drivers/video/backlight_gpio.c

   1 /*
   2  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   3  * Author: Patrick Delaunay <patrick.delaunay@st.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <backlight.h>
  11 #include <asm/gpio.h>
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 struct gpio_backlight_priv {
  16         struct gpio_desc gpio;
  17         bool def_value;
  18 };
  19
  20 static int gpio_backlight_enable(struct udevice *dev)
  21 {
  22         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  23
  24         dm_gpio_set_value(&priv->gpio, 1);
  25
  26         return 0;
  27 }
  28
  29 static int gpio_backlight_ofdata_to_platdata(struct udevice *dev)
  30 {
  31         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  32         int ret;
  33
  34         ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio,
  35                                    GPIOD_IS_OUT);
  36         if (ret) {
  37                 debug("%s: Warning: cannot get GPIO: ret=%d\n",
  38                       __func__, ret);
  39                 return ret;
  40         }
  41
  42         priv->def_value = dev_read_bool(dev, "default-on");
  43
  44         return 0;
  45 }
  46
  47 static int gpio_backlight_probe(struct udevice *dev)
  48 {
  49         struct gpio_backlight_priv *priv = dev_get_priv(dev);
  50
  51         if (priv->def_value)
  52                 gpio_backlight_enable(dev);
  53
  54         return 0;
  55 }
  56
  57 static const struct backlight_ops gpio_backlight_ops = {
  58         .enable = gpio_backlight_enable,
  59 };
  60
  61 static const struct udevice_id gpio_backlight_ids[] = {
  62         { .compatible = "gpio-backlight" },
  63         { }
  64 };
  65
  66 U_BOOT_DRIVER(gpio_backlight) = {
  67         .name   = "gpio_backlight",
  68         .id     = UCLASS_PANEL_BACKLIGHT,
  69         .of_match = gpio_backlight_ids,
  70         .ops    = &gpio_backlight_ops,
  71         .ofdata_to_platdata     = gpio_backlight_ofdata_to_platdata,
  72         .probe          = gpio_backlight_probe,
  73         .priv_auto_alloc_size   = sizeof(struct gpio_backlight_priv),
  74 };