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 <common.h>
   8 #include <dm.h>
   9 #include <backlight.h>
  10 #include <log.h>
  11 #include <asm/gpio.h>
  12
  13 struct gpio_backlight_priv {
  14         struct gpio_desc gpio;
  15         bool def_value;
  16 };
  17
  18 static int gpio_backlight_enable(struct udevice *dev)
  19 {
  20         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  21
  22         dm_gpio_set_value(&priv->gpio, 1);
  23
  24         return 0;
  25 }
  26
  27 static int gpio_backlight_of_to_plat(struct udevice *dev)
  28 {
  29         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  30         int ret;
  31
  32         ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio,
  33                                    GPIOD_IS_OUT);
  34         if (ret) {
  35                 debug("%s: Warning: cannot get GPIO: ret=%d\n",
  36                       __func__, ret);
  37                 return ret;
  38         }
  39
  40         priv->def_value = dev_read_bool(dev, "default-on");
  41
  42         return 0;
  43 }
  44
  45 static int gpio_backlight_probe(struct udevice *dev)
  46 {
  47         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  48
  49         if (priv->def_value)
  50                 gpio_backlight_enable(dev);
  51
  52         return 0;
  53 }
  54
  55 static const struct backlight_ops gpio_backlight_ops = {
  56         .enable = gpio_backlight_enable,
  57 };
  58
  59 static const struct udevice_id gpio_backlight_ids[] = {
  60         { .compatible = "gpio-backlight" },
  61         { }
  62 };
  63
  64 U_BOOT_DRIVER(gpio_backlight) = {
  65         .name   = "gpio_backlight",
  66         .id     = UCLASS_PANEL_BACKLIGHT,
  67         .of_match = gpio_backlight_ids,
  68         .ops    = &gpio_backlight_ops,
  69         .of_to_plat     = gpio_backlight_of_to_plat,
  70         .probe          = gpio_backlight_probe,
  71         .priv_auto      = sizeof(struct gpio_backlight_priv),
  72 };