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iPhone: Use kernel i2c interface, add wm8991
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Authors: ricky26 <rickytaylor26@gmail.com>, Fredrik Gustafsson <fredrik@fredrik-laptop.(none)>
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@planetbeing
Fredrik Gustafsson authored and planetbeing committed May 10, 2010
1 parent fe59c82 commit 865c42f
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Showing 12 changed files with 2,790 additions and 188 deletions.
272 changes: 197 additions & 75 deletions arch/arm/mach-apple_iphone/i2c.c
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Expand Up @@ -5,6 +5,7 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <mach/iphone-i2c.h>
#include <mach/gpio.h>
#include <mach/iphone-clock.h>
Expand All @@ -17,9 +18,9 @@
#include <linux/io.h>

static const I2CInfo I2CInit[] = {
{0, 0, I2CNoError, 0, 0, I2CDone, 0, 0, 0, 0, 0, NULL, 0, NULL, I2C0_SCL_GPIO, I2C0_SDA_GPIO, I2C0 + IICCON, I2C0 + IICSTAT, I2C0 + IICADD, I2C0 + IICDS, I2C0 + IICLC,
{NULL, 0, I2CNoError, 0, 0, 0, I2CDone, 0, 0, 0, 0, 0, NULL, 0, NULL, I2C0_SCL_GPIO, I2C0_SDA_GPIO, I2C0 + IICCON, I2C0 + IICSTAT, I2C0 + IICADD, I2C0 + IICDS, I2C0 + IICLC,
I2C0 + IICREG14, I2C0 + IICREG18, I2C0 + IICREG1C, I2C0 + IICREG20},
{0, 0, I2CNoError, 0, 0, I2CDone, 0, 0, 0, 0, 0, NULL, 0, NULL, I2C1_SCL_GPIO, I2C1_SDA_GPIO, I2C1 + IICCON, I2C1 + IICSTAT, I2C1 + IICADD, I2C1 + IICDS, I2C1 + IICLC,
{NULL, 0, I2CNoError, 0, 0, 0, I2CDone, 0, 0, 0, 0, 0, NULL, 0, NULL, I2C1_SCL_GPIO, I2C1_SDA_GPIO, I2C1 + IICCON, I2C1 + IICSTAT, I2C1 + IICADD, I2C1 + IICDS, I2C1 + IICLC,
I2C1 + IICREG14, I2C1 + IICREG18, I2C1 + IICREG1C, I2C1 + IICREG20}
};

Expand All @@ -29,42 +30,61 @@ static void init_i2c(I2CInfo* i2c, u32 frequency);
static I2CError iphone_i2c_readwrite(I2CInfo* i2c);
static void do_i2c(I2CInfo* i2c);

int __init iphone_i2c_setup(void) {
static struct i2c_adapter iphone_i2c0;
static struct i2c_adapter iphone_i2c1;

static int initialized = 0;

static int iphone_i2c_setup(void) {
printk("iphone-i2c: inside setup...\n");
memcpy(I2C, I2CInit, sizeof(I2CInfo) * 2);

I2C[0].rw_sem = (struct mutex *)kzalloc(sizeof(struct mutex), GFP_KERNEL);
I2C[1].rw_sem = (struct mutex *)kzalloc(sizeof(struct mutex), GFP_KERNEL);

mutex_init(I2C[0].rw_sem);
mutex_init(I2C[1].rw_sem);

iphone_clock_gate_switch(I2C0_CLOCKGATE, 1);
iphone_clock_gate_switch(I2C1_CLOCKGATE, 1);

init_i2c(&I2C[0], FREQUENCY_PERIPHERAL / 100000);
init_i2c(&I2C[1], FREQUENCY_PERIPHERAL / 100000);

printk("iphone-i2c: done setup!\n");
initialized = 1;
return 0;
}
module_init(iphone_i2c_setup);

I2CError iphone_i2c_rx(int bus, int iicaddr, const uint8_t* registers, int num_regs, void* buffer, int len) {
I2CError iphone_i2c_recv(int bus, int iicaddr, int send_stop, void* buffer, int len) {
I2CError ret;
mutex_lock(I2C[bus].rw_sem);
I2C[bus].address = iicaddr;
I2C[bus].is_write = 0;
I2C[bus].registers = registers;
I2C[bus].num_regs = num_regs;
I2C[bus].send_stop = send_stop;
I2C[bus].bufferLen = len;
I2C[bus].buffer = (uint8_t*) buffer;
return iphone_i2c_readwrite(&I2C[bus]);
ret = iphone_i2c_readwrite(&I2C[bus]);
mutex_unlock(I2C[bus].rw_sem);
return ret;
}

I2CError iphone_i2c_tx(int bus, int iicaddr, const void* buffer, int len) {
I2CError iphone_i2c_send(int bus, int iicaddr, int send_stop, const void* buffer, int len) {
I2CError ret;
mutex_lock(I2C[bus].rw_sem);
I2C[bus].address = iicaddr;
I2C[bus].is_write = 1;
I2C[bus].registers = NULL;
I2C[bus].num_regs = 0;
I2C[bus].send_stop = send_stop;
I2C[bus].bufferLen = len;
I2C[bus].buffer = (uint8_t*) buffer;
return iphone_i2c_readwrite(&I2C[bus]);
ret = iphone_i2c_readwrite(&I2C[bus]);
mutex_unlock(I2C[bus].rw_sem);
return ret;
}

static void init_i2c(I2CInfo* i2c, u32 frequency) {
int prescaler, divisorRequired;
int i;
printk("iphone-i2c: start initializing!\n");
i2c->frequency = 2560000 / frequency;
divisorRequired = 640000 / i2c->frequency;
if(divisorRequired < 512) {
Expand All @@ -90,13 +110,14 @@ static void init_i2c(I2CInfo* i2c, u32 frequency) {

iphone_gpio_custom_io(i2c->iic_scl_gpio, 0x2); // generate stop condition?
iphone_gpio_custom_io(i2c->iic_sda_gpio, 0x2);
printk("iphone-i2c: init done!\n");
}

static I2CError iphone_i2c_readwrite(I2CInfo* i2c) {
__raw_writel(i2c->iiccon_settings, i2c->register_IICCON);

i2c->iiccon_settings |= IICCON_ACKGEN;
i2c->state = I2CStart;
i2c->state = I2CSetup;
i2c->operation_result = 0;
i2c->error_code = I2CNoError;

Expand All @@ -122,7 +143,11 @@ static I2CError iphone_i2c_readwrite(I2CInfo* i2c) {

do_i2c(i2c);
}


if(i2c->error_code != I2CNoError)
{
printk("I2C %s Command Failed!\n", i2c->is_write ? "Write" : "Read");
}
return i2c->error_code;
}

Expand All @@ -131,78 +156,26 @@ static void do_i2c(I2CInfo* i2c) {
while(i2c->operation_result == 0 || proceed) {
proceed = 0;
switch(i2c->state) {
case I2CStart:
if(i2c->num_regs != 0) {
__raw_writel(i2c->iiccon_settings, i2c->register_IICCON);
__raw_writel(i2c->address, i2c->register_IICDS);
i2c->operation_result = OPERATION_SEND;
i2c->current_iicstat =
(IICSTAT_MODE_MASTERTX << IICSTAT_MODE_SHIFT)
| (IICSTAT_STARTSTOPGEN_START << IICSTAT_STARTSTOPGEN_SHIFT)
| (1 << IICSTAT_DATAOUTPUT_ENABLE_SHIFT);
__raw_writel(i2c->current_iicstat, i2c->register_IICSTAT);
i2c->cursor = 0;
i2c->state = I2CSendRegister;
} else {
i2c->operation_result = 0;
i2c->state = I2CSetup;
proceed = 1;
}
break;
case I2CSendRegister:
if((__raw_readl(i2c->register_IICSTAT) & IICSTAT_LASTRECEIVEDBIT) == 0) {
// ack received
if(i2c->cursor != i2c->num_regs) {
// need to send more from the register list
i2c->operation_result = OPERATION_SEND;
__raw_writel(i2c->registers[i2c->cursor++], i2c->register_IICDS);
__raw_writel(i2c->iiccon_settings | IICCON_INTPENDING, i2c->register_IICCON);
} else {
i2c->state = I2CRegistersDone;
proceed = 1;
}
} else {
// ack not received
printk("iphone-i2c: ack not received before register/command %d\n", i2c->cursor);
i2c->error_code = -1;
i2c->state = I2CFinish;
proceed = 1;
}
break;
case I2CRegistersDone:
if(i2c->is_write) {
i2c->state = I2CSetup;
proceed = 1;
} else {
i2c->operation_result = OPERATION_CONDITIONCHANGE;
i2c->current_iicstat &= (IICSTAT_MODE_SLAVETX << IICSTAT_MODE_SHIFT) | (IICSTAT_STARTSTOPGEN_MASK << IICSTAT_STARTSTOPGEN_SHIFT);
__raw_writel(i2c->current_iicstat, i2c->register_IICSTAT);
__raw_writel(i2c->iiccon_settings | IICCON_INTPENDING, i2c->register_IICCON);
i2c->state = I2CSetup;
}
break;
case I2CSetup:
__raw_writel(i2c->iiccon_settings | IICCON_ACKGEN, i2c->register_IICCON);
__raw_writel(i2c->address, i2c->register_IICDS);
i2c->operation_result = OPERATION_SEND;
if(i2c->is_write) {
__raw_writel(i2c->address & ~1, i2c->register_IICDS);
i2c->current_iicstat =
(IICSTAT_MODE_MASTERTX << IICSTAT_MODE_SHIFT)
| (IICSTAT_STARTSTOPGEN_START << IICSTAT_STARTSTOPGEN_SHIFT)
| (1 << IICSTAT_DATAOUTPUT_ENABLE_SHIFT);
i2c->state = I2CTx;
} else {
__raw_writel(i2c->address | 1, i2c->register_IICDS);
i2c->current_iicstat =
(IICSTAT_MODE_MASTERRX << IICSTAT_MODE_SHIFT)
| (IICSTAT_STARTSTOPGEN_START << IICSTAT_STARTSTOPGEN_SHIFT)
| (1 << IICSTAT_DATAOUTPUT_ENABLE_SHIFT);
i2c->state = I2CRxSetup;
}
__raw_writel(i2c->current_iicstat, i2c->register_IICSTAT);
i2c->cursor = 0;
if(i2c->is_write) {
i2c->state = I2CTx;
} else {
i2c->state = I2CRxSetup;
}
break;
case I2CTx:
if((__raw_readl(i2c->register_IICSTAT) & IICSTAT_LASTRECEIVEDBIT) == 0) {
Expand Down Expand Up @@ -247,11 +220,17 @@ static void do_i2c(I2CInfo* i2c) {
break;
case I2CFinish:
i2c->operation_result = OPERATION_CONDITIONCHANGE;
i2c->current_iicstat &= ~(IICSTAT_STARTSTOPGEN_MASK << IICSTAT_STARTSTOPGEN_SHIFT);
if(i2c->is_write) {
// turn off the tx bit in the mode
i2c->current_iicstat &= ~(IICSTAT_MODE_SLAVETX << IICSTAT_MODE_SHIFT);
/* Is this legal? */
if(i2c->send_stop) {
i2c->current_iicstat &= ~(IICSTAT_STARTSTOPGEN_MASK << IICSTAT_STARTSTOPGEN_SHIFT);
if(i2c->is_write) {
// turn off the tx bit in the mode
i2c->current_iicstat &= ~(IICSTAT_MODE_SLAVETX << IICSTAT_MODE_SHIFT);
}
} else {
i2c->current_iicstat = (IICSTAT_MODE_MASTERRX << IICSTAT_MODE_SHIFT) | (IICSTAT_STARTSTOPGEN_MASK << IICSTAT_STARTSTOPGEN_SHIFT);
}

__raw_writel(i2c->current_iicstat, i2c->register_IICSTAT);
__raw_writel(i2c->iiccon_settings | IICCON_INTPENDING, i2c->register_IICCON);
i2c->state =I2CDone;
Expand All @@ -263,3 +242,146 @@ static void do_i2c(I2CInfo* i2c) {
}
}

static int iphone_i2c_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs, int num)
{
int ret = 0;
int bus, send_stop, i;
struct i2c_msg *msg;
for(i=0; i<num; i++)
{
msg = &msgs[i];
send_stop = (i == num-1) || (msgs[i+1].addr != msg->addr);
bus = (adapter == &iphone_i2c1) ? 1 : 0;

if(msg->flags & I2C_M_RD)
ret = iphone_i2c_recv(bus, msg->addr, send_stop, msg->buf, msg->len);
else
ret = iphone_i2c_send(bus, msg->addr, send_stop, msg->buf, msg->len);

if(ret != I2CNoError)
return -EIO;
}

return num;
}

/* TEMPORARY LEGACY SUPPORT */

I2CError iphone_i2c_rx(int bus, int iicaddr, const uint8_t* registers, int num_regs, void* buffer, int len)
{
I2CError ret;
struct i2c_msg xfer[2];

/* Write register */
xfer[0].addr = iicaddr;
xfer[0].flags = 0;
xfer[0].len = num_regs;
xfer[0].buf = (u8 *)registers;

xfer[1].addr = iicaddr;
xfer[1].flags = I2C_M_RD;
xfer[1].len = len;
xfer[1].buf = (u8 *)buffer;

ret = iphone_i2c_xfer(NULL, xfer, 2);
return ret;
}

I2CError iphone_i2c_tx(int bus, int iicaddr, void* buffer, int len)
{
I2CError ret;
struct i2c_msg xfer[1];

/* Write register */
xfer[0].addr = iicaddr;
xfer[0].flags = 0;
xfer[0].len = len;
xfer[0].buf = (u8 *)buffer;

ret = iphone_i2c_xfer(NULL, xfer, 1);
return ret;
}


static u32 iphone_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C;
}

static const struct i2c_algorithm iphone_i2c_algorithm = {
.master_xfer = iphone_i2c_xfer,
.functionality = iphone_i2c_func,
};

static struct i2c_adapter iphone_i2c0 = {
.id = 0,
.owner = THIS_MODULE,
.class = 0,
.algo = &iphone_i2c_algorithm,
};

static struct i2c_adapter iphone_i2c1 = {
.id = 1,
.owner = THIS_MODULE,
.class = 0,
.algo = &iphone_i2c_algorithm,
};

static int __init iphone_i2c_init(void)
{
int ret = 0;

iphone_i2c_setup();
printk("iphone-i2c: Initialising I2C busses!\n");

ret = i2c_add_numbered_adapter(&iphone_i2c0);
if(ret)
{
printk("iphone-i2c: Failed to add I2C Bus #0.\n");
return ret;
}

ret = i2c_add_numbered_adapter(&iphone_i2c1);
if(ret)
{
printk("iphone-i2c: Failed to add I2C Bus #1.\n");
return ret;
}

return ret;
}

static void __exit iphone_i2c_exit(void)
{
i2c_del_adapter(&iphone_i2c0);
i2c_del_adapter(&iphone_i2c1);
}

module_init(iphone_i2c_init);
module_exit(iphone_i2c_exit);

static struct resource iphone_i2c_resources[] = {
[0] = {
.start = I2C0,
.end = I2C0 + 0x1000 - 1,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = I2C1,
.end = I2C1 + 0x1000 - 1,
.flags = IORESOURCE_MEM,
},
};

struct platform_device iphone_i2c = {
.name = "iphone-i2c",
.id = -1,
.num_resources = ARRAY_SIZE(iphone_i2c_resources),
.resource = iphone_i2c_resources,
};

MODULE_AUTHOR("Fredrik Gustafsson <frgustaf@kth.se>");
MODULE_DESCRIPTION("iPhone i2c adapter");
MODULE_LICENSE("GPL");

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