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Commit 5a5f5080 authored by Thomas Abraham's avatar Thomas Abraham Committed by Ben Dooks
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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: default avatarThomas Abraham <thomas.abraham@linaro.org>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 4fd81eb2

Documentation/devicetree/bindings/i2c/samsung-i2c.txt

0 → 100644
+39 −0
Original line number Diff line number Diff line 
* 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>;

		};

	};

drivers/i2c/busses/i2c-s3c2410.c

+106 −4
Original line number Diff line number Diff line
@@ -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
@@ -798,11 +881,13 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) 
	struct resource *res;

	int ret;



	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);

	if (!i2c) {
@@ -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,

	},

};