drivers/video/backlight_gpio.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   4  * Author: Patrick Delaunay <patrick.delaunay@foss.st.com>
   5  */
   6
   7 #include <dm.h>
   8 #include <backlight.h>
   9 #include <log.h>
  10 #include <asm/gpio.h>
  11
  12 struct gpio_backlight_priv {
  13         struct gpio_desc gpio;
  14         bool def_value;
  15 };
  16
  17 static int gpio_backlight_enable(struct udevice *dev)
  18 {
  19         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  20
  21         dm_gpio_set_value(&priv->gpio, 1);
  22
  23         return 0;
  24 }
  25
  26 static int gpio_backlight_of_to_plat(struct udevice *dev)
  27 {
  28         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  29         int ret;
  30
  31         ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio,
  32                                    GPIOD_IS_OUT);
  33         if (ret) {
  34                 debug("%s: Warning: cannot get GPIO: ret=%d\n",
  35                       __func__, ret);
  36                 return ret;
  37         }
  38
  39         priv->def_value = dev_read_bool(dev, "default-on");
  40
  41         return 0;
  42 }
  43
  44 static int gpio_backlight_probe(struct udevice *dev)
  45 {
  46         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  47
  48         if (priv->def_value)
  49                 gpio_backlight_enable(dev);
  50
  51         return 0;
  52 }
  53
  54 static const struct backlight_ops gpio_backlight_ops = {
  55         .enable = gpio_backlight_enable,
  56 };
  57
  58 static const struct udevice_id gpio_backlight_ids[] = {
  59         { .compatible = "gpio-backlight" },
  60         { }
  61 };
  62
  63 U_BOOT_DRIVER(gpio_backlight) = {
  64         .name   = "gpio_backlight",
  65         .id     = UCLASS_PANEL_BACKLIGHT,
  66         .of_match = gpio_backlight_ids,
  67         .ops    = &gpio_backlight_ops,
  68         .of_to_plat     = gpio_backlight_of_to_plat,
  69         .probe          = gpio_backlight_probe,
  70         .priv_auto      = sizeof(struct gpio_backlight_priv),
  71 };