1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
new file mode 100644
index 000000000..0120faa3d
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ledtrig-gio.c - LED Trigger Based on GPIO events
+ *
+ * Copyright 2009 Felipe Balbi <me@felipebalbi.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include "../leds.h"
+
+struct gpio_trig_data {
+	struct led_classdev *led;
+
+	unsigned desired_brightness;	/* desired brightness when led is on */
+	unsigned inverted;		/* true when gpio is inverted */
+	unsigned gpio;			/* gpio that triggers the leds */
+};
+
+static irqreturn_t gpio_trig_irq(int irq, void *_led)
+{
+	struct led_classdev *led = _led;
+	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
+	int tmp;
+
+	tmp = gpio_get_value_cansleep(gpio_data->gpio);
+	if (gpio_data->inverted)
+		tmp = !tmp;
+
+	if (tmp) {
+		if (gpio_data->desired_brightness)
+			led_set_brightness_nosleep(gpio_data->led,
+					   gpio_data->desired_brightness);
+		else
+			led_set_brightness_nosleep(gpio_data->led, LED_FULL);
+	} else {
+		led_set_brightness_nosleep(gpio_data->led, LED_OFF);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static ssize_t gpio_trig_brightness_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", gpio_data->desired_brightness);
+}
+
+static ssize_t gpio_trig_brightness_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t n)
+{
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+	unsigned desired_brightness;
+	int ret;
+
+	ret = sscanf(buf, "%u", &desired_brightness);
+	if (ret < 1 || desired_brightness > 255) {
+		dev_err(dev, "invalid value\n");
+		return -EINVAL;
+	}
+
+	gpio_data->desired_brightness = desired_brightness;
+
+	return n;
+}
+static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
+		gpio_trig_brightness_store);
+
+static ssize_t gpio_trig_inverted_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", gpio_data->inverted);
+}
+
+static ssize_t gpio_trig_inverted_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t n)
+{
+	struct led_classdev *led = led_trigger_get_led(dev);
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+	unsigned long inverted;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &inverted);
+	if (ret < 0)
+		return ret;
+
+	if (inverted > 1)
+		return -EINVAL;
+
+	gpio_data->inverted = inverted;
+
+	/* After inverting, we need to update the LED. */
+	if (gpio_is_valid(gpio_data->gpio))
+		gpio_trig_irq(0, led);
+
+	return n;
+}
+static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
+		gpio_trig_inverted_store);
+
+static ssize_t gpio_trig_gpio_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", gpio_data->gpio);
+}
+
+static ssize_t gpio_trig_gpio_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t n)
+{
+	struct led_classdev *led = led_trigger_get_led(dev);
+	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
+	unsigned gpio;
+	int ret;
+
+	ret = sscanf(buf, "%u", &gpio);
+	if (ret < 1) {
+		dev_err(dev, "couldn't read gpio number\n");
+		return -EINVAL;
+	}
+
+	if (gpio_data->gpio == gpio)
+		return n;
+
+	if (!gpio_is_valid(gpio)) {
+		if (gpio_is_valid(gpio_data->gpio))
+			free_irq(gpio_to_irq(gpio_data->gpio), led);
+		gpio_data->gpio = gpio;
+		return n;
+	}
+
+	ret = request_threaded_irq(gpio_to_irq(gpio), NULL, gpio_trig_irq,
+			IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
+			| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
+	if (ret) {
+		dev_err(dev, "request_irq failed with error %d\n", ret);
+	} else {
+		if (gpio_is_valid(gpio_data->gpio))
+			free_irq(gpio_to_irq(gpio_data->gpio), led);
+		gpio_data->gpio = gpio;
+		/* After changing the GPIO, we need to update the LED. */
+		gpio_trig_irq(0, led);
+	}
+
+	return ret ? ret : n;
+}
+static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
+
+static struct attribute *gpio_trig_attrs[] = {
+	&dev_attr_desired_brightness.attr,
+	&dev_attr_inverted.attr,
+	&dev_attr_gpio.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(gpio_trig);
+
+static int gpio_trig_activate(struct led_classdev *led)
+{
+	struct gpio_trig_data *gpio_data;
+
+	gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
+	if (!gpio_data)
+		return -ENOMEM;
+
+	gpio_data->led = led;
+	gpio_data->gpio = -ENOENT;
+
+	led_set_trigger_data(led, gpio_data);
+
+	return 0;
+}
+
+static void gpio_trig_deactivate(struct led_classdev *led)
+{
+	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
+
+	if (gpio_is_valid(gpio_data->gpio))
+		free_irq(gpio_to_irq(gpio_data->gpio), led);
+	kfree(gpio_data);
+}
+
+static struct led_trigger gpio_led_trigger = {
+	.name		= "gpio",
+	.activate	= gpio_trig_activate,
+	.deactivate	= gpio_trig_deactivate,
+	.groups		= gpio_trig_groups,
+};
+module_led_trigger(gpio_led_trigger);
+
+MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
+MODULE_DESCRIPTION("GPIO LED trigger");
+MODULE_LICENSE("GPL v2");