drivers/gpu/drm/gma500/backlight.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * GMA500 Backlight Interface
   4  *
   5  * Copyright (c) 2009-2011, Intel Corporation.
   6  *
   7  * Authors: Eric Knopp
   8  */
   9
  10 #include <acpi/video.h>
  11
  12 #include "psb_drv.h"
  13 #include "psb_intel_reg.h"
  14 #include "psb_intel_drv.h"
  15 #include "intel_bios.h"
  16 #include "power.h"
  17
  18 void gma_backlight_enable(struct drm_device *dev)
  19 {
  20         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  21
  22         dev_priv->backlight_enabled = true;
  23         dev_priv->ops->backlight_set(dev, dev_priv->backlight_level);
  24 }
  25
  26 void gma_backlight_disable(struct drm_device *dev)
  27 {
  28         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  29
  30         dev_priv->backlight_enabled = false;
  31         dev_priv->ops->backlight_set(dev, 0);
  32 }
  33
  34 void gma_backlight_set(struct drm_device *dev, int v)
  35 {
  36         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  37
  38         dev_priv->backlight_level = v;
  39         if (dev_priv->backlight_enabled)
  40                 dev_priv->ops->backlight_set(dev, v);
  41 }
  42
  43 static int gma_backlight_get_brightness(struct backlight_device *bd)
  44 {
  45         struct drm_device *dev = bl_get_data(bd);
  46         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  47
  48         if (dev_priv->ops->backlight_get)
  49                 return dev_priv->ops->backlight_get(dev);
  50
  51         return dev_priv->backlight_level;
  52 }
  53
  54 static int gma_backlight_update_status(struct backlight_device *bd)
  55 {
  56         struct drm_device *dev = bl_get_data(bd);
  57         int level = backlight_get_brightness(bd);
  58
  59         /* Percentage 1-100% being valid */
  60         if (level < 1)
  61                 level = 1;
  62
  63         gma_backlight_set(dev, level);
  64         return 0;
  65 }
  66
  67 static const struct backlight_ops gma_backlight_ops __maybe_unused = {
  68         .get_brightness = gma_backlight_get_brightness,
  69         .update_status  = gma_backlight_update_status,
  70 };
  71
  72 int gma_backlight_init(struct drm_device *dev)
  73 {
  74         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  75         struct backlight_properties props __maybe_unused = {};
  76         int ret;
  77
  78         dev_priv->backlight_enabled = true;
  79         dev_priv->backlight_level = 100;
  80
  81         ret = dev_priv->ops->backlight_init(dev);
  82         if (ret)
  83                 return ret;
  84
  85         if (!acpi_video_backlight_use_native()) {
  86                 drm_info(dev, "Skipping %s backlight registration\n",
  87                          dev_priv->ops->backlight_name);
  88                 return 0;
  89         }
  90
  91 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  92         props.brightness = dev_priv->backlight_level;
  93         props.max_brightness = PSB_MAX_BRIGHTNESS;
  94         props.type = BACKLIGHT_RAW;
  95
  96         dev_priv->backlight_device =
  97                 backlight_device_register(dev_priv->ops->backlight_name,
  98                                           dev->dev, dev,
  99                                           &gma_backlight_ops, &props);
 100         if (IS_ERR(dev_priv->backlight_device))
 101                 return PTR_ERR(dev_priv->backlight_device);
 102 #endif
 103
 104         return 0;
 105 }
 106
 107 void gma_backlight_exit(struct drm_device *dev)
 108 {
 109 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 110         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 111
 112         if (dev_priv->backlight_device)
 113                 backlight_device_unregister(dev_priv->backlight_device);
 114 #endif
 115 }