diff options
| -rw-r--r-- | Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt | 5 | ||||
| -rw-r--r-- | drivers/video/backlight/pwm_bl.c | 57 |
2 files changed, 55 insertions, 7 deletions
diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt index 1e4fc72..72810cc 100644 --- a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -14,8 +14,11 @@ Required properties: Optional properties: - pwm-names: a list of names for the PWM devices specified in the "pwms" property (see PWM binding[0]) + - enable-gpios: contains a single GPIO specifier for the GPIO which enables + and disables the backlight (see GPIO binding[1]) [0]: Documentation/devicetree/bindings/pwm/pwm.txt +[1]: Documentation/devicetree/bindings/gpio/gpio.txt Example: @@ -25,4 +28,6 @@ Example: brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + + enable-gpios = <&gpio 58 0>; }; diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 4053efb..cdef4a3 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -10,6 +10,8 @@ * published by the Free Software Foundation. */ +#include <linux/gpio.h> +#include <linux/of_gpio.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> @@ -28,6 +30,8 @@ struct pwm_bl_data { unsigned int lth_brightness; unsigned int *levels; bool enabled; + int enable_gpio; + unsigned long enable_gpio_flags; int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, @@ -55,6 +59,14 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness, pb->lth_brightness; pwm_config(pb->pwm, duty_cycle, pb->period); + + 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); + } + pwm_enable(pb->pwm); pb->enabled = true; } @@ -67,6 +79,13 @@ 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); + } + pb->enabled = false; } @@ -119,6 +138,7 @@ 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; @@ -159,11 +179,13 @@ static int pwm_backlight_parse_dt(struct device *dev, data->max_brightness--; } - /* - * TODO: Most users of this driver use a number of GPIOs to control - * backlight power. Support for specifying these needs to be - * added. - */ + 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; } @@ -221,6 +243,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) } else max = 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; @@ -228,6 +252,22 @@ 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; + else + flags = GPIOF_OUT_INIT_LOW; + + ret = gpio_request_one(pb->enable_gpio, flags, "enable"); + if (ret < 0) { + dev_err(&pdev->dev, "failed to request GPIO#%d: %d\n", + pb->enable_gpio, ret); + goto err_alloc; + } + } + pb->pwm = devm_pwm_get(&pdev->dev, NULL); if (IS_ERR(pb->pwm)) { dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); @@ -236,7 +276,7 @@ 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_alloc; + goto err_gpio; } } @@ -261,7 +301,7 @@ 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_alloc; + goto err_gpio; } if (data->dft_brightness > data->max_brightness) { @@ -277,6 +317,9 @@ 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); |