leds: add BD2802GU LED driver

ROHM BD2802GU is a RGB LED controller attached to i2c bus and specifically
engineered for decoration purposes.  This RGB controller incorporates
lighting patterns and illuminates.

This driver is designed to minimize power consumption, so when there is no
emitting LED, it enters to reset state.  And because the BD2802GU has lots
of features that can't be covered by the current LED framework, it
provides Advanced Configuration Function(ADF) mode, so that user
applications can set registers of BD2802GU directly.

Here are basic usage examples :
; to turn on LED (not blink)
$ echo 1 > /sys/class/leds/led1_R/brightness
; to blink LED
$ echo timer > /sys/class/leds/led1_R/trigger
$ echo 1 > /sys/class/leds/led1_R/delay_on
$ echo 1 > /sys/class/leds/led1_R/delay_off
; to turn off LED
$ echo 0 > /sys/class/leds/led1_R/brightness

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kim Kyuwon <chammoru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

drivers/leds/Kconfig

@@ -210,6 +210,13 @@ config LEDS_PWM
 	help
 	  This option enables support for pwm driven LEDs
 
+config LEDS_BD2802
+	tristate "LED driver for BD2802 RGB LED"
+	depends on LEDS_CLASS && I2C
+	help
+	  This option enables support for BD2802GU RGB LED driver chips
+	  accessed via the I2C bus.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS

drivers/leds/Makefile

@@ -6,6 +6,7 @@ obj-$(CONFIG_LEDS_TRIGGERS)		+= led-triggers.o
 
 # LED Platform Drivers
 obj-$(CONFIG_LEDS_ATMEL_PWM)		+= leds-atmel-pwm.o
+obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o
 obj-$(CONFIG_LEDS_LOCOMO)		+= leds-locomo.o
 obj-$(CONFIG_LEDS_MIKROTIK_RB532)	+= leds-rb532.o
 obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o

drivers/leds/leds-bd2802.c

@@ -0,0 +1,765 @@
+/*
+ * leds-bd2802.c - RGB LED Driver
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ * Kim Kyuwon <q1.kim@samsung.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.
+ *
+ * Datasheet: http://www.rohm.com/products/databook/driver/pdf/bd2802gu-e.pdf
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/leds-bd2802.h>
+
+
+#define LED_CTL(rgb2en, rgb1en) ((rgb2en) << 4 | ((rgb1en) << 0))
+
+#define BD2802_LED_OFFSET		0xa
+#define BD2802_COLOR_OFFSET		0x3
+
+#define BD2802_REG_CLKSETUP 		0x00
+#define BD2802_REG_CONTROL 		0x01
+#define BD2802_REG_HOURSETUP		0x02
+#define BD2802_REG_CURRENT1SETUP	0x03
+#define BD2802_REG_CURRENT2SETUP	0x04
+#define BD2802_REG_WAVEPATTERN		0x05
+
+#define BD2802_CURRENT_032		0x10 /* 3.2mA */
+#define BD2802_CURRENT_000		0x00 /* 0.0mA */
+
+#define BD2802_PATTERN_FULL		0x07
+#define BD2802_PATTERN_HALF		0x03
+
+enum led_ids {
+	LED1,
+	LED2,
+	LED_NUM,
+};
+
+enum led_colors {
+	RED,
+	GREEN,
+	BLUE,
+};
+
+enum led_bits {
+	BD2802_OFF,
+	BD2802_BLINK,
+	BD2802_ON,
+};
+
+/*
+ * State '0' : 'off'
+ * State '1' : 'blink'
+ * State '2' : 'on'.
+ */
+struct led_state {
+	unsigned r:2;
+	unsigned g:2;
+	unsigned b:2;
+};
+
+struct bd2802_led {
+	struct bd2802_led_platform_data	*pdata;
+	struct i2c_client		*client;
+	struct rw_semaphore		rwsem;
+	struct work_struct		work;
+
+	struct led_state		led[2];
+
+	/*
+	 * Making led_classdev as array is not recommended, because array
+	 * members prevent using 'container_of' macro. So repetitive works
+	 * are needed.
+	 */
+	struct led_classdev		cdev_led1r;
+	struct led_classdev		cdev_led1g;
+	struct led_classdev		cdev_led1b;
+	struct led_classdev		cdev_led2r;
+	struct led_classdev		cdev_led2g;
+	struct led_classdev		cdev_led2b;
+
+	/*
+	 * Advanced Configuration Function(ADF) mode:
+	 * In ADF mode, user can set registers of BD2802GU directly,
+	 * therefore BD2802GU doesn't enter reset state.
+	 */
+	int 				adf_on;
+
+	enum led_ids			led_id;
+	enum led_colors			color;
+	enum led_bits			state;
+};
+
+
+/*--------------------------------------------------------------*/
+/*	BD2802GU helper functions					*/
+/*--------------------------------------------------------------*/
+
+static inline int bd2802_is_rgb_off(struct bd2802_led *led, enum led_ids id,
+							enum led_colors color)
+{
+	switch (color) {
+	case RED:
+		return !led->led[id].r;
+	case GREEN:
+		return !led->led[id].g;
+	case BLUE:
+		return !led->led[id].b;
+	default:
+		dev_err(&led->client->dev, "%s: Invalid color\n", __func__);
+		return -EINVAL;
+	}
+}
+
+static inline int bd2802_is_led_off(struct bd2802_led *led, enum led_ids id)
+{
+	if (led->led[id].r || led->led[id].g || led->led[id].b)
+		return 0;
+
+	return 1;
+}
+
+static inline int bd2802_is_all_off(struct bd2802_led *led)
+{
+	int i;
+
+	for (i = 0; i < LED_NUM; i++)
+		if (!bd2802_is_led_off(led, i))
+			return 0;
+
+	return 1;
+}
+
+static inline u8 bd2802_get_base_offset(enum led_ids id, enum led_colors color)
+{
+	return id * BD2802_LED_OFFSET + color * BD2802_COLOR_OFFSET;
+}
+
+static inline u8 bd2802_get_reg_addr(enum led_ids id, enum led_colors color,
+								u8 reg_offset)
+{
+	return reg_offset + bd2802_get_base_offset(id, color);
+}
+
+
+/*--------------------------------------------------------------*/
+/*	BD2802GU core functions					*/
+/*--------------------------------------------------------------*/
+
+static int bd2802_write_byte(struct i2c_client *client, u8 reg, u8 val)
+{
+	int ret = i2c_smbus_write_byte_data(client, reg, val);
+	if (ret >= 0)
+		return 0;
+
+	dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
+						__func__, reg, val, ret);
+
+	return ret;
+}
+
+static void bd2802_update_state(struct bd2802_led *led, enum led_ids id,
+				enum led_colors color, enum led_bits led_bit)
+{
+	int i;
+	u8 value;
+
+	for (i = 0; i < LED_NUM; i++) {
+		if (i == id) {
+			switch (color) {
+			case RED:
+				led->led[i].r = led_bit;
+				break;
+			case GREEN:
+				led->led[i].g = led_bit;
+				break;
+			case BLUE:
+				led->led[i].b = led_bit;
+				break;
+			default:
+				dev_err(&led->client->dev,
+					"%s: Invalid color\n", __func__);
+				return;
+			}
+		}
+	}
+
+	if (led_bit == BD2802_BLINK || led_bit == BD2802_ON)
+		return;
+
+	if (!bd2802_is_led_off(led, id))
+		return;
+
+	if (bd2802_is_all_off(led) && !led->adf_on) {
+		gpio_set_value(led->pdata->reset_gpio, 0);
+		return;
+	}
+
+	/*
+	 * In this case, other led is turned on, and current led is turned
+	 * off. So set RGB LED Control register to stop the current RGB LED
+	 */
+	value = (id == LED1) ? LED_CTL(1, 0) : LED_CTL(0, 1);
+	bd2802_write_byte(led->client, BD2802_REG_CONTROL, value);
+}
+
+static void bd2802_configure(struct bd2802_led *led)
+{
+	struct bd2802_led_platform_data *pdata = led->pdata;
+	u8 reg;
+
+	reg = bd2802_get_reg_addr(LED1, RED, BD2802_REG_HOURSETUP);
+	bd2802_write_byte(led->client, reg, pdata->rgb_time);
+
+	reg = bd2802_get_reg_addr(LED2, RED, BD2802_REG_HOURSETUP);
+	bd2802_write_byte(led->client, reg, pdata->rgb_time);
+}
+
+static void bd2802_reset_cancel(struct bd2802_led *led)
+{
+	gpio_set_value(led->pdata->reset_gpio, 1);
+	udelay(100);
+	bd2802_configure(led);
+}
+
+static void bd2802_enable(struct bd2802_led *led, enum led_ids id)
+{
+	enum led_ids other_led = (id == LED1) ? LED2 : LED1;
+	u8 value, other_led_on;
+
+	other_led_on = !bd2802_is_led_off(led, other_led);
+	if (id == LED1)
+		value = LED_CTL(other_led_on, 1);
+	else
+		value = LED_CTL(1 , other_led_on);
+
+	bd2802_write_byte(led->client, BD2802_REG_CONTROL, value);
+}
+
+static void bd2802_set_on(struct bd2802_led *led, enum led_ids id,
+							enum led_colors color)
+{
+	u8 reg;
+
+	if (bd2802_is_all_off(led) && !led->adf_on)
+		bd2802_reset_cancel(led);
+
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT1SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_032);
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT2SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_000);
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_WAVEPATTERN);
+	bd2802_write_byte(led->client, reg, BD2802_PATTERN_FULL);
+
+	bd2802_enable(led, id);
+	bd2802_update_state(led, id, color, BD2802_ON);
+}
+
+static void bd2802_set_blink(struct bd2802_led *led, enum led_ids id,
+							enum led_colors color)
+{
+	u8 reg;
+
+	if (bd2802_is_all_off(led) && !led->adf_on)
+		bd2802_reset_cancel(led);
+
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT1SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_000);
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT2SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_032);
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_WAVEPATTERN);
+	bd2802_write_byte(led->client, reg, BD2802_PATTERN_HALF);
+
+	bd2802_enable(led, id);
+	bd2802_update_state(led, id, color, BD2802_BLINK);
+}
+
+static void bd2802_turn_on(struct bd2802_led *led, enum led_ids id,
+				enum led_colors color, enum led_bits led_bit)
+{
+	if (led_bit == BD2802_OFF) {
+		dev_err(&led->client->dev,
+					"Only 'blink' and 'on' are allowed\n");
+		return;
+	}
+
+	if (led_bit == BD2802_BLINK)
+		bd2802_set_blink(led, id, color);
+	else
+		bd2802_set_on(led, id, color);
+}
+
+static void bd2802_turn_off(struct bd2802_led *led, enum led_ids id,
+							enum led_colors color)
+{
+	u8 reg;
+
+	if (bd2802_is_rgb_off(led, id, color))
+		return;
+
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT1SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_000);
+	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT2SETUP);
+	bd2802_write_byte(led->client, reg, BD2802_CURRENT_000);
+
+	bd2802_update_state(led, id, color, BD2802_OFF);
+}
+
+static void bd2802_restore_state(struct bd2802_led *led)
+{
+	int i;
+
+	for (i = 0; i < LED_NUM; i++) {
+		if (led->led[i].r)
+			bd2802_turn_on(led, i, RED, led->led[i].r);
+		if (led->led[i].g)
+			bd2802_turn_on(led, i, GREEN, led->led[i].g);
+		if (led->led[i].b)
+			bd2802_turn_on(led, i, BLUE, led->led[i].b);
+	}
+}
+
+#define BD2802_SET_REGISTER(reg_addr, reg_name)				\
+static ssize_t bd2802_store_reg##reg_addr(struct device *dev,		\
+	struct device_attribute *attr, const char *buf, size_t count)	\
+{									\
+	struct bd2802_led *led = i2c_get_clientdata(to_i2c_client(dev));\
+	unsigned long val;						\
+	int ret;							\
+	if (!count)							\
+		return -EINVAL;						\
+	ret = strict_strtoul(buf, 16, &val);				\
+	if (ret)							\
+		return ret;						\
+	down_write(&led->rwsem);					\
+	bd2802_write_byte(led->client, reg_addr, (u8) val);		\
+	up_write(&led->rwsem);						\
+	return count;							\
+}									\
+static struct device_attribute bd2802_reg##reg_addr##_attr = {		\
+	.attr = {.name = reg_name, .mode = 0644, .owner = THIS_MODULE},	\
+	.store = bd2802_store_reg##reg_addr,				\
+};
+
+BD2802_SET_REGISTER(0x00, "0x00");
+BD2802_SET_REGISTER(0x01, "0x01");
+BD2802_SET_REGISTER(0x02, "0x02");
+BD2802_SET_REGISTER(0x03, "0x03");
+BD2802_SET_REGISTER(0x04, "0x04");
+BD2802_SET_REGISTER(0x05, "0x05");
+BD2802_SET_REGISTER(0x06, "0x06");
+BD2802_SET_REGISTER(0x07, "0x07");
+BD2802_SET_REGISTER(0x08, "0x08");
+BD2802_SET_REGISTER(0x09, "0x09");
+BD2802_SET_REGISTER(0x0a, "0x0a");
+BD2802_SET_REGISTER(0x0b, "0x0b");
+BD2802_SET_REGISTER(0x0c, "0x0c");
+BD2802_SET_REGISTER(0x0d, "0x0d");
+BD2802_SET_REGISTER(0x0e, "0x0e");
+BD2802_SET_REGISTER(0x0f, "0x0f");
+BD2802_SET_REGISTER(0x10, "0x10");
+BD2802_SET_REGISTER(0x11, "0x11");
+BD2802_SET_REGISTER(0x12, "0x12");
+BD2802_SET_REGISTER(0x13, "0x13");
+BD2802_SET_REGISTER(0x14, "0x14");
+BD2802_SET_REGISTER(0x15, "0x15");
+
+static struct device_attribute *bd2802_addr_attributes[] = {
+	&bd2802_reg0x00_attr,
+	&bd2802_reg0x01_attr,
+	&bd2802_reg0x02_attr,
+	&bd2802_reg0x03_attr,
+	&bd2802_reg0x04_attr,
+	&bd2802_reg0x05_attr,
+	&bd2802_reg0x06_attr,
+	&bd2802_reg0x07_attr,
+	&bd2802_reg0x08_attr,
+	&bd2802_reg0x09_attr,
+	&bd2802_reg0x0a_attr,
+	&bd2802_reg0x0b_attr,
+	&bd2802_reg0x0c_attr,
+	&bd2802_reg0x0d_attr,
+	&bd2802_reg0x0e_attr,
+	&bd2802_reg0x0f_attr,
+	&bd2802_reg0x10_attr,
+	&bd2802_reg0x11_attr,
+	&bd2802_reg0x12_attr,
+	&bd2802_reg0x13_attr,
+	&bd2802_reg0x14_attr,
+	&bd2802_reg0x15_attr,
+};
+
+static void bd2802_enable_adv_conf(struct bd2802_led *led)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(bd2802_addr_attributes); i++) {
+		ret = device_create_file(&led->client->dev,
+						bd2802_addr_attributes[i]);
+		if (ret) {
+			dev_err(&led->client->dev, "failed to sysfs file %s\n",
+					bd2802_addr_attributes[i]->attr.name);
+			goto failed_remove_files;
+		}
+	}
+
+	if (bd2802_is_all_off(led))
+		bd2802_reset_cancel(led);
+
+	led->adf_on = 1;
+
+	return;
+
+failed_remove_files:
+	for (i--; i >= 0; i--)
+		device_remove_file(&led->client->dev,
+						bd2802_addr_attributes[i]);
+}
+
+static void bd2802_disable_adv_conf(struct bd2802_led *led)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bd2802_addr_attributes); i++)
+		device_remove_file(&led->client->dev,
+						bd2802_addr_attributes[i]);
+
+	if (bd2802_is_all_off(led))
+		gpio_set_value(led->pdata->reset_gpio, 0);
+
+	led->adf_on = 0;
+}
+
+static ssize_t bd2802_show_adv_conf(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct bd2802_led *led = i2c_get_clientdata(to_i2c_client(dev));
+	ssize_t ret;
+
+	down_read(&led->rwsem);
+	if (led->adf_on)
+		ret = sprintf(buf, "on\n");
+	else
+		ret = sprintf(buf, "off\n");
+	up_read(&led->rwsem);
+
+	return ret;
+}
+
+static ssize_t bd2802_store_adv_conf(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct bd2802_led *led = i2c_get_clientdata(to_i2c_client(dev));
+
+	if (!count)
+		return -EINVAL;
+
+	down_write(&led->rwsem);
+	if (!led->adf_on && !strncmp(buf, "on", 2))
+		bd2802_enable_adv_conf(led);
+	else if (led->adf_on && !strncmp(buf, "off", 3))
+		bd2802_disable_adv_conf(led);
+	up_write(&led->rwsem);
+
+	return count;
+}
+
+static struct device_attribute bd2802_adv_conf_attr = {
+	.attr = {
+		.name = "advanced_configuration",
+		.mode = 0644,
+		.owner = THIS_MODULE
+	},
+	.show = bd2802_show_adv_conf,
+	.store = bd2802_store_adv_conf,
+};
+
+static void bd2802_led_work(struct work_struct *work)
+{
+	struct bd2802_led *led = container_of(work, struct bd2802_led, work);
+
+	if (led->state)
+		bd2802_turn_on(led, led->led_id, led->color, led->state);
+	else
+		bd2802_turn_off(led, led->led_id, led->color);
+}
+
+#define BD2802_CONTROL_RGBS(name, id, clr)				\
+static void bd2802_set_##name##_brightness(struct led_classdev *led_cdev,\
+					enum led_brightness value)	\
+{									\
+	struct bd2802_led *led =					\
+		container_of(led_cdev, struct bd2802_led, cdev_##name);	\
+	led->led_id = id;						\
+	led->color = clr;						\
+	if (value == LED_OFF)						\
+		led->state = BD2802_OFF;				\
+	else								\
+		led->state = BD2802_ON;					\
+	schedule_work(&led->work);					\
+}									\
+static int bd2802_set_##name##_blink(struct led_classdev *led_cdev,	\
+		unsigned long *delay_on, unsigned long *delay_off)	\
+{									\
+	struct bd2802_led *led =					\
+		container_of(led_cdev, struct bd2802_led, cdev_##name);	\
+	if (*delay_on == 0 || *delay_off == 0)				\
+		return -EINVAL;						\
+	led->led_id = id;						\
+	led->color = clr;						\
+	led->state = BD2802_BLINK;					\
+	schedule_work(&led->work);					\
+	return 0;							\
+}
+
+BD2802_CONTROL_RGBS(led1r, LED1, RED);
+BD2802_CONTROL_RGBS(led1g, LED1, GREEN);
+BD2802_CONTROL_RGBS(led1b, LED1, BLUE);
+BD2802_CONTROL_RGBS(led2r, LED2, RED);
+BD2802_CONTROL_RGBS(led2g, LED2, GREEN);
+BD2802_CONTROL_RGBS(led2b, LED2, BLUE);
+
+static int bd2802_register_led_classdev(struct bd2802_led *led)
+{
+	int ret;
+
+	INIT_WORK(&led->work, bd2802_led_work);
+
+	led->cdev_led1r.name = "led1_R";
+	led->cdev_led1r.brightness = LED_OFF;
+	led->cdev_led1r.brightness_set = bd2802_set_led1r_brightness;
+	led->cdev_led1r.blink_set = bd2802_set_led1r_blink;
+	led->cdev_led1r.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led1r);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led1r.name);
+		goto failed_unregister_led1_R;
+	}
+
+	led->cdev_led1g.name = "led1_G";
+	led->cdev_led1g.brightness = LED_OFF;
+	led->cdev_led1g.brightness_set = bd2802_set_led1g_brightness;
+	led->cdev_led1g.blink_set = bd2802_set_led1g_blink;
+	led->cdev_led1g.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led1g);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led1g.name);
+		goto failed_unregister_led1_G;
+	}
+
+	led->cdev_led1b.name = "led1_B";
+	led->cdev_led1b.brightness = LED_OFF;
+	led->cdev_led1b.brightness_set = bd2802_set_led1b_brightness;
+	led->cdev_led1b.blink_set = bd2802_set_led1b_blink;
+	led->cdev_led1b.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led1b);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led1b.name);
+		goto failed_unregister_led1_B;
+	}
+
+	led->cdev_led2r.name = "led2_R";
+	led->cdev_led2r.brightness = LED_OFF;
+	led->cdev_led2r.brightness_set = bd2802_set_led2r_brightness;
+	led->cdev_led2r.blink_set = bd2802_set_led2r_blink;
+	led->cdev_led2r.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led2r);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led2r.name);
+		goto failed_unregister_led2_R;
+	}
+
+	led->cdev_led2g.name = "led2_G";
+	led->cdev_led2g.brightness = LED_OFF;
+	led->cdev_led2g.brightness_set = bd2802_set_led2g_brightness;
+	led->cdev_led2g.blink_set = bd2802_set_led2g_blink;
+	led->cdev_led2g.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led2g);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led2g.name);
+		goto failed_unregister_led2_G;
+	}
+
+	led->cdev_led2b.name = "led2_B";
+	led->cdev_led2b.brightness = LED_OFF;
+	led->cdev_led2b.brightness_set = bd2802_set_led2b_brightness;
+	led->cdev_led2b.blink_set = bd2802_set_led2b_blink;
+	led->cdev_led2b.flags |= LED_CORE_SUSPENDRESUME;
+
+	ret = led_classdev_register(&led->client->dev, &led->cdev_led2b);
+	if (ret < 0) {
+		dev_err(&led->client->dev, "couldn't register LED %s\n",
+							led->cdev_led2b.name);
+		goto failed_unregister_led2_B;
+	}
+
+	return 0;
+
+failed_unregister_led2_B:
+	led_classdev_unregister(&led->cdev_led2g);
+failed_unregister_led2_G:
+	led_classdev_unregister(&led->cdev_led2r);
+failed_unregister_led2_R:
+	led_classdev_unregister(&led->cdev_led1b);
+failed_unregister_led1_B:
+	led_classdev_unregister(&led->cdev_led1g);
+failed_unregister_led1_G:
+	led_classdev_unregister(&led->cdev_led1r);
+failed_unregister_led1_R:
+
+	return ret;
+}
+
+static void bd2802_unregister_led_classdev(struct bd2802_led *led)
+{
+	cancel_work_sync(&led->work);
+	led_classdev_unregister(&led->cdev_led1r);
+}
+
+static int __devinit bd2802_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct bd2802_led *led;
+	struct bd2802_led_platform_data *pdata;
+	int ret;
+
+	led = kzalloc(sizeof(struct bd2802_led), GFP_KERNEL);
+	if (!led) {
+		dev_err(&client->dev, "failed to allocate driver data\n");
+		return -ENOMEM;
+	}
+
+	led->client = client;
+	pdata = led->pdata = client->dev.platform_data;
+	i2c_set_clientdata(client, led);
+
+	/* Configure RESET GPIO (L: RESET, H: RESET cancel) */
+	gpio_request(pdata->reset_gpio, "RGB_RESETB");
+	gpio_direction_output(pdata->reset_gpio, 1);
+
+	/* Tacss = min 0.1ms */
+	udelay(100);
+
+	/* Detect BD2802GU */
+	ret = bd2802_write_byte(client, BD2802_REG_CLKSETUP, 0x00);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to detect device\n");
+		goto failed_free;
+	} else
+		dev_info(&client->dev, "return 0x%02x\n", ret);
+
+	/* To save the power, reset BD2802 after detecting */
+	gpio_set_value(led->pdata->reset_gpio, 0);
+
+	init_rwsem(&led->rwsem);
+
+	ret = device_create_file(&client->dev, &bd2802_adv_conf_attr);
+	if (ret) {
+		dev_err(&client->dev, "failed to create sysfs file %s\n",
+					bd2802_adv_conf_attr.attr.name);
+		goto failed_free;
+	}
+
+	ret = bd2802_register_led_classdev(led);
+	if (ret < 0)
+		goto failed_unregister_dev_file;
+
+	return 0;
+
+failed_unregister_dev_file:
+	device_remove_file(&client->dev, &bd2802_adv_conf_attr);
+failed_free:
+	i2c_set_clientdata(client, NULL);
+	kfree(led);
+
+	return ret;
+}
+
+static int __exit bd2802_remove(struct i2c_client *client)
+{
+	struct bd2802_led *led = i2c_get_clientdata(client);
+
+	bd2802_unregister_led_classdev(led);
+	gpio_set_value(led->pdata->reset_gpio, 0);
+	if (led->adf_on)
+		bd2802_disable_adv_conf(led);
+	device_remove_file(&client->dev, &bd2802_adv_conf_attr);
+	i2c_set_clientdata(client, NULL);
+	kfree(led);
+
+	return 0;
+}
+
+static int bd2802_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	struct bd2802_led *led = i2c_get_clientdata(client);
+
+	gpio_set_value(led->pdata->reset_gpio, 0);
+
+	return 0;
+}
+
+static int bd2802_resume(struct i2c_client *client)
+{
+	struct bd2802_led *led = i2c_get_clientdata(client);
+
+	if (!bd2802_is_all_off(led) || led->adf_on) {
+		gpio_set_value(led->pdata->reset_gpio, 1);
+		udelay(100);
+		bd2802_restore_state(led);
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id bd2802_id[] = {
+	{ "BD2802", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, bd2802_id);
+
+static struct i2c_driver bd2802_i2c_driver = {
+	.driver	= {
+		.name	= "BD2802",
+	},
+	.probe		= bd2802_probe,
+	.remove		= __exit_p(bd2802_remove),
+	.suspend	= bd2802_suspend,
+	.resume		= bd2802_resume,
+	.id_table	= bd2802_id,
+};
+
+static int __init bd2802_init(void)
+{
+	return i2c_add_driver(&bd2802_i2c_driver);
+}
+module_init(bd2802_init);
+
+static void __exit bd2802_exit(void)
+{
+	i2c_del_driver(&bd2802_i2c_driver);
+}
+module_exit(bd2802_exit);
+
+MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
+MODULE_DESCRIPTION("BD2802 LED driver");
+MODULE_LICENSE("GPL");

include/linux/leds-bd2802.h

@@ -0,0 +1,26 @@
+/*
+ * leds-bd2802.h - RGB LED Driver
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ * Kim Kyuwon <q1.kim@samsung.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.
+ *
+ * Datasheet: http://www.rohm.com/products/databook/driver/pdf/bd2802gu-e.pdf
+ *
+ */
+#ifndef _LEDS_BD2802_H_
+#define _LEDS_BD2802_H_
+
+struct bd2802_led_platform_data{
+	int	reset_gpio;
+	u8	rgb_time;
+};
+
+#define RGB_TIME(slopedown, slopeup, waveform) \
+	((slopedown) << 6 | (slopeup) << 4 | (waveform))
+
+#endif /* _LEDS_BD2802_H_ */
+