diff options
Diffstat (limited to 'Documentation/spi')
| -rw-r--r-- | Documentation/spi/spidev | 168 | ||||
| -rw-r--r-- | Documentation/spi/spidev_fdx.c | 158 |
2 files changed, 160 insertions, 166 deletions
diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev index 5c8e1b988a0..ed2da5e5b28 100644 --- a/Documentation/spi/spidev +++ b/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; -} diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c new file mode 100644 index 00000000000..fc354f76038 --- /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; +} |