linux/drivers/video/backlight/adx_bl.c
Matthew Garrett bb7ca747f8 backlight: add backlight type
There may be multiple ways of controlling the backlight on a given
machine.  Allow drivers to expose the type of interface they are
providing, making it possible for userspace to make appropriate policy
decisions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:43:59 -07:00

183 lines
4.1 KiB
C

/*
* linux/drivers/video/backlight/adx.c
*
* Copyright (C) 2009 Avionic Design GmbH
*
* 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.
*
* Written by Thierry Reding <thierry.reding@avionic-design.de>
*/
#include <linux/backlight.h>
#include <linux/fb.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
/* register definitions */
#define ADX_BACKLIGHT_CONTROL 0x00
#define ADX_BACKLIGHT_CONTROL_ENABLE (1 << 0)
#define ADX_BACKLIGHT_BRIGHTNESS 0x08
#define ADX_BACKLIGHT_STATUS 0x10
#define ADX_BACKLIGHT_ERROR 0x18
struct adxbl {
void __iomem *base;
};
static int adx_backlight_update_status(struct backlight_device *bldev)
{
struct adxbl *bl = bl_get_data(bldev);
u32 value;
value = bldev->props.brightness;
writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS);
value = readl(bl->base + ADX_BACKLIGHT_CONTROL);
if (bldev->props.state & BL_CORE_FBBLANK)
value &= ~ADX_BACKLIGHT_CONTROL_ENABLE;
else
value |= ADX_BACKLIGHT_CONTROL_ENABLE;
writel(value, bl->base + ADX_BACKLIGHT_CONTROL);
return 0;
}
static int adx_backlight_get_brightness(struct backlight_device *bldev)
{
struct adxbl *bl = bl_get_data(bldev);
u32 brightness;
brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS);
return brightness & 0xff;
}
static int adx_backlight_check_fb(struct backlight_device *bldev, struct fb_info *fb)
{
return 1;
}
static const struct backlight_ops adx_backlight_ops = {
.options = 0,
.update_status = adx_backlight_update_status,
.get_brightness = adx_backlight_get_brightness,
.check_fb = adx_backlight_check_fb,
};
static int __devinit adx_backlight_probe(struct platform_device *pdev)
{
struct backlight_properties props;
struct backlight_device *bldev;
struct resource *res;
struct adxbl *bl;
int ret = 0;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENXIO;
goto out;
}
res = devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), res->name);
if (!res) {
ret = -ENXIO;
goto out;
}
bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
if (!bl) {
ret = -ENOMEM;
goto out;
}
bl->base = devm_ioremap_nocache(&pdev->dev, res->start,
resource_size(res));
if (!bl->base) {
ret = -ENXIO;
goto out;
}
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.max_brightness = 0xff;
bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev,
bl, &adx_backlight_ops, &props);
if (IS_ERR(bldev)) {
ret = PTR_ERR(bldev);
goto out;
}
bldev->props.brightness = 0xff;
bldev->props.power = FB_BLANK_UNBLANK;
platform_set_drvdata(pdev, bldev);
out:
return ret;
}
static int __devexit adx_backlight_remove(struct platform_device *pdev)
{
struct backlight_device *bldev;
int ret = 0;
bldev = platform_get_drvdata(pdev);
bldev->props.power = FB_BLANK_UNBLANK;
bldev->props.brightness = 0xff;
backlight_update_status(bldev);
backlight_device_unregister(bldev);
platform_set_drvdata(pdev, NULL);
return ret;
}
#ifdef CONFIG_PM
static int adx_backlight_suspend(struct platform_device *pdev,
pm_message_t state)
{
return 0;
}
static int adx_backlight_resume(struct platform_device *pdev)
{
return 0;
}
#else
#define adx_backlight_suspend NULL
#define adx_backlight_resume NULL
#endif
static struct platform_driver adx_backlight_driver = {
.probe = adx_backlight_probe,
.remove = __devexit_p(adx_backlight_remove),
.suspend = adx_backlight_suspend,
.resume = adx_backlight_resume,
.driver = {
.name = "adx-backlight",
.owner = THIS_MODULE,
},
};
static int __init adx_backlight_init(void)
{
return platform_driver_register(&adx_backlight_driver);
}
static void __exit adx_backlight_exit(void)
{
platform_driver_unregister(&adx_backlight_driver);
}
module_init(adx_backlight_init);
module_exit(adx_backlight_exit);
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
MODULE_LICENSE("GPL v2");