// SPDX-License-Identifier: GPL-2.0-only /* * LEDs driver for GPIOs * * Copyright (C) 2007 8D Technologies inc. * Raphael Assenat <raph@8d.com> * Copyright (C) 2008 Freescale Semiconductor, Inc. */ #include <linux/err.h> #include <linux/gpio.h> #include <linux/gpio/consumer.h> #include <linux/kernel.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/property.h> #include <linux/slab.h> struct gpio_led_data { struct led_classdev cdev; struct gpio_desc *gpiod; u8 can_sleep; u8 blinking; gpio_blink_set_t platform_gpio_blink_set; }; static inline struct gpio_led_data * cdev_to_gpio_led_data(struct led_classdev *led_cdev) { return container_of(led_cdev, struct gpio_led_data, cdev); } static void gpio_led_set(struct led_classdev *led_cdev, enum led_brightness value) { struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); int level; if (value == LED_OFF) level = 0; else level = 1; if (led_dat->blinking) { led_dat->platform_gpio_blink_set(led_dat->gpiod, level, NULL, NULL); led_dat->blinking = 0; } else { if (led_dat->can_sleep) gpiod_set_value_cansleep(led_dat->gpiod, level); else gpiod_set_value(led_dat->gpiod, level); } } static int gpio_led_set_blocking(struct led_classdev *led_cdev, enum led_brightness value) { gpio_led_set(led_cdev, value); return 0; } static int gpio_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); led_dat->blinking = 1; return led_dat->platform_gpio_blink_set(led_dat->gpiod, 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, struct fwnode_handle *fwnode, gpio_blink_set_t blink_set) { struct led_init_data init_data = {}; int ret, state; led_dat->cdev.default_trigger = template->default_trigger; led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); if (!led_dat->can_sleep) led_dat->cdev.brightness_set = gpio_led_set; else led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; led_dat->blinking = 0; if (blink_set) { led_dat->platform_gpio_blink_set = blink_set; led_dat->cdev.blink_set = gpio_blink_set; } if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { state = gpiod_get_value_cansleep(led_dat->gpiod); if (state < 0) return state; } 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; if (template->panic_indicator) led_dat->cdev.flags |= LED_PANIC_INDICATOR; if (template->retain_state_shutdown) led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; ret = gpiod_direction_output(led_dat->gpiod, state); if (ret < 0) return ret; if (template->name) { led_dat->cdev.name = template->name; ret = devm_led_classdev_register(parent, &led_dat->cdev); } else { init_data.fwnode = fwnode; ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, &init_data); } return ret; } 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); } static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct fwnode_handle *child; struct gpio_leds_priv *priv; int count, ret; count = device_get_child_node_count(dev); if (!count) return ERR_PTR(-ENODEV); priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL); if (!priv) return ERR_PTR(-ENOMEM); device_for_each_child_node(dev, child) { struct gpio_led_data *led_dat = &priv->leds[priv->num_leds]; struct gpio_led led = {}; const char *state = NULL; /* * Acquire gpiod from DT with uninitialized label, which * will be updated after LED class device is registered, * Only then the final LED name is known. */ led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child, GPIOD_ASIS, NULL); if (IS_ERR(led.gpiod)) { fwnode_handle_put(child); return ERR_CAST(led.gpiod); } led_dat->gpiod = led.gpiod; fwnode_property_read_string(child, "linux,default-trigger", &led.default_trigger); if (!fwnode_property_read_string(child, "default-state", &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; } if (fwnode_property_present(child, "retain-state-suspended")) led.retain_state_suspended = 1; if (fwnode_property_present(child, "retain-state-shutdown")) led.retain_state_shutdown = 1; if (fwnode_property_present(child, "panic-indicator")) led.panic_indicator = 1; ret = create_gpio_led(&led, led_dat, dev, child, NULL); if (ret < 0) { fwnode_handle_put(child); return ERR_PTR(ret); } /* Set gpiod label to match the corresponding LED name. */ gpiod_set_consumer_name(led_dat->gpiod, led_dat->cdev.dev->kobj.name); priv->num_leds++; } return priv; } static const struct of_device_id of_gpio_leds_match[] = { { .compatible = "gpio-leds", }, {}, }; MODULE_DEVICE_TABLE(of, of_gpio_leds_match); static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, const struct gpio_led *template) { struct gpio_desc *gpiod; unsigned long flags = GPIOF_OUT_INIT_LOW; int ret; /* * This means the LED does not come from the device tree * or ACPI, so let's try just getting it by index from the * device, this will hit the board file, if any and get * the GPIO from there. */ gpiod = devm_gpiod_get_index(dev, NULL, idx, flags); if (!IS_ERR(gpiod)) { gpiod_set_consumer_name(gpiod, template->name); return gpiod; } if (PTR_ERR(gpiod) != -ENOENT) return gpiod; /* * This is the legacy code path for platform code that * still uses GPIO numbers. Ultimately we would like to get * rid of this block completely. */ /* skip leds that aren't available */ if (!gpio_is_valid(template->gpio)) return ERR_PTR(-ENOENT); if (template->active_low) flags |= GPIOF_ACTIVE_LOW; ret = devm_gpio_request_one(dev, template->gpio, flags, template->name); if (ret < 0) return ERR_PTR(ret); gpiod = gpio_to_desc(template->gpio); if (!gpiod) return ERR_PTR(-EINVAL); return gpiod; } static int gpio_led_probe(struct platform_device *pdev) { struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); struct gpio_leds_priv *priv; int i, ret = 0; 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++) { const struct gpio_led *template = &pdata->leds[i]; struct gpio_led_data *led_dat = &priv->leds[i]; if (template->gpiod) led_dat->gpiod = template->gpiod; else led_dat->gpiod = gpio_led_get_gpiod(&pdev->dev, i, template); if (IS_ERR(led_dat->gpiod)) { dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n", template->gpio, template->name); continue; } ret = create_gpio_led(template, led_dat, &pdev->dev, NULL, pdata->gpio_blink_set); if (ret < 0) return ret; } } else { priv = gpio_leds_create(pdev); if (IS_ERR(priv)) return PTR_ERR(priv); } platform_set_drvdata(pdev, priv); return 0; } static void gpio_led_shutdown(struct platform_device *pdev) { struct gpio_leds_priv *priv = platform_get_drvdata(pdev); int i; for (i = 0; i < priv->num_leds; i++) { struct gpio_led_data *led = &priv->leds[i]; if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) gpio_led_set(&led->cdev, LED_OFF); } } static struct platform_driver gpio_led_driver = { .probe = gpio_led_probe, .shutdown = gpio_led_shutdown, .driver = { .name = "leds-gpio", .of_match_table = 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");