i2c-s3c2410: Add device tree support

Add device tree probe support for Samsung's s3c2410 i2c driver.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Thomas Abraham 2011-09-13 09:46:05 +05:30 committed by Ben Dooks
parent 4fd81eb2d6
commit 5a5f50802f
2 changed files with 145 additions and 4 deletions

View File

@ -0,0 +1,39 @@
* Samsung's I2C controller
The Samsung's I2C controller is used to interface with I2C devices.
Required properties:
- compatible: value should be either of the following.
(a) "samsung, s3c2410-i2c", for i2c compatible with s3c2410 i2c.
(b) "samsung, s3c2440-i2c", for i2c compatible with s3c2440 i2c.
- reg: physical base address of the controller and length of memory mapped
region.
- interrupts: interrupt number to the cpu.
- samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges.
- gpios: The order of the gpios should be the following: <SDA, SCL>.
The gpio specifier depends on the gpio controller.
Optional properties:
- samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
specified, default value is 0.
- samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
specified, the default value in Hz is 100000.
Example:
i2c@13870000 {
compatible = "samsung,s3c2440-i2c";
reg = <0x13870000 0x100>;
interrupts = <345>;
samsung,i2c-sda-delay = <100>;
samsung,i2c-max-bus-freq = <100000>;
gpios = <&gpd1 2 0 /* SDA */
&gpd1 3 0 /* SCL */>;
#address-cells = <1>;
#size-cells = <0>;
wm8994@1a {
compatible = "wlf,wm8994";
reg = <0x1a>;
};
};

View File

@ -35,6 +35,8 @@
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of_i2c.h>
#include <linux/of_gpio.h>
#include <asm/irq.h>
@ -79,6 +81,7 @@ struct s3c24xx_i2c {
struct i2c_adapter adap;
struct s3c2410_platform_i2c *pdata;
int gpios[2];
#ifdef CONFIG_CPU_FREQ
struct notifier_block freq_transition;
#endif
@ -96,6 +99,12 @@ static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
struct platform_device *pdev = to_platform_device(i2c->dev);
enum s3c24xx_i2c_type type;
#ifdef CONFIG_OF
if (i2c->dev->of_node)
return of_device_is_compatible(i2c->dev->of_node,
"samsung,s3c2440-i2c");
#endif
type = platform_get_device_id(pdev)->driver_data;
return type == TYPE_S3C2440;
}
@ -742,6 +751,49 @@ static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
}
#endif
#ifdef CONFIG_OF
static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
{
int idx, gpio, ret;
for (idx = 0; idx < 2; idx++) {
gpio = of_get_gpio(i2c->dev->of_node, idx);
if (!gpio_is_valid(gpio)) {
dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio);
goto free_gpio;
}
ret = gpio_request(gpio, "i2c-bus");
if (ret) {
dev_err(i2c->dev, "gpio [%d] request failed\n", gpio);
goto free_gpio;
}
}
return 0;
free_gpio:
while (--idx >= 0)
gpio_free(i2c->gpios[idx]);
return -EINVAL;
}
static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
{
unsigned int idx;
for (idx = 0; idx < 2; idx++)
gpio_free(i2c->gpios[idx]);
}
#else
static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
{
return -EINVAL;
}
static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
{
}
#endif
/* s3c24xx_i2c_init
*
* initialise the controller, set the IO lines and frequency
@ -761,6 +813,9 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
if (pdata->cfg_gpio)
pdata->cfg_gpio(to_platform_device(i2c->dev));
else
if (s3c24xx_i2c_parse_dt_gpio(i2c))
return -EINVAL;
/* write slave address */
@ -786,6 +841,34 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
return 0;
}
#ifdef CONFIG_OF
/* s3c24xx_i2c_parse_dt
*
* Parse the device tree node and retreive the platform data.
*/
static void
s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
{
struct s3c2410_platform_i2c *pdata = i2c->pdata;
if (!np)
return;
pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
of_property_read_u32(np, "samsung,i2c-max-bus-freq",
(u32 *)&pdata->frequency);
}
#else
static void
s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
{
return;
}
#endif
/* s3c24xx_i2c_probe
*
* called by the bus driver when a suitable device is found
@ -798,10 +881,12 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
struct resource *res;
int ret;
pdata = pdev->dev.platform_data;
if (!pdata) {
dev_err(&pdev->dev, "no platform data\n");
return -EINVAL;
if (!pdev->dev.of_node) {
pdata = pdev->dev.platform_data;
if (!pdata) {
dev_err(&pdev->dev, "no platform data\n");
return -EINVAL;
}
}
i2c = kzalloc(sizeof(struct s3c24xx_i2c), GFP_KERNEL);
@ -818,6 +903,8 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
if (pdata)
memcpy(i2c->pdata, pdata, sizeof(*pdata));
else
s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c);
strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
i2c->adap.owner = THIS_MODULE;
@ -914,6 +1001,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
*/
i2c->adap.nr = i2c->pdata->bus_num;
i2c->adap.dev.of_node = pdev->dev.of_node;
ret = i2c_add_numbered_adapter(&i2c->adap);
if (ret < 0) {
@ -921,6 +1009,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
goto err_cpufreq;
}
of_i2c_register_devices(&i2c->adap);
platform_set_drvdata(pdev, i2c);
dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
@ -969,6 +1058,7 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
iounmap(i2c->regs);
release_resource(i2c->ioarea);
s3c24xx_i2c_dt_gpio_free(i2c);
kfree(i2c->ioarea);
kfree(i2c);
@ -1022,6 +1112,17 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
};
MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
#ifdef CONFIG_OF
static const struct of_device_id s3c24xx_i2c_match[] = {
{ .compatible = "samsung,s3c2410-i2c" },
{ .compatible = "samsung,s3c2440-i2c" },
{},
};
MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
#else
#define s3c24xx_i2c_match NULL
#endif
static struct platform_driver s3c24xx_i2c_driver = {
.probe = s3c24xx_i2c_probe,
.remove = s3c24xx_i2c_remove,
@ -1030,6 +1131,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
.owner = THIS_MODULE,
.name = "s3c-i2c",
.pm = S3C24XX_DEV_PM_OPS,
.of_match_table = s3c24xx_i2c_match,
},
};