| commit | author | age | ||
| f5c330 | 1 | /********************************************************************************* |
| G | 2 | * Copyright: (C) 2023 Avnet |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Filename: file.c | |
| 6 | * Description: This file | |
| 7 | * | |
| 8 | * Version: 1.0.0(2023年11月02日) | |
| 9 | * Author: Guo Wenxue <guowenxue@avnet.com> | |
| 10 | * ChangeLog: 1, Release initial version on "2023年11月02日 14时47分52秒" | |
| 11 | * | |
| 12 | ********************************************************************************/ | |
| 13 | ||
| 14 | #include <stdio.h> | |
| 15 | #include <unistd.h> | |
| 16 | #include <string.h> | |
| 17 | #include <errno.h> | |
| 18 | #include <fcntl.h> | |
| 19 | #include <sys/types.h> | |
| 20 | #include <sys/stat.h> | |
| 21 | #include <sys/ioctl.h> | |
| 22 | ||
| 23 | /* ioctl definitions, use 'z' as magic number */ | |
| 24 | #define CHRDEV_IOC_MAGIC 'z' | |
| 25 | #define CHRDEV_IOCRESET _IO(CHRDEV_IOC_MAGIC, 0) | |
| 26 | #define CHRDEV_IOCSET _IOW(CHRDEV_IOC_MAGIC, 1, int) | |
| 27 | #define CHRDEV_IOCGET _IOR(CHRDEV_IOC_MAGIC, 2, int) | |
| 28 | ||
| 29 | int main (int argc, char **argv) | |
| 30 | { | |
| 31 | char *devname = "/dev/chrdev"; | |
| 32 | char buf[1024]; | |
| 33 | int rv, fd; | |
| 34 | int value = 0x12345678; | |
| 35 | ||
| 36 | fd = open(devname, O_RDWR|O_TRUNC); | |
| 37 | if( fd < 0 ) | |
| 38 | { | |
| 39 | printf("Open device %s failed: %s\n", devname, strerror(errno)); | |
| 40 | return 1; | |
| 41 | } | |
| 42 | ||
| 43 | rv = write(fd, "Hello", 5); | |
| 44 | if( rv< 0) | |
| 45 | { | |
| 46 | printf("Write data into device failed, rv=%d: %s\n", rv, strerror(errno)); | |
| 47 | return 2; | |
| 48 | } | |
| 49 | printf("Write %d bytes data okay\n", rv); | |
| 50 | ||
| 51 | memset(buf, 0, sizeof(buf)); | |
| 52 | rv = read(fd, buf, sizeof(buf)); | |
| 53 | if( rv< 0) | |
| 54 | { | |
| 55 | printf("Read data from device failed, rv=%d: %s\n", rv, strerror(errno)); | |
| 56 | return 3; | |
| 57 | } | |
| 58 | printf("Read %d bytes data: %s\n", rv, buf); | |
| 59 | ||
| 60 | ioctl(fd, CHRDEV_IOCSET, &value); | |
| 61 | value = 0; | |
| 62 | ioctl(fd, CHRDEV_IOCGET, &value); | |
| 63 | printf("ioctl() read value=0x%0x\n", value); | |
| 64 | ||
| 65 | close(fd); | |
| 66 | return 0; | |
| 67 | } | |
| 68 | ||
