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pi-serial: add a new tool that shows when rts/cts changes
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@deater
deater committed Dec 2, 2016
1 parent 385ae74 commit 4cd2d55
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Showing 2 changed files with 313 additions and 2 deletions.
12 changes: 10 additions & 2 deletions rasp-pi-serial/Makefile
View file
Expand Up @@ -2,7 +2,8 @@ CC = gcc
CFLAGS = -Wall -O2
LFLAGS =

all: toggle_rts toggle_dtr rpirtscts pulse_rts dump_serial_regs dump_rts_cts
all: toggle_rts toggle_dtr rpirtscts pulse_rts dump_serial_regs \
dump_rts_cts monitor_rts_cts


dump_rts_cts: dump_rts_cts.o
Expand All @@ -12,6 +13,13 @@ dump_rts_cts.o: dump_rts_cts.c
$(CC) $(CFLAGS) -c dump_rts_cts.c


monitor_rts_cts: monitor_rts_cts.o
$(CC) $(LFLAGS) -o monitor_rts_cts monitor_rts_cts.o

monitor_rts_cts.o: monitor_rts_cts.c
$(CC) $(CFLAGS) -c monitor_rts_cts.c



dump_serial_regs: dump_serial_regs.o
$(CC) $(LFLAGS) -o dump_serial_regs dump_serial_regs.o
Expand Down Expand Up @@ -50,4 +58,4 @@ toggle_dtr.o: toggle_dtr.c


clean:
rm -f *~ *.o toggle_rts toggle_dtr rpirtscts pulse_rts dump_serial_regs dump_rts_cts
rm -f *~ *.o toggle_rts toggle_dtr rpirtscts pulse_rts dump_serial_regs dump_rts_cts monitor_rts_cts
303 changes: 303 additions & 0 deletions rasp-pi-serial/monitor_rts_cts.c
View file
@@ -0,0 +1,303 @@
/*
Dump the current RTS/CTS pins on a Pi
*/

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>

#define VERSION "2.0"

/* See bcm2835 peripheral guide */

#define PI2_BASE 0x3F000000
#define PI_BASE 0x20000000


#define PI_GPIO_BASE (PI_BASE + 0x200000)
#define PI2_GPIO_BASE (PI2_BASE + 0x200000)

#define PI_SERIAL_BASE (PI_BASE + 0x201000)
#define PI2_SERIAL_BASE (PI2_BASE + 0x201000)


#define GFPSEL0 (0)
#define GFPSEL1 (1)
#define GFPSEL2 (2)
#define GFPSEL3 (3)


/* bits 18-23 */
#define GPIO1617MASK 0x00fc0000 /* GPIO 16 for CTS0 and 17 for RTS0 */
#define GPIO3031MASK 0x0000003f /* GPIO 30 for CTS0 and 31 for RTS0 */

#define GPIO_HEADER_26 0x00
#define GPIO_HEADER_40 0x01


#define BLOCK_SIZE (4*1024)

static uint32_t gpio_base = PI_GPIO_BASE;
static uint32_t serial_base = PI_SERIAL_BASE;
static int header_type = GPIO_HEADER_40;

static int rpi_version(void) {

int result = -1;
char string[256];

FILE *fp;

fp = fopen("/proc/cmdline", "r");
if (fp) {
while (fscanf(fp, "%255s", string) == 1) {
if (sscanf(string, "bcm2708.boardrev=%i", &result))
break;
}

if (result < 0) {
rewind(fp);
while (fscanf(fp, "%255s", string) == 1)
if (sscanf(string, "bcm2709.boardrev=%i", &result))
break;
}

fclose(fp);
}
if (result < 0) {
fprintf(stderr, "can't parse /proc/cmdline\n");
exit(EXIT_FAILURE);
}
return result;
}

static int rpi_gpio_header_type(int version) {


switch (version) {
case 0x000002:
printf("Model B Rev 1.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000003:
printf("Model B Rev 1.0+ with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000004:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000005:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000006:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000007:
printf("Model A with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000008:
printf("Model A with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000009:
printf("Model A with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x00000d:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x00000e:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x00000f:
printf("Model B Rev 2.0 with 26 pin\n");
header_type = GPIO_HEADER_26;
break;
case 0x000010:
printf("Model B+ Rev 1.0 with 40 pin\n");
break;
case 0x000014:
case 0x000011:
printf("Compute Module is not supported\n");
exit(EXIT_FAILURE);
case 0x000015:
case 0x000012:
printf("Model A+ Rev 1.1 with 40 pin\n");
break;
case 0x000013:
printf("Model B+ Rev 1.2 with 40 pin\n");
break;
case 0xa01040:
printf("Pi 2 Model B Rev 1.0 with 40 pin\n");
gpio_base=PI2_GPIO_BASE;
serial_base=PI2_SERIAL_BASE;
break;
case 0xa01041:
case 0xa21041:
printf("Pi 2 Model B Rev 1.1 with 40 pin\n");
gpio_base=PI2_GPIO_BASE;
serial_base=PI2_SERIAL_BASE;
break;
case 0x900092:
printf("Pi Zero Rev 1.2 with 40 pin\n");
break;
case 0x900093:
printf("Pi Zero Rev 1.3 with 40 pin\n");
break;
case 0xa22082:
case 0xa02082:
printf("Pi 3 Model B Rev 1.2 with 40 pin\n");
gpio_base=PI2_GPIO_BASE;
serial_base=PI2_SERIAL_BASE;
break;
default:
printf("Unknown Raspberry Pi - assuming 40 pin\n");
}
return header_type;
}


static void dump_rts_cts(int header_type) {

int fd;
void *gpio_map,*serial_map;
uint32_t temp;
uint32_t tx_gpio,rx_gpio,cts_gpio,rts_gpio;
int old_cts=10,old_rts=10;

fd = open("/dev/mem", O_RDWR|O_SYNC);
if (fd < 0) {
fprintf(stderr, "can't open /dev/mem (%s)\n", strerror(errno));
exit(EXIT_FAILURE);
}

/* Map GPIO region */
gpio_map = mmap(NULL, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED,
fd, gpio_base);


/* Map Serial region */
serial_map = mmap(NULL, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED,
fd, serial_base);

close(fd);

if (gpio_map == MAP_FAILED) {
fprintf(stderr, "gpio mmap error (%s)\n", strerror(errno));
exit(EXIT_FAILURE);
}

if (serial_map == MAP_FAILED) {
fprintf(stderr, "serial mmap error (%s)\n", strerror(errno));
exit(EXIT_FAILURE);
}


volatile uint32_t *gpio = (volatile uint32_t *)gpio_map;
volatile uint32_t *serial = (volatile uint32_t *)serial_map;

printf("*** Raspberry Pi Curent Serial Settings ***\n\n");

printf("GPIO pin settings:\n");

temp=gpio[GFPSEL1];
tx_gpio=(temp>>12)&0x7;
rx_gpio=(temp>>15)&0x7;

/* 0 = input */
/* 1 = output */
/* 4 = ALT0 */
/* 5 = ALT1 */
/* 6 = ALT2 */
/* 7 = ALT3 */
/* 3 = ALT4 */
/* 2 = ALT5 */

printf("\tPIN14/TX = ");
if (tx_gpio==4) printf("AMBA (ALT0)\n");
else if (tx_gpio==2) printf("mini-uart (ALT5)\n");
else printf("Unknown (%d)\n",tx_gpio);

printf("\tPIN15/RX = ");
if (rx_gpio==4) printf("AMBA (ALT0)\n");
else if (rx_gpio==2) printf("mini-uart (ALT5)\n");
else printf("Unknown (%d)\n",rx_gpio);


if (header_type == GPIO_HEADER_40) {
temp=gpio[GFPSEL1];
cts_gpio=(temp>>18)&0x7;
rts_gpio=(temp>>21)&0x7;

printf("\tPIN16/CTS = ");
if (cts_gpio==0) printf("not configured\n");
else if (cts_gpio==7) printf("AMBA (ALT3)\n");
else if (cts_gpio==2) printf("mini-uart (ALT5)\n");
else printf("Unknown (%d)\n",cts_gpio);

printf("\tPIN17/RTS = ");
if (rts_gpio==0) printf("not configured\n");
else if (rts_gpio==7) printf("AMBA (ALT3)\n");
else if (rts_gpio==2) printf("mini-uart (ALT5)\n");
else printf("Unknown (%d)\n",rts_gpio);

}
else {
printf("\tPIN30/CTS = \n");
printf("\tPIN31/RTS = \n");
}

printf("\nRTS/CTS pin readings:\n");
printf("Only printing if they change values\n");

#define UART_FR 6
#define UART_CR 12


while(1) {
int cts,rts;

temp=serial[UART_FR];

/* CTS */
cts=!(temp&(1<<0));

temp=serial[UART_CR];

/* RTS */
rts=!(temp&(1<<11));

if ((cts!=old_cts) || (rts!=old_rts)) {
printf("CTS=%d RTS=%d\n",cts,rts);
old_cts=cts;
old_rts=rts;
}

}

}

int main(int argc, char **argv) {

int version,header_type;

version=rpi_version();
header_type=rpi_gpio_header_type(version);


dump_rts_cts(header_type);

return EXIT_SUCCESS;
}

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