啥也不說了，先上代碼：
由于linux中的list.h不能直接用，是以單獨提取了出來使用：
//listop.h
#ifndef LISTOP_H
#define LISTOP_H
structlist_head {
structlist_head *next, *prev;
};
typedefstructlist_head list_t;
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
structlist_head name = LIST_HEAD_INIT(name)
#define INIT_LIST_HEAD(ptr) do { \
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
}while(0)
voidlist_add(structlist_head *new,structlist_head *head);
voidlist_add_tail(structlist_head *new,structlist_head *head);
voidlist_del(structlist_head *entry);
voidlist_del_init(structlist_head *entry);
voidlist_move(structlist_head *list,structlist_head *head);
voidlist_move_tail(structlist_head *list,
structlist_head *head);
voidlist_splice(structlist_head *list,structlist_head *head);
staticintlist_empty(structlist_head *head)
{
returnhead->next == head;
}
structlist_head * list_dequeue(structlist_head *list );
#define list_entry(ptr, type, member) \
((type *)((char*)(ptr)-(unsignedlong)(&((type *)0)->member)))
#define list_for_each(pos, head) \
for(pos = (head)->next; pos != (head); \
pos = pos->next)
#define list_for_each_safe(pos, n, head) \
for(pos = (head)->next, n = pos->next; pos != (head); \
pos = n, n = pos->next)
#define list_for_each_prev(pos, head) \
for(pos = (head)->prev; pos != (head); \
pos = pos->prev)
#define list_for_each_entry(pos, head, member) \
for(pos = list_entry((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
#endif// listop.c
#include "listop.h"
staticvoid__check_head(structlist_head* head)
{
if((head->next == 0) && (head->prev == 0)) {
INIT_LIST_HEAD(head);
}
}
staticvoid__list_add(structlist_head*new,
structlist_head* prev,
structlist_head* next)
{
next->prev =new;
new->next = next;
new->prev = prev;
prev->next =new;
}
staticvoid__list_del(structlist_head* prev,
structlist_head* next)
{
next->prev = prev;
prev->next = next;
}
voidlist_add(structlist_head*new,structlist_head* head)
{
__check_head(head);
__list_add(new, head, head->next);
}
voidlist_add_tail(structlist_head*new,structlist_head* head)
{
__check_head(head);
__list_add(new, head->prev, head);
}
voidlist_del(structlist_head* entry)
{
__list_del(entry->prev, entry->next);
}
voidlist_del_init(structlist_head* entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
voidlist_move(structlist_head* list,structlist_head* head)
{
__check_head(head);
__list_del(list->prev, list->next);
list_add(list, head);
}
voidlist_move_tail(structlist_head* list,
structlist_head* head)
{
__check_head(head);
__list_del(list->prev, list->next);
list_add_tail(list, head);
}
voidlist_splice(structlist_head* list,structlist_head* head)
{
structlist_head* first = list;
structlist_head* last = list->prev;
structlist_head* at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
structlist_head* list_dequeue(structlist_head* list ) {
structlist_head* next, *prev, *result = ((void*)0);
prev = list;
next = prev->next;
if( next != prev ) {
result = next;
next = next->next;
next->prev = prev;
prev->next = next;
result->prev = result->next = result;
}
returnresult;
}
主要的檔案在這裡：
//my_joystick.c
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
//#include
#include "listop.h"
#if 1
#define LOG_DBG(fmt, ...) fprintf(stdout, fmt, ##__VA_ARGS__)
#else
#define LOG_DBG(fmt, ...)
#endif
#define LOG_ERR(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
typedefstruct_joy_stick_ctx {
structlist_head list;
inti4_js_fd;
unsignedinti4_op_block;
} JOYSTICK_CTX_T;
LIST_HEAD(_t_js_ctx_head);
intjoystick_open(char* cp_js_dev_name,inti4_block)
{
inti4_open_flags = O_RDONLY;
JOYSTICK_CTX_T* pt_joystick_ctx = NULL;
if(!cp_js_dev_name) {
LOG_ERR("[%s] js device name is NULL\n", __func__);
return-1;
}
pt_joystick_ctx = (JOYSTICK_CTX_T*)calloc(sizeof(JOYSTICK_CTX_T), 1);
if(!pt_joystick_ctx) {
LOG_ERR("[%s] no memory!!\n", __func__);
return-1;
}
pt_joystick_ctx->i4_op_block = i4_block ? 1 : 0;
if(pt_joystick_ctx->i4_op_block == 0) {
i4_open_flags |= O_NONBLOCK;
}
pt_joystick_ctx->i4_js_fd = open(cp_js_dev_name, i4_open_flags);
if(pt_joystick_ctx->i4_js_fd
LOG_ERR("[%s] open device %s error\n", __func__, cp_js_dev_name);
free(pt_joystick_ctx);
return-1;
}
list_add_tail(&pt_joystick_ctx->list, &_t_js_ctx_head);
returnpt_joystick_ctx->i4_js_fd;
}
intjoystick_close(inti4_fd)
{
structlist_head* pt_entry;
structlist_head* pt_next;
JOYSTICK_CTX_T* pt_node;
if(list_empty(&_t_js_ctx_head)) {
LOG_ERR("[%s] device not opened\n", __func__);
return-1;
}
list_for_each_safe(pt_entry, pt_next, &_t_js_ctx_head) {
pt_node = list_entry(pt_entry, JOYSTICK_CTX_T, list);
if(pt_node->i4_js_fd == i4_fd) {
list_del_init(&pt_node->list);
free(pt_node);
returnclose(i4_fd);
}
}
LOG_ERR("[%s] i4_fd=%d invalid\n", __func__, i4_fd);
return-1;
}
intjoystick_read_one_event(inti4_fd,structjs_event* tp_jse)
{
inti4_rd_bytes;
i4_rd_bytes = read(i4_fd, tp_jse,sizeof(structjs_event));
if(i4_rd_bytes == -1) {
if(errno == EAGAIN) {
return0;
}
else{
return-1;
}
}
returni4_rd_bytes;
}
intjoystick_read_ready(inti4_fd)
{
inti4_block = 2;
structlist_head* pt_entry;
JOYSTICK_CTX_T* pt_node;
if(list_empty(&_t_js_ctx_head)) {
LOG_ERR("[%s] device not opened\n", __func__);
return-1;
}
list_for_each(pt_entry, &_t_js_ctx_head) {
pt_node = list_entry(pt_entry, JOYSTICK_CTX_T, list);
if(pt_node->i4_js_fd == i4_fd) {
i4_block = pt_node->i4_op_block;
break;
}
}
if(i4_block == 2) {
LOG_ERR("[%s] i4_fd=%d invalid\n", __func__, i4_fd);
return0;
}
elseif(i4_block == 1) {
fd_set readfd;
inti4_ret = 0;
structtimeval timeout = {0, 0};
FD_ZERO(&readfd);
FD_SET(i4_fd, &readfd);
i4_ret = select(i4_fd + 1, &readfd, NULL, NULL, &timeout);
if(i4_ret > 0 && FD_ISSET(i4_fd, &readfd)) {
return1;
}
else{
return0;
}
}
return1;
}
voiddebug_list(void)
{
if(! list_empty(&_t_js_ctx_head)) {
structlist_head* pt_entry;
JOYSTICK_CTX_T* pt_node;
list_for_each(pt_entry, &_t_js_ctx_head) {
pt_node = list_entry(pt_entry, JOYSTICK_CTX_T, list);
LOG_DBG("fd:%d--block:%d\n", pt_node->i4_js_fd, pt_node->i4_op_block);
}
}
else{
LOG_DBG("-----------> EMPTY NOW\n");
}
}
#if 1
typedefstruct_axes_t {
intx;
inty;
} AXES_T;
intmain(intargc,char* argv[])
{
intfd, rc;
intop_times = 0;
charnumber_of_axes = 0;
charnumber_of_btns = 0;
charjs_name_str[128];
unsignedintbuttons_state = 0;
AXES_T* tp_axes = NULL;
inti, print_init_stat = 0;
structjs_event jse;
fd = joystick_open("/dev/input/js0", 1);
if(fd
LOG_ERR("open failed.\n");
exit(1);
}
rc = ioctl(fd, JSIOCGAXES, &number_of_axes);
if(rc != -1) {
LOG_DBG("number_of_axes:%d\n", number_of_axes);
if(number_of_axes > 0) {
tp_axes = (AXES_T*)calloc(sizeof(AXES_T), 1);
}
}
rc = ioctl(fd, JSIOCGBUTTONS, &number_of_btns);
if(rc != -1) {
LOG_DBG("number_of_btns:%d\n", number_of_btns);
}
if(ioctl(fd, JSIOCGNAME(sizeof(js_name_str)), js_name_str)
LOG_DBG(js_name_str,"Unknown",sizeof(js_name_str));
}
LOG_DBG("joystick Name: %s\n", js_name_str);
for(;;) {
if(joystick_read_ready(fd)) {
rc = joystick_read_one_event(fd, &jse);
if(rc > 0) {
if((jse.type & JS_EVENT_INIT) == JS_EVENT_INIT) {
if((jse.type & ~JS_EVENT_INIT) == JS_EVENT_BUTTON) {
if(jse.value) {
buttons_state |= (1 <
}
else{
buttons_state &= ~(1 <
}
}
elseif((jse.type & ~JS_EVENT_INIT) == JS_EVENT_AXIS) {
if(tp_axes) {
if((jse.number & 1) == 0) {
tp_axes[jse.number / 2].x = jse.value;
}
else{
tp_axes[jse.number / 2].y = jse.value;
}
}
}
}
else{
op_times++;
if(print_init_stat == 0) {
for(i = 0; i
LOG_DBG("joystick init state: button %d is %s.\n", i, ((buttons_state & (1 <
}
if(tp_axes)
for(i = 0; i
LOG_DBG("joystick init state: axes %d is x=%d y=%d.\n", i, tp_axes[i].x, tp_axes[i].y);
}
print_init_stat = 1;
}
if(jse.type == JS_EVENT_BUTTON) {
if(jse.value) {
buttons_state |= (1 <
}
else{
buttons_state &= ~(1 <
}
LOG_DBG("joystick state: button %d is %s.\n", jse.number, ((buttons_state & (1 <
}
elseif(jse.type == JS_EVENT_AXIS) {
if(tp_axes) {
if((jse.number & 1) == 0) {
tp_axes[jse.number / 2].x = jse.value;
}
else{
tp_axes[jse.number / 2].y = jse.value;
}
LOG_DBG("joystick state: axes %d is x=%d y=%d.\n", jse.number / 2, tp_axes[jse.number / 2].x, tp_axes[jse.number / 2].y);
}
else{
LOG_DBG("joystick state: axes %d is %s=%d.\n", jse.number / 2, ((jse.number & 1) == 0) ?"x":"y", jse.value);
}
}
}
if(op_times >= 18) {
break;
}
}
}
usleep(1000);
}
joystick_close(fd);
if(tp_axes) {
free(tp_axes);
}
return0;
}
#endif
編譯: gcc -o my_joystick my_joystick.c listop.c
運作:
[email protected]:hid$ ./my_joystick
number_of_axes:2
number_of_btns:10
joystick Name: BETOP GAMEPAD
joystick init state: button 0 is UP.
joystick init state: button 1 is UP.
joystick init state: button 2 is UP.
joystick init state: button 3 is UP.
joystick init state: button 4 is UP.
joystick init state: button 5 is UP.
joystick init state: button 6 is UP.
joystick init state: button 7 is UP.
joystick init state: button 8 is UP.
joystick init state: button 9 is UP.
joystick init state: axes 0 is x=0 y=0.
joystick init state: axes 1 is x=0 y=135129.
joystick state: button 0 is DOWN.
joystick state: button 0 is UP.
joystick state: button 1 is DOWN.
joystick state: button 1 is UP.
joystick state: button 3 is DOWN.
joystick state: button 3 is UP.
joystick state: button 2 is DOWN.
joystick state: button 2 is UP.
joystick state: button 7 is DOWN.
joystick state: button 7 is UP.
joystick state: button 5 is DOWN.
joystick state: button 5 is UP.
joystick state: button 6 is DOWN.
joystick state: button 6 is UP.
joystick state: button 4 is DOWN.
joystick state: button 4 is UP.
joystick state: button 5 is DOWN.
joystick state: button 5 is UP.
不明白的地方可以參考linux kernel中的說明檔案：Documentation/input/joystick-api.txt