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/*
* LEDs driver for GPIOs
*
* Copyright (C) 2007 8D Technologies inc.
* Raphael Assenat <raph@8d.com>
* Copyright (C) 2008 Freescale Semiconductor, Inc.
*
* 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/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <asm/gpio.h>
struct gpio_led_data {
struct led_classdev cdev;
unsigned gpio;
struct work_struct work;
u8 new_level;
u8 can_sleep;
u8 active_low;
int (*platform_gpio_blink_set)(unsigned gpio,
unsigned long *delay_on, unsigned long *delay_off);
};
static void gpio_led_work(struct work_struct *work)
{
struct gpio_led_data *led_dat =
container_of(work, struct gpio_led_data, work);
gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
}
static void gpio_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct gpio_led_data *led_dat =
container_of(led_cdev, struct gpio_led_data, cdev);
int level;
if (value == LED_OFF)
level = 0;
else
level = 1;
if (led_dat->active_low)
level = !level;
/* Setting GPIOs with I2C/etc requires a task context, and we don't
* seem to have a reliable way to know if we're already in one; so
* let's just assume the worst.
*/
if (led_dat->can_sleep) {
led_dat->new_level = level;
schedule_work(&led_dat->work);
} else
gpio_set_value(led_dat->gpio, level);
}
static int gpio_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on, unsigned long *delay_off)
{
struct gpio_led_data *led_dat =
container_of(led_cdev, struct gpio_led_data, cdev);
return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off);
}
static int __devinit create_gpio_led(const struct gpio_led *template,
struct gpio_led_data *led_dat, struct device *parent,
int (*blink_set)(unsigned, unsigned long *, unsigned long *))
{
int ret, state;
led_dat->gpio = -1;
/* skip leds that aren't available */
if (!gpio_is_valid(template->gpio)) {
printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n",
template->gpio, template->name);
return 0;
}
ret = gpio_request(template->gpio, template->name);
if (ret < 0)
return ret;
led_dat->cdev.name = template->name;
led_dat->cdev.default_trigger = template->default_trigger;
led_dat->gpio = template->gpio;
led_dat->can_sleep = gpio_cansleep(template->gpio);
led_dat->active_low = template->active_low;
if (blink_set) {
led_dat->platform_gpio_blink_set = blink_set;
led_dat->cdev.blink_set = gpio_blink_set;
}
led_dat->cdev.brightness_set = gpio_led_set;
if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low;
else
state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
if (!template->retain_state_suspended)
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
if (ret < 0)
goto err;
INIT_WORK(&led_dat->work, gpio_led_work);
ret = led_classdev_register(parent, &led_dat->cdev);
if (ret < 0)
goto err;
return 0;
err:
gpio_free(led_dat->gpio);
return ret;
}
static void delete_gpio_led(struct gpio_led_data *led)
{
if (!gpio_is_valid(led->gpio))
return;
led_classdev_unregister(&led->cdev);
cancel_work_sync(&led->work);
gpio_free(led->gpio);
}
#ifdef CONFIG_LEDS_GPIO_PLATFORM
static int __devinit gpio_led_probe(struct platform_device *pdev)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
int i, ret = 0;
if (!pdata)
return -EBUSY;
leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
GFP_KERNEL);
if (!leds_data)
return -ENOMEM;
for (i = 0; i < pdata->num_leds; i++) {
ret = create_gpio_led(&pdata->leds[i], &leds_data[i],
&pdev->dev, pdata->gpio_blink_set);
if (ret < 0)
goto err;
}
platform_set_drvdata(pdev, leds_data);
return 0;
err:
for (i = i - 1; i >= 0; i--)
delete_gpio_led(&leds_data[i]);
kfree(leds_data);
return ret;
}
static int __devexit gpio_led_remove(struct platform_device *pdev)
{
int i;
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++)
delete_gpio_led(&leds_data[i]);
kfree(leds_data);
return 0;
}
static struct platform_driver gpio_led_driver = {
.probe = gpio_led_probe,
.remove = __devexit_p(gpio_led_remove),
.driver = {
.name = "leds-gpio",
.owner = THIS_MODULE,
},
};
MODULE_ALIAS("platform:leds-gpio");
#endif /* CONFIG_LEDS_GPIO_PLATFORM */
/* Code to create from OpenFirmware platform devices */
#ifdef CONFIG_LEDS_GPIO_OF
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
struct gpio_led_of_platform_data {
int num_leds;
struct gpio_led_data led_data[];
};
static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
const struct of_device_id *match)
{
struct device_node *np = ofdev->node, *child;
struct gpio_led_of_platform_data *pdata;
int count = 0, ret;
/* count LEDs defined by this device, so we know how much to allocate */
for_each_child_of_node(np, child)
count++;
if (!count)
return 0; /* or ENODEV? */
pdata = kzalloc(sizeof(*pdata) + sizeof(struct gpio_led_data) * count,
GFP_KERNEL);
if (!pdata)
return -ENOMEM;
for_each_child_of_node(np, child) {
struct gpio_led led = {};
enum of_gpio_flags flags;
const char *state;
led.gpio = of_get_gpio_flags(child, 0, &flags);
led.active_low = flags & OF_GPIO_ACTIVE_LOW;
led.name = of_get_property(child, "label", NULL) ? : child->name;
led.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
state = of_get_property(child, "default-state", NULL);
if (state) {
if (!strcmp(state, "keep"))
led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
else if(!strcmp(state, "on"))
led.default_state = LEDS_GPIO_DEFSTATE_ON;
else
led.default_state = LEDS_GPIO_DEFSTATE_OFF;
}
ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++],
&ofdev->dev, NULL);
if (ret < 0) {
of_node_put(child);
goto err;
}
}
dev_set_drvdata(&ofdev->dev, pdata);
return 0;
err:
for (count = pdata->num_leds - 2; count >= 0; count--)
delete_gpio_led(&pdata->led_data[count]);
kfree(pdata);
return ret;
}
static int __devexit of_gpio_leds_remove(struct of_device *ofdev)
{
struct gpio_led_of_platform_data *pdata = dev_get_drvdata(&ofdev->dev);
int i;
for (i = 0; i < pdata->num_leds; i++)
delete_gpio_led(&pdata->led_data[i]);
kfree(pdata);
dev_set_drvdata(&ofdev->dev, NULL);
return 0;
}
static const struct of_device_id of_gpio_leds_match[] = {
{ .compatible = "gpio-leds", },
{},
};
static struct of_platform_driver of_gpio_leds_driver = {
.driver = {
.name = "of_gpio_leds",
.owner = THIS_MODULE,
},
.match_table = of_gpio_leds_match,
.probe = of_gpio_leds_probe,
.remove = __devexit_p(of_gpio_leds_remove),
};
#endif
static int __init gpio_led_init(void)
{
int ret;
#ifdef CONFIG_LEDS_GPIO_PLATFORM
ret = platform_driver_register(&gpio_led_driver);
if (ret)
return ret;
#endif
#ifdef CONFIG_LEDS_GPIO_OF
ret = of_register_platform_driver(&of_gpio_leds_driver);
#endif
#ifdef CONFIG_LEDS_GPIO_PLATFORM
if (ret)
platform_driver_unregister(&gpio_led_driver);
#endif
return ret;
}
static void __exit gpio_led_exit(void)
{
#ifdef CONFIG_LEDS_GPIO_PLATFORM
platform_driver_unregister(&gpio_led_driver);
#endif
#ifdef CONFIG_LEDS_GPIO_OF
of_unregister_platform_driver(&of_gpio_leds_driver);
#endif
}
module_init(gpio_led_init);
module_exit(gpio_led_exit);
MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
MODULE_DESCRIPTION("GPIO LED driver");
MODULE_LICENSE("GPL");