leds: RGB support

4 files changed, 181 insertions, 1 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a72f97fca57b48..d000972e89267c 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -19,6 +19,14 @@ config LEDS_CLASS
 	  This option enables the led sysfs class in /sys/class/leds.  You'll
 	  need this to do anything useful with LEDs.  If unsure, say N.
 
+config LEDS_CLASS_RGB
+	bool "LED RGB Class Support"
+	depends on LEDS_CLASS
+	help
+	  This option enables support for RGB LED devices.
+	  Sysfs attribute brightness is interpreted as a HSV color value.
+	  For details see Documentation/leds/leds-class.txt.
+
 config LEDS_CLASS_FLASH
 	tristate "LED Flash Class Support"
 	depends on LEDS_CLASS
@@ -38,6 +46,10 @@ config LEDS_BRIGHTNESS_HW_CHANGED
 
 	  See Documentation/ABI/testing/sysfs-class-led for details.
 
+if LEDS_CLASS_RGB
+comment "RGB LED drivers"
+endif # LEDS_CLASS_RGB
+
 comment "LED drivers"
 
 config LEDS_88PM860X
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 3c7e3487b373b1..68aa9239dc9b3a 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -65,6 +65,83 @@ unlock:
 }
 static DEVICE_ATTR_RW(brightness);
 
+static ssize_t saturation_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	/* no lock needed for this */
+	led_update_brightness(led_cdev);
+
+	return sprintf(buf, "%u\n", led_cdev->saturation);
+}
+
+static ssize_t saturation_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	ssize_t ret;
+
+	mutex_lock(&led_cdev->led_access);
+
+	if (led_sysfs_is_disabled(led_cdev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		goto unlock;
+
+	led_cdev->saturation = state;
+
+	ret = size;
+unlock:
+	mutex_unlock(&led_cdev->led_access);
+	return ret;
+}
+static DEVICE_ATTR_RW(saturation);
+
+static ssize_t hue_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	/* no lock needed for this */
+	led_update_brightness(led_cdev);
+
+	return sprintf(buf, "%u\n", led_cdev->hue);
+}
+
+static ssize_t hue_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	ssize_t ret;
+
+	mutex_lock(&led_cdev->led_access);
+
+	if (led_sysfs_is_disabled(led_cdev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		goto unlock;
+
+	led_cdev->hue = state;
+
+	ret = size;
+unlock:
+	mutex_unlock(&led_cdev->led_access);
+	return ret;
+}
+static DEVICE_ATTR_RW(hue);
+
+
 static ssize_t max_brightness_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -88,6 +165,8 @@ static const struct attribute_group led_trigger_group = {
 static struct attribute *led_class_attrs[] = {
 	&dev_attr_brightness.attr,
 	&dev_attr_max_brightness.attr,
+	&dev_attr_hue.attr,
+	&dev_attr_saturation.attr,
 	NULL,
 };
 
diff --git a/drivers/leds/led-rgb-core.c b/drivers/leds/led-rgb-core.c
new file mode 100644
index 00000000000000..373303297374df
--- /dev/null
+++ b/drivers/leds/led-rgb-core.c
@@ -0,0 +1,64 @@
+/*
+ * LED RGB Class Support
+ *
+ * Author: Heiner Kallweit <hkallweit1@gmail.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/leds.h>
+#include "leds.h"
+
+struct led_rgb led_hsv_to_rgb(struct led_hsv hsv)
+{
+	unsigned int h = hsv.hue >> 24;
+	unsigned int s = hsv.saturation >> 24;
+	unsigned int v = hsv.value >> 24;
+	unsigned int f, p, q, t, r, g, b;
+	struct led_rgb res;
+
+	if (!v) {
+		res.red = 0;
+		res.green = 0;
+		res.blue = 0;
+		return res;
+	}
+	if (!s) {
+		res.red = v << 24;
+		res.green = v << 24;
+		res.blue = v << 24;
+		return res;
+	}
+
+	f = DIV_ROUND_CLOSEST((h % 42) * 255, 42);
+	p = v - DIV_ROUND_CLOSEST(s * v, 255);
+	q = v - DIV_ROUND_CLOSEST(f * s * v, 255 * 255);
+	t = v - DIV_ROUND_CLOSEST((255 - f) * s * v, 255 * 255);
+
+	switch (h / 42) {
+	case 0:
+		r = v; g = t; b = p; break;
+	case 1:
+		r = q; g = v; b = p; break;
+	case 2:
+		r = p; g = v; b = t; break;
+	case 3:
+		r = p; g = q; b = v; break;
+	case 4:
+		r = t; g = p; b = v; break;
+	case 5:
+		r = v; g = p; b = q; break;
+	}
+
+	printk("hsv_to: h %5d, s %5d, v %5d -> %5d, %5d, %5d\n",
+	       h*390, s*390, v*390, r*390, g*390, b*390);
+	
+	res.red = r << 24;
+	res.green = g << 24;
+	res.blue = b << 24;
+	return res;
+}
+EXPORT_SYMBOL_GPL(led_hsv_to_rgb);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 5263f87e1d2c72..cd673d3bca90b5 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -38,6 +38,8 @@ struct led_classdev {
 	const char		*name;
 	enum led_brightness	 brightness;
 	enum led_brightness	 max_brightness;
+	int			 hue;
+	int			 saturation;
 	int			 flags;
 
 	/* Lower 16 bits reflect status */
@@ -52,6 +54,7 @@ struct led_classdev {
 #define LED_BRIGHT_HW_CHANGED	BIT(21)
 #define LED_RETAIN_AT_SHUTDOWN	BIT(22)
 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
+#define LED_DEV_CAP_RGB		BIT(24)
 
 	/* set_brightness_work / blink_timer flags, atomic, private. */
 	unsigned long		work_flags;
@@ -107,7 +110,7 @@ struct led_classdev {
 	void			(*flash_resume)(struct led_classdev *led_cdev);
 
 	struct work_struct	set_brightness_work;
-	int			delayed_set_value;
+	enum led_brightness     delayed_set_value;
 
 #ifdef CONFIG_LEDS_TRIGGERS
 	/* Protects the trigger data below */
@@ -245,6 +248,28 @@ static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 	return led_cdev->flags & LED_SYSFS_DISABLE;
 }
 
+/* 0.32 fixed point */
+struct led_hsv {
+	u32 hue;
+	u32 saturation;
+	u32 value;
+};
+
+/* 0.32 fixed point */
+struct led_rgb {
+	u32 red;
+	u32 green;
+	u32 blue;
+};
+
+/**
+ * led_hsv_to_rgb - convert a hsv color value to rgb color model
+ * @hsv: the hsv value to convert
+ *
+ * Returns: the resulting rgb value
+ */
+struct led_rgb led_hsv_to_rgb(struct led_hsv hsv);
+
 /*
  * LED Triggers
  */