以下所有的内容我是参考内核文档来的,位置:lichee/linux-3.3/Documentation/usb/gadget_hid.txt
1、修改lichee/linux-3.3/drivers/usb/gadget/hid.c文件
添加内容如下:
#include <linux/platform_device.h> #include <linux/usb/g_hid.h> /* hid descriptor for a keyboard */ static struct hidg_func_descriptor my_hid_data = { .subclass = 0, /* No subclass */ .protocol = 1, /* Keyboard */ .report_length = 8, .report_desc_length = 63, .report_desc = { 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ 0x09, 0x06, /* USAGE (Keyboard) */ 0xa1, 0x01, /* COLLECTION (Application) */ 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ 0x19, 0xe0, /* USAGE_MINIMUM (Keyboard LeftControl) */ 0x29, 0xe7, /* USAGE_MAXIMUM (Keyboard Right GUI) */ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ 0x75, 0x01, /* REPORT_SIZE (1) */ 0x95, 0x08, /* REPORT_COUNT (8) */ 0x81, 0x02, /* INPUT (Data,Var,Abs) */ 0x95, 0x01, /* REPORT_COUNT (1) */ 0x75, 0x08, /* REPORT_SIZE (8) */ 0x81, 0x03, /* INPUT (Cnst,Var,Abs) */ 0x95, 0x05, /* REPORT_COUNT (5) */ 0x75, 0x01, /* REPORT_SIZE (1) */ 0x05, 0x08, /* USAGE_PAGE (LEDs) */ 0x19, 0x01, /* USAGE_MINIMUM (Num Lock) */ 0x29, 0x05, /* USAGE_MAXIMUM (Kana) */ 0x91, 0x02, /* OUTPUT (Data,Var,Abs) */ 0x95, 0x01, /* REPORT_COUNT (1) */ 0x75, 0x03, /* REPORT_SIZE (3) */ 0x91, 0x03, /* OUTPUT (Cnst,Var,Abs) */ 0x95, 0x06, /* REPORT_COUNT (6) */ 0x75, 0x08, /* REPORT_SIZE (8) */ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ 0x25, 0x65, /* LOGICAL_MAXIMUM (101) */ 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ 0x19, 0x00, /* USAGE_MINIMUM (Reserved) */ 0x29, 0x65, /* USAGE_MAXIMUM (Keyboard Application) */ 0x81, 0x00, /* INPUT (Data,Ary,Abs) */ 0xc0 /* END_COLLECTION */ } }; static struct platform_device my_hid = { .name = "hidg", .id = 0, .num_resources = 0, .resource = 0, .dev.platform_data = &my_hid_data, };
static int __init hidg_init(void) { int status; status = platform_device_register(&my_hid); if (status < 0) { printk("my hid device register failed!\n"); return status; } status = platform_driver_probe(&hidg_plat_driver, hidg_plat_driver_probe); if (status < 0) return status; status = usb_composite_probe(&hidg_driver, hid_bind); if (status < 0) platform_driver_unregister(&hidg_plat_driver); return status; } module_init(hidg_init); static void __exit hidg_cleanup(void) { platform_driver_unregister(&hidg_plat_driver); usb_composite_unregister(&hidg_driver); platform_device_unregister(&my_hid); }
2、要产生hid的功能涉及两个文件hid.c和f_hid.c
内核配置如下:
3、编译内核: lichee$./buildroot/build_linux.sh -p sun7i
打包内核: lichee$./buildroot/build_linux.sh pack
将镜像烧入内核发现在/dev/目录下长出设备节点:/dev/hidg0
4、另外,hid给应用层提供字符设备操作接口,需要应用程序配合才能产生hid的功能。
应用程序:
/* hid_gadget_test */ #include <pthread.h> #include <string.h> #include <stdio.h> #include <ctype.h> #include <fcntl.h> #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #define BUF_LEN 512 struct options { const char *opt; unsigned char val; }; static struct options kmod[] = { {.opt = "--left-ctrl", .val = 0x01}, {.opt = "--right-ctrl", .val = 0x10}, {.opt = "--left-shift", .val = 0x02}, {.opt = "--right-shift", .val = 0x20}, {.opt = "--left-alt", .val = 0x04}, {.opt = "--right-alt", .val = 0x40}, {.opt = "--left-meta", .val = 0x08}, {.opt = "--right-meta", .val = 0x80}, {.opt = NULL} }; static struct options kval[] = { {.opt = "--return", .val = 0x28}, {.opt = "--esc", .val = 0x29}, {.opt = "--bckspc", .val = 0x2a}, {.opt = "--tab", .val = 0x2b}, {.opt = "--spacebar", .val = 0x2c}, {.opt = "--caps-lock", .val = 0x39}, {.opt = "--f1", .val = 0x3a}, {.opt = "--f2", .val = 0x3b}, {.opt = "--f3", .val = 0x3c}, {.opt = "--f4", .val = 0x3d}, {.opt = "--f5", .val = 0x3e}, {.opt = "--f6", .val = 0x3f}, {.opt = "--f7", .val = 0x40}, {.opt = "--f8", .val = 0x41}, {.opt = "--f9", .val = 0x42}, {.opt = "--f10", .val = 0x43}, {.opt = "--f11", .val = 0x44}, {.opt = "--f12", .val = 0x45}, {.opt = "--insert", .val = 0x49}, {.opt = "--home", .val = 0x4a}, {.opt = "--pageup", .val = 0x4b}, {.opt = "--del", .val = 0x4c}, {.opt = "--end", .val = 0x4d}, {.opt = "--pagedown", .val = 0x4e}, {.opt = "--right", .val = 0x4f}, {.opt = "--left", .val = 0x50}, {.opt = "--down", .val = 0x51}, {.opt = "--kp-enter", .val = 0x58}, {.opt = "--up", .val = 0x52}, {.opt = "--num-lock", .val = 0x53}, {.opt = NULL} }; int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) { char *tok = strtok(buf, " "); int key = 0; int i = 0; for (; tok != NULL; tok = strtok(NULL, " ")) { if (strcmp(tok, "--quit") == 0) return -1; if (strcmp(tok, "--hold") == 0) { *hold = 1; continue; } if (key < 6) { for (i = 0; kval[i].opt != NULL; i++) if (strcmp(tok, kval[i].opt) == 0) { report[2 + key++] = kval[i].val; break; } if (kval[i].opt != NULL) continue; } if (key < 6) if (islower(tok[0])) { report[2 + key++] = (tok[0] - ('a' - 0x04)); continue; } for (i = 0; kmod[i].opt != NULL; i++) if (strcmp(tok, kmod[i].opt) == 0) { report[0] = report[0] | kmod[i].val; break; } if (kmod[i].opt != NULL) continue; if (key < 6) fprintf(stderr, "unknown option: %s\n", tok); } return 8; } static struct options mmod[] = { {.opt = "--b1", .val = 0x01}, {.opt = "--b2", .val = 0x02}, {.opt = "--b3", .val = 0x04}, {.opt = NULL} }; int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) { char *tok = strtok(buf, " "); int mvt = 0; int i = 0; for (; tok != NULL; tok = strtok(NULL, " ")) { if (strcmp(tok, "--quit") == 0) return -1; if (strcmp(tok, "--hold") == 0) { *hold = 1; continue; } for (i = 0; mmod[i].opt != NULL; i++) if (strcmp(tok, mmod[i].opt) == 0) { report[0] = report[0] | mmod[i].val; break; } if (mmod[i].opt != NULL) continue; if (!(tok[0] == '-' && tok[1] == '-') && mvt < 2) { errno = 0; report[1 + mvt++] = (char)strtol(tok, NULL, 0); if (errno != 0) { fprintf(stderr, "Bad value:'%s'\n", tok); report[1 + mvt--] = 0; } continue; } fprintf(stderr, "unknown option: %s\n", tok); } return 3; } static struct options jmod[] = { {.opt = "--b1", .val = 0x10}, {.opt = "--b2", .val = 0x20}, {.opt = "--b3", .val = 0x40}, {.opt = "--b4", .val = 0x80}, {.opt = "--hat1", .val = 0x00}, {.opt = "--hat2", .val = 0x01}, {.opt = "--hat3", .val = 0x02}, {.opt = "--hat4", .val = 0x03}, {.opt = "--hatneutral", .val = 0x04}, {.opt = NULL} }; int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) { char *tok = strtok(buf, " "); int mvt = 0; int i = 0; *hold = 1; /* set default hat position: neutral */ report[3] = 0x04; for (; tok != NULL; tok = strtok(NULL, " ")) { if (strcmp(tok, "--quit") == 0) return -1; for (i = 0; jmod[i].opt != NULL; i++) if (strcmp(tok, jmod[i].opt) == 0) { report[3] = (report[3] & 0xF0) | jmod[i].val; break; } if (jmod[i].opt != NULL) continue; if (!(tok[0] == '-' && tok[1] == '-') && mvt < 3) { errno = 0; report[mvt++] = (char)strtol(tok, NULL, 0); if (errno != 0) { fprintf(stderr, "Bad value:'%s'\n", tok); report[mvt--] = 0; } continue; } fprintf(stderr, "unknown option: %s\n", tok); } return 4; } void print_options(char c) { int i = 0; if (c == 'k') { printf(" keyboard options:\n" " --hold\n"); for (i = 0; kmod[i].opt != NULL; i++) printf("\t\t%s\n", kmod[i].opt); printf("\n keyboard values:\n" " [a-z] or\n"); for (i = 0; kval[i].opt != NULL; i++) printf("\t\t%-8s%s", kval[i].opt, i % 2 ? "\n" : ""); printf("\n"); } else if (c == 'm') { printf(" mouse options:\n" " --hold\n"); for (i = 0; mmod[i].opt != NULL; i++) printf("\t\t%s\n", mmod[i].opt); printf("\n mouse values:\n" " Two signed numbers\n" "--quit to close\n"); } else { printf(" joystick options:\n"); for (i = 0; jmod[i].opt != NULL; i++) printf("\t\t%s\n", jmod[i].opt); printf("\n joystick values:\n" " three signed numbers\n" "--quit to close\n"); } } int main(int argc, const char *argv[]) { const char *filename = NULL; int fd = 0; char buf[BUF_LEN]; int cmd_len; char report[8]; int to_send = 8; int hold = 0; fd_set rfds; int retval, i; if (argc < 3) { fprintf(stderr, "Usage: %s devname mouse|keyboard|joystick\n", argv[0]); return 1; } if (argv[2][0] != 'k' && argv[2][0] != 'm' && argv[2][0] != 'j') return 2; filename = argv[1]; if ((fd = open(filename, O_RDWR, 0666)) == -1) { perror(filename); return 3; } print_options(argv[2][0]); while (42) { FD_ZERO(&rfds); FD_SET(STDIN_FILENO, &rfds); FD_SET(fd, &rfds); retval = select(fd + 1, &rfds, NULL, NULL, NULL); if (retval == -1 && errno == EINTR) continue; if (retval < 0) { perror("select()"); return 4; } if (FD_ISSET(fd, &rfds)) { cmd_len = read(fd, buf, BUF_LEN - 1); printf("recv report:"); for (i = 0; i < cmd_len; i++) printf(" %02x", buf[i]); printf("\n"); } if (FD_ISSET(STDIN_FILENO, &rfds)) { memset(report, 0x0, sizeof(report)); cmd_len = read(STDIN_FILENO, buf, BUF_LEN - 1); if (cmd_len == 0) break; buf[cmd_len - 1] = '\0'; hold = 0; memset(report, 0x0, sizeof(report)); if (argv[2][0] == 'k') to_send = keyboard_fill_report(report, buf, &hold); else if (argv[2][0] == 'm') to_send = mouse_fill_report(report, buf, &hold); else to_send = joystick_fill_report(report, buf, &hold); if (to_send == -1) break; if (write(fd, report, to_send) != to_send) { perror(filename); return 5; } if (!hold) { memset(report, 0x0, sizeof(report)); if (write(fd, report, to_send) != to_send) { perror(filename); return 6; } } } } close(fd); return 0; }
5、编译应用程序
arm-linux-gnueabi-gcc hid_gadget_test.c -o hid_gadget_test
执行如下:
部分参考自:
http://www.oschina.net/question/1174645_135969
http://blog.chinaunix.net/uid-27661165-id-3330346.html