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 <linux/backlight.h>
  11
  12 #include <acpi/video.h>
  13
  14 #include "psb_drv.h"
  15 #include "psb_intel_reg.h"
  16 #include "psb_intel_drv.h"
  17 #include "intel_bios.h"
  18 #include "power.h"
  19
  20 void gma_backlight_enable(struct drm_device *dev)
  21 {
  22         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  23
  24         dev_priv->backlight_enabled = true;
  25         dev_priv->ops->backlight_set(dev, dev_priv->backlight_level);
  26 }
  27
  28 void gma_backlight_disable(struct drm_device *dev)
  29 {
  30         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  31
  32         dev_priv->backlight_enabled = false;
  33         dev_priv->ops->backlight_set(dev, 0);
  34 }
  35
  36 void gma_backlight_set(struct drm_device *dev, int v)
  37 {
  38         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  39
  40         dev_priv->backlight_level = v;
  41         if (dev_priv->backlight_enabled)
  42                 dev_priv->ops->backlight_set(dev, v);
  43 }
  44
  45 static int gma_backlight_get_brightness(struct backlight_device *bd)
  46 {
  47         struct drm_device *dev = bl_get_data(bd);
  48         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  49
  50         if (dev_priv->ops->backlight_get)
  51                 return dev_priv->ops->backlight_get(dev);
  52
  53         return dev_priv->backlight_level;
  54 }
  55
  56 static int gma_backlight_update_status(struct backlight_device *bd)
  57 {
  58         struct drm_device *dev = bl_get_data(bd);
  59         int level = backlight_get_brightness(bd);
  60
  61         /* Percentage 1-100% being valid */
  62         if (level < 1)
  63                 level = 1;
  64
  65         gma_backlight_set(dev, level);
  66         return 0;
  67 }
  68
  69 static const struct backlight_ops gma_backlight_ops __maybe_unused = {
  70         .get_brightness = gma_backlight_get_brightness,
  71         .update_status  = gma_backlight_update_status,
  72 };
  73
  74 int gma_backlight_init(struct drm_device *dev)
  75 {
  76         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
  77         struct backlight_properties props __maybe_unused = {};
  78         int ret;
  79
  80         dev_priv->backlight_enabled = true;
  81         dev_priv->backlight_level = 100;
  82
  83         ret = dev_priv->ops->backlight_init(dev);
  84         if (ret)
  85                 return ret;
  86
  87         if (!acpi_video_backlight_use_native()) {
  88                 drm_info(dev, "Skipping %s backlight registration\n",
  89                          dev_priv->ops->backlight_name);
  90                 return 0;
  91         }
  92
  93 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  94         props.brightness = dev_priv->backlight_level;
  95         props.max_brightness = PSB_MAX_BRIGHTNESS;
  96         props.type = BACKLIGHT_RAW;
  97
  98         dev_priv->backlight_device =
  99                 backlight_device_register(dev_priv->ops->backlight_name,
 100                                           dev->dev, dev,
 101                                           &gma_backlight_ops, &props);
 102         if (IS_ERR(dev_priv->backlight_device))
 103                 return PTR_ERR(dev_priv->backlight_device);
 104 #endif
 105
 106         return 0;
 107 }
 108
 109 void gma_backlight_exit(struct drm_device *dev)
 110 {
 111 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 112         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 113
 114         if (dev_priv->backlight_device)
 115                 backlight_device_unregister(dev_priv->backlight_device);
 116 #endif
 117 }