Commit b5a8c50e authored by Duje Mihanović's avatar Duje Mihanović Committed by Lee Jones
Browse files

leds: ktd2692: Convert to use ExpressWire library 



The KTD2692 uses the ExpressWire protocol implemented in the newly
introduced ExpressWire library. Convert the driver to use the library.

Suggested-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: default avatarDuje Mihanović <duje.mihanovic@skole.hr>
Link: https://lore.kernel.org/r/20240125-ktd2801-v5-2-e22da232a825@skole.hr


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 1368d06d

drivers/leds/flash/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ config LEDS_AS3645A 
config LEDS_KTD2692

	tristate "LED support for Kinetic KTD2692 flash LED controller"

	depends on OF

	depends on GPIOLIB || COMPILE_TEST

	select LEDS_EXPRESSWIRE

	help

	  This option enables support for Kinetic KTD2692 LED flash connected

	  through ExpressWire interface.

drivers/leds/flash/leds-ktd2692.c

+27 −89
Original line number Diff line number Diff line
@@ -6,9 +6,9 @@ 
 * Ingi Kim <ingi2.kim@samsung.com>

 */



#include <linux/delay.h>

#include <linux/err.h>

#include <linux/gpio/consumer.h>

#include <linux/leds-expresswire.h>

#include <linux/led-class-flash.h>

#include <linux/module.h>

#include <linux/mutex.h>
@@ -37,22 +37,9 @@ 
#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 */
@@ -71,7 +58,19 @@ struct ktd2692_led_config_data { 
	enum led_brightness max_brightness;

};



const struct expresswire_timing ktd2692_timing = {

	.poweroff_us = 700,

	.data_start_us = 10,

	.end_of_data_low_us = 10,

	.end_of_data_high_us = 350,

	.short_bitset_us = 4,

	.long_bitset_us = 12

};



struct ktd2692_context {

	/* Common ExpressWire properties (ctrl GPIO and timing) */

	struct expresswire_common_props props;



	/* Related LED Flash class device */

	struct led_classdev_flash fled_cdev;
@@ -80,7 +79,6 @@ struct ktd2692_context { 
	struct regulator *regulator;



	struct gpio_desc *aux_gpio;

	struct gpio_desc *ctrl_gpio;



	enum ktd2692_led_mode mode;

	enum led_brightness torch_brightness;
@@ -92,67 +90,6 @@ static struct ktd2692_context *fled_cdev_to_led( 
	return container_of(fled_cdev, struct ktd2692_context, fled_cdev);

}



static void ktd2692_expresswire_start(struct ktd2692_context *led)

{

	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);

	udelay(KTD2692_TIME_DATA_START_TIME_US);

}



static void ktd2692_expresswire_reset(struct ktd2692_context *led)

{

	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);

	udelay(KTD2692_TIME_RESET_US);

}



static void ktd2692_expresswire_end(struct ktd2692_context *led)

{

	gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);

	udelay(KTD2692_TIME_LOW_END_OF_DATA_US);

	gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);

	udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);

}



static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)

{

	/*

	 * The Low Bit(0) and High Bit(1) is based on a time detection

	 * algorithm between time low and time high

	 * Time_(L_LB) : Low time of the Low Bit(0)

	 * Time_(H_LB) : High time of the LOW Bit(0)

	 * Time_(L_HB) : Low time of the High Bit(1)

	 * Time_(H_HB) : High time of the High Bit(1)

	 *

	 * It can be simplified to:

	 * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)

	 * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)

	 * HIGH  ___           ____    _..     _________    ___

	 *          |_________|    |_..  |____|         |__|

	 * LOW        <L_LB>  <H_LB>     <L_HB>  <H_HB>

	 *          [  Low Bit (0) ]     [  High Bit(1) ]

	 */

	if (bit) {

		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);

		udelay(KTD2692_TIME_SHORT_BITSET_US);

		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);

		udelay(KTD2692_TIME_LONG_BITSET_US);

	} else {

		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);

		udelay(KTD2692_TIME_LONG_BITSET_US);

		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);

		udelay(KTD2692_TIME_SHORT_BITSET_US);

	}

}



static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)

{

	int i;



	ktd2692_expresswire_start(led);

	for (i = 7; i >= 0; i--)

		ktd2692_expresswire_set_bit(led, value & BIT(i));

	ktd2692_expresswire_end(led);

}



static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,

				       enum led_brightness brightness)

{
@@ -163,14 +100,14 @@ static int ktd2692_led_brightness_set(struct led_classdev *led_cdev, 


	if (brightness == LED_OFF) {

		led->mode = KTD2692_MODE_DISABLE;

		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

		gpiod_direction_output(led->aux_gpio, 0);

	} else {

		ktd2692_expresswire_write(led, brightness |

		expresswire_write_u8(&led->props, brightness |

					KTD2692_REG_MOVIE_CURRENT_BASE);

		led->mode = KTD2692_MODE_MOVIE;

	}



	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);

	expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);

	mutex_unlock(&led->lock);



	return 0;
@@ -187,17 +124,17 @@ static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev, 


	if (state) {

		flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);

		ktd2692_expresswire_write(led, flash_tm_reg

		expresswire_write_u8(&led->props, flash_tm_reg

				| KTD2692_REG_FLASH_TIMEOUT_BASE);



		led->mode = KTD2692_MODE_FLASH;

		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);

		gpiod_direction_output(led->aux_gpio, 1);

	} else {

		led->mode = KTD2692_MODE_DISABLE;

		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

		gpiod_direction_output(led->aux_gpio, 0);

	}



	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);

	expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);



	fled_cdev->led_cdev.brightness = LED_OFF;

	led->mode = KTD2692_MODE_DISABLE;
@@ -247,12 +184,12 @@ static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev, 
static void ktd2692_setup(struct ktd2692_context *led)

{

	led->mode = KTD2692_MODE_DISABLE;

	ktd2692_expresswire_reset(led);

	gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

	expresswire_power_off(&led->props);

	gpiod_direction_output(led->aux_gpio, 0);



	ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)

	expresswire_write_u8(&led->props, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)

				 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);

	ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)

	expresswire_write_u8(&led->props, KTD2692_FLASH_MODE_CURR_PERCENT(45)

				 | KTD2692_REG_FLASH_CURRENT_BASE);

}
@@ -277,8 +214,8 @@ static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev, 
	if (!np)

		return -ENXIO;



	led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);

	ret = PTR_ERR_OR_ZERO(led->ctrl_gpio);

	led->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);

	ret = PTR_ERR_OR_ZERO(led->props.ctrl_gpio);

	if (ret)

		return dev_err_probe(dev, ret, "cannot get ctrl-gpios\n");
@@ -412,6 +349,7 @@ static struct platform_driver ktd2692_driver = { 


module_platform_driver(ktd2692_driver);



MODULE_IMPORT_NS(EXPRESSWIRE);

MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");

MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");

MODULE_LICENSE("GPL v2");