[PATCH v3 0/3] Add ktd2692 Flash LED driver using LED Flash class

[PATCH v3 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 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      |  34 ++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 drivers/leds/Kconfig                               |   9 +
 drivers/leds/Makefile                              |   1 +
 drivers/leds/leds-ktd2692.c                        | 438 +++++++++++++++++++++
 5 files changed, 483 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
 create mode 100644 drivers/leds/leds-ktd2692.c

-- 
2.0.5

[PATCH v3 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>
---
 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

Re: [PATCH v3 1/3] of: Add vendor prefix for Kinetic technologies

[Rob Herring]

On Fri, Mar 20, 2015 at 12:31 AM, Ingi Kim <ingi2.kim@samsung.com> wrote:
> This patch adds vendor prefix for Kinetic technologies
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>

Acked-by: Rob Herring <robh@kernel.org>

> ---
>  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
>

Re: [PATCH v3 1/3] of: Add vendor prefix for Kinetic technologies

[Ingi Kim]

Hi Rob,

On 2015년 03월 21일 00:46, Rob Herring wrote:
> On Fri, Mar 20, 2015 at 12:31 AM, Ingi Kim <ingi2.kim@samsung.com> wrote:
>> This patch adds vendor prefix for Kinetic technologies
>>
>> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> 
> Acked-by: Rob Herring <robh@kernel.org>
> 

Sure, I'll fix
Thanks

>> ---
>>  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 v3 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 'flash-timeout-us' to control flash timeout
and 'vin-supply' for flash-led regulator

Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
---
 .../devicetree/bindings/leds/leds-ktd2692.txt      | 34 ++++++++++++++++++++++
 1 file changed, 34 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..75e16f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
@@ -0,0 +1,34 @@
+* 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, aux-gpio : gpio pin in order control ktd2692 flash led.
+		There is an internal 300kOhm pull-down resistor at each pin
+	- supply : "vin" LED supply (2.7V to 5.5V)
+		See Documentation/devicetree/bindings/regulator/regulator.txt
+
+Optional property:
+	- flash-timeout-us : Maximum flash timeout in microseconds.
+			flash timeout ranges from 0 to 1835000us and
+			default is 1049000us.
+
+Example:
+
+flash-led {
+	compatible = "kinetic,ktd2692";
+	ctrl-gpio = <&gpc0 1 0>;
+	aux-gpio = <&gpc0 2 0>;
+	flash-timeout-us = <1835000>;
+	vin-supply = <&vbat>;
+};
+
-- 
2.0.5

Re: [PATCH v3 2/3] leds: ktd2692: add device tree bindings for ktd2692

[Rob Herring]

On Fri, Mar 20, 2015 at 12:31 AM, Ingi Kim <ingi2.kim@samsung.com> wrote:
> This patch adds the device tree bindings for ktd2692 flash LEDs.
> Add optional properties 'flash-timeout-us' to control flash timeout
> and 'vin-supply' for flash-led regulator
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> ---
>  .../devicetree/bindings/leds/leds-ktd2692.txt      | 34 ++++++++++++++++++++++
>  1 file changed, 34 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..75e16f8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
> @@ -0,0 +1,34 @@
> +* 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, aux-gpio : gpio pin in order control ktd2692 flash led.
> +               There is an internal 300kOhm pull-down resistor at each pin
> +       - supply : "vin" LED supply (2.7V to 5.5V)

This should be "vin-supply", right?

> +               See Documentation/devicetree/bindings/regulator/regulator.txt
> +
> +Optional property:
> +       - flash-timeout-us : Maximum flash timeout in microseconds.
> +                       flash timeout ranges from 0 to 1835000us and
> +                       default is 1049000us.
> +
> +Example:
> +
> +flash-led {
> +       compatible = "kinetic,ktd2692";
> +       ctrl-gpio = <&gpc0 1 0>;
> +       aux-gpio = <&gpc0 2 0>;
> +       flash-timeout-us = <1835000>;
> +       vin-supply = <&vbat>;
> +};
> +
> --
> 2.0.5
>

Re: [PATCH v3 2/3] leds: ktd2692: add device tree bindings for ktd2692

[Ingi Kim]

Hi, Rob

On 2015년 03월 21일 00:49, Rob Herring wrote:
> On Fri, Mar 20, 2015 at 12:31 AM, Ingi Kim <ingi2.kim@samsung.com> wrote:
>> This patch adds the device tree bindings for ktd2692 flash LEDs.
>> Add optional properties 'flash-timeout-us' to control flash timeout
>> and 'vin-supply' for flash-led regulator
>>
>> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
>> ---
>>  .../devicetree/bindings/leds/leds-ktd2692.txt      | 34 ++++++++++++++++++++++
>>  1 file changed, 34 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..75e16f8
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>> @@ -0,0 +1,34 @@
>> +* 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, aux-gpio : gpio pin in order control ktd2692 flash led.
>> +               There is an internal 300kOhm pull-down resistor at each pin
>> +       - supply : "vin" LED supply (2.7V to 5.5V)
> 
> This should be "vin-supply", right?
> 

Yes, You are right.
"vin-supply" is more exact than before.
I'll fix it

Thanks


>> +               See Documentation/devicetree/bindings/regulator/regulator.txt
>> +
>> +Optional property:
>> +       - flash-timeout-us : Maximum flash timeout in microseconds.
>> +                       flash timeout ranges from 0 to 1835000us and
>> +                       default is 1049000us.
>> +
>> +Example:
>> +
>> +flash-led {
>> +       compatible = "kinetic,ktd2692";
>> +       ctrl-gpio = <&gpc0 1 0>;
>> +       aux-gpio = <&gpc0 2 0>;
>> +       flash-timeout-us = <1835000>;
>> +       vin-supply = <&vbat>;
>> +};
>> +
>> --
>> 2.0.5
>>
> 

[PATCH v3 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>
---
 drivers/leds/Kconfig        |   9 +
 drivers/leds/Makefile       |   1 +
 drivers/leds/leds-ktd2692.c | 438 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 448 insertions(+)
 create mode 100644 drivers/leds/leds-ktd2692.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 25b320d..9311cfc4 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -498,6 +498,15 @@ 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 "Flash LED support for the KTD2692 Driver"
+	depends on LEDS_CLASS_FLASH && GPIOLIB
+	help
+	  This option enables support for the KTD2692 connected through
+	  ExpressWire Interface. Say Y to enabled these.
+	  It depends on LEDS_CLASS_FLASH for using flash led (strobe) and
+	  GPIOLIB for using gpio pin to control Expresswire interface
+
 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 cbba921..289513b 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -58,6 +58,7 @@ 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..38d6145
--- /dev/null
+++ b/drivers/leds/leds-ktd2692.c
@@ -0,0 +1,438 @@
+/*
+ * 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/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/workqueue.h>
+
+#define GET_BIT(bit, val)			(((val) >> (bit)) & 0x01)
+
+/* Value related the flash mode */
+#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS	8
+#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE	0
+#define KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US	1049000
+#define KTD2692_FLASH_MODE_TIMEOUT_MAX_US	1835000
+#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))
+
+/* Adjust a multiple of brightness */
+#define KTD2692_BRIGHTNESS_RANGE_255_TO_16(x)	(((x) >> 4) & 0x0F)
+#define KTD2692_BRIGHTNESS_RANGE_255_TO_8(x)	(((x) >> 5) & 0x0F)
+#define KTD2692_BRIGHTNESS_RANGE_255_TO_4(x)	(((x) >> 6) & 0x0F)
+
+/* Base register address */
+#define KTD2692_REG_LVP_BASE			0x00
+#define KTD2692_REG_FLASH_TIMEOUT_BASE		0x20
+#define KTD2692_REG_MIN_CURRENT_SET_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
+
+/* KTD2692 default name */
+#define KTD2692_DEFAULT_NAME			"ktd2692"
+
+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_flash_timeout_setting {
+	struct led_flash_setting flash_timeout;
+};
+
+struct ktd2692_context {
+	/* Related LED Flash class device */
+	struct led_classdev_flash fled_cdev;
+
+	struct mutex lock;
+	struct regulator *regulator;
+	struct work_struct work_brightness_set;
+
+	int aux_gpio;
+	int 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 int ktd2692_led_regulator_enable(struct ktd2692_context *led)
+{
+	struct led_classdev_flash *fled_cdev = &led->fled_cdev;
+	struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+	int ret;
+
+	if (regulator_is_enabled(led->regulator) > 0)
+		return 0;
+
+	ret = regulator_enable(led->regulator);
+	if (ret)
+		dev_err(led_cdev->dev, "Failed to enable vin:%d\n", ret);
+
+	return ret;
+}
+
+static void ktd2692_led_regulator_disable(struct ktd2692_context *led)
+{
+	struct led_classdev_flash *fled_cdev = &led->fled_cdev;
+	struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+	int ret;
+
+	if (!regulator_is_enabled(led->regulator))
+		return;
+
+	ret = regulator_disable(led->regulator);
+	if (ret)
+		dev_err(led_cdev->dev, "Failed to disable vin:%d\n", ret);
+}
+
+static void ktd2692_expresswire_start(struct ktd2692_context *led)
+{
+	gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
+	udelay(KTD2692_TIME_DATA_START_TIME_US);
+}
+
+static void ktd2692_expresswire_reset(struct ktd2692_context *led)
+{
+	gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
+	udelay(KTD2692_TIME_RESET_US);
+}
+
+static void ktd2692_expresswire_end(struct ktd2692_context *led)
+{
+	gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
+	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
+	gpio_set_value(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)
+{
+	if (bit) {
+		gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
+		udelay(KTD2692_TIME_SHORT_BITSET_US);
+		gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
+		udelay(KTD2692_TIME_LONG_BITSET_US);
+	} else {
+		gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
+		udelay(KTD2692_TIME_LONG_BITSET_US);
+		gpio_set_value(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, GET_BIT(i, value));
+	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;
+		gpio_set_value(led->aux_gpio, KTD2692_LOW);
+		goto out;
+	}
+
+	if (brightness < LED_OFF) {
+		dev_err(led->fled_cdev.led_cdev.dev,
+			"Invalid brightness %d\n", brightness);
+		goto unlock;
+	}
+
+	ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
+				KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
+	led->mode = KTD2692_MODE_MOVIE;
+
+out:
+	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
+unlock:
+	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;
+		gpio_set_value(led->aux_gpio, KTD2692_LOW);
+		goto done;
+	}
+
+	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;
+	gpio_set_value(led->aux_gpio, KTD2692_HIGH);
+
+done:
+	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_flash_timeout_set(u32 flash_timeout_us,
+					struct ktd2692_flash_timeout_setting *s)
+{
+	struct led_flash_setting *setting;
+
+	setting = &s->flash_timeout;
+	setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
+	setting->max = KTD2692_FLASH_MODE_TIMEOUT_MAX_US;
+	setting->step = KTD2692_FLASH_MODE_TIMEOUT_MAX_US
+			/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
+	setting->val = flash_timeout_us;
+}
+
+static void ktd2692_init_flash_register_set(struct ktd2692_context *led)
+{
+	led->mode = KTD2692_MODE_DISABLE;
+	ktd2692_expresswire_reset(led);
+	gpio_set_value(led->aux_gpio, KTD2692_LOW);
+
+	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,
+				u32 *flash_timeout_us)
+{
+	struct device_node *np = dev->of_node;
+
+	int ret;
+
+	led->ctrl_gpio = of_get_named_gpio(np, "ctrl-gpio", 0);
+	if (!gpio_is_valid(led->ctrl_gpio)) {
+		dev_err(dev, "no ctrl-gpio property found\n");
+		return -EINVAL;
+	}
+
+	led->aux_gpio = of_get_named_gpio(np, "aux-gpio", 0);
+	if (!gpio_is_valid(led->aux_gpio)) {
+		dev_err(dev, "no aux-gpio property found\n");
+		return -EINVAL;
+	}
+
+	ret = devm_gpio_request_one(dev, led->ctrl_gpio,
+					GPIOF_OPEN_SOURCE, "ctrl-gpio");
+	if (ret) {
+		dev_err(dev, "failed to request ctrl-gpio %d error %d\n",
+				led->ctrl_gpio, ret);
+		return ret;
+	}
+
+	ret = devm_gpio_request_one(dev, led->aux_gpio,
+					GPIOF_OPEN_SOURCE, "aux-gpio");
+	if (ret) {
+		dev_err(dev, "failed to request aux-gpio %d error %d\n",
+				led->aux_gpio, ret);
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "flash-timeout-us", flash_timeout_us);
+	/* default setting */
+	if (ret)
+		*flash_timeout_us = KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US;
+
+	return 0;
+}
+
+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_flash_timeout_setting timeout_setting;
+	u32 flash_timeout_us;
+	int ret;
+
+	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	if (!pdev->dev.of_node)
+		return -ENXIO;
+
+	fled_cdev = &led->fled_cdev;
+	led_cdev = &fled_cdev->led_cdev;
+	platform_set_drvdata(pdev, led);
+
+	ret = ktd2692_parse_dt(led, &pdev->dev, &flash_timeout_us);
+	if (ret)
+		return ret;
+
+	led->regulator = devm_regulator_get(&pdev->dev, "vin");
+	if (IS_ERR(led->regulator)) {
+		dev_err(&pdev->dev, "regulator get failed\n");
+		ret = PTR_ERR(led->regulator);
+		led->regulator = NULL;
+		return ret;
+	}
+
+	ret = ktd2692_led_regulator_enable(led);
+	if (ret)
+		goto err_regulator;
+
+	ktd2692_init_flash_timeout_set(flash_timeout_us, &timeout_setting);
+
+	fled_cdev->timeout = timeout_setting.flash_timeout;
+	fled_cdev->ops = &flash_ops;
+
+	led_cdev->name = KTD2692_DEFAULT_NAME;
+	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_cdev->flags |= LED_DEV_CAP_FLASH;
+
+	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
+
+	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
+	if (ret) {
+		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
+		goto err_register;
+	}
+
+	ktd2692_init_flash_register_set(led);
+
+	mutex_init(&led->lock);
+
+	return 0;
+err_register:
+	cancel_work_sync(&led->work_brightness_set);
+err_regulator:
+	ktd2692_led_regulator_disable(led);
+	platform_set_drvdata(pdev, NULL);
+	return ret;
+}
+
+static int ktd2692_remove(struct platform_device *pdev)
+{
+	struct ktd2692_context *led = platform_get_drvdata(pdev);
+
+	cancel_work_sync(&led->work_brightness_set);
+	led_classdev_flash_unregister(&led->fled_cdev);
+	ktd2692_led_regulator_disable(led);
+
+	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  = "leds-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 v3 3/3] leds: Add ktd2692 flash LED driver

[Jacek Anaszewski]

Hi Ingi,

Thanks for the update.

On 03/20/2015 06:31 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>
> ---
>   drivers/leds/Kconfig        |   9 +
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-ktd2692.c | 438 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 448 insertions(+)
>   create mode 100644 drivers/leds/leds-ktd2692.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 25b320d..9311cfc4 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -498,6 +498,15 @@ 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 "Flash LED support for the KTD2692 Driver"
> +	depends on LEDS_CLASS_FLASH && GPIOLIB
> +	help
> +	  This option enables support for the KTD2692 connected through
> +	  ExpressWire Interface. Say Y to enabled these.
> +	  It depends on LEDS_CLASS_FLASH for using flash led (strobe) and
> +	  GPIOLIB for using gpio pin to control Expresswire interface
> +
>   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 cbba921..289513b 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -58,6 +58,7 @@ 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..38d6145
> --- /dev/null
> +++ b/drivers/leds/leds-ktd2692.c
> @@ -0,0 +1,438 @@
> +/*
> + * 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/led-class-flash.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/workqueue.h>
> +
> +#define GET_BIT(bit, val)			(((val) >> (bit)) & 0x01)
> +
> +/* Value related the flash mode */
> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS	8
> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE	0
> +#define KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US	1049000
> +#define KTD2692_FLASH_MODE_TIMEOUT_MAX_US	1835000
> +#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))
> +
> +/* Adjust a multiple of brightness */
> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_16(x)	(((x) >> 4) & 0x0F)
> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_8(x)	(((x) >> 5) & 0x0F)
> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_4(x)	(((x) >> 6) & 0x0F)
> +
> +/* Base register address */
> +#define KTD2692_REG_LVP_BASE			0x00
> +#define KTD2692_REG_FLASH_TIMEOUT_BASE		0x20
> +#define KTD2692_REG_MIN_CURRENT_SET_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
> +
> +/* KTD2692 default name */
> +#define KTD2692_DEFAULT_NAME			"ktd2692"
> +
> +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_flash_timeout_setting {
> +	struct led_flash_setting flash_timeout;
> +};

You don't need to nest these structures like that.
You probably followed previous version of the leds-aat1290 driver
patch from my LED/flash API integration patch set, but the parent
structure was named aat1290_led_settings and was intended for gathering
two settings (torch setting was added in the patch adding support
for V4L2 Flash API).


> +struct ktd2692_context {
> +	/* Related LED Flash class device */
> +	struct led_classdev_flash fled_cdev;
> +
> +	struct mutex lock;
> +	struct regulator *regulator;
> +	struct work_struct work_brightness_set;
> +
> +	int aux_gpio;
> +	int 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 int ktd2692_led_regulator_enable(struct ktd2692_context *led)
> +{
> +	struct led_classdev_flash *fled_cdev = &led->fled_cdev;
> +	struct led_classdev *led_cdev = &fled_cdev->led_cdev;
> +	int ret;
> +
> +	if (regulator_is_enabled(led->regulator) > 0)
> +		return 0;
> +
> +	ret = regulator_enable(led->regulator);
> +	if (ret)
> +		dev_err(led_cdev->dev, "Failed to enable vin:%d\n", ret);
> +
> +	return ret;
> +}
> +
> +static void ktd2692_led_regulator_disable(struct ktd2692_context *led)
> +{
> +	struct led_classdev_flash *fled_cdev = &led->fled_cdev;
> +	struct led_classdev *led_cdev = &fled_cdev->led_cdev;
> +	int ret;
> +
> +	if (!regulator_is_enabled(led->regulator))
> +		return;
> +
> +	ret = regulator_disable(led->regulator);
> +	if (ret)
> +		dev_err(led_cdev->dev, "Failed to disable vin:%d\n", ret);
> +}
> +
> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
> +{
> +	gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
> +	udelay(KTD2692_TIME_DATA_START_TIME_US);
> +}
> +
> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
> +{
> +	gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_RESET_US);
> +}
> +
> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
> +{
> +	gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
> +	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
> +	gpio_set_value(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)
> +{
> +	if (bit) {
> +		gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_SHORT_BITSET_US);
> +		gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +	} else {
> +		gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
> +		udelay(KTD2692_TIME_LONG_BITSET_US);
> +		gpio_set_value(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, GET_BIT(i, value));
> +	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;
> +		gpio_set_value(led->aux_gpio, KTD2692_LOW);
> +		goto out;
> +	}
> +
> +	if (brightness < LED_OFF) {
> +		dev_err(led->fled_cdev.led_cdev.dev,
> +			"Invalid brightness %d\n", brightness);
> +		goto unlock;
> +	}

You don't need to do this. It is not possible to get value less than
0 from brightness_store callback.

> +	ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
> +				KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
> +	led->mode = KTD2692_MODE_MOVIE;
> +
> +out:
> +	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
> +unlock:
> +	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;
> +		gpio_set_value(led->aux_gpio, KTD2692_LOW);
> +		goto done;
> +	}
> +
> +	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;
> +	gpio_set_value(led->aux_gpio, KTD2692_HIGH);
> +
> +done:
> +	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_flash_timeout_set(u32 flash_timeout_us,
> +					struct ktd2692_flash_timeout_setting *s)
> +{
> +	struct led_flash_setting *setting;
> +
> +	setting = &s->flash_timeout;
> +	setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
> +	setting->max = KTD2692_FLASH_MODE_TIMEOUT_MAX_US;
> +	setting->step = KTD2692_FLASH_MODE_TIMEOUT_MAX_US
> +			/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
> +	setting->val = flash_timeout_us;
> +}

Please skip the '_set' postfix from the function name and pass directly 
a pointer to struct led_flash_setting.

We can change it to something more generic when more settings will
need initialization to pass them to v4l2 Flash sub-device.

> +static void ktd2692_init_flash_register_set(struct ktd2692_context *led)
> +{
> +	led->mode = KTD2692_MODE_DISABLE;
> +	ktd2692_expresswire_reset(led);
> +	gpio_set_value(led->aux_gpio, KTD2692_LOW);
> +
> +	ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
> +					 | KTD2692_REG_FLASH_CURRENT_BASE);
> +}

I'd call this function ktd2692_setup().

> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
> +				u32 *flash_timeout_us)
> +{
> +	struct device_node *np = dev->of_node;
> +
> +	int ret;
> +
> +	led->ctrl_gpio = of_get_named_gpio(np, "ctrl-gpio", 0);
> +	if (!gpio_is_valid(led->ctrl_gpio)) {
> +		dev_err(dev, "no ctrl-gpio property found\n");
> +		return -EINVAL;
> +	}
> +
> +	led->aux_gpio = of_get_named_gpio(np, "aux-gpio", 0);
> +	if (!gpio_is_valid(led->aux_gpio)) {
> +		dev_err(dev, "no aux-gpio property found\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = devm_gpio_request_one(dev, led->ctrl_gpio,
> +					GPIOF_OPEN_SOURCE, "ctrl-gpio");
> +	if (ret) {
> +		dev_err(dev, "failed to request ctrl-gpio %d error %d\n",
> +				led->ctrl_gpio, ret);
> +		return ret;
> +	}
> +
> +	ret = devm_gpio_request_one(dev, led->aux_gpio,
> +					GPIOF_OPEN_SOURCE, "aux-gpio");
> +	if (ret) {
> +		dev_err(dev, "failed to request aux-gpio %d error %d\n",
> +				led->aux_gpio, ret);
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(np, "flash-timeout-us", flash_timeout_us);
> +	/* default setting */
> +	if (ret)
> +		*flash_timeout_us = KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US;
> +
> +	return 0;
> +}
> +
> +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_flash_timeout_setting timeout_setting;
> +	u32 flash_timeout_us;
> +	int ret;
> +
> +	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	if (!pdev->dev.of_node)
> +		return -ENXIO;
> +
> +	fled_cdev = &led->fled_cdev;
> +	led_cdev = &fled_cdev->led_cdev;
> +	platform_set_drvdata(pdev, led);
> +
> +	ret = ktd2692_parse_dt(led, &pdev->dev, &flash_timeout_us);
> +	if (ret)
> +		return ret;
> +
> +	led->regulator = devm_regulator_get(&pdev->dev, "vin");
> +	if (IS_ERR(led->regulator)) {
> +		dev_err(&pdev->dev, "regulator get failed\n");
> +		ret = PTR_ERR(led->regulator);
> +		led->regulator = NULL;
> +		return ret;
> +	}
> +
> +	ret = ktd2692_led_regulator_enable(led);
> +	if (ret)
> +		goto err_regulator;
> +
> +	ktd2692_init_flash_timeout_set(flash_timeout_us, &timeout_setting);
> +
> +	fled_cdev->timeout = timeout_setting.flash_timeout;
> +	fled_cdev->ops = &flash_ops;
> +
> +	led_cdev->name = KTD2692_DEFAULT_NAME;
> +	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_cdev->flags |= LED_DEV_CAP_FLASH;
> +
> +	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
> +
> +	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
> +		goto err_register;
> +	}
> +
> +	ktd2692_init_flash_register_set(led);
> +
> +	mutex_init(&led->lock);
> +
> +	return 0;
> +err_register:
> +	cancel_work_sync(&led->work_brightness_set);
> +err_regulator:
> +	ktd2692_led_regulator_disable(led);
> +	platform_set_drvdata(pdev, NULL);
> +	return ret;
> +}
> +
> +static int ktd2692_remove(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led = platform_get_drvdata(pdev);
> +
> +	cancel_work_sync(&led->work_brightness_set);
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +	ktd2692_led_regulator_disable(led);
> +
> +	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  = "leds-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 v3 3/3] leds: Add ktd2692 flash LED driver

[Ingi Kim]

Hi Jacek,

On 2015년 03월 21일 01:26, Jacek Anaszewski wrote:
> Hi Ingi,
> 
> Thanks for the update.
> 
> On 03/20/2015 06:31 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>
>> ---
>>   drivers/leds/Kconfig        |   9 +
>>   drivers/leds/Makefile       |   1 +
>>   drivers/leds/leds-ktd2692.c | 438 ++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 448 insertions(+)
>>   create mode 100644 drivers/leds/leds-ktd2692.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 25b320d..9311cfc4 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -498,6 +498,15 @@ 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 "Flash LED support for the KTD2692 Driver"
>> +    depends on LEDS_CLASS_FLASH && GPIOLIB
>> +    help
>> +      This option enables support for the KTD2692 connected through
>> +      ExpressWire Interface. Say Y to enabled these.
>> +      It depends on LEDS_CLASS_FLASH for using flash led (strobe) and
>> +      GPIOLIB for using gpio pin to control Expresswire interface
>> +
>>   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 cbba921..289513b 100644
>> --- a/drivers/leds/Makefile
>> +++ b/drivers/leds/Makefile
>> @@ -58,6 +58,7 @@ 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..38d6145
>> --- /dev/null
>> +++ b/drivers/leds/leds-ktd2692.c
>> @@ -0,0 +1,438 @@
>> +/*
>> + * 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/led-class-flash.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/workqueue.h>
>> +
>> +#define GET_BIT(bit, val)            (((val) >> (bit)) & 0x01)
>> +
>> +/* Value related the flash mode */
>> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS    8
>> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE    0
>> +#define KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US    1049000
>> +#define KTD2692_FLASH_MODE_TIMEOUT_MAX_US    1835000
>> +#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))
>> +
>> +/* Adjust a multiple of brightness */
>> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_16(x)    (((x) >> 4) & 0x0F)
>> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_8(x)    (((x) >> 5) & 0x0F)
>> +#define KTD2692_BRIGHTNESS_RANGE_255_TO_4(x)    (((x) >> 6) & 0x0F)
>> +
>> +/* Base register address */
>> +#define KTD2692_REG_LVP_BASE            0x00
>> +#define KTD2692_REG_FLASH_TIMEOUT_BASE        0x20
>> +#define KTD2692_REG_MIN_CURRENT_SET_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
>> +
>> +/* KTD2692 default name */
>> +#define KTD2692_DEFAULT_NAME            "ktd2692"
>> +
>> +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_flash_timeout_setting {
>> +    struct led_flash_setting flash_timeout;
>> +};
> 
> You don't need to nest these structures like that.
> You probably followed previous version of the leds-aat1290 driver
> patch from my LED/flash API integration patch set, but the parent
> structure was named aat1290_led_settings and was intended for gathering
> two settings (torch setting was added in the patch adding support
> for V4L2 Flash API).
> 
> 

Oh, I see,
I've wondered why this structure should nest led_flash_setting structure.
I'll fix.

Thanks

>> +struct ktd2692_context {
>> +    /* Related LED Flash class device */
>> +    struct led_classdev_flash fled_cdev;
>> +
>> +    struct mutex lock;
>> +    struct regulator *regulator;
>> +    struct work_struct work_brightness_set;
>> +
>> +    int aux_gpio;
>> +    int 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 int ktd2692_led_regulator_enable(struct ktd2692_context *led)
>> +{
>> +    struct led_classdev_flash *fled_cdev = &led->fled_cdev;
>> +    struct led_classdev *led_cdev = &fled_cdev->led_cdev;
>> +    int ret;
>> +
>> +    if (regulator_is_enabled(led->regulator) > 0)
>> +        return 0;
>> +
>> +    ret = regulator_enable(led->regulator);
>> +    if (ret)
>> +        dev_err(led_cdev->dev, "Failed to enable vin:%d\n", ret);
>> +
>> +    return ret;
>> +}
>> +
>> +static void ktd2692_led_regulator_disable(struct ktd2692_context *led)
>> +{
>> +    struct led_classdev_flash *fled_cdev = &led->fled_cdev;
>> +    struct led_classdev *led_cdev = &fled_cdev->led_cdev;
>> +    int ret;
>> +
>> +    if (!regulator_is_enabled(led->regulator))
>> +        return;
>> +
>> +    ret = regulator_disable(led->regulator);
>> +    if (ret)
>> +        dev_err(led_cdev->dev, "Failed to disable vin:%d\n", ret);
>> +}
>> +
>> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
>> +{
>> +    gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
>> +    udelay(KTD2692_TIME_DATA_START_TIME_US);
>> +}
>> +
>> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
>> +{
>> +    gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
>> +    udelay(KTD2692_TIME_RESET_US);
>> +}
>> +
>> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
>> +{
>> +    gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
>> +    udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
>> +    gpio_set_value(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)
>> +{
>> +    if (bit) {
>> +        gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
>> +        udelay(KTD2692_TIME_SHORT_BITSET_US);
>> +        gpio_set_value(led->ctrl_gpio, KTD2692_HIGH);
>> +        udelay(KTD2692_TIME_LONG_BITSET_US);
>> +    } else {
>> +        gpio_set_value(led->ctrl_gpio, KTD2692_LOW);
>> +        udelay(KTD2692_TIME_LONG_BITSET_US);
>> +        gpio_set_value(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, GET_BIT(i, value));
>> +    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;
>> +        gpio_set_value(led->aux_gpio, KTD2692_LOW);
>> +        goto out;
>> +    }
>> +
>> +    if (brightness < LED_OFF) {
>> +        dev_err(led->fled_cdev.led_cdev.dev,
>> +            "Invalid brightness %d\n", brightness);
>> +        goto unlock;
>> +    }
> 
> You don't need to do this. It is not possible to get value less than
> 0 from brightness_store callback.
> 

Thanks, Check it

>> +    ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
>> +                KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
>> +    led->mode = KTD2692_MODE_MOVIE;
>> +
>> +out:
>> +    ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
>> +unlock:
>> +    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;
>> +        gpio_set_value(led->aux_gpio, KTD2692_LOW);
>> +        goto done;
>> +    }
>> +
>> +    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;
>> +    gpio_set_value(led->aux_gpio, KTD2692_HIGH);
>> +
>> +done:
>> +    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_flash_timeout_set(u32 flash_timeout_us,
>> +                    struct ktd2692_flash_timeout_setting *s)
>> +{
>> +    struct led_flash_setting *setting;
>> +
>> +    setting = &s->flash_timeout;
>> +    setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
>> +    setting->max = KTD2692_FLASH_MODE_TIMEOUT_MAX_US;
>> +    setting->step = KTD2692_FLASH_MODE_TIMEOUT_MAX_US
>> +            / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
>> +    setting->val = flash_timeout_us;
>> +}
> 
> Please skip the '_set' postfix from the function name and pass directly a pointer to struct led_flash_setting.
> 
> We can change it to something more generic when more settings will
> need initialization to pass them to v4l2 Flash sub-device.
> 

Thanks, Check it.

>> +static void ktd2692_init_flash_register_set(struct ktd2692_context *led)
>> +{
>> +    led->mode = KTD2692_MODE_DISABLE;
>> +    ktd2692_expresswire_reset(led);
>> +    gpio_set_value(led->aux_gpio, KTD2692_LOW);
>> +
>> +    ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
>> +                     | KTD2692_REG_FLASH_CURRENT_BASE);
>> +}
> 
> I'd call this function ktd2692_setup().
> 

Suitable name, Thanks!

>> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
>> +                u32 *flash_timeout_us)
>> +{
>> +    struct device_node *np = dev->of_node;
>> +
>> +    int ret;
>> +
>> +    led->ctrl_gpio = of_get_named_gpio(np, "ctrl-gpio", 0);
>> +    if (!gpio_is_valid(led->ctrl_gpio)) {
>> +        dev_err(dev, "no ctrl-gpio property found\n");
>> +        return -EINVAL;
>> +    }
>> +
>> +    led->aux_gpio = of_get_named_gpio(np, "aux-gpio", 0);
>> +    if (!gpio_is_valid(led->aux_gpio)) {
>> +        dev_err(dev, "no aux-gpio property found\n");
>> +        return -EINVAL;
>> +    }
>> +
>> +    ret = devm_gpio_request_one(dev, led->ctrl_gpio,
>> +                    GPIOF_OPEN_SOURCE, "ctrl-gpio");
>> +    if (ret) {
>> +        dev_err(dev, "failed to request ctrl-gpio %d error %d\n",
>> +                led->ctrl_gpio, ret);
>> +        return ret;
>> +    }
>> +
>> +    ret = devm_gpio_request_one(dev, led->aux_gpio,
>> +                    GPIOF_OPEN_SOURCE, "aux-gpio");
>> +    if (ret) {
>> +        dev_err(dev, "failed to request aux-gpio %d error %d\n",
>> +                led->aux_gpio, ret);
>> +        return ret;
>> +    }
>> +
>> +    ret = of_property_read_u32(np, "flash-timeout-us", flash_timeout_us);
>> +    /* default setting */
>> +    if (ret)
>> +        *flash_timeout_us = KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US;
>> +
>> +    return 0;
>> +}
>> +
>> +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_flash_timeout_setting timeout_setting;
>> +    u32 flash_timeout_us;
>> +    int ret;
>> +
>> +    led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
>> +    if (!led)
>> +        return -ENOMEM;
>> +
>> +    if (!pdev->dev.of_node)
>> +        return -ENXIO;
>> +
>> +    fled_cdev = &led->fled_cdev;
>> +    led_cdev = &fled_cdev->led_cdev;
>> +    platform_set_drvdata(pdev, led);
>> +
>> +    ret = ktd2692_parse_dt(led, &pdev->dev, &flash_timeout_us);
>> +    if (ret)
>> +        return ret;
>> +
>> +    led->regulator = devm_regulator_get(&pdev->dev, "vin");
>> +    if (IS_ERR(led->regulator)) {
>> +        dev_err(&pdev->dev, "regulator get failed\n");
>> +        ret = PTR_ERR(led->regulator);
>> +        led->regulator = NULL;
>> +        return ret;
>> +    }
>> +
>> +    ret = ktd2692_led_regulator_enable(led);
>> +    if (ret)
>> +        goto err_regulator;
>> +
>> +    ktd2692_init_flash_timeout_set(flash_timeout_us, &timeout_setting);
>> +
>> +    fled_cdev->timeout = timeout_setting.flash_timeout;
>> +    fled_cdev->ops = &flash_ops;
>> +
>> +    led_cdev->name = KTD2692_DEFAULT_NAME;
>> +    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_cdev->flags |= LED_DEV_CAP_FLASH;
>> +
>> +    INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
>> +
>> +    ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
>> +    if (ret) {
>> +        dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
>> +        goto err_register;
>> +    }
>> +
>> +    ktd2692_init_flash_register_set(led);
>> +
>> +    mutex_init(&led->lock);
>> +
>> +    return 0;
>> +err_register:
>> +    cancel_work_sync(&led->work_brightness_set);
>> +err_regulator:
>> +    ktd2692_led_regulator_disable(led);
>> +    platform_set_drvdata(pdev, NULL);
>> +    return ret;
>> +}
>> +
>> +static int ktd2692_remove(struct platform_device *pdev)
>> +{
>> +    struct ktd2692_context *led = platform_get_drvdata(pdev);
>> +
>> +    cancel_work_sync(&led->work_brightness_set);
>> +    led_classdev_flash_unregister(&led->fled_cdev);
>> +    ktd2692_led_regulator_disable(led);
>> +
>> +    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  = "leds-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");
>>
> 
>