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-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c31
-rw-r--r--drivers/i2c/busses/i2c-i801.c1
-rw-r--r--drivers/i2c/busses/i2c-mv64xxx.c45
-rw-r--r--drivers/i2c/busses/i2c-nforce2.c2
-rw-r--r--drivers/i2c/busses/i2c-omap.c83
-rw-r--r--drivers/i2c/i2c-core.c29
-rw-r--r--drivers/i2c/muxes/Kconfig12
-rw-r--r--drivers/i2c/muxes/Makefile1
-rw-r--r--drivers/i2c/muxes/gpio-i2cmux.c184
9 files changed, 299 insertions, 89 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index a39e6cff86e7..38319a69bd0a 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -600,12 +600,14 @@ static const struct i2c_algorithm i2c_bit_algo = {
/*
* registering functions to load algorithms at runtime
*/
-static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
+static int __i2c_bit_add_bus(struct i2c_adapter *adap,
+ int (*add_adapter)(struct i2c_adapter *))
{
struct i2c_algo_bit_data *bit_adap = adap->algo_data;
+ int ret;
if (bit_test) {
- int ret = test_bus(bit_adap, adap->name);
+ ret = test_bus(bit_adap, adap->name);
if (ret < 0)
return -ENODEV;
}
@@ -614,30 +616,27 @@ static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
adap->algo = &i2c_bit_algo;
adap->retries = 3;
+ ret = add_adapter(adap);
+ if (ret < 0)
+ return ret;
+
+ /* Complain if SCL can't be read */
+ if (bit_adap->getscl == NULL) {
+ dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n");
+ dev_warn(&adap->dev, "Bus may be unreliable\n");
+ }
return 0;
}
int i2c_bit_add_bus(struct i2c_adapter *adap)
{
- int err;
-
- err = i2c_bit_prepare_bus(adap);
- if (err)
- return err;
-
- return i2c_add_adapter(adap);
+ return __i2c_bit_add_bus(adap, i2c_add_adapter);
}
EXPORT_SYMBOL(i2c_bit_add_bus);
int i2c_bit_add_numbered_bus(struct i2c_adapter *adap)
{
- int err;
-
- err = i2c_bit_prepare_bus(adap);
- if (err)
- return err;
-
- return i2c_add_numbered_adapter(adap);
+ return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter);
}
EXPORT_SYMBOL(i2c_bit_add_numbered_bus);
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 02835ce7ff4b..7979aef7ee7b 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -72,6 +72,7 @@
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/dmi.h>
+#include <linux/slab.h>
/* I801 SMBus address offsets */
#define SMBHSTSTS(p) (0 + (p)->smba)
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 16242063144f..a9941c65f226 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -59,6 +59,7 @@ enum {
MV64XXX_I2C_STATE_INVALID,
MV64XXX_I2C_STATE_IDLE,
MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
+ MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
@@ -70,6 +71,7 @@ enum {
MV64XXX_I2C_ACTION_INVALID,
MV64XXX_I2C_ACTION_CONTINUE,
MV64XXX_I2C_ACTION_SEND_START,
+ MV64XXX_I2C_ACTION_SEND_RESTART,
MV64XXX_I2C_ACTION_SEND_ADDR_1,
MV64XXX_I2C_ACTION_SEND_ADDR_2,
MV64XXX_I2C_ACTION_SEND_DATA,
@@ -91,6 +93,7 @@ struct mv64xxx_i2c_data {
u32 addr2;
u32 bytes_left;
u32 byte_posn;
+ u32 send_stop;
u32 block;
int rc;
u32 freq_m;
@@ -159,8 +162,15 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
if ((drv_data->bytes_left == 0)
|| (drv_data->aborting
&& (drv_data->byte_posn != 0))) {
- drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
+ if (drv_data->send_stop) {
+ drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
+ drv_data->state = MV64XXX_I2C_STATE_IDLE;
+ } else {
+ drv_data->action =
+ MV64XXX_I2C_ACTION_SEND_RESTART;
+ drv_data->state =
+ MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
+ }
} else {
drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
drv_data->state =
@@ -228,6 +238,15 @@ static void
mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
{
switch(drv_data->action) {
+ case MV64XXX_I2C_ACTION_SEND_RESTART:
+ drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_START;
+ drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
+ writel(drv_data->cntl_bits,
+ drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
+ drv_data->block = 0;
+ wake_up_interruptible(&drv_data->waitq);
+ break;
+
case MV64XXX_I2C_ACTION_CONTINUE:
writel(drv_data->cntl_bits,
drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
@@ -386,7 +405,8 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
}
static int
-mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
+mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
+ int is_first, int is_last)
{
unsigned long flags;
@@ -406,10 +426,18 @@ mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg)
drv_data->bytes_left--;
}
} else {
- drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
- drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
+ if (is_first) {
+ drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
+ drv_data->state =
+ MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
+ } else {
+ drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
+ drv_data->state =
+ MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
+ }
}
+ drv_data->send_stop = is_last;
drv_data->block = 1;
mv64xxx_i2c_do_action(drv_data);
spin_unlock_irqrestore(&drv_data->lock, flags);
@@ -437,9 +465,12 @@ mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
int i, rc;
- for (i=0; i<num; i++)
- if ((rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i])) < 0)
+ for (i = 0; i < num; i++) {
+ rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i],
+ i == 0, i + 1 == num);
+ if (rc < 0)
return rc;
+ }
return num;
}
diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c
index a605a5029cfe..ff1e127dfea8 100644
--- a/drivers/i2c/busses/i2c-nforce2.c
+++ b/drivers/i2c/busses/i2c-nforce2.c
@@ -432,7 +432,7 @@ static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_
static void __devexit nforce2_remove(struct pci_dev *dev)
{
- struct nforce2_smbus *smbuses = (void*) pci_get_drvdata(dev);
+ struct nforce2_smbus *smbuses = pci_get_drvdata(dev);
nforce2_set_reference(NULL);
if (smbuses[0].base) {
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index b33c78586bfc..b605ff3a1fa0 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -39,6 +39,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/i2c-omap.h>
+#include <linux/pm_runtime.h>
/* I2C controller revisions */
#define OMAP_I2C_REV_2 0x20
@@ -175,8 +176,6 @@ struct omap_i2c_dev {
void __iomem *base; /* virtual */
int irq;
int reg_shift; /* bit shift for I2C register addresses */
- struct clk *iclk; /* Interface clock */
- struct clk *fclk; /* Functional clock */
struct completion cmd_complete;
struct resource *ioarea;
u32 latency; /* maximum mpu wkup latency */
@@ -265,45 +264,18 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
(i2c_dev->regs[reg] << i2c_dev->reg_shift));
}
-static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
+static void omap_i2c_unidle(struct omap_i2c_dev *dev)
{
- int ret;
-
- dev->iclk = clk_get(dev->dev, "ick");
- if (IS_ERR(dev->iclk)) {
- ret = PTR_ERR(dev->iclk);
- dev->iclk = NULL;
- return ret;
- }
+ struct platform_device *pdev;
+ struct omap_i2c_bus_platform_data *pdata;
- dev->fclk = clk_get(dev->dev, "fck");
- if (IS_ERR(dev->fclk)) {
- ret = PTR_ERR(dev->fclk);
- if (dev->iclk != NULL) {
- clk_put(dev->iclk);
- dev->iclk = NULL;
- }
- dev->fclk = NULL;
- return ret;
- }
-
- return 0;
-}
+ WARN_ON(!dev->idle);
-static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
-{
- clk_put(dev->fclk);
- dev->fclk = NULL;
- clk_put(dev->iclk);
- dev->iclk = NULL;
-}
+ pdev = to_platform_device(dev->dev);
+ pdata = pdev->dev.platform_data;
-static void omap_i2c_unidle(struct omap_i2c_dev *dev)
-{
- WARN_ON(!dev->idle);
+ pm_runtime_get_sync(&pdev->dev);
- clk_enable(dev->iclk);
- clk_enable(dev->fclk);
if (cpu_is_omap34xx()) {
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
@@ -326,10 +298,15 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
static void omap_i2c_idle(struct omap_i2c_dev *dev)
{
+ struct platform_device *pdev;
+ struct omap_i2c_bus_platform_data *pdata;
u16 iv;
WARN_ON(dev->idle);
+ pdev = to_platform_device(dev->dev);
+ pdata = pdev->dev.platform_data;
+
dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
if (dev->rev >= OMAP_I2C_REV_ON_4430)
omap_i2c_write_reg(dev, OMAP_I2C_IRQENABLE_CLR, 1);
@@ -345,8 +322,8 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
}
dev->idle = 1;
- clk_disable(dev->fclk);
- clk_disable(dev->iclk);
+
+ pm_runtime_put_sync(&pdev->dev);
}
static int omap_i2c_init(struct omap_i2c_dev *dev)
@@ -356,6 +333,7 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
unsigned long fclk_rate = 12000000;
unsigned long timeout;
unsigned long internal_clk = 0;
+ struct clk *fclk;
if (dev->rev >= OMAP_I2C_REV_2) {
/* Disable I2C controller before soft reset */
@@ -414,7 +392,9 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
* always returns 12MHz for the functional clock, we can
* do this bit unconditionally.
*/
- fclk_rate = clk_get_rate(dev->fclk);
+ fclk = clk_get(dev->dev, "fck");
+ fclk_rate = clk_get_rate(fclk);
+ clk_put(fclk);
/* TRM for 5912 says the I2C clock must be prescaled to be
* between 7 - 12 MHz. The XOR input clock is typically
@@ -443,7 +423,9 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
internal_clk = 9600;
else
internal_clk = 4000;
- fclk_rate = clk_get_rate(dev->fclk) / 1000;
+ fclk = clk_get(dev->dev, "fck");
+ fclk_rate = clk_get_rate(fclk) / 1000;
+ clk_put(fclk);
/* Compute prescaler divisor */
psc = fclk_rate / internal_clk;
@@ -616,12 +598,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
* REVISIT: We should abort the transfer on signals, but the bus goes
* into arbitration and we're currently unable to recover from it.
*/
- if (dev->set_mpu_wkup_lat != NULL)
- dev->set_mpu_wkup_lat(dev->dev, dev->latency);
r = wait_for_completion_timeout(&dev->cmd_complete,
OMAP_I2C_TIMEOUT);
- if (dev->set_mpu_wkup_lat != NULL)
- dev->set_mpu_wkup_lat(dev->dev, -1);
dev->buf_len = 0;
if (r < 0)
return r;
@@ -672,12 +650,18 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
if (r < 0)
goto out;
+ if (dev->set_mpu_wkup_lat != NULL)
+ dev->set_mpu_wkup_lat(dev->dev, dev->latency);
+
for (i = 0; i < num; i++) {
r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
if (r != 0)
break;
}
+ if (dev->set_mpu_wkup_lat != NULL)
+ dev->set_mpu_wkup_lat(dev->dev, -1);
+
if (r == 0)
r = num;
@@ -1048,14 +1032,12 @@ omap_i2c_probe(struct platform_device *pdev)
else
dev->reg_shift = 2;
- if ((r = omap_i2c_get_clocks(dev)) != 0)
- goto err_iounmap;
-
if (cpu_is_omap44xx())
dev->regs = (u8 *) omap4_reg_map;
else
dev->regs = (u8 *) reg_map;
+ pm_runtime_enable(&pdev->dev);
omap_i2c_unidle(dev);
dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
@@ -1127,8 +1109,6 @@ err_free_irq:
err_unuse_clocks:
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
omap_i2c_idle(dev);
- omap_i2c_put_clocks(dev);
-err_iounmap:
iounmap(dev->base);
err_free_mem:
platform_set_drvdata(pdev, NULL);
@@ -1150,7 +1130,6 @@ omap_i2c_remove(struct platform_device *pdev)
free_irq(dev->irq, dev);
i2c_del_adapter(&dev->adapter);
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
- omap_i2c_put_clocks(dev);
iounmap(dev->base);
kfree(dev);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1162,7 +1141,7 @@ static struct platform_driver omap_i2c_driver = {
.probe = omap_i2c_probe,
.remove = omap_i2c_remove,
.driver = {
- .name = "i2c_omap",
+ .name = "omap_i2c",
.owner = THIS_MODULE,
},
};
@@ -1184,4 +1163,4 @@ module_exit(omap_i2c_exit_driver);
MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:i2c_omap");
+MODULE_ALIAS("platform:omap_i2c");
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6b4cc567645b..c7db6980e3a3 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1362,7 +1362,7 @@ EXPORT_SYMBOL(i2c_transfer);
*
* Returns negative errno, or else the number of bytes written.
*/
-int i2c_master_send(struct i2c_client *client, const char *buf, int count)
+int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
{
int ret;
struct i2c_adapter *adap = client->adapter;
@@ -1389,7 +1389,7 @@ EXPORT_SYMBOL(i2c_master_send);
*
* Returns negative errno, or else the number of bytes read.
*/
-int i2c_master_recv(struct i2c_client *client, char *buf, int count)
+int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
{
struct i2c_adapter *adap = client->adapter;
struct i2c_msg msg;
@@ -1679,7 +1679,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
* This executes the SMBus "receive byte" protocol, returning negative errno
* else the byte received from the device.
*/
-s32 i2c_smbus_read_byte(struct i2c_client *client)
+s32 i2c_smbus_read_byte(const struct i2c_client *client)
{
union i2c_smbus_data data;
int status;
@@ -1699,7 +1699,7 @@ EXPORT_SYMBOL(i2c_smbus_read_byte);
* This executes the SMBus "send byte" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
+s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
{
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
@@ -1714,7 +1714,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte);
* This executes the SMBus "read byte" protocol, returning negative errno
* else a data byte received from the device.
*/
-s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
+s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
int status;
@@ -1735,7 +1735,8 @@ EXPORT_SYMBOL(i2c_smbus_read_byte_data);
* This executes the SMBus "write byte" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
+s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command,
+ u8 value)
{
union i2c_smbus_data data;
data.byte = value;
@@ -1753,7 +1754,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte_data);
* This executes the SMBus "read word" protocol, returning negative errno
* else a 16-bit unsigned "word" received from the device.
*/
-s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
+s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
int status;
@@ -1774,7 +1775,8 @@ EXPORT_SYMBOL(i2c_smbus_read_word_data);
* This executes the SMBus "write word" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
+s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
+ u16 value)
{
union i2c_smbus_data data;
data.word = value;
@@ -1793,7 +1795,8 @@ EXPORT_SYMBOL(i2c_smbus_write_word_data);
* This executes the SMBus "process call" protocol, returning negative errno
* else a 16-bit unsigned "word" received from the device.
*/
-s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
+s32 i2c_smbus_process_call(const struct i2c_client *client, u8 command,
+ u16 value)
{
union i2c_smbus_data data;
int status;
@@ -1821,7 +1824,7 @@ EXPORT_SYMBOL(i2c_smbus_process_call);
* support this; its emulation through I2C messaging relies on a specific
* mechanism (I2C_M_RECV_LEN) which may not be implemented.
*/
-s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command,
u8 *values)
{
union i2c_smbus_data data;
@@ -1848,7 +1851,7 @@ EXPORT_SYMBOL(i2c_smbus_read_block_data);
* This executes the SMBus "block write" protocol, returning negative errno
* else zero on success.
*/
-s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
union i2c_smbus_data data;
@@ -1864,7 +1867,7 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
EXPORT_SYMBOL(i2c_smbus_write_block_data);
/* Returns the number of read bytes */
-s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
union i2c_smbus_data data;
@@ -1884,7 +1887,7 @@ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
}
EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
-s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
+s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
union i2c_smbus_data data;
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index 4d91d80bfd23..90b7a0163899 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -5,6 +5,18 @@
menu "Multiplexer I2C Chip support"
depends on I2C_MUX
+config I2C_MUX_GPIO
+ tristate "GPIO-based I2C multiplexer"
+ depends on GENERIC_GPIO
+ help
+ If you say yes to this option, support will be included for a
+ GPIO based I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ through GPIO pins.
+
+ This driver can also be built as a module. If so, the module
+ will be called gpio-i2cmux.
+
config I2C_MUX_PCA9541
tristate "NXP PCA9541 I2C Master Selector"
depends on EXPERIMENTAL
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index d743806d9b42..4640436ea61f 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -1,6 +1,7 @@
#
# Makefile for multiplexer I2C chip drivers.
+obj-$(CONFIG_I2C_MUX_GPIO) += gpio-i2cmux.o
obj-$(CONFIG_I2C_MUX_PCA9541) += pca9541.o
obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o
diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c
new file mode 100644
index 000000000000..7b6ce624cd6e
--- /dev/null
+++ b/drivers/i2c/muxes/gpio-i2cmux.c
@@ -0,0 +1,184 @@
+/*
+ * I2C multiplexer using GPIO API
+ *
+ * Peter Korsgaard <peter.korsgaard@barco.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/gpio-i2cmux.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+
+struct gpiomux {
+ struct i2c_adapter *parent;
+ struct i2c_adapter **adap; /* child busses */
+ struct gpio_i2cmux_platform_data data;
+};
+
+static void gpiomux_set(const struct gpiomux *mux, unsigned val)
+{
+ int i;
+
+ for (i = 0; i < mux->data.n_gpios; i++)
+ gpio_set_value(mux->data.gpios[i], val & (1 << i));
+}
+
+static int gpiomux_select(struct i2c_adapter *adap, void *data, u32 chan)
+{
+ struct gpiomux *mux = data;
+
+ gpiomux_set(mux, mux->data.values[chan]);
+
+ return 0;
+}
+
+static int gpiomux_deselect(struct i2c_adapter *adap, void *data, u32 chan)
+{
+ struct gpiomux *mux = data;
+
+ gpiomux_set(mux, mux->data.idle);
+
+ return 0;
+}
+
+static int __devinit gpiomux_probe(struct platform_device *pdev)
+{
+ struct gpiomux *mux;
+ struct gpio_i2cmux_platform_data *pdata;
+ struct i2c_adapter *parent;
+ int (*deselect) (struct i2c_adapter *, void *, u32);
+ unsigned initial_state;
+ int i, ret;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "Missing platform data\n");
+ return -ENODEV;
+ }
+
+ parent = i2c_get_adapter(pdata->parent);
+ if (!parent) {
+ dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
+ pdata->parent);
+ return -ENODEV;
+ }
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ ret = -ENOMEM;
+ goto alloc_failed;
+ }
+
+ mux->parent = parent;
+ mux->data = *pdata;
+ mux->adap = kzalloc(sizeof(struct i2c_adapter *) * pdata->n_values,
+ GFP_KERNEL);
+ if (!mux->adap) {
+ ret = -ENOMEM;
+ goto alloc_failed2;
+ }
+
+ if (pdata->idle != GPIO_I2CMUX_NO_IDLE) {
+ initial_state = pdata->idle;
+ deselect = gpiomux_deselect;
+ } else {
+ initial_state = pdata->values[0];
+ deselect = NULL;
+ }
+
+ for (i = 0; i < pdata->n_gpios; i++) {
+ ret = gpio_request(pdata->gpios[i], "gpio-i2cmux");
+ if (ret)
+ goto err_request_gpio;
+ gpio_direction_output(pdata->gpios[i],
+ initial_state & (1 << i));
+ }
+
+ for (i = 0; i < pdata->n_values; i++) {
+ u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0;
+
+ mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i,
+ gpiomux_select, deselect);
+ if (!mux->adap[i]) {
+ ret = -ENODEV;
+ dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
+ goto add_adapter_failed;
+ }
+ }
+
+ dev_info(&pdev->dev, "%d port mux on %s adapter\n",
+ pdata->n_values, parent->name);
+
+ platform_set_drvdata(pdev, mux);
+
+ return 0;
+
+add_adapter_failed:
+ for (; i > 0; i--)
+ i2c_del_mux_adapter(mux->adap[i - 1]);
+ i = pdata->n_gpios;
+err_request_gpio:
+ for (; i > 0; i--)
+ gpio_free(pdata->gpios[i - 1]);
+ kfree(mux->adap);
+alloc_failed2:
+ kfree(mux);
+alloc_failed:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static int __devexit gpiomux_remove(struct platform_device *pdev)
+{
+ struct gpiomux *mux = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < mux->data.n_values; i++)
+ i2c_del_mux_adapter(mux->adap[i]);
+
+ for (i = 0; i < mux->data.n_gpios; i++)
+ gpio_free(mux->data.gpios[i]);
+
+ platform_set_drvdata(pdev, NULL);
+ i2c_put_adapter(mux->parent);
+ kfree(mux->adap);
+ kfree(mux);
+
+ return 0;
+}
+
+static struct platform_driver gpiomux_driver = {
+ .probe = gpiomux_probe,
+ .remove = __devexit_p(gpiomux_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "gpio-i2cmux",
+ },
+};
+
+static int __init gpiomux_init(void)
+{
+ return platform_driver_register(&gpiomux_driver);
+}
+
+static void __exit gpiomux_exit(void)
+{
+ platform_driver_unregister(&gpiomux_driver);
+}
+
+module_init(gpiomux_init);
+module_exit(gpiomux_exit);
+
+MODULE_DESCRIPTION("GPIO-based I2C multiplexer driver");
+MODULE_AUTHOR("Peter Korsgaard <peter.korsgaard@barco.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:gpio-i2cmux");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 20:18:06 +0000