diff options
Diffstat (limited to 'drivers/leds/leds-gpio.c')
| -rw-r--r-- | drivers/leds/leds-gpio.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c new file mode 100644 index 00000000000..47d90db280c --- /dev/null +++ b/drivers/leds/leds-gpio.c @@ -0,0 +1,199 @@ +/* + * LEDs driver for GPIOs + * + * Copyright (C) 2007 8D Technologies inc. + * 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/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/leds.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; +}; + +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 preemptible task context */ + if (led_dat->can_sleep) { + if (preempt_count()) { + led_dat->new_level = level; + schedule_work(&led_dat->work); + } else + gpio_set_value_cansleep(led_dat->gpio, level); + } else + gpio_set_value(led_dat->gpio, level); +} + +static int __init gpio_led_probe(struct platform_device *pdev) +{ + struct gpio_led_platform_data *pdata = pdev->dev.platform_data; + struct gpio_led *cur_led; + struct gpio_led_data *leds_data, *led_dat; + 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++) { + cur_led = &pdata->leds[i]; + led_dat = &leds_data[i]; + + led_dat->cdev.name = cur_led->name; + led_dat->cdev.default_trigger = cur_led->default_trigger; + led_dat->gpio = cur_led->gpio; + led_dat->can_sleep = gpio_cansleep(cur_led->gpio); + led_dat->active_low = cur_led->active_low; + led_dat->cdev.brightness_set = gpio_led_set; + led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF; + + ret = gpio_request(led_dat->gpio, led_dat->cdev.name); + if (ret < 0) + goto err; + + gpio_direction_output(led_dat->gpio, led_dat->active_low); + + ret = led_classdev_register(&pdev->dev, &led_dat->cdev); + if (ret < 0) { + gpio_free(led_dat->gpio); + goto err; + } + + INIT_WORK(&led_dat->work, gpio_led_work); + } + + 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); + gpio_free(leds_data[i].gpio); + } + } + + flush_scheduled_work(); + kfree(leds_data); + + return ret; +} + +static int __exit 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++) { + led_classdev_unregister(&leds_data[i].cdev); + gpio_free(leds_data[i].gpio); + } + + kfree(leds_data); + + return 0; +} + +#ifdef CONFIG_PM +static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct gpio_led_platform_data *pdata = pdev->dev.platform_data; + struct gpio_led_data *leds_data; + int i; + + leds_data = platform_get_drvdata(pdev); + + for (i = 0; i < pdata->num_leds; i++) + led_classdev_suspend(&leds_data[i].cdev); + + return 0; +} + +static int gpio_led_resume(struct platform_device *pdev) +{ + struct gpio_led_platform_data *pdata = pdev->dev.platform_data; + struct gpio_led_data *leds_data; + int i; + + leds_data = platform_get_drvdata(pdev); + + for (i = 0; i < pdata->num_leds; i++) + led_classdev_resume(&leds_data[i].cdev); + + return 0; +} +#else +#define gpio_led_suspend NULL +#define gpio_led_resume NULL +#endif + +static struct platform_driver gpio_led_driver = { + .remove = __exit_p(gpio_led_remove), + .suspend = gpio_led_suspend, + .resume = gpio_led_resume, + .driver = { + .name = "leds-gpio", + .owner = THIS_MODULE, + }, +}; + +static int __init gpio_led_init(void) +{ + return platform_driver_probe(&gpio_led_driver, gpio_led_probe); +} + +static void __exit gpio_led_exit(void) +{ + platform_driver_unregister(&gpio_led_driver); +} + +module_init(gpio_led_init); +module_exit(gpio_led_exit); + +MODULE_AUTHOR("Raphael Assenat <raph@8d.com>"); +MODULE_DESCRIPTION("GPIO LED driver"); +MODULE_LICENSE("GPL"); |