Re: [PATCH] documentation: move spidev_fdx example to its own source file

From: David Brownell
Date: Mon Feb 18 2008 - 21:14:53 EST


On Monday 18 February 2008, Randy Dunlap wrote:
> From: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
>
> cc: dbrownell@xxxxxxxxxxxxxxxxxxxxx
> cc: spi-devel-general@xxxxxxxxxxxxxxxxxxxxx
>
> 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@xxxxxxxxxx>

Acked-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>

> ---
> Documentation/spi/spidev | 168 -------------------------------
> Documentation/spi/spidev_fdx.c | 158 +++++++++++++++++++++++++++++
> 2 files changed, 160 insertions(+), 166 deletions(-)
>
> --- linux-2625-rc2-docsrc.orig/Documentation/spi/spidev
> +++ linux-2625-rc2-docsrc/Documentation/spi/spidev
> @@ -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;
> -}
> --- /dev/null
> +++ linux-2625-rc2-docsrc/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;
> +}
>


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