diff options
| -rw-r--r-- | Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt | 16 | ||||
| -rw-r--r-- | drivers/video/backlight/gpio_backlight.c | 58 |
2 files changed, 67 insertions, 7 deletions
diff --git a/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt new file mode 100644 index 000000000000..321be6640533 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt @@ -0,0 +1,16 @@ +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; + }; diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c index 81fb12770c2a..a2eba12e1cb7 100644 --- a/drivers/video/backlight/gpio_backlight.c +++ b/drivers/video/backlight/gpio_backlight.c @@ -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; - gbl->fbdev = pdata->fbdev; - gbl->gpio = pdata->gpio; - gbl->active = pdata->active_low ? 0 : 1; + + 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, }; |