3 files changed, 253 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index db5e6a64c7cf..9c131f30757c 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -255,6 +255,19 @@ config LEDS_TRIGGER_BACKLIGHT
 
           If unsure, say N.
 
+config LEDS_TRIGGER_GPIO
+        tristate "LED GPIO Trigger"
+        depends on LEDS_TRIGGERS
+        depends on GPIOLIB
+        help
+          This allows LEDs to be controlled by gpio events. It's good
+          when using gpios as switches and triggering the needed LEDs
+          from there. One use case is n810's keypad LEDs that could
+          be triggered by this trigger when user slides up to show
+          keypad.
+
+          If unsure, say N.
+
 config LEDS_TRIGGER_DEFAULT_ON
         tristate "LED Default ON Trigger"
         depends on LEDS_TRIGGERS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 017f69aa2ecd..291aea22bf0c 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -35,4 +35,5 @@ obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o
 obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)     += ledtrig-ide-disk.o
 obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)    += ledtrig-heartbeat.o
 obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT)    += ledtrig-backlight.o
+obj-$(CONFIG_LEDS_TRIGGER_GPIO)         += ledtrig-gpio.o
 obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON)   += ledtrig-default-on.o
diff --git a/drivers/leds/ledtrig-gpio.c b/drivers/leds/ledtrig-gpio.c
new file mode 100644
index 000000000000..a247ae63374f
--- /dev/null
+++ b/drivers/leds/ledtrig-gpio.c
@@ -0,0 +1,239 @@
+/*
+ * ledtrig-gio.c - LED Trigger Based on GPIO events
+ *
+ * Copyright 2009 Felipe Balbi <me@felipebalbi.com>
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/leds.h>
+#include "leds.h"
+
+struct gpio_trig_data {
+        struct led_classdev *led;
+        struct work_struct work;
+
+        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->trigger_data;
+
+        /* just schedule_work since gpio_get_value can sleep */
+        schedule_work(&gpio_data->work);
+
+        return IRQ_HANDLED;
+};
+
+static void gpio_trig_work(struct work_struct *work)
+{
+        struct gpio_trig_data *gpio_data = container_of(work,
+                        struct gpio_trig_data, work);
+        int tmp;
+
+       if (!gpio_data->gpio)
+               return;
+
+       tmp = gpio_get_value(gpio_data->gpio);
+       if (gpio_data->inverted)
+               tmp = !tmp;
+
+       if (tmp) {
+               if (gpio_data->desired_brightness)
+                       led_set_brightness(gpio_data->led,
+                                       gpio_data->desired_brightness);
+               else
+                       led_set_brightness(gpio_data->led, LED_FULL);
+       } else {
+               led_set_brightness(gpio_data->led, LED_OFF);
+       }
+}
+
+static ssize_t gpio_trig_brightness_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct led_classdev *led = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+
+        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 led_classdev *led = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+        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 led_classdev *led = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+
+        return sprintf(buf, "%s\n", gpio_data->inverted ? "yes" : "no");
+}
+
+static ssize_t gpio_trig_inverted_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t n)
+{
+        struct led_classdev *led = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+        unsigned inverted;
+        int ret;
+
+        ret = sscanf(buf, "%u", &inverted);
+        if (ret < 1) {
+                dev_err(dev, "invalid value\n");
+                return -EINVAL;
+        }
+
+        gpio_data->inverted = !!inverted;
+
+        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 led_classdev *led = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+
+        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 = dev_get_drvdata(dev);
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+        unsigned gpio;
+        int ret;
+
+        ret = sscanf(buf, "%u", &gpio);
+        if (ret < 1) {
+                dev_err(dev, "couldn't read gpio number\n");
+                flush_work(&gpio_data->work);
+                return -EINVAL;
+        }
+
+        if (!gpio) {
+                free_irq(gpio_to_irq(gpio_data->gpio), led);
+                return n;
+        }
+
+        if (gpio_data->gpio > 0 && gpio_data->gpio != gpio)
+                free_irq(gpio_to_irq(gpio_data->gpio), led);
+
+        gpio_data->gpio = gpio;
+        ret = request_irq(gpio_to_irq(gpio), gpio_trig_irq,
+                        IRQF_SHARED | IRQF_TRIGGER_RISING
+                        | IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
+        if (ret)
+                dev_err(dev, "request_irq failed with error %d\n", ret);
+
+        return ret ? ret : n;
+}
+static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
+
+static void gpio_trig_activate(struct led_classdev *led)
+{
+        struct gpio_trig_data *gpio_data;
+        int ret;
+
+        gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
+        if (!gpio_data)
+                return;
+
+        ret = device_create_file(led->dev, &dev_attr_gpio);
+        if (ret)
+                goto err_gpio;
+
+        ret = device_create_file(led->dev, &dev_attr_inverted);
+        if (ret)
+                goto err_inverted;
+
+        ret = device_create_file(led->dev, &dev_attr_desired_brightness);
+        if (ret)
+                goto err_brightness;
+
+        gpio_data->led = led;
+        led->trigger_data = gpio_data;
+        INIT_WORK(&gpio_data->work, gpio_trig_work);
+
+        return;
+
+err_brightness:
+        device_remove_file(led->dev, &dev_attr_inverted);
+
+err_inverted:
+        device_remove_file(led->dev, &dev_attr_gpio);
+
+err_gpio:
+        kfree(gpio_data);
+}
+
+static void gpio_trig_deactivate(struct led_classdev *led)
+{
+        struct gpio_trig_data *gpio_data = led->trigger_data;
+
+        if (gpio_data) {
+                device_remove_file(led->dev, &dev_attr_gpio);
+                device_remove_file(led->dev, &dev_attr_inverted);
+                device_remove_file(led->dev, &dev_attr_desired_brightness);
+                flush_work(&gpio_data->work);
+                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,
+};
+
+static int __init gpio_trig_init(void)
+{
+        return led_trigger_register(&gpio_led_trigger);
+}
+module_init(gpio_trig_init);
+
+static void __exit gpio_trig_exit(void)
+{
+        led_trigger_unregister(&gpio_led_trigger);
+}
+module_exit(gpio_trig_exit);
+
+MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
+MODULE_DESCRIPTION("GPIO LED trigger");
+MODULE_LICENSE("GPL");