Richard Purdie | d00ba72 | 2009-01-08 20:52:37 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Generic Backlight Driver |
| 3 | * |
| 4 | * Copyright (c) 2004-2008 Richard Purdie |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/mutex.h> |
| 17 | #include <linux/fb.h> |
| 18 | #include <linux/backlight.h> |
| 19 | |
| 20 | static int genericbl_intensity; |
| 21 | static struct backlight_device *generic_backlight_device; |
| 22 | static struct generic_bl_info *bl_machinfo; |
| 23 | |
| 24 | /* Flag to signal when the battery is low */ |
| 25 | #define GENERICBL_BATTLOW BL_CORE_DRIVER1 |
| 26 | |
| 27 | static int genericbl_send_intensity(struct backlight_device *bd) |
| 28 | { |
| 29 | int intensity = bd->props.brightness; |
| 30 | |
| 31 | if (bd->props.power != FB_BLANK_UNBLANK) |
| 32 | intensity = 0; |
| 33 | if (bd->props.state & BL_CORE_FBBLANK) |
| 34 | intensity = 0; |
| 35 | if (bd->props.state & BL_CORE_SUSPENDED) |
| 36 | intensity = 0; |
| 37 | if (bd->props.state & GENERICBL_BATTLOW) |
| 38 | intensity &= bl_machinfo->limit_mask; |
| 39 | |
| 40 | bl_machinfo->set_bl_intensity(intensity); |
| 41 | |
| 42 | genericbl_intensity = intensity; |
| 43 | |
| 44 | if (bl_machinfo->kick_battery) |
| 45 | bl_machinfo->kick_battery(); |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | static int genericbl_get_intensity(struct backlight_device *bd) |
| 51 | { |
| 52 | return genericbl_intensity; |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Called when the battery is low to limit the backlight intensity. |
| 57 | * If limit==0 clear any limit, otherwise limit the intensity |
| 58 | */ |
| 59 | void corgibl_limit_intensity(int limit) |
| 60 | { |
| 61 | struct backlight_device *bd = generic_backlight_device; |
| 62 | |
| 63 | mutex_lock(&bd->ops_lock); |
| 64 | if (limit) |
| 65 | bd->props.state |= GENERICBL_BATTLOW; |
| 66 | else |
| 67 | bd->props.state &= ~GENERICBL_BATTLOW; |
| 68 | backlight_update_status(generic_backlight_device); |
| 69 | mutex_unlock(&bd->ops_lock); |
| 70 | } |
| 71 | EXPORT_SYMBOL(corgibl_limit_intensity); |
| 72 | |
| 73 | static struct backlight_ops genericbl_ops = { |
| 74 | .options = BL_CORE_SUSPENDRESUME, |
| 75 | .get_brightness = genericbl_get_intensity, |
| 76 | .update_status = genericbl_send_intensity, |
| 77 | }; |
| 78 | |
| 79 | static int genericbl_probe(struct platform_device *pdev) |
| 80 | { |
| 81 | struct generic_bl_info *machinfo = pdev->dev.platform_data; |
| 82 | const char *name = "generic-bl"; |
| 83 | struct backlight_device *bd; |
| 84 | |
| 85 | bl_machinfo = machinfo; |
| 86 | if (!machinfo->limit_mask) |
| 87 | machinfo->limit_mask = -1; |
| 88 | |
| 89 | if (machinfo->name) |
| 90 | name = machinfo->name; |
| 91 | |
| 92 | bd = backlight_device_register (name, |
| 93 | &pdev->dev, NULL, &genericbl_ops); |
| 94 | if (IS_ERR (bd)) |
| 95 | return PTR_ERR (bd); |
| 96 | |
| 97 | platform_set_drvdata(pdev, bd); |
| 98 | |
| 99 | bd->props.max_brightness = machinfo->max_intensity; |
| 100 | bd->props.power = FB_BLANK_UNBLANK; |
| 101 | bd->props.brightness = machinfo->default_intensity; |
| 102 | backlight_update_status(bd); |
| 103 | |
| 104 | generic_backlight_device = bd; |
| 105 | |
| 106 | printk("Generic Backlight Driver Initialized.\n"); |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static int genericbl_remove(struct platform_device *pdev) |
| 111 | { |
| 112 | struct backlight_device *bd = platform_get_drvdata(pdev); |
| 113 | |
| 114 | bd->props.power = 0; |
| 115 | bd->props.brightness = 0; |
| 116 | backlight_update_status(bd); |
| 117 | |
| 118 | backlight_device_unregister(bd); |
| 119 | |
| 120 | printk("Generic Backlight Driver Unloaded\n"); |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static struct platform_driver genericbl_driver = { |
| 125 | .probe = genericbl_probe, |
| 126 | .remove = genericbl_remove, |
| 127 | .driver = { |
| 128 | .name = "generic-bl", |
| 129 | }, |
| 130 | }; |
| 131 | |
| 132 | static int __init genericbl_init(void) |
| 133 | { |
| 134 | return platform_driver_register(&genericbl_driver); |
| 135 | } |
| 136 | |
| 137 | static void __exit genericbl_exit(void) |
| 138 | { |
| 139 | platform_driver_unregister(&genericbl_driver); |
| 140 | } |
| 141 | |
| 142 | module_init(genericbl_init); |
| 143 | module_exit(genericbl_exit); |
| 144 | |
| 145 | MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); |
| 146 | MODULE_DESCRIPTION("Generic Backlight Driver"); |
| 147 | MODULE_LICENSE("GPL"); |