qmk_firmware/drivers/arm/ws2812_spi.c
2020-02-29 11:59:30 -08:00

91 lines
2.8 KiB
C

#include "quantum.h"
#include "ws2812.h"
/* Adapted from https://github.com/gamazeps/ws2812b-chibios-SPIDMA/ */
#ifdef RGBW
# error "RGBW not supported"
#endif
// Define the spi your LEDs are plugged to here
#ifndef WS2812_SPI
# define WS2812_SPI SPID1
#endif
#ifndef WS2812_SPI_MOSI_PAL_MODE
# define WS2812_SPI_MOSI_PAL_MODE 5
#endif
#define BYTES_FOR_LED_BYTE 4
#define NB_COLORS 3
#define BYTES_FOR_LED (BYTES_FOR_LED_BYTE * NB_COLORS)
#define DATA_SIZE (BYTES_FOR_LED * RGBLED_NUM)
#define RESET_SIZE 200
#define PREAMBLE_SIZE 4
static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE] = {0};
/*
* As the trick here is to use the SPI to send a huge pattern of 0 and 1 to
* the ws2812b protocol, we use this helper function to translate bytes into
* 0s and 1s for the LED (with the appropriate timing).
*/
static uint8_t get_protocol_eq(uint8_t data, int pos) {
uint8_t eq = 0;
if (data & (1 << (2 * (3 - pos))))
eq = 0b1110;
else
eq = 0b1000;
if (data & (2 << (2 * (3 - pos))))
eq += 0b11100000;
else
eq += 0b10000000;
return eq;
}
static void set_led_color_rgb(LED_TYPE color, int pos) {
uint8_t* tx_start = &txbuf[PREAMBLE_SIZE];
for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + j] = get_protocol_eq(color.g, j);
for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE + j] = get_protocol_eq(color.r, j);
for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE * 2 + j] = get_protocol_eq(color.b, j);
}
void ws2812_init(void) {
#if defined(USE_GPIOV1)
palSetLineMode(RGB_DI_PIN, PAL_MODE_STM32_ALTERNATE_PUSHPULL);
#else
palSetLineMode(RGB_DI_PIN, PAL_MODE_ALTERNATE(WS2812_SPI_MOSI_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL);
#endif
// TODO: more dynamic baudrate
static const SPIConfig spicfg = {
0, NULL, PAL_PORT(RGB_DI_PIN), PAL_PAD(RGB_DI_PIN),
SPI_CR1_BR_1 | SPI_CR1_BR_0 // baudrate : fpclk / 8 => 1tick is 0.32us (2.25 MHz)
};
spiAcquireBus(&WS2812_SPI); /* Acquire ownership of the bus. */
spiStart(&WS2812_SPI, &spicfg); /* Setup transfer parameters. */
spiSelect(&WS2812_SPI); /* Slave Select assertion. */
}
void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) {
static bool s_init = false;
if (!s_init) {
ws2812_init();
s_init = true;
}
for (uint8_t i = 0; i < leds; i++) {
set_led_color_rgb(ledarray[i], i);
}
// Send async - each led takes ~0.03ms, 50 leds ~1.5ms, animations flushing faster than send will cause issues.
// Instead spiSend can be used to send synchronously (or the thread logic can be added back).
#ifdef WS2812_SPI_SYNC
spiSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
#else
spiStartSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
#endif
}