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[Core] Allow custom timings for WS2812 PIO driver (#18006)

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Stefan Kerkmann 2022-11-09 21:58:15 +01:00 • committed by GitHub
parent bc6f8dc8b0
commit 27dec8d16d
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2 changed files with 172 additions and 78 deletions
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248
platforms/chibios/drivers/vendor/RP/RP2040/ws2812_vendor.c vendored
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@ -1,4 +1,4 @@
// Copyright 2022 Stefan Kerkmann
// Copyright 2022 Stefan Kerkmann (@KarlK90)
// SPDX-License-Identifier: GPL-2.0-or-later
#include "quantum.h"
@ -17,53 +17,156 @@ static const PIO pio = pio0;
#endif
#if !defined(RP_DMA_PRIORITY_WS2812)
# define RP_DMA_PRIORITY_WS2812 12
# define RP_DMA_PRIORITY_WS2812 3
#endif
static int state_machine = -1;
#define WS2812_WRAP_TARGET 0
#define WS2812_WRAP 3
#define WS2812_T1 2
#define WS2812_T2 5
#define WS2812_T3 3
#if defined(WS2812_EXTERNAL_PULLUP)
# pragma message "The GPIOs of the RP2040 are NOT 5V tolerant! Make sure to NOT apply any voltage over 3.3V to the RGB data pin."
// clang-format off
static const uint16_t ws2812_program_instructions[] = {
// .wrap_target
0x7221, // 0: out x, 1 side 1 [2]
0x0123, // 1: jmp !x, 3 side 0 [1]
0x0400, // 2: jmp 0 side 0 [4]
0xb442, // 3: nop side 1 [4]
// .wrap
};
#else
static const uint16_t ws2812_program_instructions[] = {
// .wrap_target
0x6221, // 0: out x, 1 side 0 [2]
0x1123, // 1: jmp !x, 3 side 1 [1]
0x1400, // 2: jmp 0 side 1 [4]
0xa442, // 3: nop side 0 [4]
// .wrap
};
// clang-format on
#endif
/*================== WS2812 PIO TIMINGS =================*/
// WS2812_T1L rounded to 50ns intervals and split into two wait timings
#define PIO_T1L (WS2812_T1L / 50)
#define PIO_T1L_A (MAX(CEILING(PIO_T1L, 2) - 1, 0))
#define PIO_T1L_B (MAX(PIO_T1L / 2 - 1, 0))
// WS2812_T0L rounded to 50ns intervals
#define PIO_T0L (MAX(WS2812_T0L / 50 - PIO_T1L, 0))
#define PIO_T0L_A (MAX(PIO_T0L - 1, 0))
// WS2812_T0H rounded to 50ns intervals
#define PIO_T0H (WS2812_T0H / 50)
#define PIO_T0H_A MAX(PIO_T0H - 1, 0)
// WS2812_T1H rounded to 50ns intervals and split into two wait timings
#define PIO_T1H (MAX(WS2812_T1H / 50 - PIO_T0H, 0))
#define PIO_T1H_A (MAX((CEILING(PIO_T1H, 2) - 1), 0))
#define PIO_T1H_B (MAX((PIO_T1H / 2) - 1, 0))
#if (WS2812_T0L % 50) != 0
# pragma message "WS2812_T0L is not given in an 50ns interval, it will be rounded to the next 50ns"
#endif
#if (WS2812_T0H % 50) != 0
# pragma message "WS2812_T0H is not given in an 50ns interval, it will be rounded to the next 50ns"
#endif
#if (WS2812_T1L % 50) != 0
# pragma message "WS2812_T0L is not given in an 50ns interval, it will be rounded to the next 50ns"
#endif
#if (WS2812_T1H % 50) != 0
# pragma message "WS2812_T0H is not given in an 50ns interval, it will be rounded to the next 50ns"
#endif
#if WS2812_T0L < WS2812_T1L
# error WS2812_T0L is shorter than WS2812_T1L, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T1H < WS2812_T0H
# error WS2812_T1H is shorter than WS2812_T0H, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T0L > (850 + WS2812_T1L)
# error WS2812_T0L is longer than 850ns + WS2812_T1L, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T0H > 850
# error WS2812_T0H is longer than 850ns, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T1H > (1700 + WS2812_T0H)
# error WS2812_T1H is longer than 1700ns + WS2812_T0H, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T1L > 1700
# error WS2812_T1L is longer than 1700ns, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T0L < (50 + WS2812_T1L)
# error WS2812_T0L is shorter than 50ns + WS2812_T1L, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T0H < 50
# error WS2812_T0H is shorter than 50ns, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T1H < (100 + WS2812_T0H)
# error WS2812_T1H is longer than 100ns + WS2812_T0H, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
#if WS2812_T1L < 100
# error WS2812_T1L is longer than 1700ns, this is impossible to express in the RP2040 PIO driver. Please correct your timings.
#endif
/**
* @brief Helper macro to binary patch the delay part of an per-compiled PIO
* opcode.
*/
#define PIO_DELAY(delay, opcode) (((delay & 0xF) << 8U) | opcode)
#define WS2812_WRAP_TARGET 0
#define WS2812_WRAP 5
static const uint16_t ws2812_program_instructions[] = {
// .wrap_target
PIO_DELAY(PIO_T1L_A, 0x6021), // 0: out x, 1 side 0 // T1L (max. 1700ns)
PIO_DELAY(PIO_T1L_B, 0xa042), // 1: nop side 0 // T1L
PIO_DELAY(PIO_T0H_A, 0x1025), // 2: jmp !x, 5 side 1 // T0H (max. 850ns)
PIO_DELAY(PIO_T1H_A, 0xb042), // 3: nop side 1 // T1H (max. 1700ns + T0H)
PIO_DELAY(PIO_T1H_B, 0x1000), // 4: jmp 0 side 1 // T1H
PIO_DELAY(PIO_T0L_A, 0xa042), // 5: nop side 0 // T0L (max. 850ns + T1L)
// .wrap
};
static const pio_program_t ws2812_program = {
.instructions = ws2812_program_instructions,
.length = 4,
.length = ARRAY_SIZE(ws2812_program_instructions),
.origin = -1,
};
static uint32_t WS2812_BUFFER[WS2812_LED_COUNT];
static const rp_dma_channel_t* WS2812_DMA_CHANNEL;
static uint32_t RP_DMA_MODE_WS2812;
static int STATE_MACHINE = -1;
static SEMAPHORE_DECL(TRANSFER_COUNTER, 1);
static rtcnt_t LAST_TRANSFER;
/**
* @brief Convert RGBW value into WS2812 compatible 32-bit data word.
*/
__always_inline static uint32_t rgbw8888_to_u32(uint8_t red, uint8_t green, uint8_t blue, uint8_t white) {
#if (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_GRB)
return ((uint32_t)green << 24) | ((uint32_t)red << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_RGB)
return ((uint32_t)red << 24) | ((uint32_t)green << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_BGR)
return ((uint32_t)blue << 24) | ((uint32_t)green << 16) | ((uint32_t)red << 8) | ((uint32_t)white);
#endif
}
static void ws2812_dma_callback(void* p, uint32_t ct) {
// We assume that there is at least one frame left in the OSR even if the TX
// FIFO is already empty.
rtcnt_t time_to_completion = (pio_sm_get_tx_fifo_level(pio, STATE_MACHINE) + 1) * MAX(WS2812_T1H + WS2812_T1L, WS2812_T0H + WS2812_T0L);
#if defined(RGBW)
time_to_completion *= 32;
#else
time_to_completion *= 24;
#endif
// Convert from ns to us
time_to_completion /= 1000;
LAST_TRANSFER = chSysGetRealtimeCounterX() + time_to_completion + WS2812_TRST_US;
osalSysLockFromISR();
chSemSignalI(&TRANSFER_COUNTER);
osalSysUnlockFromISR();
}
bool ws2812_init(void) {
uint pio_idx = pio_get_index(pio);
@ -73,20 +176,23 @@ bool ws2812_init(void) {
// clang-format off
iomode_t rgb_pin_mode = PAL_RP_PAD_SLEWFAST |
PAL_RP_GPIO_OE |
#if defined(WS2812_EXTERNAL_PULLUP)
PAL_RP_IOCTRL_OEOVER_DRVINVPERI |
#endif
(pio_idx == 0 ? PAL_MODE_ALTERNATE_PIO0 : PAL_MODE_ALTERNATE_PIO1);
// clang-format on
palSetLineMode(RGB_DI_PIN, rgb_pin_mode);
state_machine = pio_claim_unused_sm(pio, true);
if (state_machine < 0) {
STATE_MACHINE = pio_claim_unused_sm(pio, true);
if (STATE_MACHINE < 0) {
dprintln("ERROR: Failed to acquire state machine for WS2812 output!");
return false;
}
uint offset = pio_add_program(pio, &ws2812_program);
pio_sm_set_consecutive_pindirs(pio, state_machine, RGB_DI_PIN, 1, true);
pio_sm_set_consecutive_pindirs(pio, STATE_MACHINE, RGB_DI_PIN, 1, true);
pio_sm_config config = pio_get_default_sm_config();
sm_config_set_wrap(&config, offset + WS2812_WRAP_TARGET, offset + WS2812_WRAP);
@ -113,57 +219,44 @@ bool ws2812_init(void) {
sm_config_set_out_shift(&config, false, true, 24);
#endif
int cycles_per_bit = WS2812_T1 + WS2812_T2 + WS2812_T3;
float div = clock_get_hz(clk_sys) / (800.0f * KHZ * cycles_per_bit);
// Every instruction takes 50ns to execute with a clock speed of 20 MHz,
// giving the WS2812 PIO driver its time resolution
float div = clock_get_hz(clk_sys) / (20.0f * MHZ);
sm_config_set_clkdiv(&config, div);
pio_sm_init(pio, state_machine, offset, &config);
pio_sm_set_enabled(pio, state_machine, true);
pio_sm_init(pio, STATE_MACHINE, offset, &config);
pio_sm_set_enabled(pio, STATE_MACHINE, true);
WS2812_DMA_CHANNEL = dmaChannelAlloc(RP_DMA_CHANNEL_ID_ANY, RP_DMA_PRIORITY_WS2812, NULL, NULL);
WS2812_DMA_CHANNEL = dmaChannelAlloc(RP_DMA_CHANNEL_ID_ANY, RP_DMA_PRIORITY_WS2812, (rp_dmaisr_t)ws2812_dma_callback, NULL);
dmaChannelEnableInterruptX(WS2812_DMA_CHANNEL);
dmaChannelSetDestinationX(WS2812_DMA_CHANNEL, (uint32_t)&pio->txf[STATE_MACHINE]);
// clang-format off
uint32_t mode = DMA_CTRL_TRIG_INCR_READ |
DMA_CTRL_TRIG_DATA_SIZE_WORD |
DMA_CTRL_TRIG_IRQ_QUIET |
DMA_CTRL_TRIG_TREQ_SEL(pio_idx == 0 ? state_machine : state_machine + 8);
RP_DMA_MODE_WS2812 = DMA_CTRL_TRIG_INCR_READ |
DMA_CTRL_TRIG_DATA_SIZE_WORD |
DMA_CTRL_TRIG_TREQ_SEL(pio == pio0 ? STATE_MACHINE : STATE_MACHINE + 8) |
DMA_CTRL_TRIG_PRIORITY(RP_DMA_PRIORITY_WS2812);
// clang-format on
dmaChannelSetModeX(WS2812_DMA_CHANNEL, mode);
dmaChannelSetDestinationX(WS2812_DMA_CHANNEL, (uint32_t)&pio->txf[state_machine]);
return true;
}
/**
* @brief Convert RGBW value into WS2812 compatible 32-bit data word.
*/
__always_inline static uint32_t rgbw8888_to_u32(uint8_t red, uint8_t green, uint8_t blue, uint8_t white) {
#if (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_GRB)
return ((uint32_t)green << 24) | ((uint32_t)red << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_RGB)
return ((uint32_t)red << 24) | ((uint32_t)green << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_BGR)
return ((uint32_t)blue << 24) | ((uint32_t)green << 16) | ((uint32_t)red << 8) | ((uint32_t)white);
#endif
}
static inline void sync_ws2812_transfer(void) {
if (unlikely(dmaChannelIsBusyX(WS2812_DMA_CHANNEL) || !pio_sm_is_tx_fifo_empty(pio, state_machine))) {
fast_timer_t start = timer_read_fast();
do {
// Abort the synchronization if we have to wait longer than the total
// count of LEDs in millisecounds. This is safely much longer than it
// would take to push all the data out.
if (unlikely(timer_elapsed_fast(start) > WS2812_LED_COUNT)) {
dprintln("ERROR: WS2812 DMA transfer has stalled, aborting!");
dmaChannelDisableX(WS2812_DMA_CHANNEL);
return;
}
} while (dmaChannelIsBusyX(WS2812_DMA_CHANNEL) || !pio_sm_is_tx_fifo_empty(pio, state_machine));
// We wait for the WS2812 chain to reset after all data has been pushed
// out.
if (chSemWaitTimeout(&TRANSFER_COUNTER, TIME_MS2I(RGBLED_NUM)) == MSG_TIMEOUT) {
// Abort the synchronization if we have to wait longer than the total
// count of LEDs in milliseconds. This is safely much longer than it
// would take to push all the data out.
dprintln("ERROR: WS2812 DMA transfer has stalled, aborting!");
dmaChannelDisableX(WS2812_DMA_CHANNEL);
pio_sm_clear_fifos(pio, STATE_MACHINE);
pio_sm_restart(pio, STATE_MACHINE);
chSemReset(&TRANSFER_COUNTER, 0);
wait_us(WS2812_TRST_US);
return;
}
// Busy wait until last transfer has finished
while (unlikely(!timer_expired32(chSysGetRealtimeCounterX(), LAST_TRANSFER))) {
}
}
@ -185,5 +278,6 @@ void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) {
dmaChannelSetSourceX(WS2812_DMA_CHANNEL, (uint32_t)WS2812_BUFFER);
dmaChannelSetCounterX(WS2812_DMA_CHANNEL, leds);
dmaChannelSetModeX(WS2812_DMA_CHANNEL, RP_DMA_MODE_WS2812);
dmaChannelEnableX(WS2812_DMA_CHANNEL);
}