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Commit 4add0664 authored by Kim, Milo's avatar Kim, Milo Committed by Linus Torvalds
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backlight: lp855x: add a device tree structure 



Enable supporting the DT structure of LP855x family devices.  If the
platform data is NULL, the driver tries to parse a DT structure.  Then,
the platform data is copied from the DT.  Documentation is added as well.

Signed-off-by: default avatarMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c365e59d

Documentation/devicetree/bindings/video/backlight/lp855x.txt

0 → 100644
+41 −0
Original line number Diff line number Diff line 
lp855x bindings



Required properties:

  - compatible: "ti,lp8550", "ti,lp8551", "ti,lp8552", "ti,lp8553",

                "ti,lp8556", "ti,lp8557"

  - reg: I2C slave address (u8)

  - dev-ctrl: Value of DEVICE CONTROL register (u8). It depends on the device.



Optional properties:

  - bl-name: Backlight device name (string)

  - init-brt: Initial value of backlight brightness (u8)

  - pwm-period: PWM period value. Set only PWM input mode used (u32)

  - rom-addr: Register address of ROM area to be updated (u8)

  - rom-val: Register value to be updated (u8)



Example:



	/* LP8556 */

	backlight@2c {

		compatible = "ti,lp8556";

		reg = <0x2c>;



		bl-name = "lcd-bl";

		dev-ctrl = /bits/ 8 <0x85>;

		init-brt = /bits/ 8 <0x10>;

	};



	/* LP8557 */

	backlight@2c {

		compatible = "ti,lp8557";

		reg = <0x2c>;



		dev-ctrl = /bits/ 8 <0x41>;

		init-brt = /bits/ 8 <0x0a>;



		/* 4V OV, 4 output LED string enabled */

		rom_14h {

			rom-addr = /bits/ 8 <0x14>;

			rom-val = /bits/ 8 <0xcf>;

		};

	};

drivers/video/backlight/lp855x_bl.c

+71 −2
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/i2c.h>

#include <linux/backlight.h>

#include <linux/err.h>

#include <linux/of.h>

#include <linux/platform_data/lp855x.h>

#include <linux/pwm.h>
@@ -338,15 +339,71 @@ static const struct attribute_group lp855x_attr_group = { 
	.attrs = lp855x_attributes,

};



#ifdef CONFIG_OF

static int lp855x_parse_dt(struct device *dev, struct device_node *node)

{

	struct lp855x_platform_data *pdata;

	int rom_length;



	if (!node) {

		dev_err(dev, "no platform data\n");

		return -EINVAL;

	}



	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);

	if (!pdata)

		return -ENOMEM;



	of_property_read_string(node, "bl-name", &pdata->name);

	of_property_read_u8(node, "dev-ctrl", &pdata->device_control);

	of_property_read_u8(node, "init-brt", &pdata->initial_brightness);

	of_property_read_u32(node, "pwm-period", &pdata->period_ns);



	/* Fill ROM platform data if defined */

	rom_length = of_get_child_count(node);

	if (rom_length > 0) {

		struct lp855x_rom_data *rom;

		struct device_node *child;

		int i = 0;



		rom = devm_kzalloc(dev, sizeof(*rom) * rom_length, GFP_KERNEL);

		if (!rom)

			return -ENOMEM;



		for_each_child_of_node(node, child) {

			of_property_read_u8(child, "rom-addr", &rom[i].addr);

			of_property_read_u8(child, "rom-val", &rom[i].val);

			i++;

		}



		pdata->size_program = rom_length;

		pdata->rom_data = &rom[0];

	}



	dev->platform_data = pdata;



	return 0;

}

#else

static int lp855x_parse_dt(struct device *dev, struct device_node *node)

{

	return -EINVAL;

}

#endif



static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)

{

	struct lp855x *lp;

	struct lp855x_platform_data *pdata = cl->dev.platform_data;

	struct device_node *node = cl->dev.of_node;

	int ret;



	if (!pdata) {

		dev_err(&cl->dev, "no platform data supplied\n");

		return -EINVAL;

		ret = lp855x_parse_dt(&cl->dev, node);

		if (ret < 0)

			return ret;



		pdata = cl->dev.platform_data;

	}



	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
@@ -408,6 +465,17 @@ static int lp855x_remove(struct i2c_client *cl) 
	return 0;

}



static const struct of_device_id lp855x_dt_ids[] = {

	{ .compatible = "ti,lp8550", },

	{ .compatible = "ti,lp8551", },

	{ .compatible = "ti,lp8552", },

	{ .compatible = "ti,lp8553", },

	{ .compatible = "ti,lp8556", },

	{ .compatible = "ti,lp8557", },

	{ }

};

MODULE_DEVICE_TABLE(of, lp855x_dt_ids);



static const struct i2c_device_id lp855x_ids[] = {

	{"lp8550", LP8550},

	{"lp8551", LP8551},
@@ -422,6 +490,7 @@ MODULE_DEVICE_TABLE(i2c, lp855x_ids); 
static struct i2c_driver lp855x_driver = {

	.driver = {

		   .name = "lp855x",

		   .of_match_table = of_match_ptr(lp855x_dt_ids),

		   },

	.probe = lp855x_probe,

	.remove = lp855x_remove,