backlight: lp855x: add a device tree structure (4add0664) · Commits · 戴 / test

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,

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