--- /dev/null
+/*
+ * 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/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/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+struct gpio_led_data {
+ struct led_classdev cdev;
+ struct gpio_desc *gpiod;
+ struct work_struct work;
+ u8 new_level;
+ u8 can_sleep;
+ u8 blinking;
+ int (*platform_gpio_blink_set)(struct gpio_desc *desc, 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->gpiod,
+ led_dat->new_level, NULL, NULL);
+ led_dat->blinking = 0;
+ } else
+ gpiod_set_value_cansleep(led_dat->gpiod, 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;
+
+ /* 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->gpiod, level,
+ NULL, NULL);
+ led_dat->blinking = 0;
+ } else
+ gpiod_set_value(led_dat->gpiod, 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->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,
+ int (*blink_set)(struct gpio_desc *, int, unsigned long *,
+ unsigned long *))
+{
+ int ret, state;
+
+ led_dat->gpiod = template->gpiod;
+ if (!led_dat->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.
+ */
+ unsigned long flags = 0;
+
+ /* 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;
+ }
+
+ if (template->active_low)
+ flags |= GPIOF_ACTIVE_LOW;
+
+ ret = devm_gpio_request_one(parent, template->gpio, flags,
+ template->name);
+ if (ret < 0)
+ return ret;
+
+ led_dat->gpiod = gpio_to_desc(template->gpio);
+ if (IS_ERR(led_dat->gpiod))
+ return PTR_ERR(led_dat->gpiod);
+ }
+
+ led_dat->cdev.name = template->name;
+ led_dat->cdev.default_trigger = template->default_trigger;
+ led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
+ 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 = !!gpiod_get_value_cansleep(led_dat->gpiod);
+ 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 = gpiod_direction_output(led_dat->gpiod, state);
+ if (ret < 0)
+ return ret;
+
+ INIT_WORK(&led_dat->work, gpio_led_work);
+
+ return led_classdev_register(parent, &led_dat->cdev);
+}
+
+static void delete_gpio_led(struct gpio_led_data *led)
+{
+ 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);
+}
+
+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;
+ struct device_node *np;
+
+ 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 led = {};
+ const char *state = NULL;
+
+ led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
+ if (IS_ERR(led.gpiod)) {
+ fwnode_handle_put(child);
+ ret = PTR_ERR(led.gpiod);
+ goto err;
+ }
+
+ np = of_node(child);
+
+ if (fwnode_property_present(child, "label")) {
+ fwnode_property_read_string(child, "label", &led.name);
+ } else {
+ if (IS_ENABLED(CONFIG_OF) && !led.name && np)
+ led.name = np->name;
+ if (!led.name)
+ return ERR_PTR(-EINVAL);
+ }
+ 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;
+
+ ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
+ dev, NULL);
+ if (ret < 0) {
+ fwnode_handle_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(ret);
+}
+
+static const struct of_device_id of_gpio_leds_match[] = {
+ { .compatible = "gpio-leds", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
+
+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++) {
+ 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(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]);
+
+ return 0;
+}
+
+static struct platform_driver gpio_led_driver = {
+ .probe = gpio_led_probe,
+ .remove = gpio_led_remove,
+ .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");
Code Review / kvmfornfv.git / blobdiff