/* * 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/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");