit? Are you willing to accept the first commit only? thx.

@pelwell
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pelwell commented Aug 29, 2016

I would. Even better, just drop the last section of the second commit - the first two are clearly improvements on the original code.

@SimonMaes
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OK!

@SimonMaes
i2c: fix i2c_bcm2708: avoid extra peripheral read
c589fc9 
Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed.
@popcornmix
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Okay with me if @pelwell is happy.

@pelwell pelwell merged commit 81b502c into raspberrypi:rpi-4.4.y Aug 29, 2016
@pelwell
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pelwell commented Aug 29, 2016

Thanks for persevering.

@SimonMaes
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No problem, thanks for pulling!

popcornmix pushed a commit that referenced this pull request Aug 30, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
82ef2db 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix pushed a commit that referenced this pull request Sep 5, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
3ae403b 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit to raspberrypi/firmware that referenced this pull request Sep 6, 2016
@popcornmix
kernel: i2c: fix i2c_bcm2708: Clear FIFO before sending data
36c18bb 
See: raspberrypi/linux#1574

kernel: bcm2835-sdhost: Don't exit cmd wait loop on error
kernel: BCM270X_DT: Use bcm2835-sdhost on Compute Module
See: raspberrypi/linux#1492
popcornmix added a commit to Hexxeh/rpi-firmware that referenced this pull request Sep 6, 2016
@popcornmix
kernel: i2c: fix i2c_bcm2708: Clear FIFO before sending data
67a8ae6 
See: raspberrypi/linux#1574

kernel: bcm2835-sdhost: Don't exit cmd wait loop on error
kernel: BCM270X_DT: Use bcm2835-sdhost on Compute Module
See: raspberrypi/linux#1492
popcornmix pushed a commit that referenced this pull request Sep 7, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
e2913d2 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix pushed a commit that referenced this pull request Sep 14, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
d19c612 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix pushed a commit that referenced this pull request Sep 19, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
4c70fc4 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix pushed a commit that referenced this pull request Sep 29, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
230073f 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix pushed a commit that referenced this pull request Oct 3, 2016
@SimonMaes @popcornmix
Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)
9dc54e3 
* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Oct 3, 2016
@popcornmix
Add Chris Boot's i2c driver
536501b 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Oct 9, 2016
@popcornmix
Add Chris Boot's i2c driver
54c7d49 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Oct 17, 2016
@popcornmix
Add Chris Boot's i2c driver
bef6ae3 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 6, 2024
@popcornmix
Add Chris Boot's i2c driver
87606c4 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 6, 2024
@popcornmix
Add Chris Boot's i2c driver
2171b85 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 13, 2024
@popcornmix
Add Chris Boot's i2c driver
5961398 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 19, 2024
@popcornmix
Add Chris Boot's i2c driver
7998047 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 19, 2024
@popcornmix
Add Chris Boot's i2c driver
4b496d1 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 19, 2024
@popcornmix
Add Chris Boot's i2c driver
f62028e 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 23, 2024
@popcornmix
Add Chris Boot's i2c driver
8dd0f30 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Feb 23, 2024
@popcornmix
Add Chris Boot's i2c driver
c02a5a2 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 5, 2024
@popcornmix
Add Chris Boot's i2c driver
ec299e6 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 5, 2024
@popcornmix
Add Chris Boot's i2c driver
c0cf05a 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 5, 2024
@popcornmix
Add Chris Boot's i2c driver
9c9cb5d 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 11, 2024
@popcornmix
Add Chris Boot's i2c driver
a665e14 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 11, 2024
@popcornmix
Add Chris Boot's i2c driver
a16478a 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 19, 2024
@popcornmix
Add Chris Boot's i2c driver
df71e25 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 19, 2024
@popcornmix
Add Chris Boot's i2c driver
4028a19 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 27, 2024
@popcornmix
Add Chris Boot's i2c driver
caed566 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 27, 2024
@popcornmix
Add Chris Boot's i2c driver
6807b36 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Mar 27, 2024
@popcornmix
Add Chris Boot's i2c driver
7fc1bec 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 3, 2024
@popcornmix
Add Chris Boot's i2c driver
078649a 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 5, 2024
@popcornmix
Add Chris Boot's i2c driver
fcd751a 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 5, 2024
@popcornmix
Add Chris Boot's i2c driver
87a3afd 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 8, 2024
@popcornmix
Add Chris Boot's i2c driver
628e41c 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 11, 2024
@popcornmix
Add Chris Boot's i2c driver
7d3e458 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 16, 2024
@popcornmix
Add Chris Boot's i2c driver
724cebe 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 16, 2024
@popcornmix
Add Chris Boot's i2c driver
0f0fad8 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 18, 2024
@popcornmix
Add Chris Boot's i2c driver
e7ae509 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 23, 2024
@popcornmix
Add Chris Boot's i2c driver
864733f 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 29, 2024
@popcornmix
Add Chris Boot's i2c driver
9333c41 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request Apr 29, 2024
@popcornmix
Add Chris Boot's i2c driver
4e9b191 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
popcornmix added a commit that referenced this pull request May 2, 2024
@popcornmix
Add Chris Boot's i2c driver
d420be8 
i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.

Perform I2C combined transactions when possible

Perform I2C combined transactions whenever possible, within the
restrictions of the Broadcomm Serial Controller.

Disable DONE interrupt during TA poll

Prevent interrupt from being triggered if poll is missed and transfer
starts and finishes.

i2c: Make combined transactions optional and disabled by default

i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

I2C: Only register the I2C device for the current board revision

i2c_bcm2708: Fix clock reference counting

Fix grabbing lock from atomic context in i2c driver

2 main changes:
- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
      /* poll for transfer start bit (should only take 1-20 polls) */
  This implies that the setup function can now fail so account for this everywhere it's called
- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.

i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl

i2c-bcm2708: Increase timeouts to allow larger transfers

Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting
for completion. The default timeout is 1 second.

See: #260

i2c-bcm2708/BCM270X_DT: Add support for I2C2

The third I2C bus (I2C2) is normally reserved for HDMI use. Careless
use of this bus can break an attached display - use with caution.

It is recommended to disable accesses by VideoCore by setting
hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt.

The interface is disabled by default - enable using the
i2c2_iknowwhatimdoing DT parameter.

bcm2708-spi: Don't use static pin configuration with DT

Also remove superfluous error checking - the SPI framework ensures the
validity of the chip_select value.

i2c-bcm2708: Remove non-DT support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.

Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574)

* i2c: fix i2c_bcm2708: Clear FIFO before sending data

Make sure FIFO gets cleared before trying to send
data in case of a repeated start (COMBINED=Y).

* i2c: fix i2c_bcm2708: Only write to FIFO when not full

Check if FIFO can accept data before writing.
To avoid a peripheral read on the last iteration of a loop,
both bcm2708_bsc_fifo_fill and ~drain are changed as well.
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3 participants
@SimonMaes @popcornmix @pelwell