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

Commit 257462db authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Thierry Reding
Browse files

pwm-backlight: switch to gpiod interface 



Switch to the new gpiod interface, which allows to handle GPIO
properties such as active low transparently and removes a whole bunch of
code.

There are still a couple of users of this driver that rely on passing
the enable GPIO number through platform data, so a fallback mechanism
using a GPIO number is still available to avoid breaking them. It will
be removed once current users have switched to the GPIO lookup tables
provided by the gpiod interface.

Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent a4406f16

drivers/video/backlight/pwm_bl.c

+29 −40
Original line number Diff line number Diff line
@@ -10,8 +10,8 @@ 
 * published by the Free Software Foundation.

 */



#include <linux/gpio/consumer.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>
@@ -32,8 +32,7 @@ struct pwm_bl_data { 
	unsigned int		*levels;

	bool			enabled;

	struct regulator	*power_supply;

	int			enable_gpio;

	unsigned long		enable_gpio_flags;

	struct gpio_desc	*enable_gpio;

	unsigned int		scale;

	int			(*notify)(struct device *,

					  int brightness);
@@ -54,12 +53,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) 
	if (err < 0)

		dev_err(pb->dev, "failed to enable power supply\n");



	if (gpio_is_valid(pb->enable_gpio)) {

		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)

			gpio_set_value(pb->enable_gpio, 0);

		else

			gpio_set_value(pb->enable_gpio, 1);

	}

	if (pb->enable_gpio)

		gpiod_set_value(pb->enable_gpio, 1);



	pwm_enable(pb->pwm);

	pb->enabled = true;
@@ -73,12 +68,8 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) 
	pwm_config(pb->pwm, 0, pb->period);

	pwm_disable(pb->pwm);



	if (gpio_is_valid(pb->enable_gpio)) {

		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)

			gpio_set_value(pb->enable_gpio, 1);

		else

			gpio_set_value(pb->enable_gpio, 0);

	}

	if (pb->enable_gpio)

		gpiod_set_value(pb->enable_gpio, 0);



	regulator_disable(pb->power_supply);

	pb->enabled = false;
@@ -148,7 +139,6 @@ static int pwm_backlight_parse_dt(struct device *dev, 
				  struct platform_pwm_backlight_data *data)

{

	struct device_node *node = dev->of_node;

	enum of_gpio_flags flags;

	struct property *prop;

	int length;

	u32 value;
@@ -189,14 +179,6 @@ static int pwm_backlight_parse_dt(struct device *dev, 
		data->max_brightness--;

	}



	data->enable_gpio = of_get_named_gpio_flags(node, "enable-gpios", 0,

						    &flags);

	if (data->enable_gpio == -EPROBE_DEFER)

		return -EPROBE_DEFER;



	if (gpio_is_valid(data->enable_gpio) && (flags & OF_GPIO_ACTIVE_LOW))

		data->enable_gpio_flags |= PWM_BACKLIGHT_GPIO_ACTIVE_LOW;



	return 0;

}
@@ -256,8 +238,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) 
	} else

		pb->scale = data->max_brightness;



	pb->enable_gpio = data->enable_gpio;

	pb->enable_gpio_flags = data->enable_gpio_flags;

	pb->notify = data->notify;

	pb->notify_after = data->notify_after;

	pb->check_fb = data->check_fb;
@@ -265,26 +245,38 @@ static int pwm_backlight_probe(struct platform_device *pdev) 
	pb->dev = &pdev->dev;

	pb->enabled = false;



	if (gpio_is_valid(pb->enable_gpio)) {

		unsigned long flags;



		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)

			flags = GPIOF_OUT_INIT_HIGH;

	pb->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");

	if (IS_ERR(pb->enable_gpio)) {

		ret = PTR_ERR(pb->enable_gpio);

		if (ret == -ENOENT)

			pb->enable_gpio = NULL;

		else

			flags = GPIOF_OUT_INIT_LOW;

			goto err_alloc;

	}



		ret = gpio_request_one(pb->enable_gpio, flags, "enable");

	/*

	 * Compatibility fallback for drivers still using the integer GPIO

	 * platform data. Must go away soon.

	 */

	if (!pb->enable_gpio && gpio_is_valid(data->enable_gpio)) {

		ret = devm_gpio_request_one(&pdev->dev, data->enable_gpio,

					    GPIOF_OUT_INIT_HIGH, "enable");

		if (ret < 0) {

			dev_err(&pdev->dev, "failed to request GPIO#%d: %d\n",

				pb->enable_gpio, ret);

				data->enable_gpio, ret);

			goto err_alloc;

		}



		pb->enable_gpio = gpio_to_desc(data->enable_gpio);

	}



	if (pb->enable_gpio)

		gpiod_direction_output(pb->enable_gpio, 1);



	pb->power_supply = devm_regulator_get(&pdev->dev, "power");

	if (IS_ERR(pb->power_supply)) {

		ret = PTR_ERR(pb->power_supply);

		goto err_gpio;

		goto err_alloc;

	}



	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
@@ -295,7 +287,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) 
		if (IS_ERR(pb->pwm)) {

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

			ret = PTR_ERR(pb->pwm);

			goto err_gpio;

			goto err_alloc;

		}

	}
@@ -320,7 +312,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) 
	if (IS_ERR(bl)) {

		dev_err(&pdev->dev, "failed to register backlight\n");

		ret = PTR_ERR(bl);

		goto err_gpio;

		goto err_alloc;

	}



	if (data->dft_brightness > data->max_brightness) {
@@ -336,9 +328,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) 
	platform_set_drvdata(pdev, bl);

	return 0;



err_gpio:

	if (gpio_is_valid(pb->enable_gpio))

		gpio_free(pb->enable_gpio);

err_alloc:

	if (data->exit)

		data->exit(&pdev->dev);

include/linux/pwm_backlight.h

+1 −4
Original line number Diff line number Diff line
@@ -6,9 +6,6 @@ 


#include <linux/backlight.h>



/* TODO: convert to gpiod_*() API once it has been merged */

#define PWM_BACKLIGHT_GPIO_ACTIVE_LOW	(1 << 0)



struct platform_pwm_backlight_data {

	int pwm_id;

	unsigned int max_brightness;
@@ -16,8 +13,8 @@ struct platform_pwm_backlight_data { 
	unsigned int lth_brightness;

	unsigned int pwm_period_ns;

	unsigned int *levels;

	/* TODO remove once all users are switched to gpiod_* API */

	int enable_gpio;

	unsigned long enable_gpio_flags;

	int (*init)(struct device *dev);

	int (*notify)(struct device *dev, int brightness);

	void (*notify_after)(struct device *dev, int brightness);