啥也不说了，先上代码：
由于linux中的list.h不能直接用，所以单独提取了出来使用：
//listop.h
/*itisfromlinuxlist*/
#ifndefLISTOP_H
#defineLISTOP_H
structlist_head{
structlist_head*next,*prev;
};
typedefstructlist_headlist_t;
#defineLIST_HEAD_INIT(name){&(name),&(name)}
#defineLIST_HEAD(name)\
structlist_headname=LIST_HEAD_INIT(name)
#defineINIT_LIST_HEAD(ptr)do{\
(ptr)->next=(ptr);(ptr)->prev=(ptr);\
}while(0)
/**
*list_add-addanewentry
*@new:newentrytobeadded
*@head:listheadtoadditafter
*
*Insertanewentryafterthespecifiedhead.
*Thisisgoodforimplementingstacks.
*/
voidlist_add(structlist_head*new,structlist_head*head);
/**
*list_add_tail-addanewentry
*@new:newentrytobeadded
*@head:listheadtoadditbefore
*
*Insertanewentrybeforethespecifiedhead.
*Thisisusefulforimplementingqueues.
*/
voidlist_add_tail(structlist_head*new,structlist_head*head);
/**
*list_del-deletesentryfromlist.
*@entry:theelementtodeletefromthelist.
*Note:list_emptyonentrydoesnotreturntrueafterthis,theentryisinanundefinedstate.
*/
voidlist_del(structlist_head*entry);
/**
*list_del_init-deletesentryfromlistandreinitializeit.
*@entry:theelementtodeletefromthelist.
*/
voidlist_del_init(structlist_head*entry);
/**
*list_move-deletefromonelistandaddasanother'shead
*@list:theentrytomove
*@head:theheadthatwillprecedeourentry
*/
voidlist_move(structlist_head*list,structlist_head*head);
/**
*list_move_tail-deletefromonelistandaddasanother'stail
*@list:theentrytomove
*@head:theheadthatwillfollowourentry
*/
voidlist_move_tail(structlist_head*list,
structlist_head*head);
/**
*list_splice-jointwolists
*@list:thenewlisttoadd.
*@head:theplacetoadditinthefirstlist.
*/
voidlist_splice(structlist_head*list,structlist_head*head);
/**
*list_empty-testswhetheralistisempty
*@head:thelisttotest.
*/
staticintlist_empty(structlist_head*head)
{
returnhead->next==head;
}
/**
*list_dequeue-dequeuetheheadofthelistiftherearemorethanoneentry
*@list:thelisttodequeue
*/
structlist_head*list_dequeue(structlist_head*list);
/**
*list_entry-getthestructforthisentry
*@ptr:the&structlist_headpointer.
*@type:thetypeofthestructthisisembeddedin.
*@member:thenameofthelist_structwithinthestruct.
*/
#definelist_entry(ptr,type,member)\
((type*)((char*)(ptr)-(unsignedlong)(&((type*)0)->member)))
/**
*list_for_each-iterateoveralist
*@pos:the&structlist_headtouseasaloopcounter.
*@head:theheadforyourlist.
*/
#definelist_for_each(pos,head)\
for(pos=(head)->next;pos!=(head);\
pos=pos->next)
/**
*list_for_each_safe-iterateoveralistsafeagainstremovaloflistentry
*@pos:the&structlist_headtouseasaloopcounter.
*@n:another&structlist_headtouseastemporarystorage
*@head:theheadforyourlist.
*/
#definelist_for_each_safe(pos,n,head)\
for(pos=(head)->next,n=pos->next;pos!=(head);\
pos=n,n=pos->next)
/**
*list_for_each_prev-iterateoveralistinreverseorder
*@pos:the&structlist_headtouseasaloopcounter.
*@head:theheadforyourlist.
*/
#definelist_for_each_prev(pos,head)\
for(pos=(head)->prev;pos!=(head);\
pos=pos->prev)
/**
*list_for_each_entry-iterateoverlistofgiventype
*@pos:thetype*touseasaloopcounter.
*@head:theheadforyourlist.
*@member:thenameofthelist_structwithinthestruct.
*/
#definelist_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);
}
}
/*
*Insertanewentrybetweentwoknownconsecutiveentries.
*
*Thisisonlyforinternallistmanipulationwhereweknow
*theprev/nextentriesalready!
*/
staticvoid__list_add(structlist_head*new,
structlist_head*prev,
structlist_head*next)
{
next->prev=new;
new->next=next;
new->prev=prev;
prev->next=new;
}
/*
*Deletealistentrybymakingtheprev/nextentries
*pointtoeachother.
*
*Thisisonlyforinternallistmanipulationwhereweknow
*theprev/nextentriesalready!
*/
staticvoid__list_del(structlist_head*prev,
structlist_head*next)
{
next->prev=prev;
prev->next=next;
}
/**
*list_add-addanewentry
*@new:newentrytobeadded
*@head:listheadtoadditafter
*
*Insertanewentryafterthespecifiedhead.
*Thisisgoodforimplementingstacks.
*/
voidlist_add(structlist_head*new,structlist_head*head)
{
__check_head(head);
__list_add(new,head,head->next);
}
/**
*list_add_tail-addanewentry
*@new:newentrytobeadded
*@head:listheadtoadditbefore
*
*Insertanewentrybeforethespecifiedhead.
*Thisisusefulforimplementingqueues.
*/
voidlist_add_tail(structlist_head*new,structlist_head*head)
{
__check_head(head);
__list_add(new,head->prev,head);
}
/**
*list_del-deletesentryfromlist.
*@entry:theelementtodeletefromthelist.
*Note:list_emptyonentrydoesnotreturntrueafterthis,theentryisinanundefinedstate.
*/
voidlist_del(structlist_head*entry)
{
__list_del(entry->prev,entry->next);
}
/**
*list_del_init-deletesentryfromlistandreinitializeit.
*@entry:theelementtodeletefromthelist.
*/
voidlist_del_init(structlist_head*entry)
{
__list_del(entry->prev,entry->next);
INIT_LIST_HEAD(entry);
}
/**
*list_move-deletefromonelistandaddasanother'shead
*@list:theentrytomove
*@head:theheadthatwillprecedeourentry
*/
voidlist_move(structlist_head*list,structlist_head*head)
{
__check_head(head);
__list_del(list->prev,list->next);
list_add(list,head);
}
/**
*list_move_tail-deletefromonelistandaddasanother'stail
*@list:theentrytomove
*@head:theheadthatwillfollowourentry
*/
voidlist_move_tail(structlist_head*list,
structlist_head*head)
{
__check_head(head);
__list_del(list->prev,list->next);
list_add_tail(list,head);
}
/**
*list_splice-jointwolists
*@list:thenewlisttoadd.
*@head:theplacetoadditinthefirstlist.
*/
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;
}
主要的文件在这里：
//my_joystick.c
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
//#include/*郁闷，不能直接使用linux自带的list链表，需要单独提取出来，见前面的code*/
#include"listop.h"
#if1
#defineLOG_DBG(fmt,...)fprintf(stdout,fmt,##__VA_ARGS__)
#else
#defineLOG_DBG(fmt,...)
#endif
#defineLOG_ERR(fmt,...)fprintf(stderr,fmt,##__VA_ARGS__)
typedefstruct_joy_stick_ctx{
structlist_headlist;
inti4_js_fd;
unsignedinti4_op_block;
}JOYSTICK_CTX_T;
LIST_HEAD(_t_js_ctx_head);
/*==>structlist_head_t_js_ctx_head={&_t_js_ctx_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]jsdevicenameisNULL\n",__func__);
return-1;
}
pt_joystick_ctx=(JOYSTICK_CTX_T*)calloc(sizeof(JOYSTICK_CTX_T),1);
if(!pt_joystick_ctx){
LOG_ERR("[%s]nomemory!!\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]opendevice%serror\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]devicenotopened\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=%dinvalid\n",__func__,i4_fd);
return-1;
}
intjoystick_read_one_event(inti4_fd,structjs_event*tp_jse)
{
inti4_rd_bytes;
/*donotchecki4_fdagain*/
i4_rd_bytes=read(i4_fd,tp_jse,sizeof(structjs_event));
if(i4_rd_bytes==-1){
if(errno==EAGAIN){/*whennoblock,itisnoterror*/
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]devicenotopened\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=%dinvalid\n",__func__,i4_fd);
return0;
}
elseif(i4_block==1){
fd_setreadfd;
inti4_ret=0;
structtimevaltimeout={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;/*noblockread,awaysready*/
}
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("----------->EMPTYNOW\n");
}
}
#if1
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_eventjse;
fd=joystick_open("/dev/input/js0",1);
if(fd
LOG_ERR("openfailed.\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("joystickName:%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("joystickinitstate:button%dis%s.\n",i,((buttons_state&(1<
}
if(tp_axes)
for(i=0;i
LOG_DBG("joystickinitstate:axes%disx=%dy=%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("joystickstate:button%dis%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("joystickstate:axes%disx=%dy=%d.\n",jse.number/2,tp_axes[jse.number/2].x,tp_axes[jse.number/2].y);
}
else{
LOG_DBG("joystickstate:axes%dis%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
编译: gcc -o my_joystick my_joystick.c listop.c
运行:
mayer@mayer-Ubuntu: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.
不明白的地方可以参考linux kernel中的说明文件：Documentation/input/joystick-api.txt
