spidev_test utility

This is a simple utility used to test SPI functionality.  It could stand
growing options to support using other test data patterns; this initial
version only issues full duplex transfers, which rules out 3WIRE or
Microwire links.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c
new file mode 100644 (file)
index 0000000..218e862
--- /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;
+}