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>
This commit is contained in:
Randy Dunlap
Linus Torvalds
parent
cf43369d55
commit
31a1629426
|
|
@ -126,8 +126,8 @@ NOTES:
|
|||
FULL DUPLEX CHARACTER DEVICE API
|
||||
================================
|
||||
|
||||
See the sample program below for one example showing the use of the full
|
||||
duplex programming interface. (Although it doesn't perform a full duplex
|
||||
See the spidev_fdx.c sample program for one example showing the use of the
|
||||
full duplex programming interface. (Although it doesn't perform a full duplex
|
||||
transfer.) The model is the same as that used in the kernel spi_sync()
|
||||
request; the individual transfers offer the same capabilities as are
|
||||
available to kernel drivers (except that it's not asynchronous).
|
||||
|
|
@ -141,167 +141,3 @@ and bitrate for each transfer segment.)
|
|||
|
||||
To make a full duplex request, provide both rx_buf and tx_buf for the
|
||||
same transfer. It's even OK if those are the same buffer.
|
||||
|
||||
|
||||
SAMPLE PROGRAM
|
||||
==============
|
||||
|
||||
-------------------------------- CUT HERE
|
||||
#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;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -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;
|
||||
}
|
||||
Reference in New Issue