drivers: led: Add lumissil is31fl3216a driver

The IS31FL3216A is a fun light LED controller. The LED current of each
channel can be set in 256 steps by adjusting the PWM duty cycle through
an I2C interface.

Signed-off-by: Guy Morand <guy.morand@bytesatwork.ch>

drivers/led/CMakeLists.txt

@@ -5,6 +5,7 @@ zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/drivers/led.h)
 zephyr_library()
 
 zephyr_library_sources_ifdef(CONFIG_HT16K33 ht16k33.c)
+zephyr_library_sources_ifdef(CONFIG_IS31FL3216A is31fl3216a.c)
 zephyr_library_sources_ifdef(CONFIG_LED_GPIO led_gpio.c)
 zephyr_library_sources_ifdef(CONFIG_LED_PWM led_pwm.c)
 zephyr_library_sources_ifdef(CONFIG_LED_XEC led_mchp_xec.c)

drivers/led/Kconfig

@@ -28,6 +28,7 @@ config LED_SHELL
 
 source "drivers/led/Kconfig.gpio"
 source "drivers/led/Kconfig.ht16k33"
+source "drivers/led/Kconfig.is31fl3216a"
 source "drivers/led/Kconfig.lp3943"
 source "drivers/led/Kconfig.lp503x"
 source "drivers/led/Kconfig.lp5562"

drivers/led/Kconfig.is31fl3216a

@@ -0,0 +1,11 @@
+# Copyright (c) 2023 Endor AG
+# SPDX-License-Identifier: Apache-2.0
+
+config IS31FL3216A
+	bool "IS31FL3216A LED driver"
+	default y
+	depends on DT_HAS_ISSI_IS31FL3216A_ENABLED
+	select I2C
+	help
+	  Enable LED driver for Lumissil Microsystems (a division of ISSI)
+	  IS31FL3216A. This chip supports up to 16 PWM controlled LEDs.

drivers/led/is31fl3216a.c

@@ -0,0 +1,240 @@
+/*
+ * Copyright (c) 2023 Endor AG
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT issi_is31fl3216a
+
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/led.h>
+#include <zephyr/logging/log.h>
+
+#define IS31FL3216A_REG_CONFIG		0x00
+#define IS31FL3216A_REG_CTL_1		0x01
+#define IS31FL3216A_REG_CTL_2		0x02
+#define IS31FL3216A_REG_LIGHT_EFFECT	0x03
+#define IS31FL3216A_REG_CHANNEL_CONFIG	0x04
+#define IS31FL3216A_REG_GPIO_CONFIG	0x05
+#define IS31FL3216A_REG_OUTPUT_PORT	0x06
+#define IS31FL3216A_REG_INT_CONTROL	0x07
+#define IS31FL3216A_REG_ADC_SAMPLE_RATE	0x09
+#define IS31FL3216A_REG_PWM_FIRST	0x10
+#define IS31FL3216A_REG_PWM_LAST	0x1F
+#define IS31FL3216A_REG_UPDATE		0xB0
+#define IS31FL3216A_REG_FRAME_DELAY	0xB6
+#define IS31FL3216A_REG_FRAME_START	0xB7
+
+#define IS31FL3216A_MAX_LEDS		16
+
+LOG_MODULE_REGISTER(is31fl3216a, CONFIG_LED_LOG_LEVEL);
+
+struct is31fl3216a_cfg {
+	struct i2c_dt_spec i2c;
+};
+
+static int is31fl3216a_write_buffer(const struct i2c_dt_spec *i2c,
+				    const uint8_t *buffer, uint32_t num_bytes)
+{
+	int status;
+
+	status = i2c_write_dt(i2c, buffer, num_bytes);
+	if (status < 0) {
+		LOG_ERR("Could not write buffer: %i", status);
+		return status;
+	}
+
+	return 0;
+}
+
+static int is31fl3216a_write_reg(const struct i2c_dt_spec *i2c, uint8_t reg,
+				 uint8_t val)
+{
+	uint8_t buffer[2] = {reg, val};
+
+	return is31fl3216a_write_buffer(i2c, buffer, sizeof(buffer));
+}
+
+static int is31fl3216a_update_pwm(const struct i2c_dt_spec *i2c)
+{
+	return is31fl3216a_write_reg(i2c, IS31FL3216A_REG_UPDATE, 0);
+}
+
+static uint8_t is31fl3216a_brightness_to_pwm(uint8_t brightness)
+{
+	return (0xFFU * brightness) / 100;
+}
+
+static int is31fl3216a_led_write_channels(const struct device *dev,
+					  uint32_t start_channel,
+					  uint32_t num_channels,
+					  const uint8_t *buf)
+{
+	const struct is31fl3216a_cfg *config = dev->config;
+	uint8_t i2c_buffer[IS31FL3216A_MAX_LEDS + 1];
+	int status;
+	int i;
+
+	if (num_channels == 0) {
+		return 0;
+	}
+
+	if (start_channel + num_channels > IS31FL3216A_MAX_LEDS) {
+		return -EINVAL;
+	}
+
+	/* Invert channels, last register is channel 0 */
+	i2c_buffer[0] = IS31FL3216A_REG_PWM_LAST - start_channel -
+			(num_channels - 1);
+	for (i = 0; i < num_channels; i++) {
+		if (buf[num_channels - i - 1] > 100) {
+			return -EINVAL;
+		}
+		i2c_buffer[i + 1] = is31fl3216a_brightness_to_pwm(
+			buf[num_channels - i - 1]);
+	}
+
+	status = is31fl3216a_write_buffer(&config->i2c, i2c_buffer,
+					  num_channels + 1);
+	if (status < 0) {
+		return status;
+	}
+
+	return is31fl3216a_update_pwm(&config->i2c);
+}
+
+static int is31fl3216a_led_set_brightness(const struct device *dev,
+					  uint32_t led, uint8_t value)
+{
+	const struct is31fl3216a_cfg *config = dev->config;
+	uint8_t pwm_reg = IS31FL3216A_REG_PWM_LAST - led;
+	int status;
+	uint8_t pwm_value;
+
+	if (led > IS31FL3216A_MAX_LEDS - 1 || value > 100) {
+		return -EINVAL;
+	}
+
+	pwm_value = is31fl3216a_brightness_to_pwm(value);
+	status = is31fl3216a_write_reg(&config->i2c, pwm_reg, pwm_value);
+	if (status < 0) {
+		return status;
+	}
+
+	return is31fl3216a_update_pwm(&config->i2c);
+}
+
+static int is31fl3216a_led_on(const struct device *dev, uint32_t led)
+{
+	return is31fl3216a_led_set_brightness(dev, led, 100);
+}
+
+static int is31fl3216a_led_off(const struct device *dev, uint32_t led)
+{
+	return is31fl3216a_led_set_brightness(dev, led, 0);
+}
+
+static int is31fl3216a_init_registers(const struct i2c_dt_spec *i2c)
+{
+	int i;
+	int status;
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_CTL_1, 0xFF);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_CTL_2, 0xFF);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_LIGHT_EFFECT, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_CHANNEL_CONFIG,
+				       0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_GPIO_CONFIG, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_OUTPUT_PORT, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_INT_CONTROL, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_ADC_SAMPLE_RATE,
+				       0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_FRAME_DELAY, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_FRAME_START, 0x00);
+	if (status < 0) {
+		return status;
+	}
+
+	for (i = IS31FL3216A_REG_PWM_FIRST;
+	     i <= IS31FL3216A_REG_PWM_LAST;
+	     i++) {
+		status = is31fl3216a_write_reg(i2c, i, 0);
+		if (status < 0) {
+			return status;
+		}
+	}
+
+	status = is31fl3216a_write_reg(i2c, IS31FL3216A_REG_UPDATE, 0);
+	if (status < 0) {
+		return status;
+	}
+
+	return is31fl3216a_write_reg(i2c, IS31FL3216A_REG_CONFIG, 0x00);
+}
+
+static int is31fl3216a_init(const struct device *dev)
+{
+	const struct is31fl3216a_cfg *config = dev->config;
+
+	LOG_DBG("Initializing @0x%x...", config->i2c.addr);
+
+	if (!i2c_is_ready_dt(&config->i2c)) {
+		LOG_ERR("I2C device not ready");
+		return -ENODEV;
+	}
+
+	return is31fl3216a_init_registers(&config->i2c);
+}
+
+static const struct led_driver_api is31fl3216a_led_api = {
+	.set_brightness = is31fl3216a_led_set_brightness,
+	.on = is31fl3216a_led_on,
+	.off = is31fl3216a_led_off,
+	.write_channels = is31fl3216a_led_write_channels
+};
+
+#define IS31FL3216A_INIT(id) \
+	static const struct is31fl3216a_cfg is31fl3216a_##id##_cfg = {	\
+		.i2c = I2C_DT_SPEC_INST_GET(id),			\
+	};								\
+	DEVICE_DT_INST_DEFINE(id, &is31fl3216a_init, NULL, NULL,	\
+		&is31fl3216a_##id##_cfg, POST_KERNEL,			\
+		CONFIG_LED_INIT_PRIORITY, &is31fl3216a_led_api);
+
+DT_INST_FOREACH_STATUS_OKAY(IS31FL3216A_INIT)

dts/bindings/led/issi,is31fl3216a.yaml

@@ -0,0 +1,9 @@
+# Copyright (c) 2023 Endor AG
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  is31fl3216a LED driver for Lumissil Microsystems (a division of ISSI)
+
+compatible: "issi,is31fl3216a"
+
+include: i2c-device.yaml