144 lines
3.3 KiB
C
144 lines
3.3 KiB
C
/*
|
|
* linux/drivers/leds-pwm.c
|
|
*
|
|
* simple PWM based LED control
|
|
*
|
|
* Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
|
|
*
|
|
* based on leds-gpio.c by Raphael Assenat <raph@8d.com>
|
|
*
|
|
* 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/leds.h>
|
|
#include <linux/err.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/leds_pwm.h>
|
|
#include <linux/slab.h>
|
|
|
|
struct led_pwm_data {
|
|
struct led_classdev cdev;
|
|
struct pwm_device *pwm;
|
|
unsigned int active_low;
|
|
unsigned int period;
|
|
};
|
|
|
|
static void led_pwm_set(struct led_classdev *led_cdev,
|
|
enum led_brightness brightness)
|
|
{
|
|
struct led_pwm_data *led_dat =
|
|
container_of(led_cdev, struct led_pwm_data, cdev);
|
|
unsigned int max = led_dat->cdev.max_brightness;
|
|
unsigned int period = led_dat->period;
|
|
|
|
if (brightness == 0) {
|
|
pwm_config(led_dat->pwm, 0, period);
|
|
pwm_disable(led_dat->pwm);
|
|
} else {
|
|
pwm_config(led_dat->pwm, brightness * period / max, period);
|
|
pwm_enable(led_dat->pwm);
|
|
}
|
|
}
|
|
|
|
static int led_pwm_probe(struct platform_device *pdev)
|
|
{
|
|
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
|
|
struct led_pwm *cur_led;
|
|
struct led_pwm_data *leds_data, *led_dat;
|
|
int i, ret = 0;
|
|
|
|
if (!pdata)
|
|
return -EBUSY;
|
|
|
|
leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds,
|
|
GFP_KERNEL);
|
|
if (!leds_data)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < pdata->num_leds; i++) {
|
|
cur_led = &pdata->leds[i];
|
|
led_dat = &leds_data[i];
|
|
|
|
led_dat->pwm = pwm_request(cur_led->pwm_id,
|
|
cur_led->name);
|
|
if (IS_ERR(led_dat->pwm)) {
|
|
ret = PTR_ERR(led_dat->pwm);
|
|
dev_err(&pdev->dev, "unable to request PWM %d\n",
|
|
cur_led->pwm_id);
|
|
goto err;
|
|
}
|
|
|
|
led_dat->cdev.name = cur_led->name;
|
|
led_dat->cdev.default_trigger = cur_led->default_trigger;
|
|
led_dat->active_low = cur_led->active_low;
|
|
led_dat->period = cur_led->pwm_period_ns;
|
|
led_dat->cdev.brightness_set = led_pwm_set;
|
|
led_dat->cdev.brightness = LED_OFF;
|
|
led_dat->cdev.max_brightness = cur_led->max_brightness;
|
|
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
|
|
|
|
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
|
|
if (ret < 0) {
|
|
pwm_free(led_dat->pwm);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
platform_set_drvdata(pdev, leds_data);
|
|
|
|
return 0;
|
|
|
|
err:
|
|
if (i > 0) {
|
|
for (i = i - 1; i >= 0; i--) {
|
|
led_classdev_unregister(&leds_data[i].cdev);
|
|
pwm_free(leds_data[i].pwm);
|
|
}
|
|
}
|
|
|
|
kfree(leds_data);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit led_pwm_remove(struct platform_device *pdev)
|
|
{
|
|
int i;
|
|
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
|
|
struct led_pwm_data *leds_data;
|
|
|
|
leds_data = platform_get_drvdata(pdev);
|
|
|
|
for (i = 0; i < pdata->num_leds; i++) {
|
|
led_classdev_unregister(&leds_data[i].cdev);
|
|
pwm_free(leds_data[i].pwm);
|
|
}
|
|
|
|
kfree(leds_data);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver led_pwm_driver = {
|
|
.probe = led_pwm_probe,
|
|
.remove = __devexit_p(led_pwm_remove),
|
|
.driver = {
|
|
.name = "leds_pwm",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(led_pwm_driver);
|
|
|
|
MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
|
|
MODULE_DESCRIPTION("PWM LED driver for PXA");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:leds-pwm");
|