Cc: Richard Purdie <rpurdie@xxxxxxxxx> Cc: Jingoo Han <jg1.han@xxxxxxxxxxx> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Rob Herring <rob.herring@xxxxxxxxxxx> Cc: Pawel Moll <pawel.moll@xxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Stephen Warren <swarren@xxxxxxxxxxxxx> Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: Sascha Hauer <kernel@xxxxxxxxxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: Eric Bénard <eric@xxxxxxxxxx> Signed-off-by: Denis Carikli <denis@xxxxxxxxxx> --- .../bindings/video/backlight/gpio-backlight.txt | 18 +++++ drivers/video/backlight/gpio_backlight.c | 73 ++++++++++++++++++-- 2 files changed, 84 insertions(+), 7 deletions(-) create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt 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 0000000..362dd40 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt @@ -0,0 +1,18 @@ +gpio-backlight bindings + +Required properties: + - compatible: "gpio-backlight" + - gpios: describes the gpio that is used for enabling/disabling the backlight + (see GPIO binding[0] for more details). + - default-brightness-level: the default brightness level (can be 0(off) or + 1(on) since GPIOs only support theses levels). + +[0]: Documentation/devicetree/bindings/gpio/gpio.txt + +Example: + + backlight { + compatible = "gpio-backlight"; + gpios = <&gpio3 4 0>; + default-brightness-level = <1>; + }; diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c index 81fb127..f5d31e7 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 +63,43 @@ 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; + int ret; + + gbl->fbdev = NULL; + gbl->gpio = of_get_gpio_flags(np, 0, &gpio_flags); + + gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; + + if (gbl->gpio == -EPROBE_DEFER) { + return ERR_PTR(-EPROBE_DEFER); + } else if (gbl->gpio < 0) { + dev_err(&pdev->dev, "Error: gpios is a required parameter.\n"); + return gbl->gpio; + } + + ret = of_property_read_u32(np, "default-brightness-level", + &gbl->def_value); + if (ret < 0) { + dev_err(&pdev->dev, "Error: default-brightness-level " + "is a required parameter.\n"); + return ret; + } + + if (gbl->def_value < 0 || gbl->def_value > 1) { + dev_err(&pdev->dev, "Error: Invalid " + "default-brightness-level value. Its value can be " + "either 0(off) or 1(on).\n"); + return -EINVAL; + } + + return 0; +} + static int gpio_backlight_probe(struct platform_device *pdev) { struct gpio_backlight_platform_data *pdata = @@ -67,10 +107,12 @@ 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 +121,21 @@ 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; + } 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 +152,27 @@ static int gpio_backlight_probe(struct platform_device *pdev) return PTR_ERR(bl); } - bl->props.brightness = pdata->def_value; + if (np) + bl->props.brightness = gbl->def_value; + else + bl->props.brightness = pdata->def_value; + backlight_update_status(bl); platform_set_drvdata(pdev, bl); return 0; } +static struct of_device_id gpio_backlight_of_match[] = { + { .compatible = "gpio-backlight" }, + { /* sentinel */ } +}; + 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, }; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html