Initial import

1 files changed, 304 insertions, 0 deletions

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
new file mode 100644
index 000000000..15eb3f86f
--- /dev/null
+++ b/drivers/leds/leds-gpio.c
@@ -0,0 +1,304 @@
+/*
+ * 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");