1、前言
getevent工具能够在嵌入式终端设备上运行,并且能够提供嵌入式终端输入设备和Linux内核输入事件的实时转储关系,可以确保设备驱动程序报告各个输入设备的一系列预期功能并生成输入事件所需的信息流,关于getevent工具的使用方法,可以参考文章《Android系统getevent用法》,链接如下所示:
https://www.cnblogs.com/Cqlismy/p/12626248.html
本文将主要介绍如何移植Android工具getevent到嵌入式Linux系统。
2、移植getevent工具
嵌入式的开发环境如下所示:
宿主机:Ubuntu 16.04系统
目标板:Hi3516DV300嵌入式开发板
交叉编译工具链:arm-himix200-linux-
移植修改后的getevent工具源码为getevent.c,该文件的内容如下所示:
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <dirent.h> #include <fcntl.h> #include <sys/ioctl.h> #include <sys/inotify.h> //#include <sys/limits.h> #include <sys/poll.h> #include <linux/input.h> #include <errno.h> #include <unistd.h> #include <time.h> struct label { const char *name; int value; }; #define LABEL(constant) { #constant, constant } #define LABEL_END { NULL, -1 } static struct label key_value_labels[] = { { "UP", 0 }, { "DOWN", 1 }, { "REPEAT", 2 }, LABEL_END, }; #include "input.h-labels.h" #undef LABEL #undef LABEL_END static struct pollfd *ufds; static char **device_names; static int nfds; enum { PRINT_DEVICE_ERRORS = 1U << 0, PRINT_DEVICE = 1U << 1, PRINT_DEVICE_NAME = 1U << 2, PRINT_DEVICE_INFO = 1U << 3, PRINT_VERSION = 1U << 4, PRINT_POSSIBLE_EVENTS = 1U << 5, PRINT_INPUT_PROPS = 1U << 6, PRINT_HID_DESCRIPTOR = 1U << 7, PRINT_ALL_INFO = (1U << 8) - 1, PRINT_LABELS = 1U << 16, }; static const char *get_label(const struct label *labels, int value) { while(labels->name && value != labels->value) { labels++; } return labels->name; } static int print_input_props(int fd) { uint8_t bits[INPUT_PROP_CNT / 8]; int i, j; int res; int count; const char *bit_label; printf(" input props: "); res = ioctl(fd, EVIOCGPROP(sizeof(bits)), bits); if(res < 0) { printf(" <not available "); return 1; } count = 0; for(i = 0; i < res; i++) { for(j = 0; j < 8; j++) { if (bits[i] & 1 << j) { bit_label = get_label(input_prop_labels, i * 8 + j); if(bit_label) printf(" %s ", bit_label); else printf(" %04x ", i * 8 + j); count++; } } } if (!count) printf(" <none> "); return 0; } static int print_possible_events(int fd, int print_flags) { uint8_t *bits = NULL; ssize_t bits_size = 0; const char* label; int i, j, k; int res, res2; struct label* bit_labels; const char *bit_label; printf(" events: "); for(i = EV_KEY; i <= EV_MAX; i++) { // skip EV_SYN since we cannot query its available codes int count = 0; while(1) { res = ioctl(fd, EVIOCGBIT(i, bits_size), bits); if(res < bits_size) break; bits_size = res + 16; bits = realloc(bits, bits_size * 2); if(bits == NULL) { fprintf(stderr, "failed to allocate buffer of size %d ", (int)bits_size); return 1; } } res2 = 0; switch(i) { case EV_KEY: res2 = ioctl(fd, EVIOCGKEY(res), bits + bits_size); label = "KEY"; bit_labels = key_labels; break; case EV_REL: label = "REL"; bit_labels = rel_labels; break; case EV_ABS: label = "ABS"; bit_labels = abs_labels; break; case EV_MSC: label = "MSC"; bit_labels = msc_labels; break; case EV_LED: res2 = ioctl(fd, EVIOCGLED(res), bits + bits_size); label = "LED"; bit_labels = led_labels; break; case EV_SND: res2 = ioctl(fd, EVIOCGSND(res), bits + bits_size); label = "SND"; bit_labels = snd_labels; break; case EV_SW: res2 = ioctl(fd, EVIOCGSW(bits_size), bits + bits_size); label = "SW "; bit_labels = sw_labels; break; case EV_REP: label = "REP"; bit_labels = rep_labels; break; case EV_FF: label = "FF "; bit_labels = ff_labels; break; case EV_PWR: label = "PWR"; bit_labels = NULL; break; case EV_FF_STATUS: label = "FFS"; bit_labels = ff_status_labels; break; default: res2 = 0; label = "???"; bit_labels = NULL; } for(j = 0; j < res; j++) { for(k = 0; k < 8; k++) if(bits[j] & 1 << k) { char down; if(j < res2 && (bits[j + bits_size] & 1 << k)) down = '*'; else down = ' '; if(count == 0) printf(" %s (%04x):", label, i); else if((count & (print_flags & PRINT_LABELS ? 0x3 : 0x7)) == 0 || i == EV_ABS) printf(" "); if(bit_labels && (print_flags & PRINT_LABELS)) { bit_label = get_label(bit_labels, j * 8 + k); if(bit_label) printf(" %.20s%c%*s", bit_label, down, (int) (20 - strlen(bit_label)), ""); else printf(" %04x%c ", j * 8 + k, down); } else { printf(" %04x%c", j * 8 + k, down); } if(i == EV_ABS) { struct input_absinfo abs; if(ioctl(fd, EVIOCGABS(j * 8 + k), &abs) == 0) { printf(" : value %d, min %d, max %d, fuzz %d, flat %d, resolution %d", abs.value, abs.minimum, abs.maximum, abs.fuzz, abs.flat, abs.resolution); } } count++; } } if(count) printf(" "); } free(bits); return 0; } static void print_event(int type, int code, int value, int print_flags) { const char *type_label, *code_label, *value_label; if (print_flags & PRINT_LABELS) { type_label = get_label(ev_labels, type); code_label = NULL; value_label = NULL; switch(type) { case EV_SYN: code_label = get_label(syn_labels, code); break; case EV_KEY: code_label = get_label(key_labels, code); value_label = get_label(key_value_labels, value); break; case EV_REL: code_label = get_label(rel_labels, code); break; case EV_ABS: code_label = get_label(abs_labels, code); switch(code) { case ABS_MT_TOOL_TYPE: value_label = get_label(mt_tool_labels, value); } break; case EV_MSC: code_label = get_label(msc_labels, code); break; case EV_LED: code_label = get_label(led_labels, code); break; case EV_SND: code_label = get_label(snd_labels, code); break; case EV_SW: code_label = get_label(sw_labels, code); break; case EV_REP: code_label = get_label(rep_labels, code); break; case EV_FF: code_label = get_label(ff_labels, code); break; case EV_FF_STATUS: code_label = get_label(ff_status_labels, code); break; } if (type_label) printf("%-12.12s", type_label); else printf("%04x ", type); if (code_label) printf(" %-20.20s", code_label); else printf(" %04x ", code); if (value_label) printf(" %-20.20s", value_label); else printf(" %08x ", value); } else { printf("%04x %04x %08x", type, code, value); } } static void print_hid_descriptor(int bus, int vendor, int product) { const char *dirname = "/sys/kernel/debug/hid"; char prefix[16]; DIR *dir; struct dirent *de; char filename[PATH_MAX]; FILE *file; char line[2048]; snprintf(prefix, sizeof(prefix), "%04X:%04X:%04X.", bus, vendor, product); dir = opendir(dirname); if(dir == NULL) return; while((de = readdir(dir))) { if (strstr(de->d_name, prefix) == de->d_name) { snprintf(filename, sizeof(filename), "%s/%s/rdesc", dirname, de->d_name); file = fopen(filename, "r"); if (file) { printf(" HID descriptor: %s ", de->d_name); while (fgets(line, sizeof(line), file)) { fputs(" ", stdout); fputs(line, stdout); } fclose(file); puts(""); } } } closedir(dir); } static int open_device(const char *device, int print_flags) { int version; int fd; int clkid = CLOCK_MONOTONIC; struct pollfd *new_ufds; char **new_device_names; char name[80]; char location[80]; char idstr[80]; struct input_id id; fd = open(device, O_RDWR); if(fd < 0) { if(print_flags & PRINT_DEVICE_ERRORS) fprintf(stderr, "could not open %s, %s ", device, strerror(errno)); return -1; } if(ioctl(fd, EVIOCGVERSION, &version)) { if(print_flags & PRINT_DEVICE_ERRORS) fprintf(stderr, "could not get driver version for %s, %s ", device, strerror(errno)); return -1; } if(ioctl(fd, EVIOCGID, &id)) { if(print_flags & PRINT_DEVICE_ERRORS) fprintf(stderr, "could not get driver id for %s, %s ", device, strerror(errno)); return -1; } name[sizeof(name) - 1] = '