2019-04-25 09:05:19 +03:00

255 lines
7.5 KiB
C

/*
* usart.c
*
* Copyright 2017 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include "stm32f0.h"
#include "hardware.h"
#include "usart.h"
#include <string.h>
extern volatile uint32_t Tms;
static volatile int idatalen[2] = {0,0}; // received data line length (including '\n')
static volatile int odatalen[2] = {0,0};
volatile int linerdy = 0, // received data ready
dlen = 0, // length of data (including '\n') in current buffer
bufovr = 0, // input buffer overfull
txrdy = 1 // transmission done
;
int rbufno = 0, tbufno = 0; // current rbuf/tbuf numbers
static char rbuf[2][UARTBUFSZI], tbuf[2][UARTBUFSZO]; // receive & transmit buffers
static char *recvdata = NULL;
/**
* return length of received data (without trailing zero
*/
int usart_getline(char **line){
if(bufovr){
bufovr = 0;
linerdy = 0;
return 0;
}
*line = recvdata;
linerdy = 0;
return dlen;
}
// transmit current tbuf and swap buffers
void transmit_tbuf(){
uint32_t tmout = 16000000;
while(!txrdy){if(--tmout == 0) break;}; // wait for previos buffer transmission
register int l = odatalen[tbufno];
if(!l) return;
txrdy = 0;
odatalen[tbufno] = 0;
USARTDMA->CCR &= ~DMA_CCR_EN;
USARTDMA->CMAR = (uint32_t) tbuf[tbufno]; // mem
USARTDMA->CNDTR = l;
USARTDMA->CCR |= DMA_CCR_EN;
tbufno = !tbufno;
}
void usart_putchar(const char ch){
if(odatalen[tbufno] == UARTBUFSZO) transmit_tbuf();
tbuf[tbufno][odatalen[tbufno]++] = ch;
}
void usart_send(const char *str){
uint32_t x = 512;
while(*str && --x){
if(odatalen[tbufno] == UARTBUFSZO) transmit_tbuf();
tbuf[tbufno][odatalen[tbufno]++] = *str++;
}
}
void usart_sendn(const char *str, uint8_t L){
for(uint8_t i = 0; i < L; ++i){
if(odatalen[tbufno] == UARTBUFSZO) transmit_tbuf();
tbuf[tbufno][odatalen[tbufno]++] = *str++;
}
}
void newline(){
usart_putchar('\n');
transmit_tbuf();
}
void usart_setup(){
uint32_t tmout = 16000000;
// Nucleo's USART2 connected to VCP proxy of st-link
#if USARTNUM == 2
// setup pins: PA2 (Tx - AF1), PA15 (Rx - AF1)
// AF mode (AF1)
GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER2|GPIO_MODER_MODER15))\
| (GPIO_MODER_MODER2_AF | GPIO_MODER_MODER15_AF);
GPIOA->AFR[0] = (GPIOA->AFR[0] &~GPIO_AFRH_AFRH2) | 1 << (2 * 4); // PA2
GPIOA->AFR[1] = (GPIOA->AFR[1] &~GPIO_AFRH_AFRH7) | 1 << (7 * 4); // PA15
RCC->APB1ENR |= RCC_APB1ENR_USART2EN; // clock
// USART1 of main board
#elif USARTNUM == 1
// PA9 - Tx, PA10 - Rx (AF1)
GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9 | GPIO_MODER_MODER10))\
| (GPIO_MODER_MODER9_AF | GPIO_MODER_MODER10_AF);
GPIOA->AFR[1] = (GPIOA->AFR[1] & ~(GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2)) |
1 << (1 * 4) | 1 << (2 * 4); // PA9, PA10
RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
#else
#error "Wrong USARTNUM"
#endif
// USARTX Tx DMA
USARTDMA->CPAR = (uint32_t) &USARTX->TDR; // periph
USARTDMA->CMAR = (uint32_t) tbuf; // mem
USARTDMA->CCR |= DMA_CCR_MINC | DMA_CCR_DIR | DMA_CCR_TCIE; // 8bit, mem++, mem->per, transcompl irq
// Tx CNDTR set @ each transmission due to data size
NVIC_SetPriority(DMAIRQn, 3);
NVIC_EnableIRQ(DMAIRQn);
NVIC_SetPriority(USARTIRQn, 0);
// setup usart1
USARTX->BRR = 480000 / 1152;
USARTX->CR3 = USART_CR3_DMAT; // enable DMA Tx
USARTX->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE; // 1start,8data,nstop; enable Rx,Tx,USART
while(!(USARTX->ISR & USART_ISR_TC)){if(--tmout == 0) break;} // polling idle frame Transmission
USARTX->ICR |= USART_ICR_TCCF; // clear TC flag
USARTX->CR1 |= USART_CR1_RXNEIE;
NVIC_EnableIRQ(USARTIRQn);
}
#if USARTNUM == 2
void usart2_isr(){
// USART1
#elif USARTNUM == 1
void usart1_isr(){
#else
#error "Wrong USARTNUM"
#endif
#ifdef CHECK_TMOUT
static uint32_t tmout = 0;
#endif
if(USARTX->ISR & USART_ISR_RXNE){ // RX not emty - receive next char
#ifdef CHECK_TMOUT
if(tmout && Tms >= tmout){ // set overflow flag
bufovr = 1;
idatalen[rbufno] = 0;
}
tmout = Tms + TIMEOUT_MS;
if(!tmout) tmout = 1; // prevent 0
#endif
// read RDR clears flag
uint8_t rb = USARTX->RDR;
if(idatalen[rbufno] < UARTBUFSZI){ // put next char into buf
rbuf[rbufno][idatalen[rbufno]++] = rb;
if(rb == '\n'){ // got newline - line ready
linerdy = 1;
dlen = idatalen[rbufno];
recvdata = rbuf[rbufno];
// prepare other buffer
rbufno = !rbufno;
idatalen[rbufno] = 0;
#ifdef CHECK_TMOUT
// clear timeout at line end
tmout = 0;
#endif
}
}else{ // buffer overrun
bufovr = 1;
idatalen[rbufno] = 0;
#ifdef CHECK_TMOUT
tmout = 0;
#endif
}
}
}
// print 32bit unsigned int
void printu(uint32_t val){
char bufa[11], bufb[10];
int l = 0, bpos = 0;
if(!val){
bufa[0] = '0';
l = 1;
}else{
while(val){
bufb[l++] = val % 10 + '0';
val /= 10;
}
int i;
bpos += l;
for(i = 0; i < l; ++i){
bufa[--bpos] = bufb[i];
}
}
bufa[l + bpos] = 0;
usart_send(bufa);
}
// print 32bit unsigned int as hex
void printuhex(uint32_t val){
usart_send("0x");
uint8_t *ptr = (uint8_t*)&val + 3, start = 1;
int i, j;
for(i = 0; i < 4; ++i, --ptr){
if(!*ptr && start) continue;
for(j = 1; j > -1; --j){
start = 0;
register uint8_t half = (*ptr >> (4*j)) & 0x0f;
if(half < 10) usart_putchar(half + '0');
else usart_putchar(half - 10 + 'a');
}
}
if(start){
usart_putchar('0');
usart_putchar('0');
}
}
// dump memory buffer
void hexdump(uint8_t *arr, uint16_t len){
for(uint16_t l = 0; l < len; ++l, ++arr){
for(int16_t j = 1; j > -1; --j){
register uint8_t half = (*arr >> (4*j)) & 0x0f;
if(half < 10) usart_putchar(half + '0');
else usart_putchar(half - 10 + 'a');
}
if(l % 16 == 15) usart_putchar('\n');
else if(l & 1) usart_putchar(' ');
}
}
#if USARTNUM == 2
void dma1_channel4_5_isr(){
if(DMA1->ISR & DMA_ISR_TCIF4){ // Tx
DMA1->IFCR |= DMA_IFCR_CTCIF4; // clear TC flag
txrdy = 1;
}
}
// USART1
#elif USARTNUM == 1
void dma1_channel2_3_isr(){
if(DMA1->ISR & DMA_ISR_TCIF2){ // Tx
DMA1->IFCR |= DMA_IFCR_CTCIF2; // clear TC flag
txrdy = 1;
}
}
#else
#error "Wrong USARTNUM"
#endif