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 <drm/drm_print.h> 15 16 #include "psb_drv.h" 17 #include "psb_intel_reg.h" 18 #include "psb_intel_drv.h" 19 #include "intel_bios.h" 20 #include "power.h" 21 22 void gma_backlight_enable(struct drm_device *dev) 23 { 24 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 25 26 dev_priv->backlight_enabled = true; 27 dev_priv->ops->backlight_set(dev, dev_priv->backlight_level); 28 } 29 30 void gma_backlight_disable(struct drm_device *dev) 31 { 32 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 33 34 dev_priv->backlight_enabled = false; 35 dev_priv->ops->backlight_set(dev, 0); 36 } 37 38 void gma_backlight_set(struct drm_device *dev, int v) 39 { 40 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 41 42 dev_priv->backlight_level = v; 43 if (dev_priv->backlight_enabled) 44 dev_priv->ops->backlight_set(dev, v); 45 } 46 47 static int gma_backlight_get_brightness(struct backlight_device *bd) 48 { 49 struct drm_device *dev = bl_get_data(bd); 50 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 51 52 if (dev_priv->ops->backlight_get) 53 return dev_priv->ops->backlight_get(dev); 54 55 return dev_priv->backlight_level; 56 } 57 58 static int gma_backlight_update_status(struct backlight_device *bd) 59 { 60 struct drm_device *dev = bl_get_data(bd); 61 int level = backlight_get_brightness(bd); 62 63 /* Percentage 1-100% being valid */ 64 if (level < 1) 65 level = 1; 66 67 gma_backlight_set(dev, level); 68 return 0; 69 } 70 71 static const struct backlight_ops gma_backlight_ops __maybe_unused = { 72 .get_brightness = gma_backlight_get_brightness, 73 .update_status = gma_backlight_update_status, 74 }; 75 76 int gma_backlight_init(struct drm_device *dev) 77 { 78 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 79 struct backlight_properties props __maybe_unused = {}; 80 int ret; 81 82 dev_priv->backlight_enabled = true; 83 dev_priv->backlight_level = 100; 84 85 ret = dev_priv->ops->backlight_init(dev); 86 if (ret) 87 return ret; 88 89 if (!acpi_video_backlight_use_native()) { 90 drm_info(dev, "Skipping %s backlight registration\n", 91 dev_priv->ops->backlight_name); 92 return 0; 93 } 94 95 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE 96 props.brightness = dev_priv->backlight_level; 97 props.max_brightness = PSB_MAX_BRIGHTNESS; 98 props.type = BACKLIGHT_RAW; 99 100 dev_priv->backlight_device = 101 backlight_device_register(dev_priv->ops->backlight_name, 102 dev->dev, dev, 103 &gma_backlight_ops, &props); 104 if (IS_ERR(dev_priv->backlight_device)) 105 return PTR_ERR(dev_priv->backlight_device); 106 #endif 107 108 return 0; 109 } 110 111 void gma_backlight_exit(struct drm_device *dev) 112 { 113 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE 114 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 115 116 if (dev_priv->backlight_device) 117 backlight_device_unregister(dev_priv->backlight_device); 118 #endif 119 } 120