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HAL_ChibiOS: allow handling of much higher receiver baudrates with DMA

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this uses two DMA RX bouncebuffers to minimise the time with DMA
disabled so that we can handle much higher baudrates
This commit is contained in:
Andrew Tridgell 2019-12-21 14:39:01 +11:00
parent 58292821b3
commit 4b4642dd4d
2 changed files with 58 additions and 42 deletions
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77
libraries/AP_HAL_ChibiOS/UARTDriver.cpp
View File

@ -198,14 +198,19 @@ void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
}
#ifndef HAL_UART_NODMA
if (rx_bounce_buf == nullptr) {
rx_bounce_buf = (uint8_t *)hal.util->malloc_type(RX_BOUNCE_BUFSIZE, AP_HAL::Util::MEM_DMA_SAFE);
if (rx_bounce_buf[0] == nullptr && sdef.dma_rx) {
rx_bounce_buf[0] = (uint8_t *)hal.util->malloc_type(RX_BOUNCE_BUFSIZE, AP_HAL::Util::MEM_DMA_SAFE);
}
if (tx_bounce_buf == nullptr) {
if (rx_bounce_buf[1] == nullptr && sdef.dma_rx) {
rx_bounce_buf[1] = (uint8_t *)hal.util->malloc_type(RX_BOUNCE_BUFSIZE, AP_HAL::Util::MEM_DMA_SAFE);
}
if (tx_bounce_buf == nullptr && sdef.dma_tx) {
tx_bounce_buf = (uint8_t *)hal.util->malloc_type(TX_BOUNCE_BUFSIZE, AP_HAL::Util::MEM_DMA_SAFE);
chVTObjectInit(&tx_timeout);
tx_bounce_buf_ready = true;
}
rx_dma_enabled = rx_bounce_buf[0] != nullptr && rx_bounce_buf[1] != nullptr;
tx_dma_enabled = tx_bounce_buf != nullptr;
#endif
/*
@ -256,7 +261,7 @@ void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
bool was_initialised = _device_initialised;
// setup Rx DMA
if (!_device_initialised) {
if (sdef.dma_rx) {
if (rx_dma_enabled) {
osalDbgAssert(rxdma == nullptr, "double DMA allocation");
chSysLock();
rxdma = dmaStreamAllocI(sdef.dma_rx_stream_id,
@ -274,7 +279,7 @@ void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
dmaSetRequestSource(rxdma, sdef.dma_rx_channel_id);
#endif
}
if (sdef.dma_tx) {
if (tx_dma_enabled) {
// we only allow for sharing of the TX DMA channel, not the RX
// DMA channel, as the RX side is active all the time, so
// cannot be shared
@ -294,16 +299,13 @@ void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
sercfg.cr3 = _cr3_options;
#ifndef HAL_UART_NODMA
if (!sdef.dma_tx && !sdef.dma_rx) {
} else {
if (sdef.dma_rx) {
if (rx_dma_enabled) {
sercfg.cr1 |= USART_CR1_IDLEIE;
sercfg.cr3 |= USART_CR3_DMAR;
}
if (sdef.dma_tx) {
if (tx_dma_enabled) {
sercfg.cr3 |= USART_CR3_DMAT;
}
}
sercfg.irq_cb = rx_irq_cb;
#endif // HAL_UART_NODMA
sercfg.cr2 |= USART_CR2_STOP1_BITS;
@ -312,7 +314,7 @@ void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
sdStart((SerialDriver*)sdef.serial, &sercfg);
#ifndef HAL_UART_NODMA
if(sdef.dma_rx) {
if (rx_dma_enabled) {
//Configure serial driver to skip handling RX packets
//because we will handle them via DMA
((SerialDriver*)sdef.serial)->usart->CR1 &= ~USART_CR1_RXNEIE;
@ -374,7 +376,8 @@ void UARTDriver::dma_rx_enable(void)
uint32_t dmamode = STM32_DMA_CR_DMEIE | STM32_DMA_CR_TEIE;
dmamode |= STM32_DMA_CR_CHSEL(sdef.dma_rx_channel_id);
dmamode |= STM32_DMA_CR_PL(0);
dmaStreamSetMemory0(rxdma, rx_bounce_buf);
rx_bounce_idx ^= 1;
dmaStreamSetMemory0(rxdma, rx_bounce_buf[rx_bounce_idx]);
dmaStreamSetTransactionSize(rxdma, RX_BOUNCE_BUFSIZE);
dmaStreamSetMode(rxdma, dmamode | STM32_DMA_CR_DIR_P2M |
STM32_DMA_CR_MINC | STM32_DMA_CR_TCIE);
@ -418,7 +421,7 @@ void UARTDriver::rx_irq_cb(void* self)
{
#if HAL_USE_SERIAL == TRUE
UARTDriver* uart_drv = (UARTDriver*)self;
if (!uart_drv->sdef.dma_rx) {
if (!uart_drv->rx_dma_enabled) {
return;
}
dmaStreamDisable(uart_drv->rxdma);
@ -441,16 +444,30 @@ void UARTDriver::rx_irq_cb(void* self)
}
#endif
/*
handle a RX DMA full interrupt
*/
void UARTDriver::rxbuff_full_irq(void* self, uint32_t flags)
{
#if HAL_USE_SERIAL == TRUE
UARTDriver* uart_drv = (UARTDriver*)self;
if (!uart_drv->sdef.dma_rx) {
if (!uart_drv->rx_dma_enabled) {
return;
}
stm32_cacheBufferInvalidate(uart_drv->rx_bounce_buf, RX_BOUNCE_BUFSIZE);
uint8_t len = RX_BOUNCE_BUFSIZE - dmaStreamGetTransactionSize(uart_drv->rxdma);
uint16_t len = RX_BOUNCE_BUFSIZE - dmaStreamGetTransactionSize(uart_drv->rxdma);
const uint8_t bounce_idx = uart_drv->rx_bounce_idx;
// restart the DMA transfers immediately. This switches to the
// other bounce buffer. We restart the DMA before we copy the data
// out to minimise the time with DMA disabled, which allows us to
// handle much higher receiver baudrates
dmaStreamDisable(uart_drv->rxdma);
uart_drv->dma_rx_enable();
if (len > 0) {
/*
we have data to copy out
*/
if (uart_drv->half_duplex) {
uint32_t now = AP_HAL::micros();
if (now - uart_drv->hd_write_us < uart_drv->hd_read_delay_us) {
@ -458,15 +475,11 @@ void UARTDriver::rxbuff_full_irq(void* self, uint32_t flags)
}
}
stm32_cacheBufferInvalidate(uart_drv->rx_bounce_buf, len);
uart_drv->_readbuf.write(uart_drv->rx_bounce_buf, len);
stm32_cacheBufferInvalidate(uart_drv->rx_bounce_buf[bounce_idx], len);
uart_drv->_readbuf.write(uart_drv->rx_bounce_buf[bounce_idx], len);
uart_drv->receive_timestamp_update();
}
//restart the DMA transfers
dmaStreamDisable(uart_drv->rxdma);
uart_drv->dma_rx_enable();
if (uart_drv->_wait.thread_ctx && uart_drv->_readbuf.available() >= uart_drv->_wait.n) {
chSysLockFromISR();
chEvtSignalI(uart_drv->_wait.thread_ctx, EVT_DATA);
@ -857,7 +870,7 @@ void UARTDriver::write_pending_bytes(void)
uint32_t n;
#ifndef HAL_UART_NODMA
if (sdef.dma_tx) {
if (tx_dma_enabled) {
check_dma_tx_completion();
}
#endif
@ -869,7 +882,7 @@ void UARTDriver::write_pending_bytes(void)
}
#ifndef HAL_UART_NODMA
if (sdef.dma_tx) {
if (tx_dma_enabled) {
write_pending_bytes_DMA(n);
} else
#endif
@ -883,7 +896,7 @@ void UARTDriver::write_pending_bytes(void)
_first_write_started_us = AP_HAL::micros();
}
#ifndef HAL_UART_NODMA
if (sdef.dma_tx) {
if (tx_dma_enabled) {
// when we are using DMA we have a reliable indication that a write
// has completed from the DMA completion interrupt
if (_last_write_completed_us != 0) {
@ -936,7 +949,7 @@ void UARTDriver::_timer_tick(void)
if (!_initialised) return;
#ifndef HAL_UART_NODMA
if (sdef.dma_rx && rxdma) {
if (rx_dma_enabled && rxdma) {
chSysLock();
//Check if DMA is enabled
//if not, it might be because the DMA interrupt was silenced
@ -949,8 +962,8 @@ void UARTDriver::_timer_tick(void)
if (!enabled) {
uint8_t len = RX_BOUNCE_BUFSIZE - dmaStreamGetTransactionSize(rxdma);
if (len != 0) {
stm32_cacheBufferInvalidate(rx_bounce_buf, len);
_readbuf.write(rx_bounce_buf, len);
stm32_cacheBufferInvalidate(rx_bounce_buf[rx_bounce_idx], len);
_readbuf.write(rx_bounce_buf[rx_bounce_idx], len);
receive_timestamp_update();
if (_rts_is_active) {
@ -982,7 +995,7 @@ void UARTDriver::_timer_tick(void)
_in_timer = true;
#ifndef HAL_UART_NODMA
if (!sdef.dma_rx)
if (!rx_dma_enabled)
#endif
{
// try to fill the read buffer
@ -1132,7 +1145,7 @@ bool UARTDriver::set_unbuffered_writes(bool on)
#ifdef HAL_UART_NODMA
return false;
#else
if (on && !sdef.dma_tx) {
if (on && !tx_dma_enabled) {
// we can't implement low latemcy writes safely without TX DMA
return false;
}
@ -1196,7 +1209,7 @@ void UARTDriver::configure_parity(uint8_t v)
#endif
#ifndef HAL_UART_NODMA
if(sdef.dma_rx) {
if (rx_dma_enabled) {
// Configure serial driver to skip handling RX packets
// because we will handle them via DMA
((SerialDriver*)sdef.serial)->usart->CR1 &= ~USART_CR1_RXNEIE;
@ -1229,7 +1242,7 @@ void UARTDriver::set_stop_bits(int n)
sdStart((SerialDriver*)sdef.serial, &sercfg);
#ifndef HAL_UART_NODMA
if(sdef.dma_rx) {
if (rx_dma_enabled) {
//Configure serial driver to skip handling RX packets
//because we will handle them via DMA
((SerialDriver*)sdef.serial)->usart->CR1 &= ~USART_CR1_RXNEIE;

7
libraries/AP_HAL_ChibiOS/UARTDriver.h
View File

@ -22,7 +22,7 @@
#include "shared_dma.h"
#include "Semaphores.h"
#define RX_BOUNCE_BUFSIZE 128U
#define RX_BOUNCE_BUFSIZE 64U
#define TX_BOUNCE_BUFSIZE 64U
// enough for uartA to uartH, plus IOMCU
@ -117,6 +117,8 @@ public:
private:
const SerialDef &sdef;
bool rx_dma_enabled;
bool tx_dma_enabled;
// thread used for all UARTs
static thread_t *uart_thread_ctx;
@ -149,7 +151,8 @@ private:
// of ::read() and ::write() in the main loop
#ifndef HAL_UART_NODMA
bool tx_bounce_buf_ready;
uint8_t *rx_bounce_buf;
volatile uint8_t rx_bounce_idx;
uint8_t *rx_bounce_buf[2];
uint8_t *tx_bounce_buf;
#endif
ByteBuffer _readbuf{0};