drivers/display/display_max7219.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2022 Jimmy Ou <yanagiis@gmail.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #define DT_DRV_COMPAT maxim_max7219

 /**
  * @file
  * @brief MAX7219 LED display driver
  *
  * This driver map the segment as x, digit as y.
  *
  * A MAX7219 has 8x8 pixels.
  * Two MAX7219s (with cascading) have 8x16 pixels.
  * So on and so forth.
  *
  * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf
  *
  * Limitations:
  *  1. This driver only implements no-decode mode.
  */

 #include <stddef.h>

 #include <zephyr/drivers/display.h>
 #include <zephyr/drivers/spi.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/sys/byteorder.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/kernel.h>
 LOG_MODULE_REGISTER(max7219, CONFIG_DISPLAY_LOG_LEVEL);

 #define MAX7219_SEGMENTS_PER_DIGIT 8
 #define MAX7219_DIGITS_PER_DEVICE  8

 /* clang-format off */

 /* MAX7219 registers and fields */
 #define MAX7219_REG_NOOP		0x00
 #define MAX7219_NOOP			0x00

 #define MAX7219_REG_DECODE_MODE		0x09
 #define MAX7219_NO_DECODE		0x00

 #define MAX7219_REG_INTENSITY		0x0A

 #define MAX7219_REG_SCAN_LIMIT		0x0B

 #define MAX7219_REG_SHUTDOWN		0x0C
 #define MAX7219_SHUTDOWN_MODE		0x00
 #define MAX7219_LEAVE_SHUTDOWN_MODE	0x01

 #define MAX7219_REG_DISPLAY_TEST	0x0F
 #define MAX7219_LEAVE_DISPLAY_TEST_MODE	0x00
 #define MAX7219_DISPLAY_TEST_MODE	0x01

 /* clang-format on */

 struct max7219_config {
 	struct spi_dt_spec spi;
 	uint32_t num_cascading;
 	uint8_t intensity;
 	uint8_t scan_limit;
 };

 struct max7219_data {
 	/* Keep all digit_buf for all cascading MAX7219 */
 	uint8_t *digit_buf;
 	uint8_t *tx_buf;
 };

 static int max7219_transmit_all(const struct device *dev, const uint8_t addr, const uint8_t value)
 {
 	const struct max7219_config *dev_config = dev->config;
 	struct max7219_data *dev_data = dev->data;

 	const struct spi_buf tx_buf = {
 		.buf = dev_data->tx_buf,
 		.len = dev_config->num_cascading * 2,
 	};
 	const struct spi_buf_set tx_bufs = {
 		.buffers = &tx_buf,
 		.count = 1U,
 	};

 	for (int i = 0; i < dev_config->num_cascading; i++) {
 		dev_data->tx_buf[i * 2] = addr;
 		dev_data->tx_buf[i * 2 + 1] = value;
 	}

 	return spi_write_dt(&dev_config->spi, &tx_bufs);
 }

 static int max7219_transmit_one(const struct device *dev, const uint8_t max7219_idx,
 				const uint8_t addr, const uint8_t value)
 {
 	const struct max7219_config *dev_config = dev->config;
 	struct max7219_data *dev_data = dev->data;

 	const struct spi_buf tx_buf = {
 		.buf = dev_data->tx_buf,
 		.len = dev_config->num_cascading * 2,
 	};
 	const struct spi_buf_set tx_bufs = {
 		.buffers = &tx_buf,
 		.count = 1U,
 	};

 	for (int i = 0; i < dev_config->num_cascading; i++) {
 		if (i != (dev_config->num_cascading - 1 - max7219_idx)) {
 			dev_data->tx_buf[i * 2] = MAX7219_REG_NOOP;
 			dev_data->tx_buf[i * 2 + 1] = MAX7219_NOOP;
 			continue;
 		}

 		dev_data->tx_buf[i * 2] = addr;
 		dev_data->tx_buf[i * 2 + 1] = value;
 	}

 	return spi_write_dt(&dev_config->spi, &tx_bufs);
 }

 static inline uint8_t next_pixel(uint8_t *mask, uint8_t *data, const uint8_t **buf)
 {
 	*mask <<= 1;
 	if (!*mask) {
 		*mask = 0x01;
 		*data = *(*buf)++;
 	}
 	return *data & *mask;
 }

 static inline void skip_pixel(uint8_t *mask, uint8_t *data, const uint8_t **buf, uint16_t count)
 {
 	while (count--) {
 		next_pixel(mask, data, buf);
 	}
 }

 static int max7219_blanking_on(const struct device *dev)
 {
 	ARG_UNUSED(dev);

 	return -ENOTSUP;
 }

 static int max7219_blanking_off(const struct device *dev)
 {
 	ARG_UNUSED(dev);

 	return -ENOTSUP;
 }

 static int max7219_write(const struct device *dev, const uint16_t x, const uint16_t y,
 			 const struct display_buffer_descriptor *desc, const void *buf)
 {
 	const struct max7219_config *dev_config = dev->config;
 	struct max7219_data *dev_data = dev->data;

 	const uint16_t max_width = MAX7219_SEGMENTS_PER_DIGIT;
 	const uint16_t max_height = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE;

 	/*
 	 * MAX7219 only supports PIXEL_FORMAT_MONO01. 1 bit stands for 1 pixel.
 	 */
 	__ASSERT((desc->pitch * desc->height) <= (desc->buf_size * 8U), "Input buffer to small");
 	__ASSERT(desc->width <= desc->pitch, "Pitch is smaller then width");
 	__ASSERT(desc->pitch <= max_width, "Pitch in descriptor is larger than screen size");
 	__ASSERT(desc->height <= max_height, "Height in descriptor is larger than screen size");
 	__ASSERT(x + desc->pitch <= max_width,
 		 "Writing outside screen boundaries in horizontal direction");
 	__ASSERT(y + desc->height <= max_height,
 		 "Writing outside screen boundaries in vertical direction");

 	if (desc->width > desc->pitch || (desc->pitch * desc->height) > (desc->buf_size * 8U)) {
 		return -EINVAL;
 	}

 	if ((x + desc->pitch) > max_width || (y + desc->height) > max_height) {
 		return -EINVAL;
 	}

 	const uint16_t end_x = x + desc->width;
 	const uint16_t end_y = y + desc->height;
 	const uint8_t *byte_buf = buf;
 	const uint16_t to_skip = desc->pitch - desc->width;
 	uint8_t mask = 0;
 	uint8_t data = 0;

 	for (uint16_t py = y; py < end_y; ++py) {
 		const uint8_t max7219_idx = py / MAX7219_DIGITS_PER_DEVICE;
 		const uint8_t digit_idx = py % MAX7219_DIGITS_PER_DEVICE;
 		uint8_t segment = dev_data->digit_buf[py];
 		int ret;

 		for (uint16_t px = x; px < end_x; ++px) {
 			WRITE_BIT(segment, px, next_pixel(&mask, &data, &byte_buf));
 		}

 		skip_pixel(&mask, &data, &byte_buf, to_skip);

 		/* led register address begins from 1 */
 		ret = max7219_transmit_one(dev, max7219_idx, digit_idx + 1, segment);
 		if (ret < 0) {
 			return ret;
 		}

 		dev_data->digit_buf[y] = segment;
 	}

 	return 0;
 }

 static int max7219_read(const struct device *dev, const uint16_t x, const uint16_t y,
 			const struct display_buffer_descriptor *desc, void *buf)
 {
 	ARG_UNUSED(dev);
 	ARG_UNUSED(x);
 	ARG_UNUSED(y);
 	ARG_UNUSED(desc);
 	ARG_UNUSED(buf);

 	return -ENOTSUP;
 }

 static void *max7219_get_framebuffer(const struct device *dev)
 {
 	ARG_UNUSED(dev);

 	return NULL;
 }

 static int max7219_set_brightness(const struct device *dev, const uint8_t brightness)
 {
 	int ret;

 	/*
 	 * max7219 supports intensity value from 0x0 to 0xF.
 	 * map the brightness from [0, 255] to [0, 15]
 	 */
 	ret = max7219_transmit_all(dev, MAX7219_REG_INTENSITY, brightness >> 4);
 	if (ret < 0) {
 		LOG_ERR("Failed to set brightness");
 		return ret;
 	}

 	return 0;
 }

 static int max7219_set_contrast(const struct device *dev, const uint8_t contrast)
 {
 	ARG_UNUSED(dev);
 	ARG_UNUSED(contrast);

 	return -ENOTSUP;
 }

 static int max7219_set_pixel_format(const struct device *dev,
 				    const enum display_pixel_format format)
 {
 	ARG_UNUSED(dev);

 	switch (format) {
 	case PIXEL_FORMAT_MONO01:
 		return 0;
 	default:
 		return -ENOTSUP;
 	}
 }

 static int max7219_set_orientation(const struct device *dev,
 				   const enum display_orientation orientation)
 {
 	ARG_UNUSED(dev);

 	switch (orientation) {
 	case DISPLAY_ORIENTATION_NORMAL:
 		return 0;
 	default:
 		return -ENOTSUP;
 	}
 }

 static void max7219_get_capabilities(const struct device *dev, struct display_capabilities *caps)
 {
 	const struct max7219_config *dev_config = dev->config;

 	caps->x_resolution = MAX7219_SEGMENTS_PER_DIGIT;
 	caps->y_resolution = MAX7219_DIGITS_PER_DEVICE * dev_config->num_cascading;
 	caps->supported_pixel_formats = PIXEL_FORMAT_MONO01;
 	caps->screen_info = 0;
 	caps->current_pixel_format = PIXEL_FORMAT_MONO01;
 	caps->current_orientation = DISPLAY_ORIENTATION_NORMAL;
 }

 static const struct display_driver_api max7219_api = {
 	.blanking_on = max7219_blanking_on,
 	.blanking_off = max7219_blanking_off,
 	.write = max7219_write,
 	.read = max7219_read,
 	.get_framebuffer = max7219_get_framebuffer,
 	.set_brightness = max7219_set_brightness,
 	.set_contrast = max7219_set_contrast,
 	.get_capabilities = max7219_get_capabilities,
 	.set_pixel_format = max7219_set_pixel_format,
 	.set_orientation = max7219_set_orientation,
 };

 static int max7219_init(const struct device *dev)
 {
 	const struct max7219_config *dev_config = dev->config;
 	struct max7219_data *dev_data = dev->data;
 	int ret;

 	if (!spi_is_ready(&dev_config->spi)) {
 		LOG_ERR("SPI device not ready");
 		return -ENODEV;
 	}

 	/* turn off all leds */
 	memset(dev_data->digit_buf, 0,
 	       dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE * sizeof(uint8_t));

 	ret = max7219_transmit_all(dev, MAX7219_REG_DISPLAY_TEST, MAX7219_LEAVE_DISPLAY_TEST_MODE);
 	if (ret < 0) {
 		LOG_ERR("Failed to disable display test");
 		return ret;
 	}

 	ret = max7219_transmit_all(dev, MAX7219_REG_DECODE_MODE, MAX7219_NO_DECODE);
 	if (ret < 0) {
 		LOG_ERR("Failed to set decode mode");
 		return ret;
 	}

 	ret = max7219_transmit_all(dev, MAX7219_REG_INTENSITY, dev_config->intensity);
 	if (ret < 0) {
 		LOG_ERR("Failed to set global brightness");
 		return ret;
 	}

 	ret = max7219_transmit_all(dev, MAX7219_REG_SCAN_LIMIT, dev_config->scan_limit);
 	if (ret < 0) {
 		LOG_ERR("Failed to set scan limit");
 		return ret;
 	}

 	ret = max7219_transmit_all(dev, MAX7219_REG_SHUTDOWN, MAX7219_LEAVE_SHUTDOWN_MODE);
 	if (ret < 0) {
 		LOG_ERR("Failed to leave shutdown state");
 		return ret;
 	}

 	const struct display_buffer_descriptor desc = {
 		.buf_size = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE,
 		.height = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE,
 		.width = MAX7219_DIGITS_PER_DEVICE,
 		.pitch = MAX7219_DIGITS_PER_DEVICE,
 	};

 	ret = max7219_write(dev, 0, 0, &desc, dev_data->digit_buf);
 	if (ret < 0) {
 		return ret;
 	}

 	return 0;
 }

 #define DISPLAY_MAX7219_INIT(n)                                                \
 	static uint8_t max7219_digit_data_##n[DT_INST_PROP(n, num_cascading) * \
 					      MAX7219_DIGITS_PER_DEVICE];      \
 	static uint8_t max7219_tx_buf##n[DT_INST_PROP(n, num_cascading) * 2];  \
 	static struct max7219_data max7219_data_##n = {                        \
 		.digit_buf = max7219_digit_data_##n,                           \
 		.tx_buf = max7219_tx_buf##n,                                   \
 	};                                                                     \
 	static const struct max7219_config max7219_config_##n = {              \
 		.spi = SPI_DT_SPEC_INST_GET(                                   \
 			n, SPI_OP_MODE_MASTER | SPI_WORD_SET(8U), 0U),         \
 		.num_cascading = DT_INST_PROP(n, num_cascading),               \
 		.intensity = DT_INST_PROP(n, intensity),                       \
 		.scan_limit = DT_INST_PROP(n, scan_limit),                     \
 	};                                                                     \
 	DEVICE_DT_INST_DEFINE(n, max7219_init, NULL, &max7219_data_##n,        \
 			      &max7219_config_##n, POST_KERNEL,                \
 			      CONFIG_DISPLAY_INIT_PRIORITY, &max7219_api);

 DT_INST_FOREACH_STATUS_OKAY(DISPLAY_MAX7219_INIT)
	/*
	* Copyright (c) 2022 Jimmy Ou <yanagiis@gmail.com>
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#define DT_DRV_COMPAT maxim_max7219

	/**
	* @file
	* @brief MAX7219 LED display driver
	*
	* This driver map the segment as x, digit as y.
	*
	* A MAX7219 has 8x8 pixels.
	* Two MAX7219s (with cascading) have 8x16 pixels.
	* So on and so forth.
	*
	* Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf
	*
	* Limitations:
	* 1. This driver only implements no-decode mode.
	*/

	#include <stddef.h>

	#include <zephyr/drivers/display.h>
	#include <zephyr/drivers/spi.h>
	#include <zephyr/logging/log.h>
	#include <zephyr/sys/byteorder.h>
	#include <zephyr/sys/util.h>
	#include <zephyr/kernel.h>
	LOG_MODULE_REGISTER(max7219, CONFIG_DISPLAY_LOG_LEVEL);

	#define MAX7219_SEGMENTS_PER_DIGIT 8
	#define MAX7219_DIGITS_PER_DEVICE 8

	/* clang-format off */

	/* MAX7219 registers and fields */
	#define MAX7219_REG_NOOP 0x00
	#define MAX7219_NOOP 0x00

	#define MAX7219_REG_DECODE_MODE 0x09
	#define MAX7219_NO_DECODE 0x00

	#define MAX7219_REG_INTENSITY 0x0A

	#define MAX7219_REG_SCAN_LIMIT 0x0B

	#define MAX7219_REG_SHUTDOWN 0x0C
	#define MAX7219_SHUTDOWN_MODE 0x00
	#define MAX7219_LEAVE_SHUTDOWN_MODE 0x01

	#define MAX7219_REG_DISPLAY_TEST 0x0F
	#define MAX7219_LEAVE_DISPLAY_TEST_MODE 0x00
	#define MAX7219_DISPLAY_TEST_MODE 0x01

	/* clang-format on */

	struct max7219_config {
	struct spi_dt_spec spi;
	uint32_t num_cascading;
	uint8_t intensity;
	uint8_t scan_limit;
	};

	struct max7219_data {
	/* Keep all digit_buf for all cascading MAX7219 */
	uint8_t *digit_buf;
	uint8_t *tx_buf;
	};

	static int max7219_transmit_all(const struct device *dev, const uint8_t addr, const uint8_t value)
	{
	const struct max7219_config *dev_config = dev->config;
	struct max7219_data *dev_data = dev->data;

	const struct spi_buf tx_buf = {
	.buf = dev_data->tx_buf,
	.len = dev_config->num_cascading * 2,
	};
	const struct spi_buf_set tx_bufs = {
	.buffers = &tx_buf,
	.count = 1U,
	};

	for (int i = 0; i < dev_config->num_cascading; i++) {
	dev_data->tx_buf[i * 2] = addr;
	dev_data->tx_buf[i * 2 + 1] = value;
	}

	return spi_write_dt(&dev_config->spi, &tx_bufs);
	}

	static int max7219_transmit_one(const struct device *dev, const uint8_t max7219_idx,
	const uint8_t addr, const uint8_t value)
	{
	const struct max7219_config *dev_config = dev->config;
	struct max7219_data *dev_data = dev->data;

	const struct spi_buf tx_buf = {
	.buf = dev_data->tx_buf,
	.len = dev_config->num_cascading * 2,
	};
	const struct spi_buf_set tx_bufs = {
	.buffers = &tx_buf,
	.count = 1U,
	};

	for (int i = 0; i < dev_config->num_cascading; i++) {
	if (i != (dev_config->num_cascading - 1 - max7219_idx)) {
	dev_data->tx_buf[i * 2] = MAX7219_REG_NOOP;
	dev_data->tx_buf[i * 2 + 1] = MAX7219_NOOP;
	continue;
	}

	dev_data->tx_buf[i * 2] = addr;
	dev_data->tx_buf[i * 2 + 1] = value;
	}

	return spi_write_dt(&dev_config->spi, &tx_bufs);
	}

	static inline uint8_t next_pixel(uint8_t mask, uint8_t data, const uint8_t **buf)
	{
	*mask <<= 1;
	if (!*mask) {
	*mask = 0x01;
	data = (*buf)++;
	}
	return data & mask;
	}

	static inline void skip_pixel(uint8_t mask, uint8_t data, const uint8_t **buf, uint16_t count)
	{
	while (count--) {
	next_pixel(mask, data, buf);
	}
	}

	static int max7219_blanking_on(const struct device *dev)
	{
	ARG_UNUSED(dev);

	return -ENOTSUP;
	}

	static int max7219_blanking_off(const struct device *dev)
	{
	ARG_UNUSED(dev);

	return -ENOTSUP;
	}

	static int max7219_write(const struct device *dev, const uint16_t x, const uint16_t y,
	const struct display_buffer_descriptor desc, const void buf)
	{
	const struct max7219_config *dev_config = dev->config;
	struct max7219_data *dev_data = dev->data;

	const uint16_t max_width = MAX7219_SEGMENTS_PER_DIGIT;
	const uint16_t max_height = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE;

	/*
	* MAX7219 only supports PIXEL_FORMAT_MONO01. 1 bit stands for 1 pixel.
	*/
	__ASSERT((desc->pitch * desc->height) <= (desc->buf_size * 8U), "Input buffer to small");
	__ASSERT(desc->width <= desc->pitch, "Pitch is smaller then width");
	__ASSERT(desc->pitch <= max_width, "Pitch in descriptor is larger than screen size");
	__ASSERT(desc->height <= max_height, "Height in descriptor is larger than screen size");
	__ASSERT(x + desc->pitch <= max_width,
	"Writing outside screen boundaries in horizontal direction");
	__ASSERT(y + desc->height <= max_height,
	"Writing outside screen boundaries in vertical direction");

	if (desc->width > desc->pitch \|\| (desc->pitch * desc->height) > (desc->buf_size * 8U)) {
	return -EINVAL;
	}

	if ((x + desc->pitch) > max_width \|\| (y + desc->height) > max_height) {
	return -EINVAL;
	}

	const uint16_t end_x = x + desc->width;
	const uint16_t end_y = y + desc->height;
	const uint8_t *byte_buf = buf;
	const uint16_t to_skip = desc->pitch - desc->width;
	uint8_t mask = 0;
	uint8_t data = 0;

	for (uint16_t py = y; py < end_y; ++py) {
	const uint8_t max7219_idx = py / MAX7219_DIGITS_PER_DEVICE;
	const uint8_t digit_idx = py % MAX7219_DIGITS_PER_DEVICE;
	uint8_t segment = dev_data->digit_buf[py];
	int ret;

	for (uint16_t px = x; px < end_x; ++px) {
	WRITE_BIT(segment, px, next_pixel(&mask, &data, &byte_buf));
	}

	skip_pixel(&mask, &data, &byte_buf, to_skip);

	/* led register address begins from 1 */
	ret = max7219_transmit_one(dev, max7219_idx, digit_idx + 1, segment);
	if (ret < 0) {
	return ret;
	}

	dev_data->digit_buf[y] = segment;
	}

	return 0;
	}

	static int max7219_read(const struct device *dev, const uint16_t x, const uint16_t y,
	const struct display_buffer_descriptor desc, void buf)
	{
	ARG_UNUSED(dev);
	ARG_UNUSED(x);
	ARG_UNUSED(y);
	ARG_UNUSED(desc);
	ARG_UNUSED(buf);

	return -ENOTSUP;
	}

	static void max7219_get_framebuffer(const struct device dev)
	{
	ARG_UNUSED(dev);

	return NULL;
	}

	static int max7219_set_brightness(const struct device *dev, const uint8_t brightness)
	{
	int ret;

	/*
	* max7219 supports intensity value from 0x0 to 0xF.
	* map the brightness from [0, 255] to [0, 15]
	*/
	ret = max7219_transmit_all(dev, MAX7219_REG_INTENSITY, brightness >> 4);
	if (ret < 0) {
	LOG_ERR("Failed to set brightness");
	return ret;
	}

	return 0;
	}

	static int max7219_set_contrast(const struct device *dev, const uint8_t contrast)
	{
	ARG_UNUSED(dev);
	ARG_UNUSED(contrast);

	return -ENOTSUP;
	}

	static int max7219_set_pixel_format(const struct device *dev,
	const enum display_pixel_format format)
	{
	ARG_UNUSED(dev);

	switch (format) {
	case PIXEL_FORMAT_MONO01:
	return 0;
	default:
	return -ENOTSUP;
	}
	}

	static int max7219_set_orientation(const struct device *dev,
	const enum display_orientation orientation)
	{
	ARG_UNUSED(dev);

	switch (orientation) {
	case DISPLAY_ORIENTATION_NORMAL:
	return 0;
	default:
	return -ENOTSUP;
	}
	}

	static void max7219_get_capabilities(const struct device dev, struct display_capabilities caps)
	{
	const struct max7219_config *dev_config = dev->config;

	caps->x_resolution = MAX7219_SEGMENTS_PER_DIGIT;
	caps->y_resolution = MAX7219_DIGITS_PER_DEVICE * dev_config->num_cascading;
	caps->supported_pixel_formats = PIXEL_FORMAT_MONO01;
	caps->screen_info = 0;
	caps->current_pixel_format = PIXEL_FORMAT_MONO01;
	caps->current_orientation = DISPLAY_ORIENTATION_NORMAL;
	}

	static const struct display_driver_api max7219_api = {
	.blanking_on = max7219_blanking_on,
	.blanking_off = max7219_blanking_off,
	.write = max7219_write,
	.read = max7219_read,
	.get_framebuffer = max7219_get_framebuffer,
	.set_brightness = max7219_set_brightness,
	.set_contrast = max7219_set_contrast,
	.get_capabilities = max7219_get_capabilities,
	.set_pixel_format = max7219_set_pixel_format,
	.set_orientation = max7219_set_orientation,
	};

	static int max7219_init(const struct device *dev)
	{
	const struct max7219_config *dev_config = dev->config;
	struct max7219_data *dev_data = dev->data;
	int ret;

	if (!spi_is_ready(&dev_config->spi)) {
	LOG_ERR("SPI device not ready");
	return -ENODEV;
	}

	/* turn off all leds */
	memset(dev_data->digit_buf, 0,
	dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE * sizeof(uint8_t));

	ret = max7219_transmit_all(dev, MAX7219_REG_DISPLAY_TEST, MAX7219_LEAVE_DISPLAY_TEST_MODE);
	if (ret < 0) {
	LOG_ERR("Failed to disable display test");
	return ret;
	}

	ret = max7219_transmit_all(dev, MAX7219_REG_DECODE_MODE, MAX7219_NO_DECODE);
	if (ret < 0) {
	LOG_ERR("Failed to set decode mode");
	return ret;
	}

	ret = max7219_transmit_all(dev, MAX7219_REG_INTENSITY, dev_config->intensity);
	if (ret < 0) {
	LOG_ERR("Failed to set global brightness");
	return ret;
	}

	ret = max7219_transmit_all(dev, MAX7219_REG_SCAN_LIMIT, dev_config->scan_limit);
	if (ret < 0) {
	LOG_ERR("Failed to set scan limit");
	return ret;
	}

	ret = max7219_transmit_all(dev, MAX7219_REG_SHUTDOWN, MAX7219_LEAVE_SHUTDOWN_MODE);
	if (ret < 0) {
	LOG_ERR("Failed to leave shutdown state");
	return ret;
	}

	const struct display_buffer_descriptor desc = {
	.buf_size = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE,
	.height = dev_config->num_cascading * MAX7219_DIGITS_PER_DEVICE,
	.width = MAX7219_DIGITS_PER_DEVICE,
	.pitch = MAX7219_DIGITS_PER_DEVICE,
	};

	ret = max7219_write(dev, 0, 0, &desc, dev_data->digit_buf);
	if (ret < 0) {
	return ret;
	}

	return 0;
	}

	#define DISPLAY_MAX7219_INIT(n) \
	static uint8_t max7219_digit_data_##n[DT_INST_PROP(n, num_cascading) * \
	MAX7219_DIGITS_PER_DEVICE]; \
	static uint8_t max7219_tx_buf##n[DT_INST_PROP(n, num_cascading) * 2]; \
	static struct max7219_data max7219_data_##n = { \
	.digit_buf = max7219_digit_data_##n, \
	.tx_buf = max7219_tx_buf##n, \
	}; \
	static const struct max7219_config max7219_config_##n = { \
	.spi = SPI_DT_SPEC_INST_GET( \
	n, SPI_OP_MODE_MASTER \| SPI_WORD_SET(8U), 0U), \
	.num_cascading = DT_INST_PROP(n, num_cascading), \
	.intensity = DT_INST_PROP(n, intensity), \
	.scan_limit = DT_INST_PROP(n, scan_limit), \
	}; \
	DEVICE_DT_INST_DEFINE(n, max7219_init, NULL, &max7219_data_##n, \
	&max7219_config_##n, POST_KERNEL, \
	CONFIG_DISPLAY_INIT_PRIORITY, &max7219_api);

	DT_INST_FOREACH_STATUS_OKAY(DISPLAY_MAX7219_INIT)