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leds: ktd2692: Convert to use ExpressWire library

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

Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
Link: https://lore.kernel.org/r/20240125-ktd2801-v5-2-e22da232a825@skole.hr
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Duje Mihanović 2024-01-25 16:30:54 +01:00 committed by Lee Jones
parent 1368d06dd2
commit b5a8c50e5c
2 changed files with 28 additions and 90 deletions
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2
drivers/leds/flash/Kconfig
View File

@ -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.

116
drivers/leds/flash/leds-ktd2692.c
View File

@ -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");