[PATCH v8 0/3] Add ktd2692 Flash LED driver using LED Flash class

[PATCH v8 0/3] Add ktd2692 Flash LED driver using LED Flash class

[Ingi Kim]

This patch adds ktd2692 Flash LED driver with LED Flash class

Change in v8:
	- Add led-max-microamp mandatory property for LEDs current
	  base on Jacek's patch [1]
	  patch [1] [PATCH v6] DT: leds: Improve description of
	  flash LEDs related properties
	- Fix brightness calculation by max-microamp properties

Change in v7:
	- Add flash-max-microamp property for Flash LED
	- Change gpio-legacy interface to gpio consumer interface

Change in v6 resend:
	- Adjust indent using checkpatch.pl script with strict option

Change in v6:
	- Change goto label to if-else
	- Change DT binding style for LED device binding

Change in v5:
	- Clean up the code
	- Fix help message of Kconfig
	- Fix issue related with regulator and mutex usage
	- Remove tab spaces in bindings

Change in v4:
	- Clean up the code
	- Modify binding documentation of ktd2692

Change in v3:
	- Clean up the code
	- Add aux gpio pin to control Flash LED

Change in v2:
	- Introduction of LED Flash class as Jacek's comment
	- Supplement of binding documentation
	- Rename gpio control pin and remove unused pin
	- Add regulator for the Flash LED

Ingi Kim (3):
  of: Add vendor prefix for Kinetic technologies
  leds: ktd2692: add device tree bindings for ktd2692
  leds: Add ktd2692 flash LED driver

 .../devicetree/bindings/leds/leds-ktd2692.txt      |  50 +++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 drivers/leds/Kconfig                               |   9 +
 drivers/leds/Makefile                              |   1 +
 drivers/leds/leds-ktd2692.c                        | 443 +++++++++++++++++++++
 5 files changed, 504 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
 create mode 100644 drivers/leds/leds-ktd2692.c

-- 
2.0.5

[PATCH v8 1/3] of: Add vendor prefix for Kinetic technologies

[Ingi Kim]

This patch adds vendor prefix for Kinetic technologies

Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index fae26d0..90a4be1 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -100,6 +100,7 @@ isee	ISEE 2007 S.L.
 isil	Intersil
 karo	Ka-Ro electronics GmbH
 keymile	Keymile GmbH
+kinetic Kinetic Technologies
 lacie	LaCie
 lantiq	Lantiq Semiconductor
 lenovo	Lenovo Group Ltd.
-- 
2.0.5

[PATCH v8 2/3] leds: ktd2692: add device tree bindings for ktd2692

[Ingi Kim]

This patch adds the device tree bindings for ktd2692 flash LEDs.
Add Optional properties of child node for Flash LED

Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
---
 .../devicetree/bindings/leds/leds-ktd2692.txt      | 50 ++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt

diff --git a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
new file mode 100644
index 0000000..cf45492
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
@@ -0,0 +1,50 @@
+* Kinetic Technologies - KTD2692 Flash LED Driver
+
+KTD2692 is the ideal power solution for high-power flash LEDs.
+It uses ExpressWire single-wire programming for maximum flexibility.
+
+The ExpressWire interface through CTRL pin can control LED on/off and
+enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
+Flash timeout, LVP(low voltage protection).
+
+Also, When the AUX pin is pulled high while CTRL pin is high,
+LED current will be ramped up to the flash-mode current level.
+
+Required properties:
+- compatible: "kinetic,ktd2692"
+- ctrl-gpio : gpio pin in order control CTRL pin
+- aux-gpio : gpio pin in order control AUX pin
+
+Optional properties:
+- vin-supply : "vin" LED supply (2.7V to 5.5V)
+  See Documentation/devicetree/bindings/regulator/regulator.txt
+
+A discrete LED element connected to the device must be represented by a child
+node - see Documentation/devicetree/bindings/leds/common.txt.
+
+Required properties for flash LED child nodes:
+  See Documentation/devicetree/bindings/leds/common.txt
+- led-max-microamp : Minimum Threshold for Timer protection
+  is defined internally (Maximum 300mA)
+- flash-max-microamp : Flash LED maximum current
+  Formula : I(mA) = 15000 / Rset
+- flash-max-timeout-us : Flash LED maximum timeout
+
+Optional properties for flash LED child nodes:
+- label : see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+ktd2692 {
+	compatible = "kinetic,ktd2692";
+	ctrl-gpio = <&gpc0 1 0>;
+	aux-gpio = <&gpc0 2 0>;
+	vin-supply = <&vbat>;
+
+	flash-led {
+		label = "ktd2692-flash";
+		led-max-microamp = <300000>;
+		flash-max-microamp = <1500000>;
+		flash-max-timeout-us = <1835000>;
+	};
+};
-- 
2.0.5

Re: [PATCH v8 2/3] leds: ktd2692: add device tree bindings for ktd2692

[Jacek Anaszewski]

Hi Ingi,

On 05/08/2015 05:03 AM, Ingi Kim wrote:
> This patch adds the device tree bindings for ktd2692 flash LEDs.
> Add Optional properties of child node for Flash LED
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
> ---
>   .../devicetree/bindings/leds/leds-ktd2692.txt      | 50 ++++++++++++++++++++++
>   1 file changed, 50 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>
> diff --git a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
> new file mode 100644
> index 0000000..cf45492
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
> @@ -0,0 +1,50 @@
> +* Kinetic Technologies - KTD2692 Flash LED Driver
> +
> +KTD2692 is the ideal power solution for high-power flash LEDs.
> +It uses ExpressWire single-wire programming for maximum flexibility.
> +
> +The ExpressWire interface through CTRL pin can control LED on/off and
> +enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
> +Flash timeout, LVP(low voltage protection).
> +
> +Also, When the AUX pin is pulled high while CTRL pin is high,
> +LED current will be ramped up to the flash-mode current level.
> +
> +Required properties:
> +- compatible: "kinetic,ktd2692"

How about:

compatible : Should be "kinetic,ktd2692".

Pleas put space between the property name and a colon consequently.

> +- ctrl-gpio : gpio pin in order control CTRL pin
> +- aux-gpio : gpio pin in order control AUX pin

Documentation/devicetree/bindings/gpio/gpio.txt states:

"GPIO properties should be named "[<name>-]gpios".

Please adhere to this. Also please begin description after colon
with a capital letter and put a dot at the end of sentence, e.g.:

ctrl-gpios : Specifier of the GPIO connected to CTRL pin.
aux-gpio : Specifier of the GPIO connected to AUX pin.

> +Optional properties:
> +- vin-supply : "vin" LED supply (2.7V to 5.5V)
> +  See Documentation/devicetree/bindings/regulator/regulator.txt
> +
> +A discrete LED element connected to the device must be represented by a child
> +node - see Documentation/devicetree/bindings/leds/common.txt.
> +
> +Required properties for flash LED child nodes:
> +  See Documentation/devicetree/bindings/leds/common.txt
> +- led-max-microamp : Minimum Threshold for Timer protection
> +  is defined internally (Maximum 300mA)
> +- flash-max-microamp : Flash LED maximum current
> +  Formula : I(mA) = 15000 / Rset
> +- flash-max-timeout-us : Flash LED maximum timeout
> +
> +Optional properties for flash LED child nodes:
> +- label : see Documentation/devicetree/bindings/leds/common.txt
> +
> +Example:
> +
> +ktd2692 {
> +	compatible = "kinetic,ktd2692";
> +	ctrl-gpio = <&gpc0 1 0>;
> +	aux-gpio = <&gpc0 2 0>;

ctrl-gpios = <&gpc0 1 0>;
aux-gpios = <&gpc0 2 0>;

> +	vin-supply = <&vbat>;
> +
> +	flash-led {
> +		label = "ktd2692-flash";
> +		led-max-microamp = <300000>;
> +		flash-max-microamp = <1500000>;
> +		flash-max-timeout-us = <1835000>;
> +	};
> +};
>


-- 
Best Regards,
Jacek Anaszewski

Re: [PATCH v8 2/3] leds: ktd2692: add device tree bindings for ktd2692

[Ingi Kim]

Hi Jacek,

On 2015년 05월 08일 17:33, Jacek Anaszewski wrote:
> Hi Ingi,
> 
> On 05/08/2015 05:03 AM, Ingi Kim wrote:
>> This patch adds the device tree bindings for ktd2692 flash LEDs.
>> Add Optional properties of child node for Flash LED
>>
>> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
>> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
>> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
>> ---
>>   .../devicetree/bindings/leds/leds-ktd2692.txt      | 50 ++++++++++++++++++++++
>>   1 file changed, 50 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>>
>> diff --git a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>> new file mode 100644
>> index 0000000..cf45492
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>> @@ -0,0 +1,50 @@
>> +* Kinetic Technologies - KTD2692 Flash LED Driver
>> +
>> +KTD2692 is the ideal power solution for high-power flash LEDs.
>> +It uses ExpressWire single-wire programming for maximum flexibility.
>> +
>> +The ExpressWire interface through CTRL pin can control LED on/off and
>> +enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
>> +Flash timeout, LVP(low voltage protection).
>> +
>> +Also, When the AUX pin is pulled high while CTRL pin is high,
>> +LED current will be ramped up to the flash-mode current level.
>> +
>> +Required properties:
>> +- compatible: "kinetic,ktd2692"
> 
> How about:
> 
> compatible : Should be "kinetic,ktd2692".
> 
> Pleas put space between the property name and a colon consequently.
> 
>> +- ctrl-gpio : gpio pin in order control CTRL pin
>> +- aux-gpio : gpio pin in order control AUX pin
> 
> Documentation/devicetree/bindings/gpio/gpio.txt states:
> 
> "GPIO properties should be named "[<name>-]gpios".
> 
> Please adhere to this. Also please begin description after colon
> with a capital letter and put a dot at the end of sentence, e.g.:
> 
> ctrl-gpios : Specifier of the GPIO connected to CTRL pin.
> aux-gpio : Specifier of the GPIO connected to AUX pin.
> 

I should have read binding test strictly.
I'll fix it

>> +Optional properties:
>> +- vin-supply : "vin" LED supply (2.7V to 5.5V)
>> +  See Documentation/devicetree/bindings/regulator/regulator.txt
>> +
>> +A discrete LED element connected to the device must be represented by a child
>> +node - see Documentation/devicetree/bindings/leds/common.txt.
>> +
>> +Required properties for flash LED child nodes:
>> +  See Documentation/devicetree/bindings/leds/common.txt
>> +- led-max-microamp : Minimum Threshold for Timer protection
>> +  is defined internally (Maximum 300mA)
>> +- flash-max-microamp : Flash LED maximum current
>> +  Formula : I(mA) = 15000 / Rset
>> +- flash-max-timeout-us : Flash LED maximum timeout
>> +
>> +Optional properties for flash LED child nodes:
>> +- label : see Documentation/devicetree/bindings/leds/common.txt
>> +
>> +Example:
>> +
>> +ktd2692 {
>> +    compatible = "kinetic,ktd2692";
>> +    ctrl-gpio = <&gpc0 1 0>;
>> +    aux-gpio = <&gpc0 2 0>;
> 
> ctrl-gpios = <&gpc0 1 0>;
> aux-gpios = <&gpc0 2 0>;
> 

Check it!

>> +    vin-supply = <&vbat>;
>> +
>> +    flash-led {
>> +        label = "ktd2692-flash";
>> +        led-max-microamp = <300000>;
>> +        flash-max-microamp = <1500000>;
>> +        flash-max-timeout-us = <1835000>;
>> +    };
>> +};
>>
> 
> 

[PATCH v8 3/3] leds: Add ktd2692 flash LED driver

[Ingi Kim]

This patch adds a driver to support the ktd2692 flash LEDs.
ktd2692 can control flash current by ExpressWire interface.

Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
---
 drivers/leds/Kconfig        |   9 +
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-ktd2692.c | 443 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 453 insertions(+)
 create mode 100644 drivers/leds/leds-ktd2692.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 51059bb..bfbdbd1 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -505,6 +505,15 @@ config LEDS_MENF21BMC
 	  This driver can also be built as a module. If so the module
 	  will be called leds-menf21bmc.
 
+config LEDS_KTD2692
+	tristate "KTD2692 LED flash support"
+	depends on LEDS_CLASS_FLASH && GPIOLIB && OF
+	help
+	  This option enables support for KTD2692 LED flash connected
+	  through ExpressWire interface.
+
+	  Say Y to enable this driver.
+
 comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
 
 config LEDS_BLINKM
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index a739ae2..ed5ed79 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
 obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
 obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
+obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
new file mode 100644
index 0000000..9d878a4
--- /dev/null
+++ b/drivers/leds/leds-ktd2692.c
@@ -0,0 +1,443 @@
+/*
+ * LED driver : leds-ktd2692.c
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Ingi Kim <ingi2.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.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/workqueue.h>
+
+/* Value related the movie mode */
+#define KTD2692_MOVIE_MODE_CURRENT_LEVELS	16
+#define KTD2692_MM_TO_FL_RATIO(x)		((x) / 3)
+#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE	8
+
+/* Value related the flash mode */
+#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS	8
+#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE	0
+#define KTD2692_FLASH_MODE_CURR_PERCENT(x)	(((x) * 16) / 100)
+
+/* Macro for getting offset of flash timeout */
+#define GET_TIMEOUT_OFFSET(timeout, step)	((timeout) / (step))
+
+/* Base register address */
+#define KTD2692_REG_LVP_BASE			0x00
+#define KTD2692_REG_FLASH_TIMEOUT_BASE		0x20
+#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE	0x40
+#define KTD2692_REG_MOVIE_CURRENT_BASE		0x60
+#define KTD2692_REG_FLASH_CURRENT_BASE		0x80
+#define KTD2692_REG_MODE_BASE			0xA0
+
+/* Set bit coding time for expresswire interface */
+#define KTD2692_TIME_RESET_US			700
+#define KTD2692_TIME_DATA_START_TIME_US		10
+#define KTD2692_TIME_HIGH_END_OF_DATA_US	350
+#define KTD2692_TIME_LOW_END_OF_DATA_US		10
+#define KTD2692_TIME_SHORT_BITSET_US		4
+#define KTD2692_TIME_LONG_BITSET_US		12
+
+/* KTD2692 default length of name */
+#define KTD2692_NAME_LENGTH			20
+
+enum ktd2692_bitset {
+	KTD2692_LOW = 0,
+	KTD2692_HIGH,
+};
+
+/* Movie / Flash Mode Control */
+enum ktd2692_led_mode {
+	KTD2692_MODE_DISABLE = 0,	/* default */
+	KTD2692_MODE_MOVIE,
+	KTD2692_MODE_FLASH,
+};
+
+struct ktd2692_led_config_data {
+	/* maximum LED current in movie mode */
+	u32 movie_max_microamp;
+	/* maximum LED current in flash mode */
+	u32 flash_max_microamp;
+	/* maximum flash timeout */
+	u32 flash_max_timeout;
+	/* max LED brightness level */
+	enum led_brightness max_brightness;
+};
+
+struct ktd2692_context {
+	/* Related LED Flash class device */
+	struct led_classdev_flash fled_cdev;
+
+	/* secures access to the device */
+	struct mutex lock;
+	struct regulator *regulator;
+	struct work_struct work_brightness_set;
+
+	struct gpio_desc *aux_gpio;
+	struct gpio_desc *ctrl_gpio;
+
+	enum ktd2692_led_mode mode;
+	enum led_brightness torch_brightness;
+};
+
+static struct ktd2692_context *fled_cdev_to_led(
+				struct led_classdev_flash *fled_cdev)
+{
+	return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
+}
+
+static void ktd2692_expresswire_start(struct ktd2692_context *led)
+{
+	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
+	udelay(KTD2692_TIME_DATA_START_TIME_US);
+}
+
+static void ktd2692_expresswire_reset(struct ktd2692_context *led)
+{
+	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
+	udelay(KTD2692_TIME_RESET_US);
+}
+
+static void ktd2692_expresswire_end(struct ktd2692_context *led)
+{
+	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
+	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
+	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
+	udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
+}
+
+static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
+{
+	/*
+	 * The Low Bit(0) and High Bit(1) is based on a time detection
+	 * algorithm between time low and time high
+	 * Time_(L_LB) : Low time of the Low Bit(0)
+	 * Time_(H_LB) : High time of the LOW Bit(0)
+	 * Time_(L_HB) : Low time of the High Bit(1)
+	 * Time_(H_HB) : High time of the High Bit(1)
+	 *
+	 * It can be simplified to:
+	 * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
+	 * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
+	 * HIGH  ___           ____    _..     _________    ___
+	 *          |_________|    |_..  |____|         |__|
+	 * LOW        <L_LB>  <H_LB>     <L_HB>  <H_HB>
+	 *          [  Low Bit (0) ]     [  High Bit(1) ]
+	 */
+	if (bit) {
+		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
+		udelay(KTD2692_TIME_SHORT_BITSET_US);
+		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
+		udelay(KTD2692_TIME_LONG_BITSET_US);
+	} else {
+		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
+		udelay(KTD2692_TIME_LONG_BITSET_US);
+		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
+		udelay(KTD2692_TIME_SHORT_BITSET_US);
+	}
+}
+
+static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
+{
+	int i;
+
+	ktd2692_expresswire_start(led);
+	for (i = 7; i >= 0; i--)
+		ktd2692_expresswire_set_bit(led, value & BIT(i));
+	ktd2692_expresswire_end(led);
+}
+
+static void ktd2692_brightness_set(struct ktd2692_context *led,
+				   enum led_brightness brightness)
+{
+	mutex_lock(&led->lock);
+
+	if (brightness == LED_OFF) {
+		led->mode = KTD2692_MODE_DISABLE;
+		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+	} else {
+		ktd2692_expresswire_write(led, brightness |
+					KTD2692_REG_MOVIE_CURRENT_BASE);
+		led->mode = KTD2692_MODE_MOVIE;
+	}
+
+	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
+	mutex_unlock(&led->lock);
+}
+
+static void ktd2692_brightness_set_work(struct work_struct *work)
+{
+	struct ktd2692_context *led =
+		container_of(work, struct ktd2692_context, work_brightness_set);
+
+	ktd2692_brightness_set(led, led->torch_brightness);
+}
+
+static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
+				       enum led_brightness brightness)
+{
+	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
+
+	led->torch_brightness = brightness;
+	schedule_work(&led->work_brightness_set);
+}
+
+static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
+					   enum led_brightness brightness)
+{
+	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
+
+	ktd2692_brightness_set(led, brightness);
+
+	return 0;
+}
+
+static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
+					bool state)
+{
+	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
+	struct led_flash_setting *timeout = &fled_cdev->timeout;
+	u32 flash_tm_reg;
+
+	mutex_lock(&led->lock);
+
+	if (state == 0) {
+		led->mode = KTD2692_MODE_DISABLE;
+		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+	} else {
+		flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
+		ktd2692_expresswire_write(led, flash_tm_reg
+				| KTD2692_REG_FLASH_TIMEOUT_BASE);
+
+		led->mode = KTD2692_MODE_FLASH;
+		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
+	}
+
+	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
+
+	fled_cdev->led_cdev.brightness = LED_OFF;
+	led->mode = KTD2692_MODE_DISABLE;
+
+	mutex_unlock(&led->lock);
+
+	return 0;
+}
+
+static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
+					 u32 timeout)
+{
+	return 0;
+}
+
+static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
+{
+	u32 offset, step;
+	u32 movie_current_microamp;
+
+	offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
+	step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
+		/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;
+
+	do {
+		movie_current_microamp = step * offset;
+		offset--;
+	} while ((movie_current_microamp > cfg->movie_max_microamp) &&
+		(offset > 0));
+
+	cfg->max_brightness = offset;
+}
+
+static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
+				       struct ktd2692_led_config_data *cfg)
+{
+	struct led_flash_setting *setting;
+
+	setting = &fled_cdev->timeout;
+	setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
+	setting->max = cfg->flash_max_timeout;
+	setting->step = cfg->flash_max_timeout
+			/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
+	setting->val = cfg->flash_max_timeout;
+}
+
+static void ktd2692_setup(struct ktd2692_context *led)
+{
+	led->mode = KTD2692_MODE_DISABLE;
+	ktd2692_expresswire_reset(led);
+	gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+
+	ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
+				 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
+	ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
+				 | KTD2692_REG_FLASH_CURRENT_BASE);
+}
+
+static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
+			    struct ktd2692_led_config_data *cfg)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *child_node;
+	int ret;
+
+	if (!dev->of_node)
+		return -ENXIO;
+
+	led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
+	if (IS_ERR(led->ctrl_gpio)) {
+		ret = PTR_ERR(led->ctrl_gpio);
+		dev_err(dev, "cannot get ctrl-gpio %d\n", ret);
+		return ret;
+	}
+
+	led->aux_gpio = devm_gpiod_get(dev, "aux");
+	if (IS_ERR(led->aux_gpio)) {
+		ret = PTR_ERR(led->aux_gpio);
+		dev_err(dev, "cannot get aux-gpio %d\n", ret);
+		return ret;
+	}
+
+	led->regulator = devm_regulator_get(dev, "vin");
+	if (IS_ERR(led->regulator))
+		led->regulator = NULL;
+
+	if (led->regulator) {
+		ret = regulator_enable(led->regulator);
+		if (ret)
+			dev_err(dev, "Failed to enable supply: %d\n", ret);
+	}
+
+	child_node = of_get_next_available_child(np, NULL);
+	if (!child_node) {
+		dev_err(dev, "No DT child node found for connected LED.\n");
+		return -EINVAL;
+	}
+
+	led->fled_cdev.led_cdev.name =
+		of_get_property(child_node, "label", NULL) ? : child_node->name;
+
+	ret = of_property_read_u32(child_node, "led-max-microamp",
+				   &cfg->movie_max_microamp);
+	if (ret) {
+		dev_err(dev, "failed to parse led-max-microamp\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(child_node, "flash-max-microamp",
+				   &cfg->flash_max_microamp);
+	if (ret) {
+		dev_err(dev, "failed to parse flash-max-microamp\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(child_node, "flash-max-timeout-us",
+				   &cfg->flash_max_timeout);
+	if (ret)
+		dev_err(dev, "failed to parse flash-max-timeout-us\n");
+
+	of_node_put(child_node);
+	return ret;
+}
+
+static const struct led_flash_ops flash_ops = {
+	.strobe_set = ktd2692_led_flash_strobe_set,
+	.timeout_set = ktd2692_led_flash_timeout_set,
+};
+
+static int ktd2692_probe(struct platform_device *pdev)
+{
+	struct ktd2692_context *led;
+	struct led_classdev *led_cdev;
+	struct led_classdev_flash *fled_cdev;
+	struct ktd2692_led_config_data led_cfg;
+	int ret;
+
+	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	fled_cdev = &led->fled_cdev;
+	led_cdev = &fled_cdev->led_cdev;
+
+	ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
+	if (ret)
+		return ret;
+
+	ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
+	ktd2692_init_movie_current_max(&led_cfg);
+
+	fled_cdev->ops = &flash_ops;
+
+	led_cdev->max_brightness = led_cfg.max_brightness;
+	led_cdev->brightness_set = ktd2692_led_brightness_set;
+	led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
+	led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
+
+	mutex_init(&led->lock);
+	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
+
+	platform_set_drvdata(pdev, led);
+
+	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
+	if (ret) {
+		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
+		mutex_destroy(&led->lock);
+		return ret;
+	}
+
+	ktd2692_setup(led);
+
+	return 0;
+}
+
+static int ktd2692_remove(struct platform_device *pdev)
+{
+	struct ktd2692_context *led = platform_get_drvdata(pdev);
+	int ret;
+
+	led_classdev_flash_unregister(&led->fled_cdev);
+	cancel_work_sync(&led->work_brightness_set);
+
+	if (led->regulator) {
+		ret = regulator_disable(led->regulator);
+		if (ret)
+			dev_err(&pdev->dev,
+				"Failed to disable supply: %d\n", ret);
+	}
+
+	mutex_destroy(&led->lock);
+
+	return 0;
+}
+
+static const struct of_device_id ktd2692_match[] = {
+	{ .compatible = "kinetic,ktd2692", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver ktd2692_driver = {
+	.driver = {
+		.name  = "ktd2692",
+		.of_match_table = ktd2692_match,
+	},
+	.probe  = ktd2692_probe,
+	.remove = ktd2692_remove,
+};
+
+module_platform_driver(ktd2692_driver);
+
+MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
+MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
+MODULE_LICENSE("GPL v2");
-- 
2.0.5

Re: [PATCH v8 3/3] leds: Add ktd2692 flash LED driver

[Jacek Anaszewski]

Hi Ingi,

Thanks for the update. It looks like we're almost there.
I can see only two minor issues.

On 05/08/2015 05:03 AM, Ingi Kim wrote:
> This patch adds a driver to support the ktd2692 flash LEDs.
> ktd2692 can control flash current by ExpressWire interface.
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
> ---
>   drivers/leds/Kconfig        |   9 +
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-ktd2692.c | 443 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 453 insertions(+)
>   create mode 100644 drivers/leds/leds-ktd2692.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 51059bb..bfbdbd1 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -505,6 +505,15 @@ config LEDS_MENF21BMC
>   	  This driver can also be built as a module. If so the module
>   	  will be called leds-menf21bmc.
>
> +config LEDS_KTD2692
> +	tristate "KTD2692 LED flash support"

Please keep the style of description in line with the existing
drivers. How about:

"LED support for KTD2692 flash LED controller"

> +	depends on LEDS_CLASS_FLASH && GPIOLIB && OF
> +	help
> +	  This option enables support for KTD2692 LED flash connected
> +	  through ExpressWire interface.
> +
> +	  Say Y to enable this driver.
> +
>   comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
>
>   config LEDS_BLINKM
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index a739ae2..ed5ed79 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -59,6 +59,7 @@ obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
>   obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
>   obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
>   obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
> +obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
>
>   # LED SPI Drivers
>   obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
> diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
> new file mode 100644
> index 0000000..9d878a4
> --- /dev/null
> +++ b/drivers/leds/leds-ktd2692.c
> @@ -0,0 +1,443 @@
> +/*
> + * LED driver : leds-ktd2692.c
> + *
> + * Copyright (C) 2015 Samsung Electronics
> + * Ingi Kim <ingi2.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.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/led-class-flash.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/workqueue.h>
> +
> +/* Value related the movie mode */
> +#define KTD2692_MOVIE_MODE_CURRENT_LEVELS	16
> +#define KTD2692_MM_TO_FL_RATIO(x)		((x) / 3)
> +#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE	8
> +
> +/* Value related the flash mode */
> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS	8
> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE	0
> +#define KTD2692_FLASH_MODE_CURR_PERCENT(x)	(((x) * 16) / 100)
> +
> +/* Macro for getting offset of flash timeout */
> +#define GET_TIMEOUT_OFFSET(timeout, step)	((timeout) / (step))
> +
> +/* Base register address */
> +#define KTD2692_REG_LVP_BASE			0x00
> +#define KTD2692_REG_FLASH_TIMEOUT_BASE		0x20
> +#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE	0x40
> +#define KTD2692_REG_MOVIE_CURRENT_BASE		0x60
> +#define KTD2692_REG_FLASH_CURRENT_BASE		0x80
> +#define KTD2692_REG_MODE_BASE			0xA0
> +
> +/* Set bit coding time for expresswire interface */
> +#define KTD2692_TIME_RESET_US			700
> +#define KTD2692_TIME_DATA_START_TIME_US		10
> +#define KTD2692_TIME_HIGH_END_OF_DATA_US	350
> +#define KTD2692_TIME_LOW_END_OF_DATA_US		10
> +#define KTD2692_TIME_SHORT_BITSET_US		4
> +#define KTD2692_TIME_LONG_BITSET_US		12
> +
> +/* KTD2692 default length of name */
> +#define KTD2692_NAME_LENGTH			20
> +
> +enum ktd2692_bitset {
> +	KTD2692_LOW = 0,
> +	KTD2692_HIGH,
> +};
> +
> +/* Movie / Flash Mode Control */
> +enum ktd2692_led_mode {
> +	KTD2692_MODE_DISABLE = 0,	/* default */
> +	KTD2692_MODE_MOVIE,
> +	KTD2692_MODE_FLASH,
> +};
> +
> +struct ktd2692_led_config_data {
> +	/* maximum LED current in movie mode */
> +	u32 movie_max_microamp;
> +	/* maximum LED current in flash mode */
> +	u32 flash_max_microamp;
> +	/* maximum flash timeout */
> +	u32 flash_max_timeout;
> +	/* max LED brightness level */
> +	enum led_brightness max_brightness;
> +};
> +
> +struct ktd2692_context {
> +	/* Related LED Flash class device */
> +	struct led_classdev_flash fled_cdev;
> +
> +	/* secures access to the device */
> +	struct mutex lock;
> +	struct regulator *regulator;
> +	struct work_struct work_brightness_set;
> +
> +	struct gpio_desc *aux_gpio;
> +	struct gpio_desc *ctrl_gpio;
> +
> +	enum ktd2692_led_mode mode;
> +	enum led_brightness torch_brightness;
> +};
> +
> +static struct ktd2692_context *fled_cdev_to_led(
> +				struct led_classdev_flash *fled_cdev)
> +{
> +	return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
> +}
> +
> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +	udelay(KTD2692_TIME_DATA_START_TIME_US);
> +}
> +
> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_RESET_US);
> +}
> +
> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +	udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
> +}
> +
> +static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
> +{
> +	/*
> +	 * The Low Bit(0) and High Bit(1) is based on a time detection
> +	 * algorithm between time low and time high
> +	 * Time_(L_LB) : Low time of the Low Bit(0)
> +	 * Time_(H_LB) : High time of the LOW Bit(0)
> +	 * Time_(L_HB) : Low time of the High Bit(1)
> +	 * Time_(H_HB) : High time of the High Bit(1)
> +	 *
> +	 * It can be simplified to:
> +	 * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
> +	 * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
> +	 * HIGH  ___           ____    _..     _________    ___
> +	 *          |_________|    |_..  |____|         |__|
> +	 * LOW        <L_LB>  <H_LB>     <L_HB>  <H_HB>
> +	 *          [  Low Bit (0) ]     [  High Bit(1) ]
> +	 */
> +	if (bit) {
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_SHORT_BITSET_US);
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +	} else {
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +		udelay(KTD2692_TIME_SHORT_BITSET_US);
> +	}
> +}
> +
> +static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
> +{
> +	int i;
> +
> +	ktd2692_expresswire_start(led);
> +	for (i = 7; i >= 0; i--)
> +		ktd2692_expresswire_set_bit(led, value & BIT(i));
> +	ktd2692_expresswire_end(led);
> +}
> +
> +static void ktd2692_brightness_set(struct ktd2692_context *led,
> +				   enum led_brightness brightness)
> +{
> +	mutex_lock(&led->lock);
> +
> +	if (brightness == LED_OFF) {
> +		led->mode = KTD2692_MODE_DISABLE;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +	} else {
> +		ktd2692_expresswire_write(led, brightness |
> +					KTD2692_REG_MOVIE_CURRENT_BASE);
> +		led->mode = KTD2692_MODE_MOVIE;
> +	}
> +
> +	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
> +	mutex_unlock(&led->lock);
> +}
> +
> +static void ktd2692_brightness_set_work(struct work_struct *work)
> +{
> +	struct ktd2692_context *led =
> +		container_of(work, struct ktd2692_context, work_brightness_set);
> +
> +	ktd2692_brightness_set(led, led->torch_brightness);
> +}
> +
> +static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
> +				       enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +
> +	led->torch_brightness = brightness;
> +	schedule_work(&led->work_brightness_set);
> +}
> +
> +static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
> +					   enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +
> +	ktd2692_brightness_set(led, brightness);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
> +					bool state)
> +{
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +	struct led_flash_setting *timeout = &fled_cdev->timeout;
> +	u32 flash_tm_reg;
> +
> +	mutex_lock(&led->lock);
> +
> +	if (state == 0) {

Coccinelle raises a warning here:

drivers/leds/leds-ktd2692.c:217:5-10: WARNING: Comparison of bool to 0/1

I had to fix it also in my leds-aat1290 driver recently:)

> +		led->mode = KTD2692_MODE_DISABLE;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +	} else {
> +		flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
> +		ktd2692_expresswire_write(led, flash_tm_reg
> +				| KTD2692_REG_FLASH_TIMEOUT_BASE);
> +
> +		led->mode = KTD2692_MODE_FLASH;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
> +	}
> +
> +	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
> +
> +	fled_cdev->led_cdev.brightness = LED_OFF;
> +	led->mode = KTD2692_MODE_DISABLE;
> +
> +	mutex_unlock(&led->lock);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
> +					 u32 timeout)
> +{
> +	return 0;
> +}
> +
> +static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
> +{
> +	u32 offset, step;
> +	u32 movie_current_microamp;
> +
> +	offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
> +	step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
> +		/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;
> +
> +	do {
> +		movie_current_microamp = step * offset;
> +		offset--;
> +	} while ((movie_current_microamp > cfg->movie_max_microamp) &&
> +		(offset > 0));
> +
> +	cfg->max_brightness = offset;
> +}
> +
> +static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
> +				       struct ktd2692_led_config_data *cfg)
> +{
> +	struct led_flash_setting *setting;
> +
> +	setting = &fled_cdev->timeout;
> +	setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
> +	setting->max = cfg->flash_max_timeout;
> +	setting->step = cfg->flash_max_timeout
> +			/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
> +	setting->val = cfg->flash_max_timeout;
> +}
> +
> +static void ktd2692_setup(struct ktd2692_context *led)
> +{
> +	led->mode = KTD2692_MODE_DISABLE;
> +	ktd2692_expresswire_reset(led);
> +	gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +
> +	ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
> +				 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
> +	ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
> +				 | KTD2692_REG_FLASH_CURRENT_BASE);
> +}
> +
> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
> +			    struct ktd2692_led_config_data *cfg)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct device_node *child_node;
> +	int ret;
> +
> +	if (!dev->of_node)
> +		return -ENXIO;
> +
> +	led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
> +	if (IS_ERR(led->ctrl_gpio)) {
> +		ret = PTR_ERR(led->ctrl_gpio);
> +		dev_err(dev, "cannot get ctrl-gpio %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->aux_gpio = devm_gpiod_get(dev, "aux");
> +	if (IS_ERR(led->aux_gpio)) {
> +		ret = PTR_ERR(led->aux_gpio);
> +		dev_err(dev, "cannot get aux-gpio %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->regulator = devm_regulator_get(dev, "vin");
> +	if (IS_ERR(led->regulator))
> +		led->regulator = NULL;
> +
> +	if (led->regulator) {
> +		ret = regulator_enable(led->regulator);
> +		if (ret)
> +			dev_err(dev, "Failed to enable supply: %d\n", ret);
> +	}
> +
> +	child_node = of_get_next_available_child(np, NULL);
> +	if (!child_node) {
> +		dev_err(dev, "No DT child node found for connected LED.\n");
> +		return -EINVAL;
> +	}
> +
> +	led->fled_cdev.led_cdev.name =
> +		of_get_property(child_node, "label", NULL) ? : child_node->name;
> +
> +	ret = of_property_read_u32(child_node, "led-max-microamp",
> +				   &cfg->movie_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse led-max-microamp\n");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(child_node, "flash-max-microamp",
> +				   &cfg->flash_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse flash-max-microamp\n");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(child_node, "flash-max-timeout-us",
> +				   &cfg->flash_max_timeout);
> +	if (ret)
> +		dev_err(dev, "failed to parse flash-max-timeout-us\n");
> +
> +	of_node_put(child_node);
> +	return ret;
> +}
> +
> +static const struct led_flash_ops flash_ops = {
> +	.strobe_set = ktd2692_led_flash_strobe_set,
> +	.timeout_set = ktd2692_led_flash_timeout_set,
> +};
> +
> +static int ktd2692_probe(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led;
> +	struct led_classdev *led_cdev;
> +	struct led_classdev_flash *fled_cdev;
> +	struct ktd2692_led_config_data led_cfg;
> +	int ret;
> +
> +	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	fled_cdev = &led->fled_cdev;
> +	led_cdev = &fled_cdev->led_cdev;
> +
> +	ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
> +	if (ret)
> +		return ret;
> +
> +	ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
> +	ktd2692_init_movie_current_max(&led_cfg);
> +
> +	fled_cdev->ops = &flash_ops;
> +
> +	led_cdev->max_brightness = led_cfg.max_brightness;
> +	led_cdev->brightness_set = ktd2692_led_brightness_set;
> +	led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
> +	led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
> +
> +	mutex_init(&led->lock);
> +	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
> +
> +	platform_set_drvdata(pdev, led);
> +
> +	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
> +		mutex_destroy(&led->lock);
> +		return ret;
> +	}
> +
> +	ktd2692_setup(led);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_remove(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led = platform_get_drvdata(pdev);
> +	int ret;
> +
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +	cancel_work_sync(&led->work_brightness_set);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&pdev->dev,
> +				"Failed to disable supply: %d\n", ret);
> +	}
> +
> +	mutex_destroy(&led->lock);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ktd2692_match[] = {
> +	{ .compatible = "kinetic,ktd2692", },
> +	{ /* sentinel */ },
> +};
> +
> +static struct platform_driver ktd2692_driver = {
> +	.driver = {
> +		.name  = "ktd2692",
> +		.of_match_table = ktd2692_match,
> +	},
> +	.probe  = ktd2692_probe,
> +	.remove = ktd2692_remove,
> +};
> +
> +module_platform_driver(ktd2692_driver);
> +
> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
> +MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
> +MODULE_LICENSE("GPL v2");
>


-- 
Best Regards,
Jacek Anaszewski

Re: [PATCH v8 3/3] leds: Add ktd2692 flash LED driver

[Ingi Kim]

Hi Jacek,
Thanks for the review

I can improve this driver for your attention
I'm trying to rebase source code for merging it and resending soon.

Thank you

On 2015년 05월 08일 17:33, Jacek Anaszewski wrote:
> Hi Ingi,
> 
> Thanks for the update. It looks like we're almost there.
> I can see only two minor issues.
> 
> On 05/08/2015 05:03 AM, Ingi Kim wrote:
>> This patch adds a driver to support the ktd2692 flash LEDs.
>> ktd2692 can control flash current by ExpressWire interface.
>>
>> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
>> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
>> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
>> ---
>>   drivers/leds/Kconfig        |   9 +
>>   drivers/leds/Makefile       |   1 +
>>   drivers/leds/leds-ktd2692.c | 443 ++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 453 insertions(+)
>>   create mode 100644 drivers/leds/leds-ktd2692.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 51059bb..bfbdbd1 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -505,6 +505,15 @@ config LEDS_MENF21BMC
>>         This driver can also be built as a module. If so the module
>>         will be called leds-menf21bmc.
>>
>> +config LEDS_KTD2692
>> +    tristate "KTD2692 LED flash support"
> 
> Please keep the style of description in line with the existing
> drivers. How about:
> 
> "LED support for KTD2692 flash LED controller"
> 

Sure, I'll change it

>> +    depends on LEDS_CLASS_FLASH && GPIOLIB && OF
>> +    help
>> +      This option enables support for KTD2692 LED flash connected
>> +      through ExpressWire interface.
>> +
>> +      Say Y to enable this driver.
>> +
>>   comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
>>
>>   config LEDS_BLINKM
>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>> index a739ae2..ed5ed79 100644
>> --- a/drivers/leds/Makefile
>> +++ b/drivers/leds/Makefile
>> @@ -59,6 +59,7 @@ obj-$(CONFIG_LEDS_BLINKM)        += leds-blinkm.o
>>   obj-$(CONFIG_LEDS_SYSCON)        += leds-syscon.o
>>   obj-$(CONFIG_LEDS_VERSATILE)        += leds-versatile.o
>>   obj-$(CONFIG_LEDS_MENF21BMC)        += leds-menf21bmc.o
>> +obj-$(CONFIG_LEDS_KTD2692)        += leds-ktd2692.o
>>
>>   # LED SPI Drivers
>>   obj-$(CONFIG_LEDS_DAC124S085)        += leds-dac124s085.o
>> diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
>> new file mode 100644
>> index 0000000..9d878a4
>> --- /dev/null
>> +++ b/drivers/leds/leds-ktd2692.c
>> @@ -0,0 +1,443 @@
>> +/*
>> + * LED driver : leds-ktd2692.c
>> + *
>> + * Copyright (C) 2015 Samsung Electronics
>> + * Ingi Kim <ingi2.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.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/err.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/led-class-flash.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/workqueue.h>
>> +
>> +/* Value related the movie mode */
>> +#define KTD2692_MOVIE_MODE_CURRENT_LEVELS    16
>> +#define KTD2692_MM_TO_FL_RATIO(x)        ((x) / 3)
>> +#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE    8
>> +
>> +/* Value related the flash mode */
>> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS    8
>> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE    0
>> +#define KTD2692_FLASH_MODE_CURR_PERCENT(x)    (((x) * 16) / 100)
>> +
>> +/* Macro for getting offset of flash timeout */
>> +#define GET_TIMEOUT_OFFSET(timeout, step)    ((timeout) / (step))
>> +
>> +/* Base register address */
>> +#define KTD2692_REG_LVP_BASE            0x00
>> +#define KTD2692_REG_FLASH_TIMEOUT_BASE        0x20
>> +#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE    0x40
>> +#define KTD2692_REG_MOVIE_CURRENT_BASE        0x60
>> +#define KTD2692_REG_FLASH_CURRENT_BASE        0x80
>> +#define KTD2692_REG_MODE_BASE            0xA0
>> +
>> +/* Set bit coding time for expresswire interface */
>> +#define KTD2692_TIME_RESET_US            700
>> +#define KTD2692_TIME_DATA_START_TIME_US        10
>> +#define KTD2692_TIME_HIGH_END_OF_DATA_US    350
>> +#define KTD2692_TIME_LOW_END_OF_DATA_US        10
>> +#define KTD2692_TIME_SHORT_BITSET_US        4
>> +#define KTD2692_TIME_LONG_BITSET_US        12
>> +
>> +/* KTD2692 default length of name */
>> +#define KTD2692_NAME_LENGTH            20
>> +
>> +enum ktd2692_bitset {
>> +    KTD2692_LOW = 0,
>> +    KTD2692_HIGH,
>> +};
>> +
>> +/* Movie / Flash Mode Control */
>> +enum ktd2692_led_mode {
>> +    KTD2692_MODE_DISABLE = 0,    /* default */
>> +    KTD2692_MODE_MOVIE,
>> +    KTD2692_MODE_FLASH,
>> +};
>> +
>> +struct ktd2692_led_config_data {
>> +    /* maximum LED current in movie mode */
>> +    u32 movie_max_microamp;
>> +    /* maximum LED current in flash mode */
>> +    u32 flash_max_microamp;
>> +    /* maximum flash timeout */
>> +    u32 flash_max_timeout;
>> +    /* max LED brightness level */
>> +    enum led_brightness max_brightness;
>> +};
>> +
>> +struct ktd2692_context {
>> +    /* Related LED Flash class device */
>> +    struct led_classdev_flash fled_cdev;
>> +
>> +    /* secures access to the device */
>> +    struct mutex lock;
>> +    struct regulator *regulator;
>> +    struct work_struct work_brightness_set;
>> +
>> +    struct gpio_desc *aux_gpio;
>> +    struct gpio_desc *ctrl_gpio;
>> +
>> +    enum ktd2692_led_mode mode;
>> +    enum led_brightness torch_brightness;
>> +};
>> +
>> +static struct ktd2692_context *fled_cdev_to_led(
>> +                struct led_classdev_flash *fled_cdev)
>> +{
>> +    return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
>> +}
>> +
>> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
>> +{
>> +    gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> +    udelay(KTD2692_TIME_DATA_START_TIME_US);
>> +}
>> +
>> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
>> +{
>> +    gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> +    udelay(KTD2692_TIME_RESET_US);
>> +}
>> +
>> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
>> +{
>> +    gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> +    udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
>> +    gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> +    udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
>> +}
>> +
>> +static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
>> +{
>> +    /*
>> +     * The Low Bit(0) and High Bit(1) is based on a time detection
>> +     * algorithm between time low and time high
>> +     * Time_(L_LB) : Low time of the Low Bit(0)
>> +     * Time_(H_LB) : High time of the LOW Bit(0)
>> +     * Time_(L_HB) : Low time of the High Bit(1)
>> +     * Time_(H_HB) : High time of the High Bit(1)
>> +     *
>> +     * It can be simplified to:
>> +     * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
>> +     * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
>> +     * HIGH  ___           ____    _..     _________    ___
>> +     *          |_________|    |_..  |____|         |__|
>> +     * LOW        <L_LB>  <H_LB>     <L_HB>  <H_HB>
>> +     *          [  Low Bit (0) ]     [  High Bit(1) ]
>> +     */
>> +    if (bit) {
>> +        gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> +        udelay(KTD2692_TIME_SHORT_BITSET_US);
>> +        gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> +        udelay(KTD2692_TIME_LONG_BITSET_US);
>> +    } else {
>> +        gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> +        udelay(KTD2692_TIME_LONG_BITSET_US);
>> +        gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> +        udelay(KTD2692_TIME_SHORT_BITSET_US);
>> +    }
>> +}
>> +
>> +static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
>> +{
>> +    int i;
>> +
>> +    ktd2692_expresswire_start(led);
>> +    for (i = 7; i >= 0; i--)
>> +        ktd2692_expresswire_set_bit(led, value & BIT(i));
>> +    ktd2692_expresswire_end(led);
>> +}
>> +
>> +static void ktd2692_brightness_set(struct ktd2692_context *led,
>> +                   enum led_brightness brightness)
>> +{
>> +    mutex_lock(&led->lock);
>> +
>> +    if (brightness == LED_OFF) {
>> +        led->mode = KTD2692_MODE_DISABLE;
>> +        gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> +    } else {
>> +        ktd2692_expresswire_write(led, brightness |
>> +                    KTD2692_REG_MOVIE_CURRENT_BASE);
>> +        led->mode = KTD2692_MODE_MOVIE;
>> +    }
>> +
>> +    ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
>> +    mutex_unlock(&led->lock);
>> +}
>> +
>> +static void ktd2692_brightness_set_work(struct work_struct *work)
>> +{
>> +    struct ktd2692_context *led =
>> +        container_of(work, struct ktd2692_context, work_brightness_set);
>> +
>> +    ktd2692_brightness_set(led, led->torch_brightness);
>> +}
>> +
>> +static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
>> +                       enum led_brightness brightness)
>> +{
>> +    struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
>> +    struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> +
>> +    led->torch_brightness = brightness;
>> +    schedule_work(&led->work_brightness_set);
>> +}
>> +
>> +static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
>> +                       enum led_brightness brightness)
>> +{
>> +    struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
>> +    struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> +
>> +    ktd2692_brightness_set(led, brightness);
>> +
>> +    return 0;
>> +}
>> +
>> +static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
>> +                    bool state)
>> +{
>> +    struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> +    struct led_flash_setting *timeout = &fled_cdev->timeout;
>> +    u32 flash_tm_reg;
>> +
>> +    mutex_lock(&led->lock);
>> +
>> +    if (state == 0) {
> 
> Coccinelle raises a warning here:
> 
> drivers/leds/leds-ktd2692.c:217:5-10: WARNING: Comparison of bool to 0/1
> 
> I had to fix it also in my leds-aat1290 driver recently:)
> 

Ok, I'll refer to your driver code
Thank you, so kindly :)

>> +        led->mode = KTD2692_MODE_DISABLE;
>> +        gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> +    } else {
>> +        flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
>> +        ktd2692_expresswire_write(led, flash_tm_reg
>> +                | KTD2692_REG_FLASH_TIMEOUT_BASE);
>> +
>> +        led->mode = KTD2692_MODE_FLASH;
>> +        gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
>> +    }
>> +
>> +    ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
>> +
>> +    fled_cdev->led_cdev.brightness = LED_OFF;
>> +    led->mode = KTD2692_MODE_DISABLE;
>> +
>> +    mutex_unlock(&led->lock);
>> +
>> +    return 0;
>> +}
>> +
>> +static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
>> +                     u32 timeout)
>> +{
>> +    return 0;
>> +}
>> +
>> +static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
>> +{
>> +    u32 offset, step;
>> +    u32 movie_current_microamp;
>> +
>> +    offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
>> +    step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
>> +        / KTD2692_MOVIE_MODE_CURRENT_LEVELS;
>> +
>> +    do {
>> +        movie_current_microamp = step * offset;
>> +        offset--;
>> +    } while ((movie_current_microamp > cfg->movie_max_microamp) &&
>> +        (offset > 0));
>> +
>> +    cfg->max_brightness = offset;
>> +}
>> +
>> +static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
>> +                       struct ktd2692_led_config_data *cfg)
>> +{
>> +    struct led_flash_setting *setting;
>> +
>> +    setting = &fled_cdev->timeout;
>> +    setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
>> +    setting->max = cfg->flash_max_timeout;
>> +    setting->step = cfg->flash_max_timeout
>> +            / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
>> +    setting->val = cfg->flash_max_timeout;
>> +}
>> +
>> +static void ktd2692_setup(struct ktd2692_context *led)
>> +{
>> +    led->mode = KTD2692_MODE_DISABLE;
>> +    ktd2692_expresswire_reset(led);
>> +    gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> +
>> +    ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
>> +                 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
>> +    ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
>> +                 | KTD2692_REG_FLASH_CURRENT_BASE);
>> +}
>> +
>> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
>> +                struct ktd2692_led_config_data *cfg)
>> +{
>> +    struct device_node *np = dev->of_node;
>> +    struct device_node *child_node;
>> +    int ret;
>> +
>> +    if (!dev->of_node)
>> +        return -ENXIO;
>> +
>> +    led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
>> +    if (IS_ERR(led->ctrl_gpio)) {
>> +        ret = PTR_ERR(led->ctrl_gpio);
>> +        dev_err(dev, "cannot get ctrl-gpio %d\n", ret);
>> +        return ret;
>> +    }
>> +
>> +    led->aux_gpio = devm_gpiod_get(dev, "aux");
>> +    if (IS_ERR(led->aux_gpio)) {
>> +        ret = PTR_ERR(led->aux_gpio);
>> +        dev_err(dev, "cannot get aux-gpio %d\n", ret);
>> +        return ret;
>> +    }
>> +
>> +    led->regulator = devm_regulator_get(dev, "vin");
>> +    if (IS_ERR(led->regulator))
>> +        led->regulator = NULL;
>> +
>> +    if (led->regulator) {
>> +        ret = regulator_enable(led->regulator);
>> +        if (ret)
>> +            dev_err(dev, "Failed to enable supply: %d\n", ret);
>> +    }
>> +
>> +    child_node = of_get_next_available_child(np, NULL);
>> +    if (!child_node) {
>> +        dev_err(dev, "No DT child node found for connected LED.\n");
>> +        return -EINVAL;
>> +    }
>> +
>> +    led->fled_cdev.led_cdev.name =
>> +        of_get_property(child_node, "label", NULL) ? : child_node->name;
>> +
>> +    ret = of_property_read_u32(child_node, "led-max-microamp",
>> +                   &cfg->movie_max_microamp);
>> +    if (ret) {
>> +        dev_err(dev, "failed to parse led-max-microamp\n");
>> +        return ret;
>> +    }
>> +
>> +    ret = of_property_read_u32(child_node, "flash-max-microamp",
>> +                   &cfg->flash_max_microamp);
>> +    if (ret) {
>> +        dev_err(dev, "failed to parse flash-max-microamp\n");
>> +        return ret;
>> +    }
>> +
>> +    ret = of_property_read_u32(child_node, "flash-max-timeout-us",
>> +                   &cfg->flash_max_timeout);
>> +    if (ret)
>> +        dev_err(dev, "failed to parse flash-max-timeout-us\n");
>> +
>> +    of_node_put(child_node);
>> +    return ret;
>> +}
>> +
>> +static const struct led_flash_ops flash_ops = {
>> +    .strobe_set = ktd2692_led_flash_strobe_set,
>> +    .timeout_set = ktd2692_led_flash_timeout_set,
>> +};
>> +
>> +static int ktd2692_probe(struct platform_device *pdev)
>> +{
>> +    struct ktd2692_context *led;
>> +    struct led_classdev *led_cdev;
>> +    struct led_classdev_flash *fled_cdev;
>> +    struct ktd2692_led_config_data led_cfg;
>> +    int ret;
>> +
>> +    led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
>> +    if (!led)
>> +        return -ENOMEM;
>> +
>> +    fled_cdev = &led->fled_cdev;
>> +    led_cdev = &fled_cdev->led_cdev;
>> +
>> +    ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
>> +    if (ret)
>> +        return ret;
>> +
>> +    ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
>> +    ktd2692_init_movie_current_max(&led_cfg);
>> +
>> +    fled_cdev->ops = &flash_ops;
>> +
>> +    led_cdev->max_brightness = led_cfg.max_brightness;
>> +    led_cdev->brightness_set = ktd2692_led_brightness_set;
>> +    led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
>> +    led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
>> +
>> +    mutex_init(&led->lock);
>> +    INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
>> +
>> +    platform_set_drvdata(pdev, led);
>> +
>> +    ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
>> +    if (ret) {
>> +        dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
>> +        mutex_destroy(&led->lock);
>> +        return ret;
>> +    }
>> +
>> +    ktd2692_setup(led);
>> +
>> +    return 0;
>> +}
>> +
>> +static int ktd2692_remove(struct platform_device *pdev)
>> +{
>> +    struct ktd2692_context *led = platform_get_drvdata(pdev);
>> +    int ret;
>> +
>> +    led_classdev_flash_unregister(&led->fled_cdev);
>> +    cancel_work_sync(&led->work_brightness_set);
>> +
>> +    if (led->regulator) {
>> +        ret = regulator_disable(led->regulator);
>> +        if (ret)
>> +            dev_err(&pdev->dev,
>> +                "Failed to disable supply: %d\n", ret);
>> +    }
>> +
>> +    mutex_destroy(&led->lock);
>> +
>> +    return 0;
>> +}
>> +
>> +static const struct of_device_id ktd2692_match[] = {
>> +    { .compatible = "kinetic,ktd2692", },
>> +    { /* sentinel */ },
>> +};
>> +
>> +static struct platform_driver ktd2692_driver = {
>> +    .driver = {
>> +        .name  = "ktd2692",
>> +        .of_match_table = ktd2692_match,
>> +    },
>> +    .probe  = ktd2692_probe,
>> +    .remove = ktd2692_remove,
>> +};
>> +
>> +module_platform_driver(ktd2692_driver);
>> +
>> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
>> +MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
>> +MODULE_LICENSE("GPL v2");
>>
> 
> 

Re: [PATCH v8 3/3] leds: Add ktd2692 flash LED driver

[Jacek Anaszewski]

There is one more thing - please rebase this patch on top
of linux-next as currently it conflicts with
drivers/leds/Makefile.

On 05/08/2015 05:03 AM, Ingi Kim wrote:
> This patch adds a driver to support the ktd2692 flash LEDs.
> ktd2692 can control flash current by ExpressWire interface.
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
> ---
>   drivers/leds/Kconfig        |   9 +
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-ktd2692.c | 443 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 453 insertions(+)
>   create mode 100644 drivers/leds/leds-ktd2692.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 51059bb..bfbdbd1 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -505,6 +505,15 @@ config LEDS_MENF21BMC
>   	  This driver can also be built as a module. If so the module
>   	  will be called leds-menf21bmc.
>
> +config LEDS_KTD2692
> +	tristate "KTD2692 LED flash support"
> +	depends on LEDS_CLASS_FLASH && GPIOLIB && OF
> +	help
> +	  This option enables support for KTD2692 LED flash connected
> +	  through ExpressWire interface.
> +
> +	  Say Y to enable this driver.
> +
>   comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
>
>   config LEDS_BLINKM
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index a739ae2..ed5ed79 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -59,6 +59,7 @@ obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
>   obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
>   obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
>   obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
> +obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
>
>   # LED SPI Drivers
>   obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
> diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
> new file mode 100644
> index 0000000..9d878a4
> --- /dev/null
> +++ b/drivers/leds/leds-ktd2692.c
> @@ -0,0 +1,443 @@
> +/*
> + * LED driver : leds-ktd2692.c
> + *
> + * Copyright (C) 2015 Samsung Electronics
> + * Ingi Kim <ingi2.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.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/led-class-flash.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/workqueue.h>
> +
> +/* Value related the movie mode */
> +#define KTD2692_MOVIE_MODE_CURRENT_LEVELS	16
> +#define KTD2692_MM_TO_FL_RATIO(x)		((x) / 3)
> +#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE	8
> +
> +/* Value related the flash mode */
> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS	8
> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE	0
> +#define KTD2692_FLASH_MODE_CURR_PERCENT(x)	(((x) * 16) / 100)
> +
> +/* Macro for getting offset of flash timeout */
> +#define GET_TIMEOUT_OFFSET(timeout, step)	((timeout) / (step))
> +
> +/* Base register address */
> +#define KTD2692_REG_LVP_BASE			0x00
> +#define KTD2692_REG_FLASH_TIMEOUT_BASE		0x20
> +#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE	0x40
> +#define KTD2692_REG_MOVIE_CURRENT_BASE		0x60
> +#define KTD2692_REG_FLASH_CURRENT_BASE		0x80
> +#define KTD2692_REG_MODE_BASE			0xA0
> +
> +/* Set bit coding time for expresswire interface */
> +#define KTD2692_TIME_RESET_US			700
> +#define KTD2692_TIME_DATA_START_TIME_US		10
> +#define KTD2692_TIME_HIGH_END_OF_DATA_US	350
> +#define KTD2692_TIME_LOW_END_OF_DATA_US		10
> +#define KTD2692_TIME_SHORT_BITSET_US		4
> +#define KTD2692_TIME_LONG_BITSET_US		12
> +
> +/* KTD2692 default length of name */
> +#define KTD2692_NAME_LENGTH			20
> +
> +enum ktd2692_bitset {
> +	KTD2692_LOW = 0,
> +	KTD2692_HIGH,
> +};
> +
> +/* Movie / Flash Mode Control */
> +enum ktd2692_led_mode {
> +	KTD2692_MODE_DISABLE = 0,	/* default */
> +	KTD2692_MODE_MOVIE,
> +	KTD2692_MODE_FLASH,
> +};
> +
> +struct ktd2692_led_config_data {
> +	/* maximum LED current in movie mode */
> +	u32 movie_max_microamp;
> +	/* maximum LED current in flash mode */
> +	u32 flash_max_microamp;
> +	/* maximum flash timeout */
> +	u32 flash_max_timeout;
> +	/* max LED brightness level */
> +	enum led_brightness max_brightness;
> +};
> +
> +struct ktd2692_context {
> +	/* Related LED Flash class device */
> +	struct led_classdev_flash fled_cdev;
> +
> +	/* secures access to the device */
> +	struct mutex lock;
> +	struct regulator *regulator;
> +	struct work_struct work_brightness_set;
> +
> +	struct gpio_desc *aux_gpio;
> +	struct gpio_desc *ctrl_gpio;
> +
> +	enum ktd2692_led_mode mode;
> +	enum led_brightness torch_brightness;
> +};
> +
> +static struct ktd2692_context *fled_cdev_to_led(
> +				struct led_classdev_flash *fled_cdev)
> +{
> +	return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
> +}
> +
> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +	udelay(KTD2692_TIME_DATA_START_TIME_US);
> +}
> +
> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_RESET_US);
> +}
> +
> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
> +{
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
> +	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +	udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
> +}
> +
> +static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
> +{
> +	/*
> +	 * The Low Bit(0) and High Bit(1) is based on a time detection
> +	 * algorithm between time low and time high
> +	 * Time_(L_LB) : Low time of the Low Bit(0)
> +	 * Time_(H_LB) : High time of the LOW Bit(0)
> +	 * Time_(L_HB) : Low time of the High Bit(1)
> +	 * Time_(H_HB) : High time of the High Bit(1)
> +	 *
> +	 * It can be simplified to:
> +	 * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
> +	 * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
> +	 * HIGH  ___           ____    _..     _________    ___
> +	 *          |_________|    |_..  |____|         |__|
> +	 * LOW        <L_LB>  <H_LB>     <L_HB>  <H_HB>
> +	 *          [  Low Bit (0) ]     [  High Bit(1) ]
> +	 */
> +	if (bit) {
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_SHORT_BITSET_US);
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +	} else {
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
> +		udelay(KTD2692_TIME_SHORT_BITSET_US);
> +	}
> +}
> +
> +static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
> +{
> +	int i;
> +
> +	ktd2692_expresswire_start(led);
> +	for (i = 7; i >= 0; i--)
> +		ktd2692_expresswire_set_bit(led, value & BIT(i));
> +	ktd2692_expresswire_end(led);
> +}
> +
> +static void ktd2692_brightness_set(struct ktd2692_context *led,
> +				   enum led_brightness brightness)
> +{
> +	mutex_lock(&led->lock);
> +
> +	if (brightness == LED_OFF) {
> +		led->mode = KTD2692_MODE_DISABLE;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +	} else {
> +		ktd2692_expresswire_write(led, brightness |
> +					KTD2692_REG_MOVIE_CURRENT_BASE);
> +		led->mode = KTD2692_MODE_MOVIE;
> +	}
> +
> +	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
> +	mutex_unlock(&led->lock);
> +}
> +
> +static void ktd2692_brightness_set_work(struct work_struct *work)
> +{
> +	struct ktd2692_context *led =
> +		container_of(work, struct ktd2692_context, work_brightness_set);
> +
> +	ktd2692_brightness_set(led, led->torch_brightness);
> +}
> +
> +static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
> +				       enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +
> +	led->torch_brightness = brightness;
> +	schedule_work(&led->work_brightness_set);
> +}
> +
> +static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
> +					   enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +
> +	ktd2692_brightness_set(led, brightness);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
> +					bool state)
> +{
> +	struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
> +	struct led_flash_setting *timeout = &fled_cdev->timeout;
> +	u32 flash_tm_reg;
> +
> +	mutex_lock(&led->lock);
> +
> +	if (state == 0) {
> +		led->mode = KTD2692_MODE_DISABLE;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +	} else {
> +		flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
> +		ktd2692_expresswire_write(led, flash_tm_reg
> +				| KTD2692_REG_FLASH_TIMEOUT_BASE);
> +
> +		led->mode = KTD2692_MODE_FLASH;
> +		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
> +	}
> +
> +	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
> +
> +	fled_cdev->led_cdev.brightness = LED_OFF;
> +	led->mode = KTD2692_MODE_DISABLE;
> +
> +	mutex_unlock(&led->lock);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
> +					 u32 timeout)
> +{
> +	return 0;
> +}
> +
> +static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
> +{
> +	u32 offset, step;
> +	u32 movie_current_microamp;
> +
> +	offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
> +	step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
> +		/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;
> +
> +	do {
> +		movie_current_microamp = step * offset;
> +		offset--;
> +	} while ((movie_current_microamp > cfg->movie_max_microamp) &&
> +		(offset > 0));
> +
> +	cfg->max_brightness = offset;
> +}
> +
> +static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
> +				       struct ktd2692_led_config_data *cfg)
> +{
> +	struct led_flash_setting *setting;
> +
> +	setting = &fled_cdev->timeout;
> +	setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
> +	setting->max = cfg->flash_max_timeout;
> +	setting->step = cfg->flash_max_timeout
> +			/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
> +	setting->val = cfg->flash_max_timeout;
> +}
> +
> +static void ktd2692_setup(struct ktd2692_context *led)
> +{
> +	led->mode = KTD2692_MODE_DISABLE;
> +	ktd2692_expresswire_reset(led);
> +	gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +
> +	ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
> +				 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
> +	ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
> +				 | KTD2692_REG_FLASH_CURRENT_BASE);
> +}
> +
> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
> +			    struct ktd2692_led_config_data *cfg)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct device_node *child_node;
> +	int ret;
> +
> +	if (!dev->of_node)
> +		return -ENXIO;
> +
> +	led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
> +	if (IS_ERR(led->ctrl_gpio)) {
> +		ret = PTR_ERR(led->ctrl_gpio);
> +		dev_err(dev, "cannot get ctrl-gpio %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->aux_gpio = devm_gpiod_get(dev, "aux");
> +	if (IS_ERR(led->aux_gpio)) {
> +		ret = PTR_ERR(led->aux_gpio);
> +		dev_err(dev, "cannot get aux-gpio %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->regulator = devm_regulator_get(dev, "vin");
> +	if (IS_ERR(led->regulator))
> +		led->regulator = NULL;
> +
> +	if (led->regulator) {
> +		ret = regulator_enable(led->regulator);
> +		if (ret)
> +			dev_err(dev, "Failed to enable supply: %d\n", ret);
> +	}
> +
> +	child_node = of_get_next_available_child(np, NULL);
> +	if (!child_node) {
> +		dev_err(dev, "No DT child node found for connected LED.\n");
> +		return -EINVAL;
> +	}
> +
> +	led->fled_cdev.led_cdev.name =
> +		of_get_property(child_node, "label", NULL) ? : child_node->name;
> +
> +	ret = of_property_read_u32(child_node, "led-max-microamp",
> +				   &cfg->movie_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse led-max-microamp\n");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(child_node, "flash-max-microamp",
> +				   &cfg->flash_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse flash-max-microamp\n");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(child_node, "flash-max-timeout-us",
> +				   &cfg->flash_max_timeout);
> +	if (ret)
> +		dev_err(dev, "failed to parse flash-max-timeout-us\n");
> +
> +	of_node_put(child_node);
> +	return ret;
> +}
> +
> +static const struct led_flash_ops flash_ops = {
> +	.strobe_set = ktd2692_led_flash_strobe_set,
> +	.timeout_set = ktd2692_led_flash_timeout_set,
> +};
> +
> +static int ktd2692_probe(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led;
> +	struct led_classdev *led_cdev;
> +	struct led_classdev_flash *fled_cdev;
> +	struct ktd2692_led_config_data led_cfg;
> +	int ret;
> +
> +	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	fled_cdev = &led->fled_cdev;
> +	led_cdev = &fled_cdev->led_cdev;
> +
> +	ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
> +	if (ret)
> +		return ret;
> +
> +	ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
> +	ktd2692_init_movie_current_max(&led_cfg);
> +
> +	fled_cdev->ops = &flash_ops;
> +
> +	led_cdev->max_brightness = led_cfg.max_brightness;
> +	led_cdev->brightness_set = ktd2692_led_brightness_set;
> +	led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
> +	led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
> +
> +	mutex_init(&led->lock);
> +	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
> +
> +	platform_set_drvdata(pdev, led);
> +
> +	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
> +		mutex_destroy(&led->lock);
> +		return ret;
> +	}
> +
> +	ktd2692_setup(led);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_remove(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led = platform_get_drvdata(pdev);
> +	int ret;
> +
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +	cancel_work_sync(&led->work_brightness_set);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&pdev->dev,
> +				"Failed to disable supply: %d\n", ret);
> +	}
> +
> +	mutex_destroy(&led->lock);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ktd2692_match[] = {
> +	{ .compatible = "kinetic,ktd2692", },
> +	{ /* sentinel */ },
> +};
> +
> +static struct platform_driver ktd2692_driver = {
> +	.driver = {
> +		.name  = "ktd2692",
> +		.of_match_table = ktd2692_match,
> +	},
> +	.probe  = ktd2692_probe,
> +	.remove = ktd2692_remove,
> +};
> +
> +module_platform_driver(ktd2692_driver);
> +
> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
> +MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
> +MODULE_LICENSE("GPL v2");
>


-- 
Best Regards,
Jacek Anaszewski