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stm32samples/F0-nolib/usbcdc/can.c
eddyem 6df3b9f5c2 add CDC for STM32F042 (not working yet)
2018-09-08 19:51:02 +03:00

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/*
* geany_encoding=koi8-r
* can.c
*
* Copyright 2018 Edward V. Emelianov <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 <string.h> // memcpy
#include "can.h"
#include "hardware.h"
#include "usart.h"
#define CMD_TOGGLE (0xDA)
#define CMD_BCAST (0xAD)
#define CAN_ID_MASK (0x7F8)
#define CAN_ID_PREFIX (0xAAA)
#define TARG_ID (CAN_ID_PREFIX & CAN_ID_MASK)
#define BCAST_ID (0x7F7)
#define CAN_FLAG_GOTDUMMY (1)
// incoming message buffer size
#define CAN_INMESSAGE_SIZE (6)
extern volatile uint32_t Tms;
// circular buffer for received messages
static CAN_message messages[CAN_INMESSAGE_SIZE];
static uint8_t first_free_idx = 0; // index of first empty cell
static int8_t first_nonfree_idx = -1; // index of first data cell
static uint16_t CANID = 0xFFFF;
static uint32_t last_err_code = 0;
static CAN_status can_status = CAN_STOP;
static void can_process_fifo(uint8_t fifo_num);
CAN_status CAN_get_status(){
CAN_status st = can_status;
// give overrun message only once
if(st == CAN_FIFO_OVERRUN) can_status = CAN_READY;
return st;
}
// push next message into buffer; return 1 if buffer overfull
static int CAN_messagebuf_push(CAN_message *msg){
MSG("Try to push\n");
if(first_free_idx == first_nonfree_idx) return 1; // no free space
if(first_nonfree_idx < 0) first_nonfree_idx = 0; // first message in empty buffer
memcpy(&messages[first_free_idx++], msg, sizeof(CAN_message));
// need to roll?
if(first_free_idx == CAN_INMESSAGE_SIZE) first_free_idx = 0;
#ifdef EBUG
MSG("1st free: "); usart_putchar('0' + first_free_idx); newline();
#endif
return 0;
}
// pop message from buffer
CAN_message *CAN_messagebuf_pop(){
if(first_nonfree_idx < 0) return NULL;
#ifdef EBUG
MSG("read from idx "); usart_putchar('0' + first_nonfree_idx); newline();
#endif
CAN_message *msg = &messages[first_nonfree_idx++];
if(first_nonfree_idx == CAN_INMESSAGE_SIZE) first_nonfree_idx = 0;
if(first_nonfree_idx == first_free_idx){ // buffer is empty - refresh it
first_nonfree_idx = -1;
first_free_idx = 0;
MSG("refresh buffer\n");
}
return msg;
}
// get CAN address data from GPIO pins
void readCANID(){
uint8_t CAN_addr = READ_CAN_INV_ADDR();
CAN_addr = ~CAN_addr & 0x7;
CANID = (CAN_ID_PREFIX & CAN_ID_MASK) | CAN_addr;
}
uint16_t getCANID(){
return CANID;
}
void CAN_reinit(){
readCANID();
CAN->TSR |= CAN_TSR_ABRQ0 | CAN_TSR_ABRQ1 | CAN_TSR_ABRQ2;
RCC->APB1RSTR |= RCC_APB1RSTR_CANRST;
RCC->APB1RSTR &= ~RCC_APB1RSTR_CANRST;
CAN_setup();
}
void CAN_setup(){
if(CANID == 0xFFFF) readCANID();
// Configure GPIO: PB8 - CAN_Rx, PB9 - CAN_Tx
/* (1) Select AF mode (10) on PB8 and PB9 */
/* (2) AF4 for CAN signals */
GPIOB->MODER = (GPIOB->MODER & ~(GPIO_MODER_MODER8 | GPIO_MODER_MODER9))
| (GPIO_MODER_MODER8_AF | GPIO_MODER_MODER9_AF); /* (1) */
GPIOB->AFR[1] = (GPIOB->AFR[1] &~ (GPIO_AFRH_AFRH0 | GPIO_AFRH_AFRH1))\
| (4 << (0 * 4)) | (4 << (1 * 4)); /* (2) */
/* Enable the peripheral clock CAN */
RCC->APB1ENR |= RCC_APB1ENR_CANEN;
/* Configure CAN */
/* (1) Enter CAN init mode to write the configuration */
/* (2) Wait the init mode entering */
/* (3) Exit sleep mode */
/* (4) Loopback mode, set timing to 100kb/s: BS1 = 4, BS2 = 3, prescaler = 60 */
/* (5) Leave init mode */
/* (6) Wait the init mode leaving */
/* (7) Enter filter init mode, (16-bit + mask, filter 0 for FIFO 0) */
/* (8) Acivate filter 0 for two IDs */
/* (9) Identifier list mode */
/* (10) Set the Id list */
/* (12) Leave filter init */
/* (13) Set error interrupts enable */
CAN->MCR |= CAN_MCR_INRQ; /* (1) */
while((CAN->MSR & CAN_MSR_INAK)!=CAN_MSR_INAK) /* (2) */
{
/* add time out here for a robust application */
}
CAN->MCR &=~ CAN_MCR_SLEEP; /* (3) */
CAN->MCR |= CAN_MCR_ABOM;
CAN->BTR |= 2 << 20 | 3 << 16 | 59 << 0; /* (4) */
CAN->MCR &=~ CAN_MCR_INRQ; /* (5) */
while((CAN->MSR & CAN_MSR_INAK)==CAN_MSR_INAK) /* (6) */
{
/* add time out here for a robust application */
}
CAN->FMR = CAN_FMR_FINIT; /* (7) */
CAN->FA1R = CAN_FA1R_FACT0; /* (8) */
CAN->FM1R = CAN_FM1R_FBM0; /* (9) */
CAN->sFilterRegister[0].FR1 = CANID << 5 | ((BCAST_ID << 5) << 16); /* (10) */
CAN->FMR &=~ CAN_FMR_FINIT; /* (12) */
CAN->IER |= CAN_IER_ERRIE | CAN_IER_FOVIE0 | CAN_IER_FOVIE1; /* (13) */
/* Configure IT */
/* (14) Set priority for CAN_IRQn */
/* (15) Enable CAN_IRQn */
NVIC_SetPriority(CEC_CAN_IRQn, 0); /* (14) */
NVIC_EnableIRQ(CEC_CAN_IRQn); /* (15) */
can_status = CAN_READY;
}
void can_proc(){
if(last_err_code){
#ifdef EBUG
MSG("Error, ESR=");
printu(last_err_code);
newline();
#endif
last_err_code = 0;
}
// check for messages in FIFO0 & FIFO1
if(CAN->RF0R & CAN_RF0R_FMP0){
can_process_fifo(0);
}
if(CAN->RF1R & CAN_RF1R_FMP1){
can_process_fifo(1);
}
if(CAN->ESR & (CAN_ESR_BOFF | CAN_ESR_EPVF | CAN_ESR_EWGF)){ // much errors - restart CAN BUS
MSG("bus-off, restarting\n");
// request abort for all mailboxes
CAN->TSR |= CAN_TSR_ABRQ0 | CAN_TSR_ABRQ1 | CAN_TSR_ABRQ2;
// reset CAN bus
RCC->APB1RSTR |= RCC_APB1RSTR_CANRST;
RCC->APB1RSTR &= ~RCC_APB1RSTR_CANRST;
CAN_setup();
}
LED_off(LED1);
#ifdef EBUG
static uint32_t esr, msr, tsr;
uint32_t msr_now = CAN->MSR & 0xf;
if(esr != CAN->ESR || msr != msr_now || tsr != CAN->TSR){
MSG("Timestamp: ");
printu(Tms);
newline();
}
if((CAN->ESR) != esr){
usart_putchar(((CAN->ESR & CAN_ESR_BOFF) != 0) + '0');
esr = CAN->ESR;
MSG("CAN->ESR: ");
printuhex(esr); newline();
}
if(msr_now != msr){
msr = msr_now;
MSG("CAN->MSR & 0xf: ");
printuhex(msr); newline();
}
if(CAN->TSR != tsr){
tsr = CAN->TSR;
MSG("CAN->TSR: ");
printuhex(tsr); newline();
}
#endif
}
CAN_status can_send(uint8_t *msg, uint8_t len, uint16_t target_id){
uint8_t mailbox = 0;
// check first free mailbox
if(CAN->TSR & (CAN_TSR_TME)){
mailbox = (CAN->TSR & CAN_TSR_CODE) >> 24;
#ifdef EBUG
MSG("select "); usart_putchar('0'+mailbox); SEND(" mailbox\n");
#endif
}else{ // no free mailboxes
return CAN_BUSY;
}
CAN_TxMailBox_TypeDef *box = &CAN->sTxMailBox[mailbox];
uint32_t lb = 0, hb = 0;
switch(len){
case 8:
hb |= (uint32_t)msg[7] << 24;
case 7:
hb |= (uint32_t)msg[6] << 16;
case 6:
hb |= (uint32_t)msg[5] << 8;
case 5:
hb |= (uint32_t)msg[4];
case 4:
lb |= (uint32_t)msg[3] << 24;
case 3:
lb |= (uint32_t)msg[2] << 16;
case 2:
lb |= (uint32_t)msg[1] << 8;
default:
lb |= (uint32_t)msg[0];
}
box->TDLR = lb;
box->TDHR = hb;
box->TDTR = len;
box->TIR = (target_id & 0x7FF) << 21 | CAN_TI0R_TXRQ;
return CAN_OK;
}
void can_send_dummy(){
uint8_t msg = CMD_TOGGLE;
if(CAN_OK != can_send(&msg, 1, TARG_ID)) SEND("Bus busy!\n");
MSG("CAN->MSR: ");
printuhex(CAN->MSR); newline();
MSG("CAN->TSR: ");
printuhex(CAN->TSR); newline();
MSG("CAN->ESR: ");
printuhex(CAN->ESR); newline();
}
void can_send_broadcast(){
uint8_t msg = CMD_BCAST;
if(CAN_OK != can_send(&msg, 1, BCAST_ID)) SEND("Bus busy!\n");
MSG("Broadcast message sent\n");
}
static void can_process_fifo(uint8_t fifo_num){
if(fifo_num > 1) return;
LED_on(LED1); // Toggle LED1
CAN_FIFOMailBox_TypeDef *box = &CAN->sFIFOMailBox[fifo_num];
volatile uint32_t *RFxR = (fifo_num) ? &CAN->RF1R : &CAN->RF0R;
MSG("Receive, RDTR=");
#ifdef EBUG
printuhex(box->RDTR);
newline();
#endif
// read all
while(*RFxR & CAN_RF0R_FMP0){ // amount of messages pending
// CAN_RDTxR: (16-31) - timestamp, (8-15) - filter match index, (0-3) - data length
/* TODO: check filter match index if more than one ID can receive */
CAN_message msg;
uint8_t *dat = msg.data;
uint8_t len = box->RDTR & 0x7;
msg.length = len;
if(len){ // message can be without data
uint32_t hb = box->RDHR, lb = box->RDLR;
switch(len){
case 8:
dat[7] = hb>>24;
case 7:
dat[6] = (hb>>16) & 0xff;
case 6:
dat[5] = (hb>>8) & 0xff;
case 5:
dat[4] = hb & 0xff;
case 4:
dat[3] = lb>>24;
case 3:
dat[2] = (lb>>16) & 0xff;
case 2:
dat[1] = (lb>>8) & 0xff;
case 1:
dat[0] = lb & 0xff;
}
}
if(CAN_messagebuf_push(&msg)) return; // error: buffer is full, try later
*RFxR |= CAN_RF0R_RFOM0; // release fifo for access to next message
}
if(*RFxR & CAN_RF0R_FULL0) *RFxR &= ~CAN_RF0R_FULL0;
}
void cec_can_isr(){
if(CAN->RF0R & CAN_RF0R_FOVR0){ // FIFO overrun
CAN->RF0R &= ~CAN_RF0R_FOVR0;
can_status = CAN_FIFO_OVERRUN;
}
if(CAN->RF1R & CAN_RF1R_FOVR1){
CAN->RF1R &= ~CAN_RF1R_FOVR1;
can_status = CAN_FIFO_OVERRUN;
}
#ifdef EBUG
if(can_status == CAN_FIFO_OVERRUN) MSG("fifo 0 overrun\n");
#endif
if(CAN->MSR & CAN_MSR_ERRI){ // Error
CAN->MSR &= ~CAN_MSR_ERRI;
// request abort for problem mailbox
if(CAN->TSR & CAN_TSR_TERR0) CAN->TSR |= CAN_TSR_ABRQ0;
if(CAN->TSR & CAN_TSR_TERR1) CAN->TSR |= CAN_TSR_ABRQ1;
if(CAN->TSR & CAN_TSR_TERR2) CAN->TSR |= CAN_TSR_ABRQ2;
last_err_code = CAN->ESR;
}
}
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