| /* |
| * 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_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_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_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 = { |
| .write = max7219_write, |
| .set_brightness = max7219_set_brightness, |
| .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_dt(&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) |