diff options
Diffstat (limited to 'Documentation/spi')
| -rw-r--r-- | Documentation/spi/spidev_test.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c new file mode 100644 index 000000000000..218e86215297 --- /dev/null +++ b/Documentation/spi/spidev_test.c @@ -0,0 +1,202 @@ +/* + * SPI testing utility (using spidev driver) + * + * Copyright (c) 2007 MontaVista Software, Inc. + * Copyright (c) 2007 Anton Vorontsov <avorontsov@ru.mvista.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. + * + * Cross-compile with cross-gcc -I/path/to/cross-kernel/include + */ + +#include <stdint.h> +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <getopt.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <linux/types.h> +#include <linux/spi/spidev.h> + +#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) + +static void pabort(const char *s) +{ + perror(s); + abort(); +} + +static char *device = "/dev/spidev1.1"; +static uint8_t mode; +static uint8_t bits = 8; +static uint32_t speed = 500000; +static uint16_t delay; + +static void transfer(int fd) +{ + int ret; + uint8_t tx[] = { + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, + 0x40, 0x00, 0x00, 0x00, 0x00, 0x95, + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, + 0xDE, 0xAD, 0xBE, 0xEF, 0xBA, 0xAD, + 0xF0, 0x0D, + }; + uint8_t rx[ARRAY_SIZE(tx)] = {0, }; + struct spi_ioc_transfer tr = { + .tx_buf = (unsigned long)tx, + .rx_buf = (unsigned long)rx, + .len = ARRAY_SIZE(tx), + .delay_usecs = delay, + .speed_hz = speed, + .bits_per_word = bits, + }; + + ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); + if (ret == 1) + pabort("can't send spi message"); + + for (ret = 0; ret < ARRAY_SIZE(tx); ret++) { + if (!(ret % 6)) + puts(""); + printf("%.2X ", rx[ret]); + } + puts(""); +} + +void print_usage(char *prog) +{ + printf("Usage: %s [-DsbdlHOLC3]\n", prog); + puts(" -D --device device to use (default /dev/spidev1.1)\n" + " -s --speed max speed (Hz)\n" + " -d --delay delay (usec)\n" + " -b --bpw bits per word \n" + " -l --loop loopback\n" + " -H --cpha clock phase\n" + " -O --cpol clock polarity\n" + " -L --lsb least significant bit first\n" + " -C --cs-high chip select active high\n" + " -3 --3wire SI/SO signals shared\n"); + exit(1); +} + +void parse_opts(int argc, char *argv[]) +{ + while (1) { + static struct option lopts[] = { + { "device", 1, 0, 'D' }, + { "speed", 1, 0, 's' }, + { "delay", 1, 0, 'd' }, + { "bpw", 1, 0, 'b' }, + { "loop", 0, 0, 'l' }, + { "cpha", 0, 0, 'H' }, + { "cpol", 0, 0, 'O' }, + { "lsb", 0, 0, 'L' }, + { "cs-high", 0, 0, 'C' }, + { "3wire", 0, 0, '3' }, + { NULL, 0, 0, 0 }, + }; + int c; + + c = getopt_long(argc, argv, "D:s:d:b:lHOLC3", lopts, NULL); + + if (c == -1) + break; + + switch (c) { + case 'D': + device = optarg; + break; + case 's': + speed = atoi(optarg); + break; + case 'd': + delay = atoi(optarg); + break; + case 'b': + bits = atoi(optarg); + break; + case 'l': + mode |= SPI_LOOP; + break; + case 'H': + mode |= SPI_CPHA; + break; + case 'O': + mode |= SPI_CPOL; + break; + case 'L': + mode |= SPI_LSB_FIRST; + break; + case 'C': + mode |= SPI_CS_HIGH; + break; + case '3': + mode |= SPI_3WIRE; + break; + default: + print_usage(argv[0]); + break; + } + } +} + +int main(int argc, char *argv[]) +{ + int ret = 0; + int fd; + + parse_opts(argc, argv); + + fd = open(device, O_RDWR); + if (fd < 0) + pabort("can't open device"); + + /* + * spi mode + */ + ret = ioctl(fd, SPI_IOC_WR_MODE, &mode); + if (ret == -1) + pabort("can't set spi mode"); + + ret = ioctl(fd, SPI_IOC_RD_MODE, &mode); + if (ret == -1) + pabort("can't get spi mode"); + + /* + * bits per word + */ + ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits); + if (ret == -1) + pabort("can't set bits per word"); + + ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits); + if (ret == -1) + pabort("can't get bits per word"); + + /* + * max speed hz + */ + ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed); + if (ret == -1) + pabort("can't set max speed hz"); + + ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed); + if (ret == -1) + pabort("can't get max speed hz"); + + printf("spi mode: %d\n", mode); + printf("bits per word: %d\n", bits); + printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000); + + transfer(fd); + + close(fd); + + return ret; +} |