| commit | author | age | ||
| b8e5f6 | 1 | /* |
| G | 2 | * Copyright (C) 2024 LingYun IoT System Studio |
| 3 | * Author: Guo Wenxue <guowenxue@gmail.com> | |
| 4 | * | |
| 5 | * A character skeleton driver test code in user space. | |
| 6 | */ | |
| 7 | ||
| 8 | #include <stdio.h> | |
| 9 | #include <unistd.h> | |
| 10 | #include <string.h> | |
| 11 | #include <errno.h> | |
| 12 | #include <sys/types.h> | |
| 13 | #include <sys/stat.h> | |
| 14 | #include <sys/ioctl.h> | |
| 15 | #include <fcntl.h> | |
| 16 | ||
| 17 | #define CHR_MAGIC 'c' | |
| 18 | #define CMD_READ _IOR(CHR_MAGIC, 0, int) | |
| 19 | #define CMD_WRITE _IOW(CHR_MAGIC, 1, int) | |
| 20 | ||
| 21 | int main (int argc, char **argv) | |
| 22 | { | |
| 23 | char *devname = "/dev/chrdev0"; | |
| 24 | int value; | |
| 25 | int fd; | |
| 26 | ||
| 27 | fd = open(devname, O_RDWR); | |
| 28 | if( fd < 0 ) | |
| 29 | { | |
| 30 | printf("Open device %s failed: %s\n", devname, strerror(errno)); | |
| 31 | return 1; | |
| 32 | } | |
| 33 | ||
| 34 | if( ioctl(fd, CMD_READ, &value) < 0 ) | |
| 35 | { | |
| 36 | printf("ioctl() failed: %s\n", strerror(errno)); | |
| 37 | goto cleanup; | |
| 38 | } | |
| 39 | printf("Default value in driver: 0x%0x\n", value); | |
| 40 | ||
| 41 | value = 0x12345678; | |
| 42 | if( ioctl(fd, CMD_WRITE, &value) < 0 ) | |
| 43 | { | |
| 44 | printf("ioctl() failed: %s\n", strerror(errno)); | |
| 45 | goto cleanup; | |
| 46 | } | |
| 47 | printf("Wriee value into driver: 0x%0x\n", value); | |
| 48 | ||
| 49 | value = 0; | |
| 50 | if( ioctl(fd, CMD_READ, &value) < 0 ) | |
| 51 | { | |
| 52 | printf("ioctl() failed: %s\n", strerror(errno)); | |
| 53 | goto cleanup; | |
| 54 | } | |
| 55 | printf("Read value from driver : 0x%0x\n", value); | |
| 56 | ||
| 57 | cleanup: | |
| 58 | close(fd); | |
| 59 | return 0; | |
| 60 | } | |
