這幾天在調試序列槽觸摸屏，網上找了下似乎說的都不大清楚，這裡記錄下.
實作方法網上說有好幾種，這裡是将序列槽作為一個serio總線裝置，利用linux核心提供serio總線驅動，通過設定對應的序列槽，調用serport提供的函數将序列槽當做serio總線裝置，在驅動裡面需要按照serio總線裝置驅動的架構來實作，在核心源碼drivers/input/touchscreen下提供了兩個例子,touchright.c和touchit123.c，可以參考這兩個例子編寫驅動.我的驅動是在網上抄的，源碼如下
#include
#include
#include
#include
#include
#include
#include
#define DRIVER_DESC"EETI Egalax serial touchscreen driver"
MODULE_AUTHOR("Zolt??n B??sz??rm??nyi ");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
#define SERIO_EGALAX0x3f
#define EGALAX_FORMAT_MAX_LENGTH 6
#define EGALAX_RESPONSE_BEGIN_BYTE 0x80
#define EGALAX_FORMAT_PRESSURE_BIT 0x40
#define EGALAX_FORMAT_TOUCH_BIT 0x01
#define EGALAX_FORMAT_RESOLUTION 0x06
#define EGALAX_MIN_XC 0
#define EGALAX_MAX_XC 0x4000
#define EGALAX_MIN_YC 0
#define EGALAX_MAX_YC 0x4000
#define EGALAX_GET_XC(data, resbits, shift) ((((data[1] & (resbits)) << 7) | (data[2] & 0x7f)) << shift)
#define EGALAX_GET_YC(data, resbits, shift) ((((data[3] & (resbits)) << 7) | (data[4] & 0x7f)) << shift)
#define EGALAX_GET_TOUCHED(data) (EGALAX_FORMAT_TOUCH_BIT & data[0])
struct egalax {
struct input_dev *dev;
struct serio *serio;
int idx;
int bytes;
int resbits;
int shift;
unsigned char data[EGALAX_FORMAT_MAX_LENGTH];
char phys[32];
};
static void egalax_process_data(struct egalax *pegalax)
{
struct input_dev *dev = pegalax->dev;
if (++pegalax->idx == pegalax->bytes) {
input_report_abs(dev, ABS_X, EGALAX_GET_XC(pegalax->data, pegalax->resbits, pegalax->shift));
input_report_abs(dev, ABS_Y, EGALAX_GET_YC(pegalax->data, pegalax->resbits, pegalax->shift));
//input_report_key(dev, BTN_TOUCH, EGALAX_GET_TOUCHED(pegalax->data));
input_report_abs(dev, ABS_PRESSURE, EGALAX_GET_TOUCHED(pegalax->data));
input_sync(dev);
pegalax->idx = 0;
}
}
static irqreturn_t egalax_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct egalax *pegalax = serio_get_drvdata(serio);
pegalax->data[pegalax->idx] = data;
if (EGALAX_RESPONSE_BEGIN_BYTE & pegalax->data[0]) {
pegalax->bytes = (EGALAX_FORMAT_PRESSURE_BIT & pegalax->data[0] ? 6 : 5);
switch ((EGALAX_FORMAT_RESOLUTION & pegalax->data[0]) >> 1) {
case 0:
pegalax->resbits = 0x0f;
pegalax->shift = 3;
break;
case 1:
pegalax->resbits = 0x1f;
pegalax->shift = 2;
break;
case 2:
pegalax->resbits = 0x3f;
pegalax->shift = 1;
break;
default:
pegalax->resbits = 0x7f;
pegalax->shift = 0;
break;
}
egalax_process_data(pegalax);
}
else
dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
pegalax->data[0]);
return IRQ_HANDLED;
}
static void egalax_disconnect(struct serio *serio)
{
struct egalax *pegalax = serio_get_drvdata(serio);
input_get_device(pegalax->dev);
input_unregister_device(pegalax->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_put_device(pegalax->dev);
kfree(pegalax);
}
static int egalax_connect(struct serio *serio, struct serio_driver *drv)
{
struct egalax *pegalax;
struct input_dev *input_dev;
int err;
pegalax = kzalloc(sizeof(struct egalax), GFP_KERNEL);
input_dev = input_allocate_device();
if (!pegalax || !input_dev) {
err = -ENOMEM;
goto fail1;
}
pegalax->serio = serio;
pegalax->dev = input_dev;
snprintf(pegalax->phys, sizeof(pegalax->phys),
"%s/input1", serio->phys);
input_dev->name = "EETI eGalaxTouch Serial TouchScreen";
input_dev->phys = pegalax->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_EGALAX;
input_dev->id.product = 0;
input_dev->id.version = 0x0001;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
//input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(pegalax->dev, ABS_X,
EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0);
input_set_abs_params(pegalax->dev, ABS_Y,
EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0);
input_set_abs_params(pegalax->dev, ABS_PRESSURE, 0, 1, 0, 0);
serio_set_drvdata(serio, pegalax);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = input_register_device(pegalax->dev);
if (err)
goto fail3;
return 0;
fail3:serio_close(serio);
fail2:serio_set_drvdata(serio, NULL);
fail1:input_free_device(input_dev);
kfree(pegalax);
return err;
}
static struct serio_device_id egalax_serio_ids[] = {
{
.type= SERIO_RS232,
.proto= SERIO_EGALAX,
.id= SERIO_ANY,
.extra= SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, egalax_serio_ids);
static struct serio_driver egalax_drv = {
.driver= {
.name= "egalax",
},
.description= DRIVER_DESC,
.id_table= egalax_serio_ids,
.interrupt= egalax_interrupt,
.connect= egalax_connect,
.disconnect= egalax_disconnect,
};
static int __init egalax_init(void)
{
return serio_register_driver(&egalax_drv);
}
static void __exit egalax_exit(void)
{
serio_unregister_driver(&egalax_drv);
}
module_init(egalax_init);
module_exit(egalax_exit);
隻是修改了最後一點,其中egalax_serio_ids中的幾個參數在應用程式中需要用到，加上驅動編譯核心更新後，此時這個驅動是沒有起作用的，需要通過應用程式将序列槽與之綁定，後才能正常工作.
應用程式如下,這個代碼網上也有
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define SERIO_ANY0xff
#define SERIO_EGALAX0x3f
int main(int argc, char* argv[])
{
int dev,ret;
char comdev[20];
int ldisc;
unsigned long type;
struct termios option;
int fd = -1;
if(argc != 2)
{
printf("-----------------------------------------\n");
printf("\nUsage: %s [serial device(1-5)]\n", argv[0]);
printf("Example: %s 5 n", argv[0]);
printf("-----------------------------------------\n");
return 0;
}
dev = strtol(argv[1],NULL,10);
sprintf(comdev,"/dev/ttyAMA%d",dev);
fd = open(comdev,O_RDWR|O_NONBLOCK|O_NOCTTY);
if (fd < 0) {
perror(comdev);
exit(1);
}
tcgetattr(fd, &option);
option.c_iflag = IGNPAR | IGNBRK;
option.c_cflag = HUPCL | CS8 | CREAD | CLOCAL | B9600;
option.c_cc[VMIN] = 1;
option.c_cc[VTIME] = 0;
cfsetispeed(&option,B9600);
cfsetospeed(&option,B9600);
ret = tcsetattr(fd, TCSANOW, &option);
if(ret < 0) {
perror("TCSANOW");
exit(1);
}
ldisc = N_MOUSE;
ret = ioctl(fd,TIOCSETD,&ldisc);
if(ret) {
perror("TIOCSETD");
}
type = SERIO_EGALAX | (SERIO_ANY << 8) | (SERIO_ANY << 16);
ret = ioctl(fd,SPIOCSTYPE, &type);
if(ret) {
perror("SPIOCSTYPE");
}
read(fd,NULL,0);
//close(fd);
return 0;
}
需要注意的是，應用程式最後這個read一定要執行，不然驅動裡不會進行連接配接.
編譯生成可執行檔案seriotouch
應用程式配制完序列槽後需要與之前的驅動連接配接，看設定spiocstype的設定，需要保證這裡的幾個參數與驅動進行對應。
系統啟動後執行seriotouch 5 &
後面這個５對應的是序列槽号,執行這個後會看到驅動裡的connect執行了，同時會生成一個input節點，如下圖
此時将tslib裡的tsdevice修改為這個，進行校準後，就可以正常使用了