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