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: 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>

diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index 4e08dbc057096f7239b5f628cf3cb6bb7407040c..a0fb755b58dcc5037b5d08b83ca4698e207dca6a 100644 (file)
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -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.

diff --git a/drivers/leds/flash/leds-ktd2692.c b/drivers/leds/flash/leds-ktd2692.c
index 598eee5daa527137117cd3498c2816066987f557..7bb0aa2753e365ef386835767bfe357690631ff3 100644 (file)
--- a/drivers/leds/flash/leds-ktd2692.c
+++ b/drivers/leds/flash/leds-ktd2692.c
@@ -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");