led_strip_spi_dev.c File Reference

#include <stdlib.h>
#include <string.h>
#include <sys/cdefs.h>
#include "esp_heap_caps.h"
#include "esp_log.h"
#include "esp_check.h"
#include "esp_rom_gpio.h"
#include "soc/spi_periph.h"
#include "led_strip.h"
#include "led_strip_interface.h"
#include "hal/spi_hal.h"

Include dependency graph for led_strip_spi_dev.c:

Go to the source code of this file.

Data Structures
struct	led_strip_spi_obj

Macros
#define	LED_STRIP_SPI_DEFAULT_RESOLUTION   (2.5 * 1000 * 1000)
#define	LED_STRIP_SPI_DEFAULT_TRANS_QUEUE_SIZE   4
#define	SPI_BYTES_PER_COLOR_BYTE   3
#define	SPI_BITS_PER_COLOR_BYTE   (SPI_BYTES_PER_COLOR_BYTE * 8)

Functions
static void	__led_strip_spi_bit (uint8_t data, uint8_t *buf)
static esp_err_t	led_strip_spi_set_pixel (led_strip_t *strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue)
static esp_err_t	led_strip_spi_set_pixel_rgbw (led_strip_t *strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue, uint32_t white)
static esp_err_t	led_strip_spi_refresh (led_strip_t *strip)
static esp_err_t	led_strip_spi_clear (led_strip_t *strip)
static esp_err_t	led_strip_spi_del (led_strip_t *strip)
esp_err_t	led_strip_new_spi_device (const led_strip_config_t *led_config, const led_strip_spi_config_t *spi_config, led_strip_handle_t *ret_strip)
	Create LED strip based on SPI MOSI channel.

Variables
static const char *	TAG = "led_strip_spi"

Macro Definition Documentation

LED_STRIP_SPI_DEFAULT_RESOLUTION

#define LED_STRIP_SPI_DEFAULT_RESOLUTION   (2.5 * 1000 * 1000)

Definition at line 18 of file led_strip_spi_dev.c.

Referenced by led_strip_new_spi_device().

LED_STRIP_SPI_DEFAULT_TRANS_QUEUE_SIZE

#define LED_STRIP_SPI_DEFAULT_TRANS_QUEUE_SIZE   4

Definition at line 19 of file led_strip_spi_dev.c.

Referenced by led_strip_new_spi_device().

SPI_BITS_PER_COLOR_BYTE

#define SPI_BITS_PER_COLOR_BYTE   (SPI_BYTES_PER_COLOR_BYTE * 8)

Definition at line 22 of file led_strip_spi_dev.c.

Referenced by led_strip_spi_refresh().

SPI_BYTES_PER_COLOR_BYTE

#define SPI_BYTES_PER_COLOR_BYTE   3

Definition at line 21 of file led_strip_spi_dev.c.

Referenced by led_strip_new_spi_device(), led_strip_spi_clear(), led_strip_spi_set_pixel(), and led_strip_spi_set_pixel_rgbw().

Function Documentation

__led_strip_spi_bit()

void __led_strip_spi_bit ( uint8_t data, uint8_t * buf )

static

Definition at line 36 of file led_strip_spi_dev.c.

{
    // Each color of 1 bit is represented by 3 bits of SPI, low_level:100 ,high_level:110
    // So a color byte occupies 3 bytes of SPI.
    *(buf + 2) |= data & BIT(0) ? BIT(2) | BIT(1) : BIT(2);
    *(buf + 2) |= data & BIT(1) ? BIT(5) | BIT(4) : BIT(5);
    *(buf + 2) |= data & BIT(2) ? BIT(7) : 0x00;
    *(buf + 1) |= BIT(0);
    *(buf + 1) |= data & BIT(3) ? BIT(3) | BIT(2) : BIT(3);
    *(buf + 1) |= data & BIT(4) ? BIT(6) | BIT(5) : BIT(6);
    *(buf + 0) |= data & BIT(5) ? BIT(1) | BIT(0) : BIT(1);
    *(buf + 0) |= data & BIT(6) ? BIT(4) | BIT(3) : BIT(4);
    *(buf + 0) |= data & BIT(7) ? BIT(7) | BIT(6) : BIT(7);
}

References data.

Referenced by led_strip_spi_clear(), led_strip_spi_set_pixel(), and led_strip_spi_set_pixel_rgbw().

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led_strip_new_spi_device()

esp_err_t led_strip_new_spi_device	(	const led_strip_config_t *	led_config,
		const led_strip_spi_config_t *	spi_config,
		led_strip_handle_t *	ret_strip )

Create LED strip based on SPI MOSI channel.

Note

Although only the MOSI line is used for generating the signal, the whole SPI bus can't be used for other purposes.

Parameters

led_config	LED strip configuration
spi_config	SPI specific configuration
ret_strip	Returned LED strip handle

Returns

• ESP_OK: create LED strip handle successfully
• ESP_ERR_INVALID_ARG: create LED strip handle failed because of invalid argument
• ESP_ERR_NOT_SUPPORTED: create LED strip handle failed because of unsupported configuration
• ESP_ERR_NO_MEM: create LED strip handle failed because of out of memory
• ESP_FAIL: create LED strip handle failed because some other error

Definition at line 123 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = NULL;
    esp_err_t ret = ESP_OK;
    ESP_GOTO_ON_FALSE(led_config && spi_config && ret_strip, ESP_ERR_INVALID_ARG, err, TAG, "invalid argument");
    ESP_GOTO_ON_FALSE(led_config->led_pixel_format < LED_PIXEL_FORMAT_INVALID, ESP_ERR_INVALID_ARG, err, TAG, "invalid led_pixel_format");
    uint8_t bytes_per_pixel = 3;
    if (led_config->led_pixel_format == LED_PIXEL_FORMAT_GRBW) {
        bytes_per_pixel = 4;
    } else if (led_config->led_pixel_format == LED_PIXEL_FORMAT_GRB) {
        bytes_per_pixel = 3;
    } else {
        assert(false);
    }
    uint32_t mem_caps = MALLOC_CAP_DEFAULT;
    if (spi_config->flags.with_dma) {
        // DMA buffer must be placed in internal SRAM
        mem_caps |= MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA;
    }
    spi_strip = heap_caps_calloc(1, sizeof(led_strip_spi_obj) + led_config->max_leds * bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE, mem_caps);
 
    ESP_GOTO_ON_FALSE(spi_strip, ESP_ERR_NO_MEM, err, TAG, "no mem for spi strip");
 
    spi_strip->spi_host = spi_config->spi_bus;
    // for backward compatibility, if the user does not set the clk_src, use the default value
    spi_clock_source_t clk_src = SPI_CLK_SRC_DEFAULT;
    if (spi_config->clk_src) {
        clk_src = spi_config->clk_src;
    }
 
    spi_bus_config_t spi_bus_cfg = {
        .mosi_io_num = led_config->strip_gpio_num,
        //Only use MOSI to generate the signal, set -1 when other pins are not used.
        .miso_io_num = -1,
        .sclk_io_num = -1,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
        .max_transfer_sz = led_config->max_leds * bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE,
    };
    ESP_GOTO_ON_ERROR(spi_bus_initialize(spi_strip->spi_host, &spi_bus_cfg, spi_config->flags.with_dma ? SPI_DMA_CH_AUTO : SPI_DMA_DISABLED), err, TAG, "create SPI bus failed");
 
    if (led_config->flags.invert_out == true) {
        esp_rom_gpio_connect_out_signal(led_config->strip_gpio_num, spi_periph_signal[spi_strip->spi_host].spid_out, true, false);
    }
 
    spi_device_interface_config_t spi_dev_cfg = {
        .clock_source = clk_src,
        .command_bits = 0,
        .address_bits = 0,
        .dummy_bits = 0,
        .clock_speed_hz = LED_STRIP_SPI_DEFAULT_RESOLUTION,
        .mode = 0,
        //set -1 when CS is not used
        .spics_io_num = -1,
        .queue_size = LED_STRIP_SPI_DEFAULT_TRANS_QUEUE_SIZE,
    };
 
    ESP_GOTO_ON_ERROR(spi_bus_add_device(spi_strip->spi_host, &spi_dev_cfg, &spi_strip->spi_device), err, TAG, "Failed to add spi device");
    //ensure the reset time is enough
    esp_rom_delay_us(10);
    int clock_resolution_khz = 0;
    spi_device_get_actual_freq(spi_strip->spi_device, &clock_resolution_khz);
    // TODO: ideally we should decide the SPI_BYTES_PER_COLOR_BYTE by the real clock resolution
    // But now, let's fixed the resolution, the downside is, we don't support a clock source whose frequency is not multiple of LED_STRIP_SPI_DEFAULT_RESOLUTION
    // clock_resolution between 2.2MHz to 2.8MHz is supported
    ESP_GOTO_ON_FALSE((clock_resolution_khz < LED_STRIP_SPI_DEFAULT_RESOLUTION / 1000 + 300) && (clock_resolution_khz > LED_STRIP_SPI_DEFAULT_RESOLUTION / 1000 - 300), ESP_ERR_NOT_SUPPORTED, err,
                      TAG, "unsupported clock resolution:%dKHz", clock_resolution_khz);
 
    spi_strip->bytes_per_pixel = bytes_per_pixel;
    spi_strip->strip_len = led_config->max_leds;
    spi_strip->base.set_pixel = led_strip_spi_set_pixel;
    spi_strip->base.set_pixel_rgbw = led_strip_spi_set_pixel_rgbw;
    spi_strip->base.refresh = led_strip_spi_refresh;
    spi_strip->base.clear = led_strip_spi_clear;
    spi_strip->base.del = led_strip_spi_del;
 
    *ret_strip = &spi_strip->base;
    return ESP_OK;
err:
    if (spi_strip) {
        if (spi_strip->spi_device) {
            spi_bus_remove_device(spi_strip->spi_device);
        }
        if (spi_strip->spi_host) {
            spi_bus_free(spi_strip->spi_host);
        }
        free(spi_strip);
    }
    return ret;
}

References led_strip_spi_obj::base, led_strip_spi_obj::bytes_per_pixel, led_strip_t::clear, led_strip_spi_config_t::clk_src, led_strip_t::del, ESP_GOTO_ON_ERROR, ESP_OK, led_strip_config_t::flags, led_strip_spi_config_t::flags, led_strip_config_t::invert_out, led_strip_config_t::led_pixel_format, LED_PIXEL_FORMAT_GRB, LED_PIXEL_FORMAT_GRBW, LED_PIXEL_FORMAT_INVALID, led_strip_spi_clear(), LED_STRIP_SPI_DEFAULT_RESOLUTION, LED_STRIP_SPI_DEFAULT_TRANS_QUEUE_SIZE, led_strip_spi_del(), led_strip_spi_refresh(), led_strip_spi_set_pixel(), led_strip_spi_set_pixel_rgbw(), led_strip_config_t::max_leds, led_strip_t::refresh, led_strip_t::set_pixel, led_strip_t::set_pixel_rgbw, led_strip_spi_config_t::spi_bus, SPI_BYTES_PER_COLOR_BYTE, led_strip_spi_obj::spi_device, led_strip_spi_obj::spi_host, led_strip_config_t::strip_gpio_num, led_strip_spi_obj::strip_len, TAG, and led_strip_spi_config_t::with_dma.

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led_strip_spi_clear()

esp_err_t led_strip_spi_clear ( led_strip_t * strip )

static

Definition at line 98 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = __containerof(strip, led_strip_spi_obj, base);
    //Write zero to turn off all leds
    memset(spi_strip->pixel_buf, 0, spi_strip->strip_len * spi_strip->bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE);
    uint8_t *buf = spi_strip->pixel_buf;
    for (int index = 0; index < spi_strip->strip_len * spi_strip->bytes_per_pixel; index++) {
        __led_strip_spi_bit(0, buf);
        buf += SPI_BYTES_PER_COLOR_BYTE;
    }
 
    return led_strip_spi_refresh(strip);
}

References __led_strip_spi_bit(), led_strip_spi_obj::bytes_per_pixel, led_strip_spi_refresh(), led_strip_spi_obj::pixel_buf, SPI_BYTES_PER_COLOR_BYTE, and led_strip_spi_obj::strip_len.

Referenced by led_strip_new_spi_device().

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led_strip_spi_del()

esp_err_t led_strip_spi_del ( led_strip_t * strip )

static

Definition at line 112 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = __containerof(strip, led_strip_spi_obj, base);
 
    ESP_RETURN_ON_ERROR(spi_bus_remove_device(spi_strip->spi_device), TAG, "delete spi device failed");
    ESP_RETURN_ON_ERROR(spi_bus_free(spi_strip->spi_host), TAG, "free spi bus failed");
 
    free(spi_strip);
    return ESP_OK;
}

References ESP_OK, ESP_RETURN_ON_ERROR, led_strip_spi_obj::spi_device, led_strip_spi_obj::spi_host, and TAG.

Referenced by led_strip_new_spi_device().

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led_strip_spi_refresh()

esp_err_t led_strip_spi_refresh ( led_strip_t * strip )

static

Definition at line 84 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = __containerof(strip, led_strip_spi_obj, base);
    spi_transaction_t tx_conf;
    memset(&tx_conf, 0, sizeof(tx_conf));
 
    tx_conf.length = spi_strip->strip_len * spi_strip->bytes_per_pixel * SPI_BITS_PER_COLOR_BYTE;
    tx_conf.tx_buffer = spi_strip->pixel_buf;
    tx_conf.rx_buffer = NULL;
    ESP_RETURN_ON_ERROR(spi_device_transmit(spi_strip->spi_device, &tx_conf), TAG, "transmit pixels by SPI failed");
 
    return ESP_OK;
}

References led_strip_spi_obj::bytes_per_pixel, ESP_OK, ESP_RETURN_ON_ERROR, led_strip_spi_obj::pixel_buf, SPI_BITS_PER_COLOR_BYTE, led_strip_spi_obj::spi_device, led_strip_spi_obj::strip_len, and TAG.

Referenced by led_strip_new_spi_device(), and led_strip_spi_clear().

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led_strip_spi_set_pixel()

esp_err_t led_strip_spi_set_pixel ( led_strip_t * strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue )

static

Definition at line 51 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = __containerof(strip, led_strip_spi_obj, base);
    ESP_RETURN_ON_FALSE(index < spi_strip->strip_len, ESP_ERR_INVALID_ARG, TAG, "index out of maximum number of LEDs");
    // LED_PIXEL_FORMAT_GRB takes 72bits(9bytes)
    uint32_t start = index * spi_strip->bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE;
    memset(spi_strip->pixel_buf + start, 0, spi_strip->bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE);
    __led_strip_spi_bit(green, &spi_strip->pixel_buf[start]);
    __led_strip_spi_bit(red, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE]);
    __led_strip_spi_bit(blue, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE * 2]);
    if (spi_strip->bytes_per_pixel > 3) {
        __led_strip_spi_bit(0, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE * 3]);
    }
    return ESP_OK;
}

References __led_strip_spi_bit(), led_strip_spi_obj::bytes_per_pixel, ESP_OK, led_strip_spi_obj::pixel_buf, SPI_BYTES_PER_COLOR_BYTE, and TAG.

Referenced by led_strip_new_spi_device().

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led_strip_spi_set_pixel_rgbw()

esp_err_t led_strip_spi_set_pixel_rgbw ( led_strip_t * strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue, uint32_t white )

static

Definition at line 67 of file led_strip_spi_dev.c.

{
    led_strip_spi_obj *spi_strip = __containerof(strip, led_strip_spi_obj, base);
    ESP_RETURN_ON_FALSE(index < spi_strip->strip_len, ESP_ERR_INVALID_ARG, TAG, "index out of maximum number of LEDs");
    ESP_RETURN_ON_FALSE(spi_strip->bytes_per_pixel == 4, ESP_ERR_INVALID_ARG, TAG, "wrong LED pixel format, expected 4 bytes per pixel");
    // LED_PIXEL_FORMAT_GRBW takes 96bits(12bytes)
    uint32_t start = index * spi_strip->bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE;
    // SK6812 component order is GRBW
    memset(spi_strip->pixel_buf + start, 0, spi_strip->bytes_per_pixel * SPI_BYTES_PER_COLOR_BYTE);
    __led_strip_spi_bit(green, &spi_strip->pixel_buf[start]);
    __led_strip_spi_bit(red, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE]);
    __led_strip_spi_bit(blue, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE * 2]);
    __led_strip_spi_bit(white, &spi_strip->pixel_buf[start + SPI_BYTES_PER_COLOR_BYTE * 3]);
 
    return ESP_OK;
}

References __led_strip_spi_bit(), led_strip_spi_obj::bytes_per_pixel, ESP_OK, led_strip_spi_obj::pixel_buf, SPI_BYTES_PER_COLOR_BYTE, and TAG.

Referenced by led_strip_new_spi_device().

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Variable Documentation

TAG

const char* TAG = "led_strip_spi"

static

Definition at line 24 of file led_strip_spi_dev.c.