/*
* This file is part of Betaflight.
*
* Betaflight is free software. You can redistribute this software
* and/or modify this software under the terms of the GNU General
* Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later
* version.
*
* Betaflight is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this software.
*
* If not, see .
*/
#include
#include
#include
#include "platform.h"
#ifdef USE_LED_STRIP
#include "common/color.h"
#include "drivers/dma.h"
#include "platform/dma.h"
#include "drivers/io.h"
#include "drivers/light_ws2811strip.h"
#include "hardware/clocks.h"
#include "hardware/pio.h"
#define WS2812_WRAP_TARGET 0
#define WS2812_WRAP 3
#define WS2812_PIO_VERSION 0
#define WS2812_T1 3
#define WS2812_T2 3
#define WS2812_T3 4
#define WS2812_BYTES_PER_LED 4 // Number of bytes per WS2812 LED (RGB)
static IO_t ledStripIO = IO_NONE;
static ioTag_t ledStripIoTag = IO_TAG_NONE;
static ledStripFormatRGB_e ledStripFormat = LED_GRB; // Default format is RGB
// DMA channel
static uint8_t dma_chan;
// Buffer to hold the LED color data
static uint8_t led_data[WS2811_LED_STRIP_LENGTH][WS2812_BYTES_PER_LED];
static const uint16_t ws2812_program_instructions[] = {
// .wrap_target
0x6321, // 0: out x, 1 side 0 [3]
0x1223, // 1: jmp !x, 3 side 1 [2]
0x1200, // 2: jmp 0 side 1 [2]
0xa242, // 3: nop side 0 [2]
// .wrap
};
static const struct pio_program ws2812_program = {
.instructions = ws2812_program_instructions,
.length = ARRAYLEN(ws2812_program_instructions),
.origin = -1,
.pio_version = WS2812_PIO_VERSION,
.used_gpio_ranges = 0x0
};
static inline pio_sm_config ws2812_program_get_default_config(uint offset)
{
pio_sm_config c = pio_get_default_sm_config();
sm_config_set_wrap(&c, offset + WS2812_WRAP_TARGET, offset + WS2812_WRAP);
sm_config_set_sideset(&c, 1, false, false);
return c;
}
static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw)
{
pio_gpio_init(pio, pin);
pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
pio_sm_config c = ws2812_program_get_default_config(offset);
sm_config_set_sideset_pins(&c, pin);
sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
int cycles_per_bit = WS2812_T1 + WS2812_T2 + WS2812_T3;
int div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
sm_config_set_clkdiv(&c, div);
pio_sm_init(pio, sm, offset, &c);
pio_sm_set_enabled(pio, sm, true);
}
static FAST_IRQ_HANDLER void ws2811LedStripDmaHandler(dmaChannelDescriptor_t* descriptor)
{
UNUSED(descriptor);
ws2811LedDataTransferInProgress = false;
}
void ws2811LedStripInit(ioTag_t ioTag, ledStripFormatRGB_e ledFormat)
{
ledStripFormat = ledFormat; // Store the format globally
memset(led_data, 0, sizeof(led_data));
ledStripIoTag = ioTag;
}
bool ws2811LedStripHardwareInit(void)
{
if (!ledStripIoTag) {
return false;
}
IO_t io = IOGetByTag(ledStripIoTag);
if (!IOIsFreeOrPreinit(io)) {
return false;
}
// This will find a free pio and state machine for our program and load it for us
PIO pio;
uint sm;
uint offset;
int pinIndex = DEFIO_TAG_PIN(ledStripIoTag);
bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&ws2812_program, &pio, &sm, &offset, pinIndex, 1, true);
if (!success) {
return false; // No free PIO or state machine available
}
ws2812_program_init(pio, sm, offset, pinIndex, WS2811_CARRIER_HZ, ledStripFormat == LED_GRBW);
// --- DMA Configuration ---
const dmaIdentifier_e dma_id = dmaGetFreeIdentifier();
if (dma_id == DMA_NONE) {
return false; // No free DMA channel available
}
dma_chan = DMA_IDENTIFIER_TO_CHANNEL(dma_id);
dma_channel_config c = dma_channel_get_default_config(dma_chan);
channel_config_set_transfer_data_size(&c, DMA_SIZE_32);
channel_config_set_read_increment(&c, true);
channel_config_set_write_increment(&c, false);
channel_config_set_dreq(&c, pio_get_dreq(pio, sm, true));
dma_channel_configure(
dma_chan,
&c,
&pio->txf[sm], // Write address (PIO TX FIFO)
NULL, // Read address (set later)
WS2811_LED_STRIP_LENGTH, // Number of transfers
false // Don't start immediately
);
// --- Interrupt Configuration ---
dmaSetHandler(dma_id, ws2811LedStripDmaHandler, 0, 0);
IOInit(io, OWNER_LED_STRIP, 0);
ledStripIO = io;
return true;
}
void ws2811LedStripStartTransfer(void)
{
if (!ledStripIO) {
ws2811LedDataTransferInProgress = false;
return; // Not initialized
}
// Set the read address to the led_data buffer
dma_channel_set_read_addr(dma_chan, led_data, false);
// Start the DMA transfer
dma_channel_set_trans_count(dma_chan, WS2811_LED_STRIP_LENGTH, true);
}
void ws2811LedStripUpdateTransferBuffer(rgbColor24bpp_t *color, unsigned ledIndex)
{
if (ledIndex >= WS2811_LED_STRIP_LENGTH) {
return; // Index out of bounds
}
switch(ledStripFormat) {
case LED_RGB: // WS2811 drivers use RGB format
led_data[ledIndex][0] = color->rgb.r;
led_data[ledIndex][1] = color->rgb.g;
led_data[ledIndex][2] = color->rgb.b;
break;
case LED_GRBW: // SK6812 drivers use this
// Reconstruct white channel from RGB, making the intensity a bit nonlinear, but that's fine for this use case
{
uint8_t white = MIN(MIN(color->rgb.r, color->rgb.g), color->rgb.b);
led_data[ledIndex][0] = color->rgb.g; // Green
led_data[ledIndex][1] = color->rgb.r; // Red
led_data[ledIndex][2] = color->rgb.b; // Blue
led_data[ledIndex][3] = white; // White
}
break;
case LED_GRB: // WS2812 drivers use GRB format
default:
led_data[ledIndex][0] = color->rgb.g;
led_data[ledIndex][1] = color->rgb.r;
led_data[ledIndex][2] = color->rgb.b;
break;
}
}
#endif