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OK, I2C read by DMA works

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This commit is contained in:
Edward Emelianov 2025-09-19 21:24:19 +03:00
parent 934f4fbddd
commit 080be6a1ec
8 changed files with 103 additions and 109 deletions
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135
F3:F303/I2C_scan/i2c.c
View File

@ -136,40 +136,35 @@ static void i2cDMAsetup(int tx, uint16_t len){
// wait until bit set or clear; return 1 if OK, 0 in case of timeout
static uint8_t waitISRbit(uint32_t bit, uint8_t isset){
uint32_t waitwhile = (isset) ? 0 : bit; // wait until !=
const char *errmsg = NULL;
//const char *errmsg = NULL;
cntr = Tms;
if(bit != I2C_ISR_RXNE){ U("ISR wait "); U(uhex2str(bit)); USND(isset ? "set" : "reset"); }
//if(bit != I2C_ISR_RXNE){ U("ISR wait "); U(uhex2str(bit)); USND(isset ? "set" : "reset"); }
while((I2C1->ISR & bit) == waitwhile){
IWDG->KR = IWDG_REFRESH;
if(I2C1->ISR & I2C_ISR_NACKF){
errmsg = "NAK";
//errmsg = "NAK";
goto goterr;
}
if(Tms - cntr > I2C_TIMEOUT){
errmsg = "timeout";
//errmsg = "timeout";
goto goterr;
}
}
return 1;
goterr:
U("wait ISR bit: "); USND(errmsg);
U("I2c->ISR = "); USND(uhex2str(I2C1->ISR));
/*U("wait ISR bit: "); USND(errmsg);
U("I2c->ISR = "); USND(uhex2str(I2C1->ISR));*/
I2C1->ICR = 0xff;
return 0;
}
// start writing
static uint8_t i2c_startw(uint8_t addr, uint16_t nbytes, uint8_t stop){
static uint8_t i2c_startw(uint8_t addr, uint8_t nbytes, uint8_t stop){
if(!waitISRbit(I2C_ISR_BUSY, 0)) return 0;
I2C1->CR2 = nbytes << 16 | addr;
if(stop){
I2C1->CR2 |= I2C_CR2_AUTOEND; // autoend
}else{
//I2C1->CR2 &= ~I2C_CR2_AUTOEND;
//I2C1->CR2 |= I2C_CR2_RELOAD;
}
uint32_t cr2 = nbytes << 16 | addr | I2C_CR2_START;
if(stop) cr2 |= I2C_CR2_AUTOEND;
// now start transfer
I2C1->CR2 |= I2C_CR2_START;
I2C1->CR2 = cr2;
return 1;
}
@ -181,7 +176,7 @@ static uint8_t i2c_startw(uint8_t addr, uint16_t nbytes, uint8_t stop){
* @param stop - to set STOP
* @return 0 if error
*/
static uint8_t write_i2cs(uint8_t addr, uint8_t *data, uint16_t nbytes, uint8_t stop){
static uint8_t i2c_writes(uint8_t addr, uint8_t *data, uint8_t nbytes, uint8_t stop){
if(!i2c_startw(addr, nbytes, stop)) return 0;
for(int i = 0; i < nbytes; ++i){
cntr = Tms;
@ -189,16 +184,16 @@ static uint8_t write_i2cs(uint8_t addr, uint8_t *data, uint16_t nbytes, uint8_t
IWDG->KR = IWDG_REFRESH;
if(I2C1->ISR & I2C_ISR_NACKF){
I2C1->ICR |= I2C_ICR_NACKCF;
USND("write_i2cs: NAK");
//USND("i2c_writes: NAK");
return 0;
}
if(Tms - cntr > I2C_TIMEOUT){
USND("write_i2cs: Timeout");
//USND("i2c_writes: Timeout");
return 0;
}
}
I2C1->TXDR = data[i]; // send data
U("write_i2cs: "); USND(uhex2str(data[i]));
//U("i2c_writes: "); USND(uhex2str(data[i]));
}
cntr = Tms;
if(stop){
@ -209,19 +204,13 @@ static uint8_t write_i2cs(uint8_t addr, uint8_t *data, uint16_t nbytes, uint8_t
return 1;
}
uint8_t write_i2c(uint8_t addr, uint8_t *data, uint16_t nbytes){
uint8_t i2c_write(uint8_t addr, uint8_t *data, uint8_t nbytes){
if(isI2Cbusy()) return 0;
return write_i2cs(addr, data, nbytes, 1);
return i2c_writes(addr, data, nbytes, 1);
}
/*
uint8_t write_i2c16(uint8_t addr, uint8_t *data, uint8_t nbytes){
if(isI2Cbusy()) return 0;
return write_i2cs(addr, data, nbytes, 1);
}*/
uint8_t write_i2c_dma(uint8_t addr, uint8_t *data, uint16_t nbytes){
if(!data || nbytes < 1 || nbytes > I2C_BUFSIZE) return 0;
uint8_t i2c_write_dma(uint8_t addr, uint8_t *data, uint8_t nbytes){
if(!data || nbytes < 1) return 0;
if(isI2Cbusy()) return 0;
memcpy(I2Cbuf, data, nbytes);
i2cDMAsetup(1, nbytes);
@ -232,8 +221,8 @@ uint8_t write_i2c_dma(uint8_t addr, uint8_t *data, uint16_t nbytes){
return 1;
}
uint8_t write_i2c_dma16(uint8_t addr, uint16_t *data, uint16_t nwords){
if(!data || nwords < 1 || nwords > I2C_BUFSIZE/2) return 0;
uint8_t i2c_write_dma16(uint8_t addr, uint16_t *data, uint8_t nwords){
if(!data || nwords < 1 || nwords > 127) return 0;
if(isI2Cbusy()) return 0;
uint16_t nbytes = nwords << 1;
if(bigendian){
@ -251,10 +240,8 @@ uint8_t write_i2c_dma16(uint8_t addr, uint16_t *data, uint16_t nwords){
// start reading of `nbytes` from `addr`; if `start`==`, set START
static uint8_t i2c_startr(uint8_t addr, uint16_t nbytes, uint8_t start){
uint32_t cr2 = addr | I2C_CR2_RD_WRN;
if(nbytes > 255){
nbytes = 255; cr2 |= I2C_CR2_RELOAD;
}else cr2 |= I2C_CR2_AUTOEND;
cr2 |= (nbytes << 16);
if(nbytes > 255) cr2 |= I2C_CR2_RELOAD | (0xff0000);
else cr2 |= I2C_CR2_AUTOEND | (nbytes << 16);
I2C1->CR2 = (start) ? cr2 | I2C_CR2_START : cr2;
return 1;
}
@ -265,64 +252,64 @@ static uint8_t i2c_startr(uint8_t addr, uint16_t nbytes, uint8_t start){
* `data` should be an array with at least `nbytes` length
* @return 1 if all OK, 0 if NACK or no device found
*/
static uint8_t *read_i2cb(uint8_t addr, uint16_t nbytes, uint8_t busychk){
if(busychk && !waitISRbit(I2C_ISR_BUSY, 0)) return NULL;
static uint8_t *i2c_readb(uint8_t addr, uint16_t nbytes){
uint8_t start = 1;
uint8_t *bptr = I2Cbuf;
while(nbytes){
U("Read "); U(u2str(nbytes)); USND(" bytes");
//U("Read "); U(u2str(nbytes)); USND(" bytes");
if(!i2c_startr(addr, nbytes, start)) return NULL;
if(nbytes < 256){
for(int i = 0; i < nbytes; ++i){
if(!waitISRbit(I2C_ISR_RXNE, 1)) goto tmout;
*bptr++ = I2C1->RXDR;
}
while(waitISRbit(I2C_ISR_RXNE, 1)){
/*while(waitISRbit(I2C_ISR_RXNE, 1)){
U("OOOps! We have another byte: "); USND(uhex2str(I2C1->RXDR));
}
}*/
break;
}else while(!(I2C1->ISR & I2C_ISR_TCR)){ // until first part read
if(!waitISRbit(I2C_ISR_RXNE, 1)) goto tmout;
*bptr++ = I2C1->RXDR;
}
USND("next");
//USND("next");
nbytes -= 255;
start = 0;
}
return I2Cbuf;
tmout:
USND("read I2C: Timeout");
//USND("read I2C: Timeout");
return NULL;
}
uint8_t *read_i2c(uint8_t addr, uint16_t nbytes){
if(isI2Cbusy()) return 0;
return read_i2cb(addr, nbytes, 1);
uint8_t *i2c_read(uint8_t addr, uint16_t nbytes){
if(isI2Cbusy() || !waitISRbit(I2C_ISR_BUSY, 0)) return 0;
return i2c_readb(addr, nbytes);
}
static uint8_t dmard(uint8_t addr, uint16_t nbytes, uint8_t stop){
static uint8_t dmard(uint8_t addr, uint16_t nbytes){
if(nbytes < 1 || nbytes > I2C_BUFSIZE) return 0;
if(isI2Cbusy()) return 0;
i2cDMAsetup(0, nbytes);
goterr = 0;
i2c_got_DMA = 0;
if(!i2c_startr(addr, nbytes, stop)) return 0;
dma_remain = nbytes > 255 ? nbytes - 255 : 0; // remainder after first read finish
(void) I2C1->RXDR; // avoid wrong first byte
DMA1_Channel7->CCR = DMARXCCR | DMA_CCR_EN; // init DMA before START sequence
if(!i2c_startr(addr, nbytes, 1)) return 0;
dma_remain = nbytes > 255 ? nbytes - 255 : 0; // remainder after first read finish
I2Cbusy = 1;
return 1;
}
uint8_t read_i2c_dma(uint8_t addr, uint16_t nbytes){
uint8_t got = dmard(addr, nbytes, 1);
uint8_t i2c_read_dma(uint8_t addr, uint16_t nbytes){
if(isI2Cbusy() || !waitISRbit(I2C_ISR_BUSY, 0)) return 0;
uint8_t got = dmard(addr, nbytes);
if(got) dma16bit = 0;
return got;
}
uint8_t read_i2c_dma16(uint8_t addr, uint16_t nwords){
uint8_t i2c_read_dma16(uint8_t addr, uint16_t nwords){
if(nwords > I2C_BUFSIZE/2) return 0; // what if `nwords` is very large? we should check it
uint8_t got = dmard(addr, nwords<<1, 1);
if(isI2Cbusy() || !waitISRbit(I2C_ISR_BUSY, 0)) return 0;
uint8_t got = dmard(addr, nwords<<1);
if(got) dma16bit = 1;
return got;
}
@ -334,30 +321,29 @@ static void swapbytes(uint16_t *data, uint16_t datalen){
}
// read register reg
uint8_t *read_i2c_reg(uint8_t addr, uint8_t reg, uint16_t nbytes, uint8_t isdma){
if(isI2Cbusy()) return NULL;
if(!write_i2cs(addr, &reg, 1, 0)) return NULL;
uint8_t *i2c_read_reg(uint8_t addr, uint8_t reg, uint16_t nbytes, uint8_t isdma){
if(isI2Cbusy() || !waitISRbit(I2C_ISR_BUSY, 0)) return NULL;
if(!i2c_writes(addr, &reg, 1, 0)) return NULL;
if(isdma){
if(dmard(addr, nbytes, 0)){ dma16bit = 0; return I2Cbuf;} // for DMA we just return something non-null to check OK
if(dmard(addr, nbytes)){ dma16bit = 0; return I2Cbuf;} // for DMA we just return something non-null to check OK
return NULL;
}
return read_i2cb(addr, nbytes, 0);
return i2c_readb(addr, nbytes);
}
// read 16bit register reg
uint16_t *read_i2c_reg16(uint8_t addr, uint16_t reg16, uint16_t nwords, uint8_t isdma){
if(isI2Cbusy() || nwords < 1 || nwords > I2C_BUFSIZE/2) return 0;
uint16_t *i2c_read_reg16(uint8_t addr, uint16_t reg16, uint16_t nwords, uint8_t isdma){
if(isI2Cbusy() || !waitISRbit(I2C_ISR_BUSY, 0) || nwords < 1 || nwords > I2C_BUFSIZE/2) return 0;
if(bigendian) reg16 = __REV16(reg16);
if(!write_i2cs(addr, (uint8_t*)&reg16, 2, 0)) return NULL;
if(!i2c_writes(addr, (uint8_t*)&reg16, 2, 0)) return NULL;
if(isdma){
if(dmard(addr, nwords<<1, 0)){ dma16bit = 1; return (uint16_t*)I2Cbuf; }
if(dmard(addr, nwords<<1)){ dma16bit = 1; return (uint16_t*)I2Cbuf; }
return NULL;
}
if(!read_i2cb(addr, nwords*2, 0)) return NULL;
uint16_t *buf = (uint16_t*)I2Cbuf;
if(bigendian) swapbytes(buf, nwords);
return buf;
if(!i2c_readb(addr, nwords<<1)) return NULL;
if(bigendian) swapbytes((uint16_t*)I2Cbuf, nwords);
return (uint16_t*)I2Cbuf;
}
void i2c_init_scan_mode(){
@ -376,7 +362,7 @@ int i2c_scan_next_addr(uint8_t *addr){
i2c_scanmode = 0;
return 0;
}
if(!read_i2c((i2caddr++)<<1, 1)) return 0;
if(!i2c_read((i2caddr++)<<1, 1)) return 0;
return 1;
}
@ -389,31 +375,30 @@ void i2c_bufdudump(){
if(i2cbuflen < 1) return;
USND("I2C buffer:");
if(dma16bit) hexdump16(USB_sendstr, (uint16_t*)I2Cbuf, i2cbuflen);
hexdump(USB_sendstr, I2Cbuf, i2cbuflen);
else hexdump(USB_sendstr, I2Cbuf, i2cbuflen);
}
// get DMA buffer with conversion to little-endian (if transfer was for 16-bit)
uint8_t *i2cdma_getbuf(uint16_t *len){
uint8_t *i2c_dma_getbuf(uint16_t *len){
if(!i2c_got_DMA || i2cbuflen < 1) return NULL;
i2c_got_DMA = 0;
if(dma16bit){
i2cbuflen >>= 1; // for hexdump16 - now buffer have uint16_t!
uint16_t *b = (uint16_t*)I2Cbuf;
if(bigendian){
for(int i = 0; i < i2cbuflen; ++i) b[i] = __REV(b[i]);
}
if(bigendian) swapbytes((uint16_t*)I2Cbuf, i2cbuflen);
}
if(len) *len = i2cbuflen;
return I2Cbuf;
}
int i2cdma_haderr(){
int i2c_dma_haderr(){
int r = goterr;
goterr = 0;
return r;
}
void endianness(uint8_t isbig){
int i2c_busy(){ return I2Cbusy;}
void i2c_endianness(uint8_t isbig){
bigendian = isbig;
}

26
F3:F303/I2C_scan/i2c.h
View File

@ -35,23 +35,25 @@ extern i2c_speed_t i2c_curspeed;
extern volatile uint8_t i2c_scanmode;
// timeout of I2C bus in ms
#define I2C_TIMEOUT (5)
#define I2C_TIMEOUT (5)
void i2c_setup(i2c_speed_t speed);
uint8_t *read_i2c(uint8_t addr, uint16_t nbytes);
uint8_t *read_i2c_reg(uint8_t addr, uint8_t reg, uint16_t nbytes, uint8_t isdma);
uint16_t *read_i2c_reg16(uint8_t addr, uint16_t reg16, uint16_t nbytes, uint8_t isdma);
uint8_t write_i2c(uint8_t addr, uint8_t *data, uint16_t nbytes);
int i2c_busy();
uint8_t write_i2c_dma(uint8_t addr, uint8_t *data, uint16_t nbytes);
uint8_t write_i2c_dma16(uint8_t addr, uint16_t *data, uint16_t nwords);
uint8_t read_i2c_dma(uint8_t addr, uint16_t nbytes);
uint8_t *i2c_read(uint8_t addr, uint16_t nbytes);
uint8_t i2c_read_dma(uint8_t addr, uint16_t nbytes);
uint8_t i2c_read_dma16(uint8_t addr, uint16_t nwords);
uint8_t *i2c_read_reg(uint8_t addr, uint8_t reg, uint16_t nbytes, uint8_t isdma);
uint16_t *i2c_read_reg16(uint8_t addr, uint16_t reg16, uint16_t nbytes, uint8_t isdma);
uint8_t i2c_write(uint8_t addr, uint8_t *data, uint8_t nbytes);
uint8_t i2c_write_dma(uint8_t addr, uint8_t *data, uint8_t nbytes);
uint8_t i2c_write_dma16(uint8_t addr, uint16_t *data, uint8_t nwords);
void i2c_bufdudump();
int i2cdma_haderr();
uint8_t *i2cdma_getbuf(uint16_t *len);
uint8_t read_i2c_dma16(uint8_t addr, uint16_t nwords);
void endianness(uint8_t isbig);
int i2c_dma_haderr();
uint8_t *i2c_dma_getbuf(uint16_t *len);
void i2c_endianness(uint8_t isbig);
int i2c_getwords(uint16_t *buf, int bufsz);
void i2c_init_scan_mode();

BIN
F3:F303/I2C_scan/i2cscan.bin
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Binary file not shown.

2
F3:F303/I2C_scan/i2cscan.creator.user
View File

@ -1,6 +1,6 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE QtCreatorProject>
<!-- Written by QtCreator 17.0.1, 2025-09-18T23:52:40. -->
<!-- Written by QtCreator 17.0.1, 2025-09-19T20:47:53. -->
<qtcreator>
<data>
<variable>EnvironmentId</variable>

6
F3:F303/I2C_scan/main.c
View File

@ -53,7 +53,7 @@ int main(void){
if(l < 0) USND("ERROR: USB buffer overflow or string was too long");
else if(l){
const char *ans = parse_cmd(inbuff);
if(ans) USND(ans);
if(ans) U(ans);
}
if(i2c_scanmode){
uint8_t addr;
@ -65,7 +65,7 @@ int main(void){
U(") - found device\n");
}
}
if(i2cdma_haderr()) USND("Error reading I2C using DMA");
if(i2cdma_getbuf(NULL)) i2c_bufdudump();
if(i2c_dma_haderr()) USND("Error reading I2C using DMA");
if(i2c_dma_getbuf(NULL)) i2c_bufdudump();
}
}

26
F3:F303/I2C_scan/proto.c
View File

@ -26,6 +26,7 @@
#define LOCBUFFSZ (32)
// local buffer for I2C data to send
static uint8_t locBuffer[LOCBUFFSZ];
static uint8_t I2Caddress = 0x33 << 1;
extern volatile uint32_t Tms;
static const char *OK = "OK\n";
@ -33,6 +34,7 @@ static const char *helpstring =
"https://github.com/eddyem/stm32samples/tree/master/F3:F303/I2C_scan build#" BUILD_NUMBER " @ " BUILD_DATE "\n"
"i0..3 - setup I2C with speed 10k, 100k, 400k, 1M or 2M (experimental!)\n"
"B - switch to big-endian format for 16-bit registers\n"
"G - get busy state\n"
"Ia addr - set I2C address\n"
"Ig - dump content of I2Cbuf\n"
"Iw bytes - send bytes (hex/dec/oct/bin) to I2C\n"
@ -59,7 +61,6 @@ TRUE_INLINE const char *setupI2C(char *buf){
return OK;
}
static uint8_t I2Caddress = 0;
TRUE_INLINE const char *saI2C(const char *buf){
uint32_t addr;
U("saI2C: '"); U(buf); U("'\n");
@ -98,24 +99,24 @@ static void rdI2C(const char *buf, int is16, int dmaflag){
if(noreg){ // don't write register
if(dmaflag){
U("Try to read using DMA .. ");
if(!read_i2c_dma(I2Caddress, N)) U(erd);
if(!i2c_read_dma(I2Caddress, N)) U(erd);
else U(OK);
return;
}else{
USND("Simple read:");
if(!(b8 = read_i2c(I2Caddress, N))){
if(!(b8 = i2c_read(I2Caddress, N))){
U(erd);
return;
}
}
}else{
if(is16){
if(!(b16 = read_i2c_reg16(I2Caddress, reg, N, dmaflag))){
if(!(b16 = i2c_read_reg16(I2Caddress, reg, N, dmaflag))){
U(erd);
return;
}
}else{
if(!(b8 = read_i2c_reg(I2Caddress, reg, N, dmaflag))){
if(!(b8 = i2c_read_reg(I2Caddress, reg, N, dmaflag))){
U(erd);
return;
}
@ -142,8 +143,8 @@ TRUE_INLINE uint16_t readNnumbers(const char *buf){
static const char *wrI2C(const char *buf, int isdma){
uint16_t N = readNnumbers(buf);
if(N == 0) return "Enter at least one number\n";
int result = isdma ? write_i2c_dma(I2Caddress, locBuffer, N) :
write_i2c(I2Caddress, locBuffer, N);
int result = isdma ? i2c_write_dma(I2Caddress, locBuffer, N) :
i2c_write(I2Caddress, locBuffer, N);
if(!result) return "Error writing I2C\n";
return OK;
}
@ -185,12 +186,15 @@ const char *parse_cmd(char *buf){
switch(*buf){
case 'i': return setupI2C(NULL); // current settings
case 'B':
endianness(1);
return OK;
i2c_endianness(1);
return OK;
break;
case 'G':
U("I2Cbusy="); USB_putbyte('0' + i2c_busy()); newline();
break;
case 'L':
endianness(0);
return OK;
i2c_endianness(0);
return OK;
break;
case 'T':
U("T=");

13
F3:F303/I2C_scan/ringbuffer.c
View File

@ -15,6 +15,8 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include "ringbuffer.h"
static int datalen(ringbuffer *b){
@ -58,10 +60,11 @@ int RB_hasbyte(ringbuffer *b, uint8_t byte){
return ret;
}
/*
// poor memcpy
static void mcpy(uint8_t *targ, const uint8_t *src, int l){
while(l--) *targ++ = *src++;
}
}*/
// increment head or tail
TRUE_INLINE void incr(ringbuffer *b, volatile int *what, int n){
@ -76,9 +79,9 @@ static int read(ringbuffer *b, uint8_t *s, int len){
int _1st = b->length - b->head;
if(_1st > l) _1st = l;
if(_1st > len) _1st = len;
mcpy(s, b->data + b->head, _1st);
memcpy(s, b->data + b->head, _1st);
if(_1st < len && l > _1st){
mcpy(s+_1st, b->data, l - _1st);
memcpy(s+_1st, b->data, l - _1st);
incr(b, &b->head, l);
return l;
}
@ -132,9 +135,9 @@ static int write(ringbuffer *b, const uint8_t *str, int l){
if(l > r || !l) return 0;
int _1st = b->length - b->tail;
if(_1st > l) _1st = l;
mcpy(b->data + b->tail, str, _1st);
memcpy(b->data + b->tail, str, _1st);
if(_1st < l){ // add another piece from start
mcpy(b->data, str+_1st, l-_1st);
memcpy(b->data, str+_1st, l-_1st);
}
incr(b, &b->tail, l);
return l;

4
F3:F303/I2C_scan/version.inc
View File

@ -1,2 +1,2 @@
#define BUILD_NUMBER "136"
#define BUILD_DATE "2025-09-18"
#define BUILD_NUMBER "152"
#define BUILD_DATE "2025-09-19"