From 257462dbf3ed233de0dc2e489dcc58579535b33f Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Thu, 27 Feb 2014 14:53:34 +0900 Subject: [PATCH] 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: Alexandre Courbot Signed-off-by: Thierry Reding --- drivers/video/backlight/pwm_bl.c | 69 ++++++++++++++------------------ include/linux/pwm_backlight.h | 5 +-- 2 files changed, 30 insertions(+), 44 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index fa7f5c35b7fb..cc49347bbcc0 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -10,8 +10,8 @@ * published by the Free Software Foundation. */ +#include #include -#include #include #include #include @@ -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); diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index 2de2e275b2cb..efdd9227a49c 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -6,9 +6,6 @@ #include -/* 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); -- 2.20.1