GSLX680触摸屏驱动移植

向右看齐 2022-01-17 15:59 502阅读 0赞

1.  GSLX680 触摸屏  
    触摸屏按照触摸屏的工作原理和传输信息的介质，可以分为四种，它们分别为电阻式、电容感应式、红外线式以及表面声波式。GSLX680 为电容式触摸屏，挂接在I2C总线上，通过I2C总线来传输触摸屏数据。该芯片的连接方式如所示及与T3板子的I2C连接如所示。  
    ![GSLX680触摸屏驱动移植][GSLX680]
    
    1.  SylixOS 电容式触摸屏分析  
        SylixOS下将电容式触摸屏封装成一个字符设备，应用程序只需通过read函数读取触摸屏设备，即可获取到填充有触摸坐标信息的mouse\_event\_notify 结构体。  
        1， 电容屏初始化  
        INT touchDrv (VOID)  
        \{  
        struct file\_operations fileOper;  
        INT iDrvNum;  
        lib\_memset(&fileOper, 0, sizeof(struct file\_operations));  
        fileOper.owner = THIS\_MODULE;  
        fileOper.fo\_create = **touchOpen;  
        fileOper.fo\_open = \_\_touchOpen;  
        fileOper.fo\_close =** touchClose;  
        fileOper.fo\_read = **touchRead;  
        fileOper.fo\_lstat = \_\_touchLstat;  
        fileOper.fo\_ioctl =** touchIoctl;  
        iDrvNum = iosDrvInstallEx2(&fileOper, LW\_DRV\_TYPE\_NEW\_1);  
        DRIVER\_LICENSE(iDrvNum, "Dual BSD/GPL->Ver 1.0");  
        DRIVER\_AUTHOR(iDrvNum, "Xu.Guizhou");  
        DRIVER\_DESCRIPTION(iDrvNum, "touch driver.")  
        return (iDrvNum);  
        \}  
        创建触摸屏设备的逻辑如下：  
        iError = iosDevAddEx(&pTouchDev->TOUCH\_devHdr, pcName, iDrvNum, DT\_CHR);  
        if (iError) \{  
        \_ErrorHandle(ERROR\_SYSTEM\_LOW\_MEMORY);  
        \_\_SHEAP\_FREE(pTouchDev);  
        printk(KERN\_ERR "touchDevCreate(): failed to create touch device %s!\\n", pcName);  
        return (PX\_ERROR);  
        \}

2， 电容触摸屏事件上抛线程  
触摸事件提交分为上下半程处理，下半程线程会阻塞等待触摸中断事件产生。当产生了触摸中断时，会调用**touchHandleEvents 获取坐标值，并将获取到的坐标值填入mouse\_event\_notify 结构体，最终通过消息队列传送到触摸屏定义的 read 函数中。用户调用触摸驱动的 read 函数时，即可获取到触摸事件信息。  
static PVOID** touchThread (PVOID pvArg)  
\{  
INT iEventNum;  
PTOUCH\_DEV pTouchDev = (PTOUCH\_DEV)pvArg;  
while (!pTouchDev->TOUCH\_bQuit) \{  
API\_SemaphoreBPend(pTouchDev->TOUCH\_hSignal, LW\_OPTION\_WAIT\_INFINITE);  
if (pTouchDev->TOUCH\_bQuit) \{  
break;  
\}  
iEventNum = \_\_touchHandleEvents(pTouchDev);  
if (iEventNum == PX\_ERROR) \{  
printk(KERN\_ERR "touch: handle touch event fail!\\n");  
\} else if (iEventNum > 0) \{  
SEL\_WAKE\_UP\_ALL(&pTouchDev->TOUCH\_selList, SELREAD);  
\}  
\}  
return (LW\_NULL);  
\}

3． 电容触摸屏触摸中断产生  
手指触摸时中断处理逻辑如下：  
static irqreturn\_t \_\_touchIsr (PTOUCH\_DEV pTouchDev, ULONG ulVector)  
\{  
irqreturn\_t irqreturn;  
irqreturn = API\_GpioSvrIrq(pTouchDev->TOUCH\_data.T\_uiIrq);  
if (irqreturn == LW\_IRQ\_HANDLED) \{  
API\_GpioClearIrq(pTouchDev->TOUCH\_data.T\_uiIrq);  
API\_SemaphoreBPost(pTouchDev->TOUCH\_hSignal);  
\}  
return (irqreturn);  
\}

1.  移植GSLX680 触摸屏  
    将Linux下的驱动代码移植到SylixOS下，需要将硬件初始化动作及获取触摸屏坐标值。  
    1， 硬件初始化动作放在设备的open动作下，包括创建I2C子设备，GPIO中断申请，芯片初始化：  
    static INT **touchHwInit (PTOUCH\_DEV pTouchDev, PCHAR pcName)  
    \{  
    INT iError;  
    pTouchDev->TOUCH\_pI2cDevice =  
    API\_I2cDeviceCreate(pTouchDev->TOUCH\_data.T\_pcBusName,  
    pcName,  
    pTouchDev->TOUCH\_data.T\_usAddr,  
    0);  
    if (pTouchDev->TOUCH\_pI2cDevice == LW\_NULL) \{  
    printk(KERN\_ERR "**touchHwInit(): failed to create i2c device %s, slave addr 0x%x!\\n",  
    pTouchDev->TOUCH\_data.T\_pcBusName,  
    pTouchDev->TOUCH\_data.T\_usAddr);  
    goto \_\_error\_handle;  
    \}  
    /\*
    
     *  设置触摸屏中断  
        \*/
    
    iError = API\_GpioRequestOne(pTouchDev->TOUCH\_data.T\_uiIrq,  
    pTouchDev->TOUCH\_data.T\_uiIrqCfg,  
    "touch\_eint");  
    if (iError != ERROR\_NONE) \{  
    printk(KERN\_ERR "**touchHwInit(): failed to request irq gpio!\\n");  
    goto** error\_handle;  
    \}  
    iError = API\_GpioSetupIrq(pTouchDev->TOUCH\_data.T\_uiIrq, pTouchDev->TOUCH\_data.T\_uiIrqCfg, 1);  
    if (iError == PX\_ERROR) \{  
    printk(KERN\_ERR "**touchHwInit(): failed to setup gpio irq!\\n");  
    goto** error\_handle;  
    \}  
    pTouchDev->TOUCH\_ulVector = (ULONG)iError;  
    printk("\_\_touchHwInit %d\\n\\r",iError);  
    /\*
    
     *  申请触摸屏复位管脚  
        */  
        iError = API\_GpioRequestOne(pTouchDev->TOUCH\_data.T\_uiReset,  
        pTouchDev->TOUCH\_data.T\_uiRstVal | LW\_GPIOF\_DIR\_OUT,  
        "touch\_reset");  
        if (iError != ERROR\_NONE) \{  
        printk(KERN\_ERR "**touchHwInit(): failed to request rst gpio!\\n");  
        goto** error\_handle;  
        \}  
        \_\_touchReset(pTouchDev); /* Reset Touch Screen */  
        if (pTouchDev->pDrvFunc->init) \{ /* Init Touch Screen \*/  
        pTouchDev->pDrvFunc->init(pTouchDev);  
        \}  
        return (ERROR\_NONE);  
        \_\_error\_handle:  
        API\_GpioFree(pTouchDev->TOUCH\_data.T\_uiIrq);  
        API\_GpioFree(pTouchDev->TOUCH\_data.T\_uiReset);
    
    if (pTouchDev->TOUCH\_pI2cDevice) \{  
    API\_I2cDeviceDelete(pTouchDev->TOUCH\_pI2cDevice);  
    pTouchDev->TOUCH\_pI2cDevice = LW\_NULL;  
    \}  
    return (PX\_ERROR);  
    \}

2， 获取坐标事件函数，gslX680GetEvent 将获取的坐标上报：  
static TOUCH\_DRV\_FUNC \_G\_Gsl680DrvFunc = \{  
.getevent = gslX680GetEvent,  
.init = gslX680Init,  
.deinit = NULL,  
.reset = NULL,  
\};  
INT gslX680GetEvent (PTOUCH\_DEV pTouchDev, mouse\_event\_notify events\[\])  
\{  
INT iError;  
UCHAR ucBuffer\[36\];  
u8 read\_buf\[4\] = \{0\};

iError =  gsl_ts_read(pTouchDev, 0x80, ucBuffer, GSL_CONTACT_SIZE);
    if (iError == PX_ERROR) {
        printk(KERN_WARNING "touch: get touch point error!\n");
        return  (PX_ERROR);
    }
    
    if(ucBuffer[0] == 0xff) {
        return  (iError);
    }
    
    iError = gsl_ts_read( pTouchDev, 0xbc, read_buf, sizeof(read_buf));
    
    if (iError == PX_ERROR) {
        printk(KERN_WARNING "touch: read 0xbc failed!\n");
        return  (iError);
    }
    
    if (read_buf[3] == 0 && read_buf[2] == 0 && read_buf[1] == 0 && read_buf[0] == 0){
        iError = process_gslX680_data(pTouchDev,events,ucBuffer);
    } else {
        reset_chip(pTouchDev);
        startup_chip(pTouchDev);
        iError = 0;
    }
    
    return  (iError);

1.  参考资料  
    《SylixOS应用程序开发手册》

转载于:https://blog.51cto.com/13927802/2386483

[GSLX680]: https://s1.51cto.com/images/blog/201904/29/257f3b681b7c831a1f9b6a534bc440ba.png?x-oss-process=image/watermark,size_16,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_90,type_ZmFuZ3poZW5naGVpdGk=