Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds:
  leds: Futher document blink_set
  leds: Add options to have GPIO LEDs start on or keep their state
  leds: LED driver for National Semiconductor LP3944 Funlight Chip
  leds: pca9532 - Indent using tabs, not spaces.
  leds: Remove an orphan Kconfig entry
  leds: Further document parameters for blink_set()
  leds: alix-leds2 fixed for Award BIOS
  leds: leds-gpio - fix a section mismatch
  leds: add the sysfs interface into the leds-bd2802 driver for changing wave pattern and led current.
  leds: change the license information
  leds: fix led-bd2802 errors while resuming

Documentation/leds-lp3944.txt

+Kernel driver lp3944
+====================
+
+  * National Semiconductor LP3944 Fun-light Chip
+    Prefix: 'lp3944'
+    Addresses scanned: None (see the Notes section below)
+    Datasheet: Publicly available at the National Semiconductor website
+               http://www.national.com/pf/LP/LP3944.html
+
+Authors:
+        Antonio Ospite <ospite@studenti.unina.it>
+
+
+Description
+-----------
+The LP3944 is a helper chip that can drive up to 8 leds, with two programmable
+DIM modes; it could even be used as a gpio expander but this driver assumes it
+is used as a led controller.
+
+The DIM modes are used to set _blink_ patterns for leds, the pattern is
+specified supplying two parameters:
+  - period: from 0s to 1.6s
+  - duty cycle: percentage of the period the led is on, from 0 to 100
+
+Setting a led in DIM0 or DIM1 mode makes it blink according to the pattern.
+See the datasheet for details.
+
+LP3944 can be found on Motorola A910 smartphone, where it drives the rgb
+leds, the camera flash light and the lcds power.
+
+
+Notes
+-----
+The chip is used mainly in embedded contexts, so this driver expects it is
+registered using the i2c_board_info mechanism.
+
+To register the chip at address 0x60 on adapter 0, set the platform data
+according to include/linux/leds-lp3944.h, set the i2c board info:
+
+	static struct i2c_board_info __initdata a910_i2c_board_info[] = {
+		{
+			I2C_BOARD_INFO("lp3944", 0x60),
+			.platform_data = &a910_lp3944_leds,
+		},
+	};
+
+and register it in the platform init function
+
+	i2c_register_board_info(0, a910_i2c_board_info,
+			ARRAY_SIZE(a910_i2c_board_info));

Documentation/powerpc/dts-bindings/gpio/led.txt

@@ -16,10 +16,17 @@ LED sub-node properties:
   string defining the trigger assigned to the LED.  Current triggers are:
     "backlight" - LED will act as a back-light, controlled by the framebuffer
 		  system
-    "default-on" - LED will turn on
+    "default-on" - LED will turn on, but see "default-state" below
     "heartbeat" - LED "double" flashes at a load average based rate
     "ide-disk" - LED indicates disk activity
     "timer" - LED flashes at a fixed, configurable rate
+- default-state:  (optional) The initial state of the LED.  Valid
+  values are "on", "off", and "keep".  If the LED is already on or off
+  and the default-state property is set the to same value, then no
+  glitch should be produced where the LED momentarily turns off (or
+  on).  The "keep" setting will keep the LED at whatever its current
+  state is, without producing a glitch.  The default is off if this
+  property is not present.
 
 Examples:
 
@@ -30,14 +37,22 @@ leds {
 		gpios = <&mcu_pio 0 1>; /* Active low */
 		linux,default-trigger = "ide-disk";
 	};
+
+	fault {
+		gpios = <&mcu_pio 1 0>;
+		/* Keep LED on if BIOS detected hardware fault */
+		default-state = "keep";
+	};
 };
 
 run-control {
 	compatible = "gpio-leds";
 	red {
 		gpios = <&mpc8572 6 0>;
+		default-state = "off";
 	};
 	green {
 		gpios = <&mpc8572 7 0>;
+		default-state = "on";
 	};
 }

drivers/leds/Kconfig

@@ -75,6 +75,7 @@ config LEDS_ALIX2
 	depends on LEDS_CLASS && X86 && EXPERIMENTAL
 	help
 	  This option enables support for the PCEngines ALIX.2 and ALIX.3 LEDs.
+	  You have to set leds-alix2.force=1 for boards with Award BIOS.
 
 config LEDS_H1940
 	tristate "LED Support for iPAQ H1940 device"
@@ -145,15 +146,16 @@ config LEDS_GPIO_OF
 	  of_platform devices.  For instance, LEDs which are listed in a "dts"
 	  file.
 
-config LEDS_LP5521
-	tristate "LED Support for the LP5521 LEDs"
+config LEDS_LP3944
+	tristate "LED Support for N.S. LP3944 (Fun Light) I2C chip"
 	depends on LEDS_CLASS && I2C
 	help
-	  If you say 'Y' here you get support for the National Semiconductor
-	  LP5521 LED driver used in n8x0 boards.
+    This option enables support for LEDs connected to the National
+    Semiconductor LP3944 Lighting Management Unit (LMU) also known as
+    Fun Light Chip.
 
-	  This driver can be built as a module by choosing 'M'. The module
-	  will be called leds-lp5521.
+	  To compile this driver as a module, choose M here: the
+	  module will be called leds-lp3944.
 
 config LEDS_CLEVO_MAIL
 	tristate "Mail LED on Clevo notebook"

drivers/leds/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_LEDS_COBALT_RAQ)		+= leds-cobalt-raq.o
 obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o
 obj-$(CONFIG_LEDS_PCA9532)		+= leds-pca9532.o
 obj-$(CONFIG_LEDS_GPIO)			+= leds-gpio.o
+obj-$(CONFIG_LEDS_LP3944)		+= leds-lp3944.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
 obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
 obj-$(CONFIG_LEDS_FSG)			+= leds-fsg.o

drivers/leds/leds-alix2.c

@@ -14,7 +14,7 @@
 
 static int force = 0;
 module_param(force, bool, 0444);
-MODULE_PARM_DESC(force, "Assume system has ALIX.2 style LEDs");
+MODULE_PARM_DESC(force, "Assume system has ALIX.2/ALIX.3 style LEDs");
 
 struct alix_led {
 	struct led_classdev cdev;
@@ -155,6 +155,11 @@ static int __init alix_led_init(void)
 		goto out;
 	}
 
+	/* enable output on GPIO for LED 1,2,3 */
+	outl(1 << 6, 0x6104);
+	outl(1 << 9, 0x6184);
+	outl(1 << 11, 0x6184);
+
 	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
 	if (!IS_ERR(pdev)) {
 		ret = platform_driver_probe(&alix_led_driver, alix_led_probe);

drivers/leds/leds-bd2802.c

@@ -97,6 +97,10 @@ struct bd2802_led {
 	enum led_ids			led_id;
 	enum led_colors			color;
 	enum led_bits			state;
+
+	/* General attributes of RGB LEDs */
+	int				wave_pattern;
+	int				rgb_current;
 };
 
 
@@ -254,7 +258,7 @@ static void bd2802_set_on(struct bd2802_led *led, enum led_ids id,
 		bd2802_reset_cancel(led);
 
 	reg = bd2802_get_reg_addr(id, color, BD2802_REG_CURRENT1SETUP);
-	bd2802_write_byte(led->client, reg, BD2802_CURRENT_032);
+	bd2802_write_byte(led->client, reg, led->rgb_current);
 	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);
@@ -275,9 +279,9 @@ static void bd2802_set_blink(struct bd2802_led *led, enum led_ids id,
 	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);
+	bd2802_write_byte(led->client, reg, led->rgb_current);
 	reg = bd2802_get_reg_addr(id, color, BD2802_REG_WAVEPATTERN);
-	bd2802_write_byte(led->client, reg, BD2802_PATTERN_HALF);
+	bd2802_write_byte(led->client, reg, led->wave_pattern);
 
 	bd2802_enable(led, id);
 	bd2802_update_state(led, id, color, BD2802_BLINK);
@@ -406,7 +410,7 @@ static void bd2802_enable_adv_conf(struct bd2802_led *led)
 		ret = device_create_file(&led->client->dev,
 						bd2802_addr_attributes[i]);
 		if (ret) {
-			dev_err(&led->client->dev, "failed to sysfs file %s\n",
+			dev_err(&led->client->dev, "failed: sysfs file %s\n",
 					bd2802_addr_attributes[i]->attr.name);
 			goto failed_remove_files;
 		}
@@ -483,6 +487,52 @@ static struct device_attribute bd2802_adv_conf_attr = {
 	.store = bd2802_store_adv_conf,
 };
 
+#define BD2802_CONTROL_ATTR(attr_name, name_str)			\
+static ssize_t bd2802_show_##attr_name(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);						\
+	ret = sprintf(buf, "0x%02x\n", led->attr_name);			\
+	up_read(&led->rwsem);						\
+	return ret;							\
+}									\
+static ssize_t bd2802_store_##attr_name(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);					\
+	led->attr_name = val;						\
+	up_write(&led->rwsem);						\
+	return count;							\
+}									\
+static struct device_attribute bd2802_##attr_name##_attr = {		\
+	.attr = {							\
+		.name = name_str,					\
+		.mode = 0644,						\
+		.owner = THIS_MODULE					\
+	},								\
+	.show = bd2802_show_##attr_name,				\
+	.store = bd2802_store_##attr_name,				\
+};
+
+BD2802_CONTROL_ATTR(wave_pattern, "wave_pattern");
+BD2802_CONTROL_ATTR(rgb_current, "rgb_current");
+
+static struct device_attribute *bd2802_attributes[] = {
+	&bd2802_adv_conf_attr,
+	&bd2802_wave_pattern_attr,
+	&bd2802_rgb_current_attr,
+};
+
 static void bd2802_led_work(struct work_struct *work)
 {
 	struct bd2802_led *led = container_of(work, struct bd2802_led, work);
@@ -538,7 +588,6 @@ static int bd2802_register_led_classdev(struct bd2802_led *led)
 	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) {
@@ -551,7 +600,6 @@ static int bd2802_register_led_classdev(struct bd2802_led *led)
 	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) {
@@ -564,7 +612,6 @@ static int bd2802_register_led_classdev(struct bd2802_led *led)
 	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) {
@@ -577,7 +624,6 @@ static int bd2802_register_led_classdev(struct bd2802_led *led)
 	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) {
@@ -590,7 +636,6 @@ static int bd2802_register_led_classdev(struct bd2802_led *led)
 	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) {
@@ -640,7 +685,7 @@ static int __devinit bd2802_probe(struct i2c_client *client,
 {
 	struct bd2802_led *led;
 	struct bd2802_led_platform_data *pdata;
-	int ret;
+	int ret, i;
 
 	led = kzalloc(sizeof(struct bd2802_led), GFP_KERNEL);
 	if (!led) {
@@ -670,13 +715,20 @@ static int __devinit bd2802_probe(struct i2c_client *client,
 	/* To save the power, reset BD2802 after detecting */
 	gpio_set_value(led->pdata->reset_gpio, 0);
 
+	/* Default attributes */
+	led->wave_pattern = BD2802_PATTERN_HALF;
+	led->rgb_current = BD2802_CURRENT_032;
+
 	init_rwsem(&led->rwsem);
 
-	ret = device_create_file(&client->dev, &bd2802_adv_conf_attr);
+	for (i = 0; i < ARRAY_SIZE(bd2802_attributes); i++) {
+		ret = device_create_file(&led->client->dev,
+						bd2802_attributes[i]);
 		if (ret) {
-		dev_err(&client->dev, "failed to create sysfs file %s\n",
-					bd2802_adv_conf_attr.attr.name);
-		goto failed_free;
+			dev_err(&led->client->dev, "failed: sysfs file %s\n",
+					bd2802_attributes[i]->attr.name);
+			goto failed_unregister_dev_file;
+		}
 	}
 
 	ret = bd2802_register_led_classdev(led);
@@ -686,7 +738,8 @@ static int __devinit bd2802_probe(struct i2c_client *client,
 	return 0;
 
 failed_unregister_dev_file:
-	device_remove_file(&client->dev, &bd2802_adv_conf_attr);
+	for (i--; i >= 0; i--)
+		device_remove_file(&led->client->dev, bd2802_attributes[i]);
 failed_free:
 	i2c_set_clientdata(client, NULL);
 	kfree(led);
@@ -697,12 +750,14 @@ static int __devinit bd2802_probe(struct i2c_client *client,
 static int __exit bd2802_remove(struct i2c_client *client)
 {
 	struct bd2802_led *led = i2c_get_clientdata(client);
+	int i;
 
-	bd2802_unregister_led_classdev(led);
 	gpio_set_value(led->pdata->reset_gpio, 0);
+	bd2802_unregister_led_classdev(led);
 	if (led->adf_on)
 		bd2802_disable_adv_conf(led);
-	device_remove_file(&client->dev, &bd2802_adv_conf_attr);
+	for (i = 0; i < ARRAY_SIZE(bd2802_attributes); i++)
+		device_remove_file(&led->client->dev, bd2802_attributes[i]);
 	i2c_set_clientdata(client, NULL);
 	kfree(led);
 
@@ -723,8 +778,7 @@ 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_reset_cancel(led);
 		bd2802_restore_state(led);
 	}
 
@@ -762,4 +816,4 @@ module_exit(bd2802_exit);
 
 MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
 MODULE_DESCRIPTION("BD2802 LED driver");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");

drivers/leds/leds-gpio.c

@@ -76,7 +76,7 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
 	struct gpio_led_data *led_dat, struct device *parent,
 	int (*blink_set)(unsigned, unsigned long *, unsigned long *))
 {
-	int ret;
+	int ret, state;
 
 	/* skip leds that aren't available */
 	if (!gpio_is_valid(template->gpio)) {
@@ -99,11 +99,15 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
 		led_dat->cdev.blink_set = gpio_blink_set;
 	}
 	led_dat->cdev.brightness_set = gpio_led_set;
-	led_dat->cdev.brightness = LED_OFF;
+	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
+		state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low;
+	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 = gpio_direction_output(led_dat->gpio, led_dat->active_low);
+	ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
 	if (ret < 0)
 		goto err;
 
@@ -129,7 +133,7 @@ static void delete_gpio_led(struct gpio_led_data *led)
 }
 
 #ifdef CONFIG_LEDS_GPIO_PLATFORM
-static int gpio_led_probe(struct platform_device *pdev)
+static int __devinit gpio_led_probe(struct platform_device *pdev)
 {
 	struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
 	struct gpio_led_data *leds_data;
@@ -223,12 +227,22 @@ static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
 	memset(&led, 0, sizeof(led));
 	for_each_child_of_node(np, child) {
 		enum of_gpio_flags flags;
+		const char *state;
 
 		led.gpio = of_get_gpio_flags(child, 0, &flags);
 		led.active_low = flags & OF_GPIO_ACTIVE_LOW;
 		led.name = of_get_property(child, "label", NULL) ? : child->name;
 		led.default_trigger =
 			of_get_property(child, "linux,default-trigger", NULL);
+		state = of_get_property(child, "default-state", NULL);
+		if (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;
+		}
 
 		ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++],
 				      &ofdev->dev, NULL);

drivers/leds/leds-lp3944.c

+/*
+ * leds-lp3944.c - driver for National Semiconductor LP3944 Funlight Chip
+ *
+ * Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
+ *
+ * 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.
+ *
+ */
+
+/*
+ * I2C driver for National Semiconductor LP3944 Funlight Chip
+ * http://www.national.com/pf/LP/LP3944.html
+ *
+ * This helper chip can drive up to 8 leds, with two programmable DIM modes;
+ * it could even be used as a gpio expander but this driver assumes it is used
+ * as a led controller.
+ *
+ * The DIM modes are used to set _blink_ patterns for leds, the pattern is
+ * specified supplying two parameters:
+ *   - period: from 0s to 1.6s
+ *   - duty cycle: percentage of the period the led is on, from 0 to 100
+ *
+ * LP3944 can be found on Motorola A910 smartphone, where it drives the rgb
+ * leds, the camera flash light and the displays backlights.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+#include <linux/leds-lp3944.h>
+
+/* Read Only Registers */
+#define LP3944_REG_INPUT1     0x00 /* LEDs 0-7 InputRegister (Read Only) */
+#define LP3944_REG_REGISTER1  0x01 /* None (Read Only) */
+
+#define LP3944_REG_PSC0       0x02 /* Frequency Prescaler 0 (R/W) */
+#define LP3944_REG_PWM0       0x03 /* PWM Register 0 (R/W) */
+#define LP3944_REG_PSC1       0x04 /* Frequency Prescaler 1 (R/W) */
+#define LP3944_REG_PWM1       0x05 /* PWM Register 1 (R/W) */
+#define LP3944_REG_LS0        0x06 /* LEDs 0-3 Selector (R/W) */
+#define LP3944_REG_LS1        0x07 /* LEDs 4-7 Selector (R/W) */
+
+/* These registers are not used to control leds in LP3944, they can store
+ * arbitrary values which the chip will ignore.
+ */
+#define LP3944_REG_REGISTER8  0x08
+#define LP3944_REG_REGISTER9  0x09
+
+#define LP3944_DIM0 0
+#define LP3944_DIM1 1
+
+/* period in ms */
+#define LP3944_PERIOD_MIN 0
+#define LP3944_PERIOD_MAX 1600
+
+/* duty cycle is a percentage */
+#define LP3944_DUTY_CYCLE_MIN 0
+#define LP3944_DUTY_CYCLE_MAX 100
+
+#define ldev_to_led(c)       container_of(c, struct lp3944_led_data, ldev)
+
+/* Saved data */
+struct lp3944_led_data {
+	u8 id;
+	enum lp3944_type type;
+	enum lp3944_status status;
+	struct led_classdev ldev;
+	struct i2c_client *client;
+	struct work_struct work;
+};
+
+struct lp3944_data {
+	struct mutex lock;
+	struct i2c_client *client;
+	struct lp3944_led_data leds[LP3944_LEDS_MAX];
+};
+
+static int lp3944_reg_read(struct i2c_client *client, u8 reg, u8 *value)
+{
+	int tmp;
+
+	tmp = i2c_smbus_read_byte_data(client, reg);
+	if (tmp < 0)
+		return -EINVAL;
+
+	*value = tmp;
+
+	return 0;
+}
+
+static int lp3944_reg_write(struct i2c_client *client, u8 reg, u8 value)
+{
+	return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+/**
+ * Set the period for DIM status
+ *
+ * @client: the i2c client
+ * @dim: either LP3944_DIM0 or LP3944_DIM1
+ * @period: period of a blink, that is a on/off cycle, expressed in ms.
+ */
+static int lp3944_dim_set_period(struct i2c_client *client, u8 dim, u16 period)
+{
+	u8 psc_reg;
+	u8 psc_value;
+	int err;
+
+	if (dim == LP3944_DIM0)
+		psc_reg = LP3944_REG_PSC0;
+	else if (dim == LP3944_DIM1)
+		psc_reg = LP3944_REG_PSC1;
+	else
+		return -EINVAL;
+
+	/* Convert period to Prescaler value */
+	if (period > LP3944_PERIOD_MAX)
+		return -EINVAL;
+
+	psc_value = (period * 255) / LP3944_PERIOD_MAX;
+
+	err = lp3944_reg_write(client, psc_reg, psc_value);
+
+	return err;
+}
+
+/**
+ * Set the duty cycle for DIM status
+ *
+ * @client: the i2c client
+ * @dim: either LP3944_DIM0 or LP3944_DIM1
+ * @duty_cycle: percentage of a period during which a led is ON
+ */
+static int lp3944_dim_set_dutycycle(struct i2c_client *client, u8 dim,
+				    u8 duty_cycle)
+{
+	u8 pwm_reg;
+	u8 pwm_value;
+	int err;
+
+	if (dim == LP3944_DIM0)
+		pwm_reg = LP3944_REG_PWM0;
+	else if (dim == LP3944_DIM1)
+		pwm_reg = LP3944_REG_PWM1;
+	else
+		return -EINVAL;
+
+	/* Convert duty cycle to PWM value */
+	if (duty_cycle > LP3944_DUTY_CYCLE_MAX)
+		return -EINVAL;
+
+	pwm_value = (duty_cycle * 255) / LP3944_DUTY_CYCLE_MAX;
+
+	err = lp3944_reg_write(client, pwm_reg, pwm_value);
+
+	return err;
+}
+
+/**
+ * Set the led status
+ *
+ * @led: a lp3944_led_data structure
+ * @status: one of LP3944_LED_STATUS_OFF
+ *                 LP3944_LED_STATUS_ON
+ *                 LP3944_LED_STATUS_DIM0
+ *                 LP3944_LED_STATUS_DIM1
+ */
+static int lp3944_led_set(struct lp3944_led_data *led, u8 status)
+{
+	struct lp3944_data *data = i2c_get_clientdata(led->client);
+	u8 id = led->id;
+	u8 reg;
+	u8 val = 0;
+	int err;
+
+	dev_dbg(&led->client->dev, "%s: %s, status before normalization:%d\n",
+		__func__, led->ldev.name, status);
+
+	switch (id) {
+	case LP3944_LED0:
+	case LP3944_LED1:
+	case LP3944_LED2:
+	case LP3944_LED3:
+		reg = LP3944_REG_LS0;
+		break;
+	case LP3944_LED4:
+	case LP3944_LED5:
+	case LP3944_LED6:
+	case LP3944_LED7:
+		id -= LP3944_LED4;
+		reg = LP3944_REG_LS1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (status > LP3944_LED_STATUS_DIM1)
+		return -EINVAL;
+
+	/* invert only 0 and 1, leave unchanged the other values,
+	 * remember we are abusing status to set blink patterns
+	 */
+	if (led->type == LP3944_LED_TYPE_LED_INVERTED && status < 2)
+		status = 1 - status;
+
+	mutex_lock(&data->lock);
+	lp3944_reg_read(led->client, reg, &val);
+
+	val &= ~(LP3944_LED_STATUS_MASK << (id << 1));
+	val |= (status << (id << 1));
+
+	dev_dbg(&led->client->dev, "%s: %s, reg:%d id:%d status:%d val:%#x\n",
+		__func__, led->ldev.name, reg, id, status, val);
+
+	/* set led status */
+	err = lp3944_reg_write(led->client, reg, val);
+	mutex_unlock(&data->lock);
+
+	return err;
+}
+
+static int lp3944_led_set_blink(struct led_classdev *led_cdev,
+				unsigned long *delay_on,
+				unsigned long *delay_off)
+{
+	struct lp3944_led_data *led = ldev_to_led(led_cdev);
+	u16 period;
+	u8 duty_cycle;
+	int err;
+
+	/* units are in ms */
+	if (*delay_on + *delay_off > LP3944_PERIOD_MAX)
+		return -EINVAL;
+
+	if (*delay_on == 0 && *delay_off == 0) {
+		/* Special case: the leds subsystem requires a default user
+		 * friendly blink pattern for the LED.  Let's blink the led
+		 * slowly (1Hz).
+		 */
+		*delay_on = 500;
+		*delay_off = 500;
+	}
+
+	period = (*delay_on) + (*delay_off);
+
+	/* duty_cycle is the percentage of period during which the led is ON */
+	duty_cycle = 100 * (*delay_on) / period;
+
+	/* invert duty cycle for inverted leds, this has the same effect of
+	 * swapping delay_on and delay_off
+	 */
+	if (led->type == LP3944_LED_TYPE_LED_INVERTED)
+		duty_cycle = 100 - duty_cycle;
+
+	/* NOTE: using always the first DIM mode, this means that all leds
+	 * will have the same blinking pattern.
+	 *
+	 * We could find a way later to have two leds blinking in hardware
+	 * with different patterns at the same time, falling back to software
+	 * control for the other ones.
+	 */
+	err = lp3944_dim_set_period(led->client, LP3944_DIM0, period);
+	if (err)
+		return err;
+
+	err = lp3944_dim_set_dutycycle(led->client, LP3944_DIM0, duty_cycle);
+	if (err)
+		return err;
+
+	dev_dbg(&led->client->dev, "%s: OK hardware accelerated blink!\n",
+		__func__);
+
+	led->status = LP3944_LED_STATUS_DIM0;
+	schedule_work(&led->work);
+
+	return 0;
+}
+
+static void lp3944_led_set_brightness(struct led_classdev *led_cdev,
+				      enum led_brightness brightness)
+{
+	struct lp3944_led_data *led = ldev_to_led(led_cdev);
+
+	dev_dbg(&led->client->dev, "%s: %s, %d\n",
+		__func__, led_cdev->name, brightness);
+
+	led->status = brightness;
+	schedule_work(&led->work);
+}
+
+static void lp3944_led_work(struct work_struct *work)
+{
+	struct lp3944_led_data *led;
+
+	led = container_of(work, struct lp3944_led_data, work);
+	lp3944_led_set(led, led->status);
+}
+
+static int lp3944_configure(struct i2c_client *client,
+			    struct lp3944_data *data,
+			    struct lp3944_platform_data *pdata)
+{
+	int i, err = 0;
+
+	for (i = 0; i < pdata->leds_size; i++) {
+		struct lp3944_led *pled = &pdata->leds[i];
+		struct lp3944_led_data *led = &data->leds[i];
+		led->client = client;
+		led->id = i;
+
+		switch (pled->type) {
+
+		case LP3944_LED_TYPE_LED:
+		case LP3944_LED_TYPE_LED_INVERTED:
+			led->type = pled->type;
+			led->status = pled->status;
+			led->ldev.name = pled->name;
+			led->ldev.max_brightness = 1;
+			led->ldev.brightness_set = lp3944_led_set_brightness;
+			led->ldev.blink_set = lp3944_led_set_blink;
+			led->ldev.flags = LED_CORE_SUSPENDRESUME;
+
+			INIT_WORK(&led->work, lp3944_led_work);
+			err = led_classdev_register(&client->dev, &led->ldev);
+			if (err < 0) {
+				dev_err(&client->dev,
+					"couldn't register LED %s\n",
+					led->ldev.name);
+				goto exit;
+			}
+
+			/* to expose the default value to userspace */
+			led->ldev.brightness = led->status;
+
+			/* Set the default led status */
+			err = lp3944_led_set(led, led->status);
+			if (err < 0) {
+				dev_err(&client->dev,
+					"%s couldn't set STATUS %d\n",
+					led->ldev.name, led->status);
+				goto exit;
+			}
+			break;
+
+		case LP3944_LED_TYPE_NONE:
+		default:
+			break;
+
+		}
+	}
+	return 0;
+
+exit:
+	if (i > 0)
+		for (i = i - 1; i >= 0; i--)
+			switch (pdata->leds[i].type) {
+
+			case LP3944_LED_TYPE_LED:
+			case LP3944_LED_TYPE_LED_INVERTED:
+				led_classdev_unregister(&data->leds[i].ldev);
+				cancel_work_sync(&data->leds[i].work);
+				break;
+
+			case LP3944_LED_TYPE_NONE:
+			default:
+				break;
+			}
+
+	return err;
+}
+
+static int __devinit lp3944_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	struct lp3944_platform_data *lp3944_pdata = client->dev.platform_data;
+	struct lp3944_data *data;
+
+	if (lp3944_pdata == NULL) {
+		dev_err(&client->dev, "no platform data\n");
+		return -EINVAL;
+	}
+
+	/* Let's see whether this adapter can support what we need. */
+	if (!i2c_check_functionality(client->adapter,
+				I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(&client->dev, "insufficient functionality!\n");
+		return -ENODEV;
+	}
+
+	data = kzalloc(sizeof(struct lp3944_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	i2c_set_clientdata(client, data);
+
+	mutex_init(&data->lock);
+
+	dev_info(&client->dev, "lp3944 enabled\n");
+
+	lp3944_configure(client, data, lp3944_pdata);
+	return 0;
+}
+
+static int __devexit lp3944_remove(struct i2c_client *client)
+{
+	struct lp3944_platform_data *pdata = client->dev.platform_data;
+	struct lp3944_data *data = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 0; i < pdata->leds_size; i++)
+		switch (data->leds[i].type) {
+		case LP3944_LED_TYPE_LED:
+		case LP3944_LED_TYPE_LED_INVERTED:
+			led_classdev_unregister(&data->leds[i].ldev);
+			cancel_work_sync(&data->leds[i].work);
+			break;
+
+		case LP3944_LED_TYPE_NONE:
+		default:
+			break;
+		}
+
+	kfree(data);
+	i2c_set_clientdata(client, NULL);
+
+	return 0;
+}
+
+/* lp3944 i2c driver struct */
+static const struct i2c_device_id lp3944_id[] = {
+	{"lp3944", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, lp3944_id);
+
+static struct i2c_driver lp3944_driver = {
+	.driver   = {
+		   .name = "lp3944",
+	},
+	.probe    = lp3944_probe,
+	.remove   = __devexit_p(lp3944_remove),
+	.id_table = lp3944_id,
+};
+
+static int __init lp3944_module_init(void)
+{
+	return i2c_add_driver(&lp3944_driver);
+}
+
+static void __exit lp3944_module_exit(void)
+{
+	i2c_del_driver(&lp3944_driver);
+}
+
+module_init(lp3944_module_init);
+module_exit(lp3944_module_exit);
+
+MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
+MODULE_DESCRIPTION("LP3944 Fun Light Chip");
+MODULE_LICENSE("GPL");

include/linux/leds-lp3944.h

+/*
+ * leds-lp3944.h - platform data structure for lp3944 led controller
+ *
+ * Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __LINUX_LEDS_LP3944_H
+#define __LINUX_LEDS_LP3944_H
+
+#include <linux/leds.h>
+#include <linux/workqueue.h>
+
+#define LP3944_LED0 0
+#define LP3944_LED1 1
+#define LP3944_LED2 2
+#define LP3944_LED3 3
+#define LP3944_LED4 4
+#define LP3944_LED5 5
+#define LP3944_LED6 6
+#define LP3944_LED7 7
+#define LP3944_LEDS_MAX 8
+
+#define LP3944_LED_STATUS_MASK	0x03
+enum lp3944_status {
+	LP3944_LED_STATUS_OFF  = 0x0,
+	LP3944_LED_STATUS_ON   = 0x1,
+	LP3944_LED_STATUS_DIM0 = 0x2,
+	LP3944_LED_STATUS_DIM1 = 0x3
+};
+
+enum lp3944_type {
+	LP3944_LED_TYPE_NONE,
+	LP3944_LED_TYPE_LED,
+	LP3944_LED_TYPE_LED_INVERTED,
+};
+
+struct lp3944_led {
+	char *name;
+	enum lp3944_type type;
+	enum lp3944_status status;
+};
+
+struct lp3944_platform_data {
+	struct lp3944_led leds[LP3944_LEDS_MAX];
+	u8 leds_size;
+};
+
+#endif /* __LINUX_LEDS_LP3944_H */

include/linux/leds.h

@@ -45,7 +45,10 @@ struct led_classdev {
 	/* Get LED brightness level */
 	enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
 
-	/* Activate hardware accelerated blink */
+	/* Activate hardware accelerated blink, delays are in
+	 * miliseconds and if none is provided then a sensible default
+	 * should be chosen. The call can adjust the timings if it can't
+	 * match the values specified exactly. */
 	int		(*blink_set)(struct led_classdev *led_cdev,
 				     unsigned long *delay_on,
 				     unsigned long *delay_off);
@@ -141,9 +144,14 @@ struct gpio_led {
 	const char *name;
 	const char *default_trigger;
 	unsigned 	gpio;
-	u8 		active_low : 1;
-	u8		retain_state_suspended : 1;
+	unsigned	active_low : 1;
+	unsigned	retain_state_suspended : 1;
+	unsigned	default_state : 2;
+	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 };
+#define LEDS_GPIO_DEFSTATE_OFF	0
+#define LEDS_GPIO_DEFSTATE_ON	1
+#define LEDS_GPIO_DEFSTATE_KEEP	2
 
 struct gpio_led_platform_data {
 	int 		num_leds;