driver: led: add support for TI TLC59731 RGB STRIP controller

TLC59731 is a 3-Channel, 8-Bit, PWM LED Driver with
TI Single-Wire interface (EasySet) protocol.

Signed-off-by: Javad Rahimipetroudi <javad.rahimipetroudi@mind.be>

drivers/led_strip/CMakeLists.txt

@@ -9,3 +9,4 @@ zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_SPI    ws2812_spi.c)
 zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_I2S    ws2812_i2s.c)
 zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_RPI_PICO_PIO	ws2812_rpi_pico_pio.c)
 zephyr_library_sources_ifdef(CONFIG_TLC5971_STRIP       tlc5971.c)
+zephyr_library_sources_ifdef(CONFIG_TLC59731_STRIP      tlc59731.c)

drivers/led_strip/Kconfig

@@ -35,4 +35,6 @@ source "drivers/led_strip/Kconfig.apa102"
 
 source "drivers/led_strip/Kconfig.tlc5971"
 
+source "drivers/led_strip/Kconfig.tlc59731"
+
 endif # LED_STRIP

drivers/led_strip/Kconfig.tlc59731

@@ -0,0 +1,11 @@
+# Copyright (c) 2024 Javad Rahimipetroudi <javad.rahimipetroudi@mind.be>
+# SPDX-License-Identifier: Apache-2.0
+
+config TLC59731_STRIP
+	bool "TLC59731 LED controller"
+	default y
+	depends on DT_HAS_TI_TLC59731_ENABLED
+	select GPIO
+	help
+	  Enable driver for the Texas Instruments TLC59731 EasySet LED
+	  controllers.

drivers/led_strip/tlc59731.c

@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2024 Javad Rahimipetroudi <javad.rahimipetroudi@mind.be>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT ti_tlc59731
+
+/**
+ * @file
+ * @brief LED driver for the TLC59731 LED driver.
+ *
+ * TLC59731 is a 3-Channel, 8-Bit, PWM LED Driver
+ * With Single-Wire Interface (EasySet)
+ *
+ * The EasySet protocol is based on short pulses and the time between
+ * them. At least one pulse must be sent every T_CYCLE, which can be
+ * between 1.67us and 50us. We want to go as fast as possible, but
+ * delays under 1us don't work very well, so we settle on 5us for the
+ * cycle time.
+ * A pulse must be high for at least 14ns. In practice, turning a GPIO on
+ * and immediately off again already takes longer than that, so no delay
+ * is needed there.
+ * A zero is represented by no additional pulses within a cycle.
+ * A one is represented by an additional pulse between 275ns and 2.5us
+ * (half a cycle) after the first one. We need at least some delay to get to
+ * 275ns, but because of the limited granularity of k_busy_wait we use a
+ * full 1us. After the pulse, we wait an additional T_CYCLE_1 to complete
+ * the cycle. This time can be slightly shorter because the second pulse
+ * already closes the cycle.
+ * Finally we need to keep the line low for T_H0 to complete the address
+ * for a single chip, and T_H1 to complete the write for all chips.
+ */
+
+#include <zephyr/drivers/led_strip.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(tlc59731, CONFIG_LED_STRIP_LOG_LEVEL);
+
+/* Pulse timing */
+#define TLC59731_DELAY     0x01 /* us */
+#define TLC59731_T_CYCLE_0 0x04 /* us */
+#define TLC59731_T_CYCLE_1 0x01 /* us */
+#define TLC59731_T_H0      (4 * TLC59731_T_CYCLE_0)
+#define TLC59731_T_H1      (8 * TLC59731_T_CYCLE_0)
+/* Threshould levels */
+#define TLC59731_HIGH      0x01
+#define TLC59731_LOW       0x00
+
+/* Write command */
+#define TLC59731_WR 0x3A
+
+struct tlc59731_cfg {
+	struct gpio_dt_spec sdi_gpio;
+	size_t length;
+};
+
+static inline int rgb_pulse(const struct gpio_dt_spec *led_dev)
+{
+	int fret = 0;
+
+	fret = gpio_pin_set_dt(led_dev, TLC59731_HIGH);
+	if (fret != 0) {
+		return fret;
+	}
+
+	fret = gpio_pin_set_dt(led_dev, TLC59731_LOW);
+	if (fret != 0) {
+		return fret;
+	}
+
+	return fret;
+}
+
+static int rgb_write_bit(const struct gpio_dt_spec *led_dev, uint8_t data)
+{
+	rgb_pulse(led_dev);
+
+	k_busy_wait(TLC59731_DELAY);
+
+	if (data) {
+		rgb_pulse(led_dev);
+		k_busy_wait(TLC59731_T_CYCLE_1);
+	} else {
+		k_busy_wait(TLC59731_T_CYCLE_0);
+	}
+
+	return 0;
+}
+
+static int rgb_write_data(const struct gpio_dt_spec *led_dev, uint8_t data)
+{
+	int8_t idx = 7;
+
+	while (idx >= 0) {
+		rgb_write_bit(led_dev, data & BIT((idx--)));
+	}
+
+	return 0;
+}
+
+static int tlc59731_led_set_color(const struct device *dev, struct led_rgb *pixel)
+{
+
+	const struct tlc59731_cfg *tlc_conf = dev->config;
+	const struct gpio_dt_spec *led_gpio = &tlc_conf->sdi_gpio;
+
+	rgb_write_data(led_gpio, TLC59731_WR);
+	rgb_write_data(led_gpio, pixel->r);
+	rgb_write_data(led_gpio, pixel->g);
+	rgb_write_data(led_gpio, pixel->b);
+
+	return 0;
+}
+
+static int tlc59731_gpio_update_rgb(const struct device *dev, struct led_rgb *pixels,
+				    size_t num_pixels)
+{
+	size_t i;
+	int err = 0;
+
+	for (i = 0; i < num_pixels; i++) {
+		err = tlc59731_led_set_color(dev, &pixels[i]);
+		if (err) {
+			break;
+		}
+	}
+
+	return err;
+}
+
+static size_t tlc59731_length(const struct device *dev)
+{
+	const struct tlc59731_cfg *config = dev->config;
+
+	return config->length;
+}
+
+static const struct led_strip_driver_api tlc59731_gpio_api = {
+	.update_rgb = tlc59731_gpio_update_rgb,
+	.length = tlc59731_length,
+};
+
+static int tlc59731_gpio_init(const struct device *dev)
+{
+	const struct tlc59731_cfg *tlc_conf = dev->config;
+	const struct gpio_dt_spec *led = &tlc_conf->sdi_gpio;
+	int err = 0;
+
+	if (!device_is_ready(led->port)) {
+		LOG_ERR("%s: no LEDs found (DT child nodes missing)", dev->name);
+		err = -ENODEV;
+		goto scape;
+	}
+
+	err = gpio_pin_configure_dt(led, GPIO_OUTPUT_ACTIVE);
+	if (err < 0) {
+		LOG_ERR("%s: Unable to setup SDI port", dev->name);
+		err = -EIO;
+		goto scape;
+	}
+
+	err = gpio_pin_set_dt(led, TLC59731_LOW);
+	if (err < 0) {
+		LOG_ERR("%s: Unable to set the SDI-GPIO)", dev->name);
+		err = -EIO;
+		goto scape;
+	}
+
+	gpio_pin_set_dt(led, TLC59731_HIGH);
+	gpio_pin_set_dt(led, TLC59731_LOW);
+
+	k_busy_wait((TLC59731_DELAY + TLC59731_T_CYCLE_0));
+scape:
+	return err;
+}
+
+#define TLC59731_DEVICE(i)                                                                         \
+	static struct tlc59731_cfg tlc59731_cfg_##i = {                                            \
+		.sdi_gpio = GPIO_DT_SPEC_INST_GET(i, gpios),                                       \
+		.length = DT_INST_PROP(i, chain_length),                                           \
+	};                                                                                         \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(i, tlc59731_gpio_init, NULL, NULL, &tlc59731_cfg_##i, POST_KERNEL,   \
+			      CONFIG_LED_STRIP_INIT_PRIORITY, &tlc59731_gpio_api);
+DT_INST_FOREACH_STATUS_OKAY(TLC59731_DEVICE)

dts/bindings/led_strip/ti,tlc59731.yaml

@@ -0,0 +1,13 @@
+# Copyright (c) 2024 Javad Rahimipetroudi <javad.rahimipetroudi@mind.be>
+# SPDX-License-Identifier: Apache-2.0
+
+compatible: "ti,tlc59731"
+description: TLC59731 RGB LED Controller
+include: [led-strip.yaml]
+
+properties:
+  gpios:
+    required: true
+    type: phandle-array
+    description: |
+      GPIO to send command data to the controller.