[PATCH v6 0/3] Add ktd2692 Flash LED driver using LED Flash class

[PATCH v6 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 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      |  40 ++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 drivers/leds/Kconfig                               |   9 +
 drivers/leds/Makefile                              |   1 +
 drivers/leds/leds-ktd2692.c                        | 408 +++++++++++++++++++++
 5 files changed, 459 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
 create mode 100644 drivers/leds/leds-ktd2692.c

-- 
2.0.5

[PATCH v6 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>
---
 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 v6 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>
---
 .../devicetree/bindings/leds/leds-ktd2692.txt      | 40 ++++++++++++++++++++++
 1 file changed, 40 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..68bb59e
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
@@ -0,0 +1,40 @@
+* 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
+- 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.
+
+Optional properties of flash LED child node:
+- label : see Documentation/devicetree/bindings/leds/common.txt
+- flash-timeout-us : Maximum flash timeout in microseconds.
+  flash timeout ranges from 0 to 1835000us and default is 1049000us.
+
+Example:
+
+ktd2692 {
+	compatible = "kinetic,ktd2692";
+	ctrl-gpio = <&gpc0 1 0>;
+	aux-gpio = <&gpc0 2 0>;
+	vin-supply = <&vbat>;
+
+	flash-led {
+		label = "ktd2692-flash";
+		flash-timeout-us = <1835000>;
+	};
+};
-- 
2.0.5

[PATCH v6 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 | 408 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 418 insertions(+)
 create mode 100644 drivers/leds/leds-ktd2692.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 51059bb..86197ef 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
+	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..a9e4862
--- /dev/null
+++ b/drivers/leds/leds-ktd2692.c
@@ -0,0 +1,408 @@
+/*
+ * 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>
+
+/* 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
+
+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_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 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)
+{
+	/*
+	 * 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) {
+		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, 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;
+		gpio_set_value(led->aux_gpio, KTD2692_LOW);
+	} else {
+		ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
+				KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
+		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;
+		gpio_set_value(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;
+		gpio_set_value(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_flash_timeout(u32 flash_timeout_us,
+					struct led_flash_setting *setting)
+{
+	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_setup(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;
+	struct device_node *child_node;
+	int ret;
+
+	if (!dev->of_node)
+		return -ENXIO;
+
+	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;
+	}
+
+	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,
+				"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 led_flash_setting flash_timeout;
+	u32 flash_timeout_us;
+	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, &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");
+		return PTR_ERR(led->regulator);
+	}
+
+	ret = regulator_enable(led->regulator);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable supply: %d\n", ret);
+		return ret;
+	}
+
+	ktd2692_init_flash_timeout(flash_timeout_us, &flash_timeout);
+
+	fled_cdev->timeout = flash_timeout;
+	fled_cdev->ops = &flash_ops;
+
+	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);
+
+	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 v6 3/3] leds: Add ktd2692 flash LED driver

[Sakari Ailus]

Hi Ingi,

Thanks for the update. Just a few comments below. Let's also wait for the
final agreement on the limit properties, hopefully we have that soon.

On Fri, Apr 10, 2015 at 03:45:59PM +0900, 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 | 408 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 418 insertions(+)
>  create mode 100644 drivers/leds/leds-ktd2692.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 51059bb..86197ef 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
> +	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..a9e4862
> --- /dev/null
> +++ b/drivers/leds/leds-ktd2692.c
> @@ -0,0 +1,408 @@
> +/*
> + * 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>

Shouldn't this be linux/of.h?

> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/workqueue.h>
> +
> +/* 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
> +
> +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_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 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)
> +{
> +	/*
> +	 * 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) {
> +		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, 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;
> +		gpio_set_value(led->aux_gpio, KTD2692_LOW);
> +	} else {
> +		ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
> +				KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
> +		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;
> +		gpio_set_value(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;
> +		gpio_set_value(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_flash_timeout(u32 flash_timeout_us,
> +					struct led_flash_setting *setting)
> +{
> +	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_setup(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;
> +	struct device_node *child_node;
> +	int ret;
> +
> +	if (!dev->of_node)
> +		return -ENXIO;
> +
> +	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");

I think you could simply use devm_gpio_get(), and start using the new API
instead. It'd save quite a few lines of code, too.

> +	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;
> +	}
> +
> +	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,
> +				"flash-timeout-us", flash_timeout_us);

You should do of_node_put(child_node) once you no longer need it.

> +	/* 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 led_flash_setting flash_timeout;
> +	u32 flash_timeout_us;
> +	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, &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");
> +		return PTR_ERR(led->regulator);
> +	}
> +
> +	ret = regulator_enable(led->regulator);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to enable supply: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ktd2692_init_flash_timeout(flash_timeout_us, &flash_timeout);
> +
> +	fled_cdev->timeout = flash_timeout;
> +	fled_cdev->ops = &flash_ops;
> +
> +	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);
> +
> +	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");

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

Re: [PATCH v6 3/3] leds: Add ktd2692 flash LED driver

[Ingi Kim]

Hi Sakari,

Thanks for the review.
I'm also anticipated decision for flash properties.

On 2015년 04월 10일 17:11, Sakari Ailus wrote:
> Hi Ingi,
> 
> Thanks for the update. Just a few comments below. Let's also wait for the
> final agreement on the limit properties, hopefully we have that soon.
> 
> On Fri, Apr 10, 2015 at 03:45:59PM +0900, 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 | 408 ++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 418 insertions(+)
>>  create mode 100644 drivers/leds/leds-ktd2692.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 51059bb..86197ef 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
>> +	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..a9e4862
>> --- /dev/null
>> +++ b/drivers/leds/leds-ktd2692.c
>> @@ -0,0 +1,408 @@
>> +/*
>> + * 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>
> 
> Shouldn't this be linux/of.h?
> 

I think it is enough to include of_gpio
because it includes linux/of and linux/gpio
but I should change for using new gpio APIs

>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/workqueue.h>
>> +
>> +/* 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
>> +
>> +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_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 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)
>> +{
>> +	/*
>> +	 * 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) {
>> +		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, 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;
>> +		gpio_set_value(led->aux_gpio, KTD2692_LOW);
>> +	} else {
>> +		ktd2692_expresswire_write(led, KTD2692_REG_MOVIE_CURRENT_BASE |
>> +				KTD2692_BRIGHTNESS_RANGE_255_TO_8(brightness));
>> +		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;
>> +		gpio_set_value(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;
>> +		gpio_set_value(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_flash_timeout(u32 flash_timeout_us,
>> +					struct led_flash_setting *setting)
>> +{
>> +	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_setup(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;
>> +	struct device_node *child_node;
>> +	int ret;
>> +
>> +	if (!dev->of_node)
>> +		return -ENXIO;
>> +
>> +	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");
> 
> I think you could simply use devm_gpio_get(), and start using the new API
> instead. It'd save quite a few lines of code, too.
> 

did you mean devm_gpiod_get()
Ok, I'll check it

>> +	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;
>> +	}
>> +
>> +	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,
>> +				"flash-timeout-us", flash_timeout_us);
> 
> You should do of_node_put(child_node) once you no longer need it.
> 

Ok, I'll check it
Thanks for the notification of other APIs :)

>> +	/* 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 led_flash_setting flash_timeout;
>> +	u32 flash_timeout_us;
>> +	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, &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");
>> +		return PTR_ERR(led->regulator);
>> +	}
>> +
>> +	ret = regulator_enable(led->regulator);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to enable supply: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ktd2692_init_flash_timeout(flash_timeout_us, &flash_timeout);
>> +
>> +	fled_cdev->timeout = flash_timeout;
>> +	fled_cdev->ops = &flash_ops;
>> +
>> +	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);
>> +
>> +	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 v6 3/3] leds: Add ktd2692 flash LED driver

[Sakari Ailus]

Hi Ingi,

On Fri, Apr 10, 2015 at 05:45:30PM +0900, Ingi Kim wrote:
...
> >> +	ret = devm_gpio_request_one(dev, led->ctrl_gpio,
> >> +					GPIOF_OPEN_SOURCE, "ctrl-gpio");
> >
> > I think you could simply use devm_gpio_get(), and start using the new API
> > instead. It'd save quite a few lines of code, too.
> >
> 
> did you mean devm_gpiod_get()
> Ok, I'll check it

Yes, that's what I meant.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

Re: [PATCH v6 0/3] Add ktd2692 Flash LED driver using LED Flash class

[Varka Bhadram]

On 04/10/2015 12:15 PM, Ingi Kim wrote:

> This patch adds ktd2692 Flash LED driver with LED Flash class
>
> 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      |  40 ++
>  .../devicetree/bindings/vendor-prefixes.txt        |   1 +
>  drivers/leds/Kconfig                               |   9 +
>  drivers/leds/Makefile                              |   1 +
>  drivers/leds/leds-ktd2692.c                        | 408 +++++++++++++++++++++
>  5 files changed, 459 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>  create mode 100644 drivers/leds/leds-ktd2692.c
>
Run checkpatch.pl with --strict option on this series..

./scripts/checkpatch.pl --strict 000*

Reported "CHECK: Alignment should match open parenthesis"..

-- 
Varka Bhadram

Re: [PATCH v6 0/3] Add ktd2692 Flash LED driver using LED Flash class

[Ingi Kim]

Hi Varka,

On 2015년 04월 10일 15:59, Varka Bhadram wrote:
> On 04/10/2015 12:15 PM, Ingi Kim wrote:
> 
>> This patch adds ktd2692 Flash LED driver with LED Flash class
>>
>> 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      |  40 ++
>>  .../devicetree/bindings/vendor-prefixes.txt        |   1 +
>>  drivers/leds/Kconfig                               |   9 +
>>  drivers/leds/Makefile                              |   1 +
>>  drivers/leds/leds-ktd2692.c                        | 408 +++++++++++++++++++++
>>  5 files changed, 459 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
>>  create mode 100644 drivers/leds/leds-ktd2692.c
>>
> Run checkpatch.pl with --strict option on this series..
> 
> ./scripts/checkpatch.pl --strict 000*
> 
> Reported "CHECK: Alignment should match open parenthesis"..
> 

I used checkpatch.pl script but I wasn't aware of this option.
It reveals my mistakes more :)

Thanks