/* * 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/gpio.h> #include <linux/leds.h> #include <linux/of_platform.h> #include <linux/of_gpio.h> #include <linux/slab.h> #include <linux/workqueue.h> #include <linux/module.h> #include <linux/pinctrl/consumer.h> #include <linux/err.h> struct gpio_led_data { struct led_classdev cdev; unsigned gpio; struct work_struct work; u8 new_level; u8 can_sleep; u8 active_low; u8 blinking; int (*platform_gpio_blink_set)(unsigned gpio, int state, 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); if (led_dat->blinking) { led_dat->platform_gpio_blink_set(led_dat->gpio, led_dat->new_level, NULL, NULL); led_dat->blinking = 0; } else 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 { if (led_dat->blinking) { led_dat->platform_gpio_blink_set(led_dat->gpio, level, NULL, NULL); led_dat->blinking = 0; } 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); led_dat->blinking = 1; return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK, delay_on, delay_off); } static int create_gpio_led(const struct gpio_led *template, struct gpio_led_data *led_dat, struct device *parent, int (*blink_set)(unsigned, int, unsigned long *, unsigned long *)) { int ret, state; led_dat->gpio = -1; /* skip leds that aren't available */ if (!gpio_is_valid(template->gpio)) { dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n", template->gpio, template->name); return 0; } 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; led_dat->blinking = 0; 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_cansleep(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 = devm_gpio_request_one(parent, template->gpio, (led_dat->active_low ^ state) ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, template->name); if (ret < 0) return ret; INIT_WORK(&led_dat->work, gpio_led_work); ret = led_classdev_register(parent, &led_dat->cdev); if (ret < 0) return ret; return 0; } 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); } struct gpio_leds_priv { int num_leds; struct gpio_led_data leds[]; }; static inline int sizeof_gpio_leds_priv(int num_leds) { return sizeof(struct gpio_leds_priv) + (sizeof(struct gpio_led_data) * num_leds); } /* Code to create from OpenFirmware platform devices */ #ifdef CONFIG_OF_GPIO static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node, *child; struct gpio_leds_priv *priv; int count, ret; /* count LEDs in this device, so we know how much to allocate */ count = of_get_child_count(np); if (!count) return ERR_PTR(-ENODEV); for_each_child_of_node(np, child) if (of_get_gpio(child, 0) == -EPROBE_DEFER) return ERR_PTR(-EPROBE_DEFER); priv = devm_kzalloc(&pdev->dev, sizeof_gpio_leds_priv(count), GFP_KERNEL); if (!priv) return ERR_PTR(-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, &priv->leds[priv->num_leds++], &pdev->dev, NULL); if (ret < 0) { of_node_put(child); goto err; } } return priv; err: for (count = priv->num_leds - 2; count >= 0; count--) delete_gpio_led(&priv->leds[count]); return ERR_PTR(-ENODEV); } static const struct of_device_id of_gpio_leds_match[] = { { .compatible = "gpio-leds", }, {}, }; #else /* CONFIG_OF_GPIO */ static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev) { return ERR_PTR(-ENODEV); } #endif /* CONFIG_OF_GPIO */ static int gpio_led_probe(struct platform_device *pdev) { struct gpio_led_platform_data *pdata = pdev->dev.platform_data; struct gpio_leds_priv *priv; struct pinctrl *pinctrl; int i, ret = 0; pinctrl = devm_pinctrl_get_select_default(&pdev->dev); if (IS_ERR(pinctrl)) dev_warn(&pdev->dev, "pins are not configured from the driver\n"); if (pdata && pdata->num_leds) { priv = devm_kzalloc(&pdev->dev, sizeof_gpio_leds_priv(pdata->num_leds), GFP_KERNEL); if (!priv) return -ENOMEM; priv->num_leds = pdata->num_leds; for (i = 0; i < priv->num_leds; i++) { ret = create_gpio_led(&pdata->leds[i], &priv->leds[i], &pdev->dev, pdata->gpio_blink_set); if (ret < 0) { /* On failure: unwind the led creations */ for (i = i - 1; i >= 0; i--) delete_gpio_led(&priv->leds[i]); return ret; } } } else { priv = gpio_leds_create_of(pdev); if (IS_ERR(priv)) return PTR_ERR(priv); } platform_set_drvdata(pdev, priv); return 0; } static int gpio_led_remove(struct platform_device *pdev) { struct gpio_leds_priv *priv = platform_get_drvdata(pdev); int i; for (i = 0; i < priv->num_leds; i++) delete_gpio_led(&priv->leds[i]); platform_set_drvdata(pdev, NULL); return 0; } static struct platform_driver gpio_led_driver = { .probe = gpio_led_probe, .remove = gpio_led_remove, .driver = { .name = "leds-gpio", .owner = THIS_MODULE, .of_match_table = of_match_ptr(of_gpio_leds_match), }, }; module_platform_driver(gpio_led_driver); MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); MODULE_DESCRIPTION("GPIO LED driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:leds-gpio");