[spi-devel-general] [PATCH 2/3] [SPI] Add new mode: SPI_LOOP
Anton Vorontsov
avorontsov at ru.mvista.com
Fri Jul 27 23:27:21 EST 2007
On Thu, Jul 26, 2007 at 08:07:07PM -0700, David Brownell wrote:
> On Thursday 26 July 2007, Anton Vorontsov wrote:
> > Loopback mode is supported by various controllers, this mode
> > is useful for testing, especially in conjunction with spidev
> > driver.
>
> ISTR that Stephen Street provided a loopback mode for debug
> in his pxa2xx_spi code. And I know you're fight that this
> mode shows up in a lot of hardware.
>
> Comments, anyone? This seems like a fair way to expose this
> mechanism. And I tend to agree that it'd mostly be useful in
> conjunction with "spidev".
>
> Anton -- assuming this goes in, it'd be nice if you could
> contribute a simple test program using this, which we could
> keep in Documentation/spi somewhere. (Maybe with other testing
> notes, if anyone comes up with such.)
Sure. Test utility is below.
I'm aware it's not perfect, it sends just one transfer message,
which not covers all testing requirements. So implementing
--datafile switch to pass .ppm-alike files (as in
drivers/video/logo/) would be great. But I'm leaving this feature
implementation to those who will really need it. ;-)
Thanks!
- - - -
From: Anton Vorontsov <avorontsov at ru.mvista.com>
Subject: [SPI] spidev_test utility
This is simple utility used to test SPI functionality.
Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
Documentation/spi/spidev_test.c | 202 +++++++++++++++++++++++++++++++++++++++
1 files changed, 202 insertions(+), 0 deletions(-)
create mode 100644 Documentation/spi/spidev_test.c
diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c
new file mode 100644
index 0000000..d76a72b
--- /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 at 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
+ */
+
+#define _GNU_SOURCE
+#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 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: Hz (kHz): %d (%d)\n", speed, speed/1000);
+
+ transfer(fd);
+
+ close(fd);
+
+ return ret;
+}
--
1.5.0.6
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