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/*
* drivers/leds/leds-pwm.c
*
* Copyright (C) 2009 by Digi International Inc.
* All rights reserved.
*
* Code rebased on original leds-pwm.c from Bill Gatliff
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/io.h>
#include <linux/pwm.h>
#include <linux/pwm-led.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/slab.h>
struct led_pwm {
struct led_classdev led;
struct pwm_channel *pwm;
unsigned long period;
};
static void
led_pwm_brightness_set(struct led_classdev *c,
enum led_brightness b)
{
struct led_pwm *led;
unsigned long period;
period = 1000000000UL;
led = container_of(c, struct led_pwm, led);
led->period = period;
pwm_set_period_ns(led->pwm, period);
}
static enum led_brightness
led_pwm_brightness_get(struct led_classdev *c)
{
struct led_pwm *led;
led = container_of(c, struct led_pwm, led);
return led->period;
}
static int
led_pwm_blink_set(struct led_classdev *c,
unsigned long *on_ms,
unsigned long *off_ms)
{
struct led_pwm *led;
struct pwm_channel_config cfg;
led = container_of(c, struct led_pwm, led);
if (*on_ms == 0 && *off_ms == 0) {
*on_ms = 1000UL;
*off_ms = 1000UL;
}
cfg.config_mask = PWM_CONFIG_DUTY_NS
| PWM_CONFIG_PERIOD_NS;
cfg.duty_ns = *on_ms * 1000000000UL;
cfg.period_ns = (*on_ms + *off_ms) * 1000000000UL;
return pwm_config(led->pwm, &cfg);
}
static int __init
led_pwm_probe(struct platform_device *pdev)
{
struct pwm_led_platform_data *pdata = pdev->dev.platform_data;
struct led_pwm *led;
int ret;
if (!pdata || !pdata->led_info) {
return -EINVAL;
}
led = kzalloc(sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;
led->pwm = pwm_request(pdata->bus_id, pdata->chan,
pdata->led_info->name);
if (!led->pwm) {
ret = -EINVAL;
goto err_pwm_request;
}
platform_set_drvdata(pdev, led);
led->led.name = pdata->led_info->name;
led->led.default_trigger = pdata->led_info->default_trigger;
led->led.brightness_set = led_pwm_brightness_set;
led->led.brightness_get = led_pwm_brightness_get;
led->led.blink_set = led_pwm_blink_set;
led->led.brightness = LED_OFF;
ret = pwm_config(led->pwm, pdata->config);
if (ret)
goto err_pwm_config;
pwm_start(led->pwm);
ret = led_classdev_register(&pdev->dev, &led->led);
if (ret < 0)
goto err_classdev_register;
return 0;
err_classdev_register:
pwm_stop(led->pwm);
err_pwm_config:
pwm_free(led->pwm);
err_pwm_request:
kfree(led);
return ret;
}
static int
led_pwm_remove(struct platform_device *pdev)
{
struct led_pwm *led = platform_get_drvdata(pdev);
led_classdev_unregister(&led->led);
if (led->pwm) {
pwm_stop(led->pwm);
pwm_free(led->pwm);
}
kfree(led);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver led_pwm_driver = {
.driver = {
.name = "leds-pwm",
.owner = THIS_MODULE,
},
.probe = led_pwm_probe,
.remove = led_pwm_remove,
};
static int __init led_pwm_modinit(void)
{
return platform_driver_register(&led_pwm_driver);
}
late_initcall(led_pwm_modinit);
static void __exit led_pwm_modexit(void)
{
platform_driver_unregister(&led_pwm_driver);
}
module_exit(led_pwm_modexit);
MODULE_AUTHOR("Hector Oron <Hector.Oron <at> digi.com>");
MODULE_DESCRIPTION("Driver for LEDs with PWM-controlled brightness");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-pwm");
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