Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9a6adb33 authored by Denis Carikli's avatar Denis Carikli Committed by Lee Jones
Browse files

backlight: gpio-backlight: Add DT support 



Signed-off-by: default avatarDenis Carikli <denis@eukrea.com>
Acked-by: default avatarJingoo Han <jg1.han@samsung.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 35762a47

Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt

0 → 100644
+16 −0
Original line number Diff line number Diff line 
gpio-backlight bindings



Required properties:

  - compatible: "gpio-backlight"

  - gpios: describes the gpio that is used for enabling/disabling the backlight.

    refer to bindings/gpio/gpio.txt for more details.



Optional properties:

  - default-on: enable the backlight at boot.



Example:

	backlight {

		compatible = "gpio-backlight";

		gpios = <&gpio3 4 GPIO_ACTIVE_HIGH>;

		default-on;

	};

drivers/video/backlight/gpio_backlight.c

+51 −7
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 
#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/platform_data/gpio_backlight.h>

#include <linux/platform_device.h>

#include <linux/slab.h>
@@ -23,6 +25,7 @@ struct gpio_backlight { 


	int gpio;

	int active;

	int def_value;

};



static int gpio_backlight_update_status(struct backlight_device *bl)
@@ -60,6 +63,29 @@ static const struct backlight_ops gpio_backlight_ops = { 
	.check_fb	= gpio_backlight_check_fb,

};



static int gpio_backlight_probe_dt(struct platform_device *pdev,

				   struct gpio_backlight *gbl)

{

	struct device_node *np = pdev->dev.of_node;

	enum of_gpio_flags gpio_flags;



	gbl->gpio = of_get_gpio_flags(np, 0, &gpio_flags);



	if (!gpio_is_valid(gbl->gpio)) {

		if (gbl->gpio != -EPROBE_DEFER) {

			dev_err(&pdev->dev,

				"Error: The gpios parameter is missing or invalid.\n");

		}

		return gbl->gpio;

	}



	gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1;



	gbl->def_value = of_property_read_bool(np, "default-on");



	return 0;

}



static int gpio_backlight_probe(struct platform_device *pdev)

{

	struct gpio_backlight_platform_data *pdata =
@@ -67,10 +93,12 @@ static int gpio_backlight_probe(struct platform_device *pdev) 
	struct backlight_properties props;

	struct backlight_device *bl;

	struct gpio_backlight *gbl;

	struct device_node *np = pdev->dev.of_node;

	int ret;



	if (!pdata) {

		dev_err(&pdev->dev, "failed to find platform data\n");

	if (!pdata && !np) {

		dev_err(&pdev->dev,

			"failed to find platform data or device tree node.\n");

		return -ENODEV;

	}
@@ -79,14 +107,22 @@ static int gpio_backlight_probe(struct platform_device *pdev) 
		return -ENOMEM;



	gbl->dev = &pdev->dev;



	if (np) {

		ret = gpio_backlight_probe_dt(pdev, gbl);

		if (ret)

			return ret;

	} else {

		gbl->fbdev = pdata->fbdev;

		gbl->gpio = pdata->gpio;

		gbl->active = pdata->active_low ? 0 : 1;

		gbl->def_value = pdata->def_value;

	}



	ret = devm_gpio_request_one(gbl->dev, gbl->gpio, GPIOF_DIR_OUT |

				    (gbl->active ? GPIOF_INIT_LOW

						 : GPIOF_INIT_HIGH),

				    pdata->name);

				    pdata ? pdata->name : "backlight");

	if (ret < 0) {

		dev_err(&pdev->dev, "unable to request GPIO\n");

		return ret;
@@ -103,17 +139,25 @@ static int gpio_backlight_probe(struct platform_device *pdev) 
		return PTR_ERR(bl);

	}



	bl->props.brightness = pdata->def_value;

	bl->props.brightness = gbl->def_value;

	backlight_update_status(bl);



	platform_set_drvdata(pdev, bl);

	return 0;

}



#ifdef CONFIG_OF

static struct of_device_id gpio_backlight_of_match[] = {

	{ .compatible = "gpio-backlight" },

	{ /* sentinel */ }

};

#endif



static struct platform_driver gpio_backlight_driver = {

	.driver		= {

		.name		= "gpio-backlight",

		.owner		= THIS_MODULE,

		.of_match_table = of_match_ptr(gpio_backlight_of_match),

	},

	.probe		= gpio_backlight_probe,

};