documentation: move spidev_fdx example to its own source file
Move sample source code to its own source file so that it can be used
easier and build-tested/check/maintained by anyone.
(Makefile changes are in a separate patch for all of Documentation/.)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-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_fdx.c b/Documentation/spi/spidev_fdx.c
new file mode 100644
index 0000000..fc354f7
--- /dev/null
+++ b/Documentation/spi/spidev_fdx.c
@@ -0,0 +1,158 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <linux/types.h>
+#include <linux/spi/spidev.h>
+
+
+static int verbose;
+
+static void do_read(int fd, int len)
+{
+ unsigned char buf[32], *bp;
+ int status;
+
+ /* read at least 2 bytes, no more than 32 */
+ if (len < 2)
+ len = 2;
+ else if (len > sizeof(buf))
+ len = sizeof(buf);
+ memset(buf, 0, sizeof buf);
+
+ status = read(fd, buf, len);
+ if (status < 0) {
+ perror("read");
+ return;
+ }
+ if (status != len) {
+ fprintf(stderr, "short read\n");
+ return;
+ }
+
+ printf("read(%2d, %2d): %02x %02x,", len, status,
+ buf[0], buf[1]);
+ status -= 2;
+ bp = buf + 2;
+ while (status-- > 0)
+ printf(" %02x", *bp++);
+ printf("\n");
+}
+
+static void do_msg(int fd, int len)
+{
+ struct spi_ioc_transfer xfer[2];
+ unsigned char buf[32], *bp;
+ int status;
+
+ memset(xfer, 0, sizeof xfer);
+ memset(buf, 0, sizeof buf);
+
+ if (len > sizeof buf)
+ len = sizeof buf;
+
+ buf[0] = 0xaa;
+ xfer[0].tx_buf = (__u64) buf;
+ xfer[0].len = 1;
+
+ xfer[1].rx_buf = (__u64) buf;
+ xfer[1].len = len;
+
+ status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
+ if (status < 0) {
+ perror("SPI_IOC_MESSAGE");
+ return;
+ }
+
+ printf("response(%2d, %2d): ", len, status);
+ for (bp = buf; len; len--)
+ printf(" %02x", *bp++);
+ printf("\n");
+}
+
+static void dumpstat(const char *name, int fd)
+{
+ __u8 mode, lsb, bits;
+ __u32 speed;
+
+ if (ioctl(fd, SPI_IOC_RD_MODE, &mode) < 0) {
+ perror("SPI rd_mode");
+ return;
+ }
+ if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
+ perror("SPI rd_lsb_fist");
+ return;
+ }
+ if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
+ perror("SPI bits_per_word");
+ return;
+ }
+ if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
+ perror("SPI max_speed_hz");
+ return;
+ }
+
+ printf("%s: spi mode %d, %d bits %sper word, %d Hz max\n",
+ name, mode, bits, lsb ? "(lsb first) " : "", speed);
+}
+
+int main(int argc, char **argv)
+{
+ int c;
+ int readcount = 0;
+ int msglen = 0;
+ int fd;
+ const char *name;
+
+ while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
+ switch (c) {
+ case 'm':
+ msglen = atoi(optarg);
+ if (msglen < 0)
+ goto usage;
+ continue;
+ case 'r':
+ readcount = atoi(optarg);
+ if (readcount < 0)
+ goto usage;
+ continue;
+ case 'v':
+ verbose++;
+ continue;
+ case 'h':
+ case '?':
+usage:
+ fprintf(stderr,
+ "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n",
+ argv[0]);
+ return 1;
+ }
+ }
+
+ if ((optind + 1) != argc)
+ goto usage;
+ name = argv[optind];
+
+ fd = open(name, O_RDWR);
+ if (fd < 0) {
+ perror("open");
+ return 1;
+ }
+
+ dumpstat(name, fd);
+
+ if (msglen)
+ do_msg(fd, msglen);
+
+ if (readcount)
+ do_read(fd, readcount);
+
+ close(fd);
+ return 0;
+}