restructuring

F1:F103/F1_testbrd/usart.c

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+/*
+ * usart.c
+ *
+ * Copyright 2018 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 "stm32f1.h"
+#include "usart.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 = 72000;
+    while(!txrdy){if(--tmout == 0) return;}; // wait for previos buffer transmission
+    register int l = odatalen[tbufno];
+    if(!l) return;
+    txrdy = 0;
+    odatalen[tbufno] = 0;
+    DMA1_Channel4->CCR &= ~DMA_CCR_EN;
+    DMA1_Channel4->CMAR = (uint32_t) tbuf[tbufno]; // mem
+    DMA1_Channel4->CNDTR = l;
+    DMA1_Channel4->CCR |= DMA_CCR_EN;
+    tbufno = !tbufno;
+}
+
+void usart_putchar(const char ch){
+    for(int i = 0; odatalen[tbufno] == UARTBUFSZO && i < 1024; ++i) 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();
+            continue;
+        }
+        tbuf[tbufno][odatalen[tbufno]++] = *str++;
+    }
+}
+
+void newline(){
+    usart_putchar('\n');
+    transmit_tbuf();
+}
+
+
+/*
+ * USART speed: baudrate = Fck/(USARTDIV)
+ * USARTDIV stored in USART->BRR
+ *
+ * for 72MHz USARTDIV=72000/f(kboud); so for 115200 USARTDIV=72000/115.2=625 -> BRR=0x271
+ *         9600: BRR = 7500 (0x1D4C)
+ */
+
+void usart_setup(){
+    uint32_t tmout = 16000000;
+    // PA9 - Tx, PA10 - Rx
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_USART1EN;
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    GPIOA->CRH |= CRH(9, CNF_AFPP|MODE_NORMAL) | CRH(10, CNF_FLINPUT|MODE_INPUT);
+
+    // USART1 Tx DMA - Channel4 (Rx - channel 5)
+    DMA1_Channel4->CPAR = (uint32_t) &USART1->DR; // periph
+    DMA1_Channel4->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(DMA1_Channel4_IRQn, 3);
+    NVIC_EnableIRQ(DMA1_Channel4_IRQn);
+    NVIC_SetPriority(USART1_IRQn, 0);
+    // setup usart1
+    USART1->BRR = 72000000 / 115200;
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE; // 1start,8data,nstop; enable Rx,Tx,USART
+    while(!(USART1->SR & USART_SR_TC)){if(--tmout == 0) break;} // polling idle frame Transmission
+    USART1->SR = 0; // clear flags
+    USART1->CR1 |= USART_CR1_RXNEIE; // allow Rx IRQ
+    USART1->CR3 = USART_CR3_DMAT; // enable DMA Tx
+    NVIC_EnableIRQ(USART1_IRQn);
+}
+
+
+void usart1_isr(){
+    #ifdef CHECK_TMOUT
+    static uint32_t tmout = 0;
+    #endif
+    if(USART1->SR & USART_SR_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
+        uint8_t rb = USART1->DR;
+        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
+        }
+    }
+}
+
+// return string buffer with val
+char *u2str(uint32_t val){
+    static char bufa[11];
+    char 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;
+    return bufa;
+}
+// print 32bit unsigned int
+void printu(uint32_t val){
+    usart_send(u2str(val));
+}
+
+// print 32bit unsigned int as hex
+void printuhex(uint32_t val){
+    usart_send("0x");
+    uint8_t *ptr = (uint8_t*)&val + 3;
+    int i, j;
+    for(i = 0; i < 4; ++i, --ptr){
+        for(j = 1; j > -1; --j){
+            register uint8_t half = (*ptr >> (4*j)) & 0x0f;
+            if(half < 10) usart_putchar(half + '0');
+            else usart_putchar(half - 10 + 'a');
+        }
+    }
+}
+
+// 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 & 3) == 3) usart_putchar(' ');
+    }
+}
+
+// dump USB memory (uint16_t mapped as uint32_t); len - in uint16_t
+void hexdump16(uint16_t *arr, uint16_t len){
+    for(uint16_t l = 0; l < len; ++l, ++arr){
+        uint16_t x = arr[l];
+        for(int8_t i = 0; i < 2; ++i){
+            for(int16_t j = 1; j > -1; --j){
+                register uint8_t half = (x >> (4*j+8*i)) & 0x0f;
+                if(half < 10) usart_putchar(half + '0');
+                else usart_putchar(half - 10 + 'a');
+            }
+        }
+        if(l % 8 == 7) usart_putchar('\n');
+        else if(l & 1) usart_putchar(' ');
+    }
+}
+
+void hexdump32(uint32_t *arr, uint16_t len){
+    for(uint16_t l = 0; l < len; ++l, ++arr){
+        uint16_t x = (uint16_t)arr[l];
+        for(int8_t i = 0; i < 2; ++i){
+            for(int16_t j = 1; j > -1; --j){
+                register uint8_t half = (x >> (4*j+8*i)) & 0x0f;
+                if(half < 10) usart_putchar(half + '0');
+                else usart_putchar(half - 10 + 'a');
+            }
+        }
+        if(l % 8 == 7) usart_putchar('\n');
+        else if(l & 1) usart_putchar(' ');
+    }
+}
+
+void dma1_channel4_isr(){
+    if(DMA1->ISR & DMA_ISR_TCIF4){ // Tx
+        DMA1->IFCR = DMA_IFCR_CTCIF4; // clear TC flag
+        txrdy = 1;
+    }
+}