Windows CE 觸摸屏(TouchPanel)驅動簡析(2)-DDSI函數-(基于WinCE5.0 SMDK2410 BSP的TouchPanel驅動)

接下來我們來看看具體的DDSI函數.

1.DdsiTouchPanelAttach和DdsiTouchPanelDetach

DLL entry進入或結束執行,這裡不需要任何工作,直接傳回0

LONG

DdsiTouchPanelAttach(VOID)

{

return(0);

}

LONG

DdsiTouchPanelDetach(VOID)

{

return(0);

}

2.DdsiTouchPanelEnable

DdsiTouchPanelEnable使能觸摸屏并進行相應的初始化工作.

首先調用TSP_VirtualAlloc給寄存器(GPIO,ADC,INTR,PWM)配置設定虛拟位址空間.調用TSP_RegAlloc,而TSP_RegAlloc則調用VirtualAlloc和VirtualCopy進行配置設定虛拟位址.

TSP_VirtualAlloc:

PRIVATE BOOL

TSP_VirtualAlloc(VOID)

{

BOOL r = FALSE;

RETAILMSG(0,(TEXT("::: TSP_VirtualAlloc()/r/n")));

do

{

v_pIOPregs = (volatile S3C2410X_IOPORT_REG *)TSP_RegAlloc((PVOID)S3C2410X_BASE_REG_PA_IOPORT, sizeof(S3C2410X_IOPORT_REG));

if (v_pIOPregs == NULL)

{

ERRORMSG(1,(TEXT("For IOPreg: VirtualAlloc failed!/r/n")));

break;

}

v_pADCregs = (volatile S3C2410X_ADC_REG *)TSP_RegAlloc((PVOID)S3C2410X_BASE_REG_PA_ADC, sizeof(S3C2410X_ADC_REG));

if (v_pADCregs == NULL)

{

ERRORMSG(1,(TEXT("For ADCreg: VirtualAlloc failed!/r/n")));

break;

}

v_pINTregs = (volatile S3C2410X_INTR_REG *)TSP_RegAlloc((PVOID)S3C2410X_BASE_REG_PA_INTR, sizeof(S3C2410X_INTR_REG));

if (v_pADCregs == NULL)

{

ERRORMSG(1,(TEXT("For INTregs: VirtualAlloc failed!/r/n")));

break;

}

v_pPWMregs = (volatile S3C2410X_PWM_REG *)TSP_RegAlloc((PVOID)S3C2410X_BASE_REG_PA_PWM, sizeof(S3C2410X_PWM_REG));

if (v_pPWMregs == NULL)

{

ERRORMSG(1,(TEXT("For PWMregs: VirtualAlloc failed!/r/n")));

break;

}

r = TRUE;

} while (0);

if (!r)

{

TSP_VirtualFree();

RETAILMSG(0,(TEXT("::: TSP_VirtualAlloc() - Fail/r/n")));

}

else

{

RETAILMSG(0,(TEXT("::: TSP_VirtualAlloc() - Success/r/n")));

}

return (r);

}

TSP_RegAlloc:

PRIVATE PVOID

TSP_RegAlloc(PVOID addr, INT sz)

{

PVOID reg;

reg = (PVOID)VirtualAlloc(0, sz, MEM_RESERVE, PAGE_NOACCESS);

if (reg)

{

if (!VirtualCopy(reg, (PVOID)((UINT32)addr >> 8), sz, PAGE_PHYSICAL | PAGE_READWRITE | PAGE_NOCACHE ))

{

VirtualFree(reg, 0, MEM_RELEASE);

reg = NULL;

}

}

return (reg);

}

然和調用KernelIoControl來申請ADC和TIMER3的邏輯中斷号,獲得CPU的時鐘,進而計算出給Timer3的分頻值.

最後調用TSP_PowerOn來初始化GPIO,ADC,INTR,TIMER3寄存器.

關于具體寄存器引腳的含義可以參考s3c2410的datasheet.

TSP_PowerOn:

PRIVATE VOID

TSP_PowerOn(VOID)

{

RETAILMSG(0,(TEXT("::: TSP_PowerOn()/r/n")));

RETAILMSG(1,(TEXT("++TSP_PowerOn for GEC2410 TouchPanel/r/n")));

/* Use TSXM, TSXP, TSYM, TSYP */

v_pIOPregs->GPGCON |= ((0x3 << 30) | (0x3 << 28) | (0x3 << 26) | (0x3 << 24));

v_pADCregs->ADCDLY = 50000;

v_pADCregs->ADCCON = (1 << 14) | /* A/D Converter Enable */

(ADCPRS << 6) | /* Prescaler Setting */

(0 << 3) | /* Analog Input Channel : 0 */

(0 << 2) | /* Normal Operation Mode */

(0 << 1) | /* Disable Read Start */

(0 << 0); /* No Operation */

v_pADCregs->ADCTSC = (0 << 8) | /* UD_Sen */

(1 << 7) | /* YMON 1 (YM = GND) */

(1 << 6) | /* nYPON 1 (YP Connected AIN[n]) */

(0 << 5) | /* XMON 0 (XM = Z) */

(1 << 4) | /* nXPON 1 (XP = AIN[7]) */

(0 << 3) | /* Pull Up Disable */

(0 << 2) | /* Normal ADC Conversion Mode */

(3 << 0); /* Waiting Interrupt */

v_pINTregs->INTSUBMSK &= ~(1<<IRQ_SUB_TC);

v_pPWMregs->TCFG1 &= ~(0xf << 12); /* Timer3's Divider Value */

v_pPWMregs->TCFG1 |= (0 << 12); /* 1/2 */

v_pPWMregs->TCNTB3 = g_timer3_sampleticks; /* Interrupt Frequency */

}

DdsiTouchPanelEnable:

PUBLIC BOOL

DdsiTouchPanelEnable(VOID)

{

BOOL r;

UINT32 Irq;

PROCESSOR_INFO procInfo;

RETAILMSG(0, (TEXT("::: DdsiTouchPanelEnable()/r/n")));

r = TSP_VirtualAlloc();

// Obtain sysintr values from the OAL for the touch and touch changed interrupts.

//

Irq = IRQ_ADC;

if (!KernelIoControl(IOCTL_HAL_REQUEST_SYSINTR, &Irq, sizeof(UINT32), &gIntrTouch, sizeof(UINT32), NULL))

{

RETAILMSG(1, (TEXT("ERROR: Failed to request the touch sysintr./r/n")));

gIntrTouch = SYSINTR_UNDEFINED;

return(FALSE);

}

Irq = IRQ_TIMER3;

if (!KernelIoControl(IOCTL_HAL_REQUEST_SYSINTR, &Irq, sizeof(UINT32), &gIntrTouchChanged, sizeof(UINT32), NULL))

{

RETAILMSG(1, (TEXT("ERROR: Failed to request the touch changed sysintr./r/n")));

gIntrTouchChanged = SYSINTR_UNDEFINED;

return(FALSE);

}

// Get the processor's pclk frequency.

//

if (!KernelIoControl(IOCTL_PROCESSOR_INFORMATION, NULL, 0, &procInfo, sizeof(PROCESSOR_INFO), NULL))

{

DEBUGMSG(1, (TEXT("WARNING: Touch driver failed to obtain processor frequency - using default value(%d Hz)./r/n"), g_s3c2410_pclk));

}

else

{

g_s3c2410_pclk = procInfo.dwClockSpeed;

DEBUGMSG(1, (TEXT("INFO: Touch driver using processor frequency reported by the OAL (%d Hz)./r/n"), g_s3c2410_pclk));

}

// Compute the OS timer frequency and number of pen-down sampling ticks.

//

g_timer3_freq = (g_s3c2410_pclk / TIMER3_DIVIDER);

g_timer3_sampleticks = (g_timer3_freq / TSP_SAMPLE_RATE_LOW);

if (r)

{

TSP_PowerOn();

}

return (r);

}

3.DdsiTouchPanelDisable

對應的就有DdsiTouchPanelDisable函數,将DdsiTouchPanelEnable申請的資源進行釋放.屏蔽中斷.

PUBLIC VOID

DdsiTouchPanelDisable(VOID)

{

RETAILMSG(0, (TEXT("::: DdsiTouchPanelDisable()/r/n")));

if (v_pADCregs)

{

TSP_PowerOff();

TSP_VirtualFree();

}

}

4.DdsiTouchPanelSetMode

DdsiTouchPanelSetMode用來設定觸摸屏的采樣率周期.函數傳入TPSM_SAMPLERATE_LOW_ID或TPSM_SAMPLERATE_HIGH_ID來進行相應的設定.這裡隻有一個采樣率周期,是以函數不做實際工作.

PUBLIC BOOL

DdsiTouchPanelSetMode(INT iIndex, LPVOID lpInput)

{

BOOL ReturnCode = FALSE;

RETAILMSG(0, (TEXT("::: DdsiTouchPanelSetMode()/r/n")));

switch ( iIndex )

{

case TPSM_SAMPLERATE_LOW_ID:

case TPSM_SAMPLERATE_HIGH_ID:

SetLastError( ERROR_SUCCESS );

ReturnCode = TRUE;

break;

default:

SetLastError( ERROR_INVALID_PARAMETER );

break;

}

return( ReturnCode );

}

5.DdsiTouchPanelPowerHandler

DdsiTouchPanelPowerHandler用來通知驅動系統正進入或離開挂起狀态.

參數bOff為TRUE表明系統正在關閉, FALSE表明系統正在開啟.

該函數調用TSP_PowerOff和TSP_PowerOn來處理關閉或開啟狀态.

TSP_PowerOn前面已經看到了,TSP_PowerOff如下,屏蔽了INT_TC觸摸屏中斷(這裡定義為IRQ_SUB_TC):

TSP_PowerOff:

PRIVATE VOID

TSP_PowerOff(VOID)

{

RETAILMSG(0,(TEXT("::: TSP_PowerOff()/r/n")));

v_pINTregs->INTSUBMSK |= (1<<IRQ_SUB_TC);

}

DdsiTouchPanelPowerHandler:

PUBLIC VOID

DdsiTouchPanelPowerHandler(BOOL bOff)

{

RETAILMSG(0, (TEXT("::: DdsiTouchPanelPowerHandler()/r/n")));

if (bOff)

{

TSP_PowerOff();

}

else

{

TSP_PowerOn();

}

}

6.DdsiTouchPanelGetDeviceCaps

DdsiTouchPanelGetDeviceCaps用來查詢觸摸屏裝置的性能參數.

iIndex可能為以下3個參數:

TPDC_SAMPLE_RATE_ID: 傳回采樣周期,這裡TSP_SAMPLE_RATE_LOW,TSP_SAMPLE_RATE_HIGH,TSP_CurRate都為100,即一直使用同一個采樣周期.

TPDC_CALIBRATION_POINT_ID:傳回需要校準點的XY坐标.校準點坐标索引在PointNumber(lpOutput傳遞的結構成員).調用TSP_CalibrationPointGet來獲得.這5個點分别位于四個角和中間,也就是我們調用觸摸屏校準程式時會調用到的函數.

TPDC_CALIBRATION_POINT_COUNT_ID:傳回用來校準觸摸屏的校準點數目.這裡的數目設定為5.

lpOutput傳遞iIndex值對應的結構.

TPDC_SAMPLE_RATE_ID	Pointer to a TPDC_SAMPLE_RATE structure.
TPDC_CALIBRATION_POINT_ID	Pointer to a TPDC_CALIBRATION_POINT structure.
TPDC_CALIBRATION_POINT_COUNT_ID	Pointer to a TPDC_CALIBRATION_POINT_COUNT structure.

CalibrationPointGet:

用來計算校準觸摸屏時的5個校準點的位置:

PRIVATE BOOL

TSP_CalibrationPointGet(TPDC_CALIBRATION_POINT *pTCP)

{

INT32 cDisplayWidth = pTCP->cDisplayWidth;

INT32 cDisplayHeight = pTCP->cDisplayHeight;

int CalibrationRadiusX = cDisplayWidth / 20;

int CalibrationRadiusY = cDisplayHeight / 20;

switch (pTCP -> PointNumber)

{

case 0:

pTCP->CalibrationX = cDisplayWidth / 2;

pTCP->CalibrationY = cDisplayHeight / 2;

break;

case 1:

pTCP->CalibrationX = CalibrationRadiusX * 2;

pTCP->CalibrationY = CalibrationRadiusY * 2;

break;

case 2:

pTCP->CalibrationX = CalibrationRadiusX * 2;

pTCP->CalibrationY = cDisplayHeight - CalibrationRadiusY * 2;

break;

case 3:

pTCP->CalibrationX = cDisplayWidth - CalibrationRadiusX * 2;

pTCP->CalibrationY = cDisplayHeight - CalibrationRadiusY * 2;

break;

case 4:

pTCP->CalibrationX = cDisplayWidth - CalibrationRadiusX * 2;

pTCP->CalibrationY = CalibrationRadiusY * 2;

break;

default:

pTCP->CalibrationX = cDisplayWidth / 2;

pTCP->CalibrationY = cDisplayHeight / 2;

SetLastError(ERROR_INVALID_PARAMETER);

return (FALSE);

}

RETAILMSG(0, (TEXT("::: TSP_CalibrationPointGet()/r/n")));

RETAILMSG(0, (TEXT("cDisplayWidth : %4X/r/n"), cDisplayWidth ));

RETAILMSG(0, (TEXT("cDisplayHeight : %4X/r/n"), cDisplayHeight ));

RETAILMSG(0, (TEXT("CalibrationRadiusX : %4d/r/n"), CalibrationRadiusX));

RETAILMSG(0, (TEXT("CalibrationRadiusY : %4d/r/n"), CalibrationRadiusY));

RETAILMSG(0, (TEXT("pTCP -> PointNumber : %4d/r/n"), pTCP->PointNumber));

RETAILMSG(0, (TEXT("pTCP -> CalibrationX : %4d/r/n"), pTCP->CalibrationX));

RETAILMSG(0, (TEXT("pTCP -> CalibrationY : %4d/r/n"), pTCP->CalibrationY));

return (TRUE);

}

DdsiTouchPanelGetDeviceCaps:

PUBLIC BOOL

DdsiTouchPanelGetDeviceCaps(INT iIndex, LPVOID lpOutput)

{

RETAILMSG(0, (TEXT("::: DdsiTouchPanelGetDeviceCaps/r/n")));

if ( lpOutput == NULL )

{

ERRORMSG(1, (__TEXT("TouchPanelGetDeviceCaps: invalid parameter./r/n")));

SetLastError(ERROR_INVALID_PARAMETER);

DebugBreak();

return (FALSE);

}

switch ( iIndex )

{

case TPDC_SAMPLE_RATE_ID:

{

TPDC_SAMPLE_RATE *pTSR = (TPDC_SAMPLE_RATE*)lpOutput;

RETAILMSG(0, (TEXT("TouchPanelGetDeviceCaps::TPDC_SAMPLE_RATE_ID/r/n")));

pTSR->SamplesPerSecondLow = TSP_SAMPLE_RATE_LOW;

pTSR->SamplesPerSecondHigh = TSP_SAMPLE_RATE_HIGH;

pTSR->CurrentSampleRateSetting = TSP_CurRate;

}

break;

case TPDC_CALIBRATION_POINT_COUNT_ID:

{

TPDC_CALIBRATION_POINT_COUNT *pTCPC = (TPDC_CALIBRATION_POINT_COUNT*)lpOutput;

RETAILMSG(0, (TEXT("TouchPanelGetDeviceCaps::TPDC_CALIBRATION_POINT_COUNT_ID/r/n")));

pTCPC->flags = 0;

pTCPC->cCalibrationPoints = 5;

}

break;

case TPDC_CALIBRATION_POINT_ID:

RETAILMSG(0, (TEXT("TouchPanelGetDeviceCaps::TPDC_CALIBRATION_POINT_ID/r/n")));

return(TSP_CalibrationPointGet((TPDC_CALIBRATION_POINT*)lpOutput));

default:

ERRORMSG(1, (__TEXT("TouchPanelGetDeviceCaps: invalid parameter./r/n")));

SetLastError(ERROR_INVALID_PARAMETER);

DebugBreak();

return (FALSE);

}

return (TRUE);

}

7.DdsiTouchPanelGetPoint

傳回最近查詢點的資訊,如坐标等.這個函數被TouchPanelpISR調用,而TouchPanelpISR就是觸摸屏中斷IST.在TouchPanelEnable中會進行中斷線程IST的建立.TouchPanelpISR會等待hTouchPanelEvent事件的發生.hTouchPanelEvent關聯了兩個中斷,觸摸屏中斷(INT_TC)和TIMER3中斷.即觸點中斷和觸點變化中斷.當中斷發生時,TouchPanelpISR調用DdsiTouchPanelGetPoint來獲得采樣點資訊.

詳情可參考tchmain.c(/WINCE500/PUBLIC/COMMON/OAK/DRIVERS/TOUCH/TCHMAIN)

代碼及注釋如下:

PUBLIC VOID

DdsiTouchPanelGetPoint(TOUCH_PANEL_SAMPLE_FLAGS * pTipStateFlags,

INT * pUncalX,

INT * pUncalY)

{

static INT x, y;

//DEBUGMSG(1, (TEXT("::: DdsiTouchPanelGetPoint()/r/n")));

if (v_pINTregs->SUBSRCPND & (1<<IRQ_SUB_TC)) /* SYSINTR_TOUCH Interrupt Case */

{ //觸點中斷(INT_TC)

*pTipStateFlags = TouchSampleValidFlag;

//讀取ADC Conversion DATA Register, 1-Stylus down state 0-Stylus up state

if ( (v_pADCregs->ADCDAT0 & (1 << 15)) |

(v_pADCregs->ADCDAT1 & (1 << 15)) )

{

//Stylus up state

bTSP_DownFlag = FALSE;

DEBUGMSG(ZONE_TIPSTATE, (TEXT("up/r/n")));

//重新設定ADC TOUCH SCREEN CONTROL REGISTER

v_pADCregs->ADCTSC &= 0xff;

//讀取上次的坐标值

*pUncalX = x;

*pUncalY = y;

//停止取樣(停止Timer3 PWM)

TSP_SampleStop();

//停止取樣後忽略TIMER3中斷

/* At this point SYSINTR_TOUCH_CHANGED (timer3) interrupt could also be pending (and masked).

Since we do not care about the timer3 interrupt after calling TSP_SampleStop, signal it Done.

If we do not signal done and it was indeed pending and masked, IRQ_TIMER3 will not be unmasked

and won't fire again unless unmasked */

if (v_pINTregs->SRCPND & (1<<IRQ_TIMER3))

InterruptDone(gIntrTouchChanged);

}

else

{

//Stylus down state

bTSP_DownFlag = TRUE;

//讀觸摸屏AD資料

if (!TSP_GetXY(&x, &y))

*pTipStateFlags = TouchSampleIgnore;

//轉換成LCD上的坐标

TSP_TransXY(&x, &y);

*pUncalX = x;

*pUncalY = y;

*pTipStateFlags |= TouchSampleDownFlag;

DEBUGMSG(ZONE_TIPSTATE, (TEXT("down %x %x/r/n"), x, y));

//啟動Timer3 PWM

TSP_SampleStart();

}

//屏蔽觸摸屏中斷,清除中斷标志

v_pINTregs->SUBSRCPND = (1<<IRQ_SUB_TC);

v_pINTregs->INTSUBMSK &= ~(1<<IRQ_SUB_TC);

//通知系統中斷處理完成

InterruptDone(gIntrTouch);

}

else /* SYSINTR_TOUCH_CHANGED Interrupt Case */

{

// TSP_SampleStart();

//Timer3 PWM中斷發生

if (bTSP_DownFlag)

{

//觸摸筆還處于down狀态

INT tx, ty;

INT dx, dy;

//讀取觸摸屏AD資料

if (!TSP_GetXY(&tx, &ty))

*pTipStateFlags = TouchSampleIgnore;

else

{ //讀到的是壞資料,進行相應處理,如不能修正則忽略該資料

TSP_TransXY(&tx, &ty);

// insert by [email protected]

#define X_ERRV 0x3bf

#define Y_ERRV 0x4ff

// Subsequent info: If the ADC provides a bad reading, this catches it and

// skips over it. Instead, it should be fixed at the source

// so as not to provide a bad reading.

if ((tx == X_ERRV) || (ty == Y_ERRV))

{

tx = x;

ty = y;

}

// =================== mostek

dx = (tx > x) ? (tx - x) : (x - tx);

dy = (ty > y) ? (ty - y) : (y - ty);

if (dx > TSP_CHANGE || dy > TSP_CHANGE)

{

*pUncalX = x = tx;

*pUncalY = y = ty;

DEBUGMSG(ZONE_TIPSTATE, (TEXT("down-c-v %x %x/r/n"), x, y));

*pTipStateFlags = TouchSampleValidFlag | TouchSampleDownFlag;

}

else

{

*pUncalX = x;

*pUncalY = y;

DEBUGMSG(ZONE_TIPSTATE, (TEXT("down-c %x %x/r/n"), x, y));

*pTipStateFlags = TouchSampleIgnore;

}

}

}

else

{

*pTipStateFlags = TouchSampleIgnore;

TSP_SampleStop();

}

InterruptDone(gIntrTouchChanged);

}

}

TSP_GetXY:

TSP_GetXY從觸摸屏的ADC寄存器讀取觸摸點資料,讀4次計算平均值.

PRIVATE BOOL

TSP_GetXY(INT *px, INT *py)

{

INT i;

INT xsum, ysum;

INT x, y;

INT dx, dy;

xsum = ysum = 0;

for (i = 0; i < TSP_SAMPLE_NUM; i++)

{

v_pADCregs->ADCTSC = (0 << 8) | /* UD_Sen */

(1 << 7) | /* YMON 1 (YM = GND) */

(1 << 6) | /* nYPON 1 (YP Connected AIN[n]) */

(0 << 5) | /* XMON 0 (XM = Z) */

(1 << 4) | /* nXPON 1 (XP = AIN[7]) */

(1 << 3) | /* Pull Up Enable */

(1 << 2) | /* Auto ADC Conversion Mode */

(0 << 0); /* No Operation Mode */

v_pADCregs->ADCCON |= (1 << 0); /* Start Auto conversion */

while (v_pADCregs->ADCCON & 0x1); /* check if Enable_start is low */

while (!(v_pADCregs->ADCCON & (1 << 15))); /* Check ECFLG */

x = (0x3ff & v_pADCregs->ADCDAT1);

y = 0x3ff - (0x3ff & v_pADCregs->ADCDAT0);

xsum += x;

ysum += y;

}

*px = xsum / TSP_SAMPLE_NUM;

*py = ysum / TSP_SAMPLE_NUM;

v_pADCregs->ADCTSC = (1 << 8) | /* UD_Sen */

(1 << 7) | /* YMON 1 (YM = GND) */

(1 << 6) | /* nYPON 1 (YP Connected AIN[n]) */

(0 << 5) | /* XMON 0 (XM = Z) */

(1 << 4) | /* nXPON 1 (XP = AIN[7]) */

(0 << 3) | /* Pull Up Disable */

(0 << 2) | /* Normal ADC Conversion Mode */

(3 << 0); /* Waiting Interrupt */

dx = (*px > x) ? (*px - x) : (x - *px);

dy = (*py > y) ? (*py - y) : (y - *py);

return((dx > TSP_INVALIDLIMIT || dy > TSP_INVALIDLIMIT) ? FALSE : TRUE);

}

TSP_TransXY:

PRIVATE void

TSP_TransXY(INT *px, INT *py)

{

*px = (*px - TSP_MINX) * TSP_LCDX / (TSP_MAXX - TSP_MINX);

*py = (*py - TSP_MINY) * TSP_LCDY / (TSP_MAXY - TSP_MINY);

if (*px < 0) *px = 0;

if (*px >= TSP_LCDX) *px = TSP_LCDX - 1;

if (*py < 0) *py = 0;

if (*py >= TSP_LCDY) *py = TSP_LCDY - 1;

}

讀到的坐标資料最終交由MDD層的函數進行諸如最小二乘法的數學運算,這裡就不仔細分析了,有興趣可以參考tchmdd.lib和tch_cal.lib裡的代碼(/WINCE500/PUBLIC/COMMON/OAK/DRIVERS).