diff options
Diffstat (limited to 'gm_platform/fw/serial.c')
| -rw-r--r-- | gm_platform/fw/serial.c | 251 |
1 files changed, 0 insertions, 251 deletions
diff --git a/gm_platform/fw/serial.c b/gm_platform/fw/serial.c deleted file mode 100644 index ae05fc9..0000000 --- a/gm_platform/fw/serial.c +++ /dev/null @@ -1,251 +0,0 @@ -#include "global.h"
-#include "serial.h"
-#include "cobs.h"
-
-#include <string.h>
-#include <stdarg.h>
-#include <stdlib.h>
-
-volatile struct dma_tx_buf usart_tx_buf;
-
-static uint32_t tx_overruns=0, rx_overruns=0;
-static uint32_t rx_framing_errors=0, rx_protocol_errors=0;
-
-static struct cobs_decode_state cobs_state;
-
-static volatile uint8_t rx_buf[32];
-
-
-static void usart_schedule_dma(void);
-static int usart_putc_nonblocking(uint8_t c);
-
-
-void usart_dma_reset() {
- usart_tx_buf.xfr_start = -1;
- usart_tx_buf.xfr_end = 0;
- usart_tx_buf.wr_pos = 0;
- usart_tx_buf.wr_idx = 0;
- usart_tx_buf.xfr_next = 0;
- usart_tx_buf.wraparound = false;
- usart_tx_buf.ack = true;
-
- for (size_t i=0; i<ARRAY_LEN(usart_tx_buf.packet_end); i++)
- usart_tx_buf.packet_end[i] = -1;
-
- cobs_decode_incremental_initialize(&cobs_state);
-}
-
-void usart_dma_init() {
- usart_dma_reset();
-
- /* Configure DMA 1 Channel 2 to handle uart transmission */
- DMA1_Channel2->CPAR = (uint32_t)&(USART1->TDR);
- DMA1_Channel2->CCR = (0<<DMA_CCR_PL_Pos)
- | DMA_CCR_DIR
- | (0<<DMA_CCR_MSIZE_Pos) /* 8 bit */
- | (0<<DMA_CCR_PSIZE_Pos) /* 8 bit */
- | DMA_CCR_MINC
- | DMA_CCR_TCIE; /* Enable transfer complete interrupt. */
-
- DMA1_Channel3->CMAR = (uint32_t)&(CRC->DR);
- DMA1_Channel3->CCR = (1<<DMA_CCR_PL_Pos)
- | (0<<DMA_CCR_MSIZE_Pos) /* 8 bit */
- | (0<<DMA_CCR_PSIZE_Pos) /* 8 bit */
- | DMA_CCR_PINC
- | DMA_CCR_TCIE; /* Enable transfer complete interrupt. */
-
- /* triggered on transfer completion. We use this to process the ADC data */
- NVIC_EnableIRQ(DMA1_Channel2_3_IRQn);
- NVIC_SetPriority(DMA1_Channel2_3_IRQn, 2<<5);
-
- USART1->CR1 = /* 8-bit -> M1, M0 clear */
- /* OVER8 clear. Use default 16x oversampling */
- /* CMIF clear */
- USART_CR1_MME
- /* WAKE clear */
- /* PCE, PS clear */
- | USART_CR1_RXNEIE /* Enable receive interrupt */
- /* other interrupts clear */
- | USART_CR1_TE
- | USART_CR1_RE;
- /* Set divider for 115.2kBd @48MHz system clock. */
- //USART1->BRR = 417;
-
- //USART1->BRR = 48; /* 1MBd */
- //USART1->BRR = 96; /* 500kBd */
- USART1->BRR = 192; /* 250kBd */
- //USART1->BRR = 208; /* 230400 */
-
- USART1->CR2 = USART_CR2_TXINV | USART_CR2_RXINV;
-
- USART1->CR3 |= USART_CR3_DMAT; /* TX DMA enable */
-
- /* Enable receive interrupt */
- NVIC_EnableIRQ(USART1_IRQn);
- NVIC_SetPriority(USART1_IRQn, 1<<5);
-
- /* And... go! */
- USART1->CR1 |= USART_CR1_UE;
-}
-
-void USART1_IRQHandler() {
- uint32_t isr = USART1->ISR;
-
- if (isr & USART_ISR_ORE) {
- USART1->ICR = USART_ICR_ORECF;
- rx_overruns++;
- return;
- }
-
- if (isr & USART_ISR_RXNE) {
- uint8_t c = USART1->RDR;
-
- int rc = cobs_decode_incremental(&cobs_state, (char *)rx_buf, sizeof(rx_buf), c);
- if (rc == 0) /* packet still incomplete */
- return;
-
- if (rc < 0) {
- rx_framing_errors++;
- return;
- }
-
- /* A complete frame received */
- if (rc != 2) {
- rx_protocol_errors++;
- return;
- }
-
- volatile struct ctrl_pkt *pkt = (volatile struct ctrl_pkt *)rx_buf;
-
- switch (pkt->type) {
- case CTRL_PKT_RESET:
- usart_dma_reset();
- break;
-
- case CTRL_PKT_ACK:
- usart_tx_buf.ack = true;
- if (!(DMA1_Channel2->CCR & DMA_CCR_EN))
- usart_schedule_dma();
- break;
-
- default:
- rx_protocol_errors++;
- }
- return;
- }
-}
-
-
-void usart_schedule_dma() {
- volatile struct dma_tx_buf *buf = &usart_tx_buf;
-
- ssize_t xfr_start, xfr_end, xfr_len;
- if (buf->wraparound) {
- buf->wraparound = false;
- xfr_start = 0;
- xfr_len = buf->xfr_end;
- xfr_end = buf->xfr_end;
-
- } else if (buf->ack) {
- if (buf->packet_end[buf->xfr_next] == -1)
- return; /* Nothing to trasnmit */
-
- buf->ack = false;
-
- xfr_start = buf->xfr_end;
- xfr_end = buf->packet_end[buf->xfr_next];
- buf->packet_end[buf->xfr_next] = -1;
- buf->xfr_next = (buf->xfr_next + 1) % ARRAY_LEN(buf->packet_end);
-
- if (xfr_end > xfr_start) { /* no wraparound */
- xfr_len = xfr_end - xfr_start;
-
- } else { /* wraparound */
- if (xfr_end != 0)
- buf->wraparound = true;
- xfr_len = sizeof(buf->data) - xfr_start;
- }
-
- } else {
- /* retransmit */
- /* First, send a zero to delimit any garbage from the following good packet */
- USART1->TDR = 0x00;
-
- xfr_start = buf->xfr_start;
- xfr_end = buf->xfr_end;
-
- if (xfr_end > xfr_start) { /* no wraparound */
- xfr_len = xfr_end - xfr_start;
-
- } else { /* wraparound */
- if (xfr_end != 0)
- buf->wraparound = true;
- xfr_len = sizeof(buf->data) - xfr_start;
- }
-
- leds.error = 250;
- }
-
- buf->xfr_start = xfr_start;
- buf->xfr_end = xfr_end;
-
- /* initiate transmission of new buffer */
- DMA1_Channel2->CMAR = (uint32_t)(buf->data + xfr_start);
- DMA1_Channel2->CNDTR = xfr_len;
- DMA1_Channel2->CCR |= DMA_CCR_EN;
-}
-
-int usart_putc_nonblocking(uint8_t c) {
- volatile struct dma_tx_buf *buf = &usart_tx_buf;
-
- if (buf->wr_pos == buf->xfr_start)
- return -EBUSY;
-
- buf->data[buf->wr_pos] = c;
- buf->wr_pos = (buf->wr_pos + 1) % sizeof(buf->data);
- return 0;
-}
-
-
-void DMA1_Channel2_3_IRQHandler(void) {
- /* Transfer complete */
- DMA1->IFCR |= DMA_IFCR_CTCIF2;
-
- DMA1_Channel2->CCR &= ~DMA_CCR_EN;
- if (usart_tx_buf.wraparound)
- usart_schedule_dma();
-}
-
-/* len is the packet length including headers */
-int usart_send_packet_nonblocking(struct ll_pkt *pkt, size_t pkt_len) {
-
- if (usart_tx_buf.packet_end[usart_tx_buf.wr_idx] != -1) {
- /* Find a free slot for this packet */
- tx_overruns++;
- return -EBUSY;
- }
-
- pkt->pid = usart_tx_buf.wr_idx;
- pkt->_pad = usart_tx_buf.xfr_next;
-
- /* make the value this wonky-ass CRC implementation produces match zlib etc. */
- CRC->CR = CRC_CR_REV_OUT | (1<<CRC_CR_REV_IN_Pos) | CRC_CR_RESET;
- for (size_t i=offsetof(struct ll_pkt, pid); i<pkt_len; i++)
- CRC->DR = ((uint8_t *)pkt)[i];
-
- pkt->crc32 = ~CRC->DR;
-
- int rc = cobs_encode_usart((int (*)(char))usart_putc_nonblocking, (char *)pkt, pkt_len);
- if (rc)
- return rc;
-
- usart_tx_buf.packet_end[usart_tx_buf.wr_idx] = usart_tx_buf.wr_pos;
- usart_tx_buf.wr_idx = (usart_tx_buf.wr_idx + 1) % ARRAY_LEN(usart_tx_buf.packet_end);
-
- leds.usb = 100;
-
- if (!(DMA1_Channel2->CCR & DMA_CCR_EN))
- usart_schedule_dma();
- return 0;
-}
-
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