/*
   * 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 const 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("");
  }
  
  static void print_usage(const char *prog)
  {
  	printf("Usage: %s [-DsbdlHOLC3]
  ", prog);
  	puts("  -D --device   device to use (default /dev/spidev1.1)
  "
  	     "  -s --speed    max speed (Hz)
  "
  	     "  -d --delay    delay (usec)
  "
  	     "  -b --bpw      bits per word 
  "
  	     "  -l --loop     loopback
  "
  	     "  -H --cpha     clock phase
  "
  	     "  -O --cpol     clock polarity
  "
  	     "  -L --lsb      least significant bit first
  "
  	     "  -C --cs-high  chip select active high
  "
  	     "  -3 --3wire    SI/SO signals shared
  ");
  	exit(1);
  }
  
  static void parse_opts(int argc, char *argv[])
  {
  	while (1) {
  		static const 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' },
  			{ "no-cs",   0, 0, 'N' },
  			{ "ready",   0, 0, 'R' },
  			{ NULL, 0, 0, 0 },
  		};
  		int c;
  
  		c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", 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;
  		case 'N':
  			mode |= SPI_NO_CS;
  			break;
  		case 'R':
  			mode |= SPI_READY;
  			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
  ", mode);
  	printf("bits per word: %d
  ", bits);
  	printf("max speed: %d Hz (%d KHz)
  ", speed, speed/1000);
  
  	transfer(fd);
  
  	close(fd);
  
  	return ret;
  }