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 20static int genericbl_intensity; 21static struct backlight_device *generic_backlight_device; 22static struct generic_bl_info *bl_machinfo; 23 24/* Flag to signal when the battery is low */ 25#define GENERICBL_BATTLOW BL_CORE_DRIVER1 26 27static 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 50static int genericbl_get_intensity(struct backlight_device *bd) 51{ 52 return genericbl_intensity; 53} 54 55static const struct backlight_ops genericbl_ops = { 56 .options = BL_CORE_SUSPENDRESUME, 57 .get_brightness = genericbl_get_intensity, 58 .update_status = genericbl_send_intensity, 59}; 60 61static int genericbl_probe(struct platform_device *pdev) 62{ 63 struct backlight_properties props; 64 struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev); 65 const char *name = "generic-bl"; 66 struct backlight_device *bd; 67 68 bl_machinfo = machinfo; 69 if (!machinfo->limit_mask) 70 machinfo->limit_mask = -1; 71 72 if (machinfo->name) 73 name = machinfo->name; 74 75 memset(&props, 0, sizeof(struct backlight_properties)); 76 props.type = BACKLIGHT_RAW; 77 props.max_brightness = machinfo->max_intensity; 78 bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, 79 NULL, &genericbl_ops, &props); 80 if (IS_ERR(bd)) 81 return PTR_ERR(bd); 82 83 platform_set_drvdata(pdev, bd); 84 85 bd->props.power = FB_BLANK_UNBLANK; 86 bd->props.brightness = machinfo->default_intensity; 87 backlight_update_status(bd); 88 89 generic_backlight_device = bd; 90 91 dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n"); 92 return 0; 93} 94 95static int genericbl_remove(struct platform_device *pdev) 96{ 97 struct backlight_device *bd = platform_get_drvdata(pdev); 98 99 bd->props.power = 0; 100 bd->props.brightness = 0; 101 backlight_update_status(bd); 102 103 dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n"); 104 return 0; 105} 106 107static struct platform_driver genericbl_driver = { 108 .probe = genericbl_probe, 109 .remove = genericbl_remove, 110 .driver = { 111 .name = "generic-bl", 112 }, 113}; 114 115module_platform_driver(genericbl_driver); 116 117MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); 118MODULE_DESCRIPTION("Generic Backlight Driver"); 119MODULE_LICENSE("GPL"); 120