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).
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
+#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;
+}
projects / linux-2.6 / commitdiff