linux/drivers/video/backlight/pwm_bl.c
Ben Dooks cfc3899fcd backlight: Pass device through notify callback in the pwm driver
Add the device to the notify callback's arguments in the PWM backlight 
driver. This brings the notify callback into line with the other 
callbacks defined by this driver.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-12-17 11:46:01 +00:00

196 lines
4.6 KiB
C

/*
* linux/drivers/video/backlight/pwm_bl.c
*
* simple PWM based backlight control, board code has to setup
* 1) pin configuration so PWM waveforms can output
* 2) platform_data being correctly configured
*
* 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/fb.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/pwm.h>
#include <linux/pwm_backlight.h>
struct pwm_bl_data {
struct pwm_device *pwm;
struct device *dev;
unsigned int period;
int (*notify)(struct device *,
int brightness);
};
static int pwm_backlight_update_status(struct backlight_device *bl)
{
struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
int brightness = bl->props.brightness;
int max = bl->props.max_brightness;
if (bl->props.power != FB_BLANK_UNBLANK)
brightness = 0;
if (bl->props.fb_blank != FB_BLANK_UNBLANK)
brightness = 0;
if (pb->notify)
brightness = pb->notify(pb->dev, brightness);
if (brightness == 0) {
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
} else {
pwm_config(pb->pwm, brightness * pb->period / max, pb->period);
pwm_enable(pb->pwm);
}
return 0;
}
static int pwm_backlight_get_brightness(struct backlight_device *bl)
{
return bl->props.brightness;
}
static const struct backlight_ops pwm_backlight_ops = {
.update_status = pwm_backlight_update_status,
.get_brightness = pwm_backlight_get_brightness,
};
static int pwm_backlight_probe(struct platform_device *pdev)
{
struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
struct backlight_device *bl;
struct pwm_bl_data *pb;
int ret;
if (!data) {
dev_err(&pdev->dev, "failed to find platform data\n");
return -EINVAL;
}
if (data->init) {
ret = data->init(&pdev->dev);
if (ret < 0)
return ret;
}
pb = kzalloc(sizeof(*pb), GFP_KERNEL);
if (!pb) {
dev_err(&pdev->dev, "no memory for state\n");
ret = -ENOMEM;
goto err_alloc;
}
pb->period = data->pwm_period_ns;
pb->notify = data->notify;
pb->dev = &pdev->dev;
pb->pwm = pwm_request(data->pwm_id, "backlight");
if (IS_ERR(pb->pwm)) {
dev_err(&pdev->dev, "unable to request PWM for backlight\n");
ret = PTR_ERR(pb->pwm);
goto err_pwm;
} else
dev_dbg(&pdev->dev, "got pwm for backlight\n");
bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev,
pb, &pwm_backlight_ops);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
ret = PTR_ERR(bl);
goto err_bl;
}
bl->props.max_brightness = data->max_brightness;
bl->props.brightness = data->dft_brightness;
backlight_update_status(bl);
platform_set_drvdata(pdev, bl);
return 0;
err_bl:
pwm_free(pb->pwm);
err_pwm:
kfree(pb);
err_alloc:
if (data->exit)
data->exit(&pdev->dev);
return ret;
}
static int pwm_backlight_remove(struct platform_device *pdev)
{
struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
struct backlight_device *bl = platform_get_drvdata(pdev);
struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
backlight_device_unregister(bl);
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
pwm_free(pb->pwm);
kfree(pb);
if (data->exit)
data->exit(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM
static int pwm_backlight_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct backlight_device *bl = platform_get_drvdata(pdev);
struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
if (pb->notify)
pb->notify(pb->dev, 0);
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
return 0;
}
static int pwm_backlight_resume(struct platform_device *pdev)
{
struct backlight_device *bl = platform_get_drvdata(pdev);
backlight_update_status(bl);
return 0;
}
#else
#define pwm_backlight_suspend NULL
#define pwm_backlight_resume NULL
#endif
static struct platform_driver pwm_backlight_driver = {
.driver = {
.name = "pwm-backlight",
.owner = THIS_MODULE,
},
.probe = pwm_backlight_probe,
.remove = pwm_backlight_remove,
.suspend = pwm_backlight_suspend,
.resume = pwm_backlight_resume,
};
static int __init pwm_backlight_init(void)
{
return platform_driver_register(&pwm_backlight_driver);
}
module_init(pwm_backlight_init);
static void __exit pwm_backlight_exit(void)
{
platform_driver_unregister(&pwm_backlight_driver);
}
module_exit(pwm_backlight_exit);
MODULE_DESCRIPTION("PWM based Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pwm-backlight");