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hw/i2c: Introduce i2c_start_recv() and i2c_start_send()
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To ease reviewing code using the I2C bus API, introduce the
i2c_start_recv() and i2c_start_send() helpers which don't
take the confusing 'is_recv' boolean argument.

Use these new helpers in the SMBus / AUX bus models.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
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@philmd @cminyard
philmd authored and cminyard committed Jul 8, 2021
1 parent 265caf4 commit 90603c5
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Showing 5 changed files with 53 additions and 19 deletions.
10 changes: 10 additions & 0 deletions hw/i2c/core.c
View file
Expand Up @@ -180,6 +180,16 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv)
: I2C_START_SEND);
}

int i2c_start_recv(I2CBus *bus, uint8_t address)
{
return i2c_do_start_transfer(bus, address, I2C_START_RECV);
}

int i2c_start_send(I2CBus *bus, uint8_t address)
{
return i2c_do_start_transfer(bus, address, I2C_START_SEND);
}

void i2c_end_transfer(I2CBus *bus)
{
I2CSlaveClass *sc;
Expand Down
4 changes: 2 additions & 2 deletions hw/i2c/pm_smbus.c
View file
Expand Up @@ -128,14 +128,14 @@ static void smb_transaction(PMSMBus *s)
* So at least Linux may or may not set the read bit here.
* So just ignore the read bit for this command.
*/
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
goto error;
}
ret = i2c_send(bus, s->smb_data1);
if (ret) {
goto error;
}
if (i2c_start_transfer(bus, addr, 1)) {
if (i2c_start_recv(bus, addr)) {
goto error;
}
s->in_i2c_block_read = true;
Expand Down
22 changes: 11 additions & 11 deletions hw/i2c/smbus_master.c
View file
Expand Up @@ -29,7 +29,7 @@ int smbus_receive_byte(I2CBus *bus, uint8_t addr)
{
uint8_t data;

if (i2c_start_transfer(bus, addr, 1)) {
if (i2c_start_recv(bus, addr)) {
return -1;
}
data = i2c_recv(bus);
Expand All @@ -40,7 +40,7 @@ int smbus_receive_byte(I2CBus *bus, uint8_t addr)

int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
{
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, data);
Expand All @@ -51,11 +51,11 @@ int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)
{
uint8_t data;
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
if (i2c_start_transfer(bus, addr, 1)) {
if (i2c_start_recv(bus, addr)) {
i2c_end_transfer(bus);
return -1;
}
Expand All @@ -67,7 +67,7 @@ int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)

int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
{
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
Expand All @@ -79,11 +79,11 @@ int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)
{
uint16_t data;
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
if (i2c_start_transfer(bus, addr, 1)) {
if (i2c_start_recv(bus, addr)) {
i2c_end_transfer(bus);
return -1;
}
Expand All @@ -96,7 +96,7 @@ int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)

int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
{
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
Expand All @@ -113,12 +113,12 @@ int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
int i;

if (send_cmd) {
if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
}
if (i2c_start_transfer(bus, addr, 1)) {
if (i2c_start_recv(bus, addr)) {
if (send_cmd) {
i2c_end_transfer(bus);
}
Expand Down Expand Up @@ -149,7 +149,7 @@ int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
len = 32;
}

if (i2c_start_transfer(bus, addr, 0)) {
if (i2c_start_send(bus, addr)) {
return -1;
}
i2c_send(bus, command);
Expand Down
12 changes: 6 additions & 6 deletions hw/misc/auxbus.c
View file
Expand Up @@ -135,7 +135,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
i2c_end_transfer(i2c_bus);
}

if (i2c_start_transfer(i2c_bus, address, true)) {
if (i2c_start_recv(i2c_bus, address)) {
ret = AUX_I2C_NACK;
break;
}
Expand All @@ -151,7 +151,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
i2c_end_transfer(i2c_bus);
}

if (i2c_start_transfer(i2c_bus, address, false)) {
if (i2c_start_send(i2c_bus, address)) {
ret = AUX_I2C_NACK;
break;
}
Expand Down Expand Up @@ -179,7 +179,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
/*
* No transactions started..
*/
if (i2c_start_transfer(i2c_bus, address, false)) {
if (i2c_start_send(i2c_bus, address)) {
break;
}
} else if ((address != bus->last_i2c_address) ||
Expand All @@ -188,7 +188,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
* Transaction started but we need to restart..
*/
i2c_end_transfer(i2c_bus);
if (i2c_start_transfer(i2c_bus, address, false)) {
if (i2c_start_send(i2c_bus, address)) {
break;
}
}
Expand All @@ -210,7 +210,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
/*
* No transactions started..
*/
if (i2c_start_transfer(i2c_bus, address, true)) {
if (i2c_start_recv(i2c_bus, address)) {
break;
}
} else if ((address != bus->last_i2c_address) ||
Expand All @@ -219,7 +219,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
* Transaction started but we need to restart..
*/
i2c_end_transfer(i2c_bus);
if (i2c_start_transfer(i2c_bus, address, true)) {
if (i2c_start_recv(i2c_bus, address)) {
break;
}
}
Expand Down
24 changes: 24 additions & 0 deletions include/hw/i2c/i2c.h
View file
Expand Up @@ -88,9 +88,33 @@ int i2c_bus_busy(I2CBus *bus);
* @address: address of the slave
* @is_recv: indicates the transfer direction
*
* When @is_recv is a known boolean constant, use the
* i2c_start_recv() or i2c_start_send() helper instead.
*
* Returns: 0 on success, -1 on error
*/
int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv);

/**
* i2c_start_recv: start a 'receive' transfer on an I2C bus.
*
* @bus: #I2CBus to be used
* @address: address of the slave
*
* Returns: 0 on success, -1 on error
*/
int i2c_start_recv(I2CBus *bus, uint8_t address);

/**
* i2c_start_send: start a 'send' transfer on an I2C bus.
*
* @bus: #I2CBus to be used
* @address: address of the slave
*
* Returns: 0 on success, -1 on error
*/
int i2c_start_send(I2CBus *bus, uint8_t address);

void i2c_end_transfer(I2CBus *bus);
void i2c_nack(I2CBus *bus);
int i2c_send(I2CBus *bus, uint8_t data);
Expand Down

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