/* * 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 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); INIT_WORK(&led_dat->work, gpio_led_work); ret = led_classdev_register(&pdev->dev, &led_dat->cdev); if (ret < 0) { gpio_free(led_dat->gpio); 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); cancel_work_sync(&leds_data[i].work); gpio_free(leds_data[i].gpio); } } 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++) { led_classdev_unregister(&leds_data[i].cdev); cancel_work_sync(&leds_data[i].work); 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 = { .probe = gpio_led_probe, .remove = __devexit_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_register(&gpio_led_driver); } 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");