/* * Generic Backlight Driver * * Copyright (c) 2004-2008 Richard Purdie * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/mutex.h> #include <linux/fb.h> #include <linux/backlight.h> static int genericbl_intensity; static struct backlight_device *generic_backlight_device; static struct generic_bl_info *bl_machinfo; /* Flag to signal when the battery is low */ #define GENERICBL_BATTLOW BL_CORE_DRIVER1 static int genericbl_send_intensity(struct backlight_device *bd) { int intensity = bd->props.brightness; if (bd->props.power != FB_BLANK_UNBLANK) intensity = 0; if (bd->props.state & BL_CORE_FBBLANK) intensity = 0; if (bd->props.state & BL_CORE_SUSPENDED) intensity = 0; if (bd->props.state & GENERICBL_BATTLOW) intensity &= bl_machinfo->limit_mask; bl_machinfo->set_bl_intensity(intensity); genericbl_intensity = intensity; if (bl_machinfo->kick_battery) bl_machinfo->kick_battery(); return 0; } static int genericbl_get_intensity(struct backlight_device *bd) { return genericbl_intensity; } /* * Called when the battery is low to limit the backlight intensity. * If limit==0 clear any limit, otherwise limit the intensity */ void genericbl_limit_intensity(int limit) { struct backlight_device *bd = generic_backlight_device; mutex_lock(&bd->ops_lock); if (limit) bd->props.state |= GENERICBL_BATTLOW; else bd->props.state &= ~GENERICBL_BATTLOW; backlight_update_status(generic_backlight_device); mutex_unlock(&bd->ops_lock); } EXPORT_SYMBOL(genericbl_limit_intensity); static const struct backlight_ops genericbl_ops = { .options = BL_CORE_SUSPENDRESUME, .get_brightness = genericbl_get_intensity, .update_status = genericbl_send_intensity, }; static int genericbl_probe(struct platform_device *pdev) { struct backlight_properties props; struct generic_bl_info *machinfo = pdev->dev.platform_data; const char *name = "generic-bl"; struct backlight_device *bd; bl_machinfo = machinfo; if (!machinfo->limit_mask) machinfo->limit_mask = -1; if (machinfo->name) name = machinfo->name; memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; props.max_brightness = machinfo->max_intensity; bd = backlight_device_register(name, &pdev->dev, NULL, &genericbl_ops, &props); if (IS_ERR (bd)) return PTR_ERR (bd); platform_set_drvdata(pdev, bd); bd->props.power = FB_BLANK_UNBLANK; bd->props.brightness = machinfo->default_intensity; backlight_update_status(bd); generic_backlight_device = bd; printk("Generic Backlight Driver Initialized.\n"); return 0; } static int genericbl_remove(struct platform_device *pdev) { struct backlight_device *bd = platform_get_drvdata(pdev); bd->props.power = 0; bd->props.brightness = 0; backlight_update_status(bd); backlight_device_unregister(bd); printk("Generic Backlight Driver Unloaded\n"); return 0; } static struct platform_driver genericbl_driver = { .probe = genericbl_probe, .remove = genericbl_remove, .driver = { .name = "generic-bl", }, }; module_platform_driver(genericbl_driver); MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); MODULE_DESCRIPTION("Generic Backlight Driver"); MODULE_LICENSE("GPL");