WinCE的LCD驱动程序编写指南

WinCE的LCD驱动程序编写指南

本文以1024*768分辨率的TFT_16BPP真彩LCD为例,说明在WIN CE 4.2中驱动程序的修改事项，目标板的微处理器是S3C2410A。   该LCD的时序图如下图所示：   Note：LCD时序的参数和时钟相位因不同LCD而异,请参考相应LCD的datasheet. 在WIN CE 4.2中修改LCD驱动程序有五个相关文件,分别是： 1.    …\WINCE420\PLATFORM\SMDK2410\INC\s2410.h 2.    …\WINCE420\PLATFORM\SMDK2410\KERNEL\HAL\cfw.c 3.    …\WINCE420\PLATFORM\SMDK2410\DRIVERS\DISPLAY\S3C2410LCD\s3c2410disp.cpp 4.    …\WINCE420\PLATFORM\SMDK2410\FILES\config.bib 5.    …\ WINCE420\PLATFORM\SMDK2410\FILES\platform.reg   1.  s2410.h …\WINCE420\PLATFORM\SMDK2410\INC\s2410.h 主要有 LCD 控制器的寄存器定义、 LCD 控制器的工作时序定义、分辨率的定义等等。红色部分为修改后的内容： #define LCDTYPE                       TFT16BPP #define LCD_TYPE                     TFTxxx_xxx #define SCR_XSIZE_TFT            (1280) #define SCR_YSIZE_TFT            (960) #define LCD_XSIZE_TFT           (1024) #define LCD_YSIZE_TFT            (768) #define VBPD                            ((2-1)&0xff) #define VFPD                            ((2-1)&0xff) #define VSPW                           ((2-1) &0x3f) #define HBPD                            ((16-1)&0x7f) #define HFPD                            ((200-1)&0xff) #define HSPW                           ((16-1)&0xff) #define CLKVAL_TFT               (1)   // 这个值的定义在 LCD 初始化函数中并不用到 , 而是直接用数值表示。 2.  cfw.c …\WINCE420\PLATFORM\SMDK2410\KERNEL\HAL\cfw.c 红色部分为修改后的内容： static void InitDisplay() {        ********        s2410LCD->rLCDCON1=(1<<8)|(MVAL_USED<<7)|(3<<5)|(12<<1)|0;                                               // CLKVAL_TFT = 1 , HCLK = 100MHz -> VCLK = 25MHz                                                                                      // TFT LCD panel                                                                                                 //16 bpp for TFT        s2410LCD->rLCDCON2=(VBPD<<24)|(LINEVAL_TFT<<14)|(VFPD<<6)|(VSPW);        s2410LCD->rLCDCON3=(HBPD<<19)|(HOZVAL_TFT<<8)|(HFPD);        s2410LCD->rLCDCON4=(MVAL<<8)|(HSPW);        s2410LCD->rLCDCON5=        (1<<11)|(0<<10)|(0<<9)|(0<<8)|(0<<7)|(0<<6)|(0<<3)|(0<<1)|(1<<0);         // 5:6:5 Format                     //The video data is fetched at VCLK falling edge                                  //VLINE/HSYNC pulse polarity-Normal                                             //VFRAME/VSYNC pulse polarity-Normal                                                       //VD (video data) pulse polarity-Normal                                                                  //VDEN signal polarity-Normal                                                                            //Disable PWREN signal                                                                                       //Byte swap Disable                                                                                                 //Half-Word swap Enable        ******** }   红色部分为修改后的内容： WORD    TempBuffer[1025][768]; S3C2410DISP::S3C2410DISP (void) {        ********        m_nScreenWidth = 1024;        m_nScreenHeight = 768;        ********* }        到此修改工作基本完成，但还要一个问题： 1024*768 分辨率占用的显示缓冲区大小是： 1024*768*2 = 1536 K Bytes, 因此要确认所分配的内存空间够不够 , 是在 config.bib 文件中定义的。如果以前定义的足够大 , 后面的步骤可以省略了。   4.  config.bib …\WINCE420\PLATFORM\SMDK2410\FILES\config.bib        #define NKNAME NK        #define NKSTART         8C200000        #define NKLEN              01D00000        #define RAMSTART      8E000000        #define RAMLEN           01F00000        $(NKNAME)              $(NKSTART)        $(NKLEN)            RAMIMAGE        RAM                         $(RAMSTART)      $(RAMLEN)        RAM        AUD_DMA                  8c002000             00002000             RESERVED        DRV_GLB                   8c010000             00010000             RESERVED        DBGSER_DMA            8c022000             00002000             RESERVED        SER_DMA                   8c024000             00002000             RESERVED        IR_DMA                     8c026000             00002000             RESERVED        SD_DMA                    8c028000             00008000             RESERVED        EDBG                         8c030000             00020000             RESERVED        CPXIPCHAIN              8c050000             00008000             RESERVED        SLEEP_BUFF              8c058000             00004000             RESERVED        DISPLAY                    8c100000             00100000             RESERVED        DISPLAY        AUD_DMA                 8c002000             00002000             RESERVED        DRV_GLB                  8c010000             00010000             RESERVED        DBGSER_DMA           8c022000            00002000              RESERVED        SER_DMA                 8c024000             00002000              RESERVED        IR_DMA                    8c026000             00002000              RESERVED        SD_DMA                   8c028000             00008000             RESERVED        EDBG                        8c030000             00020000             RESERVED        CPXIPCHAIN             8c050000             00008000             RESERVED        SLEEP_BUFF              8c058000              00004000              RESERVED        ;DISPLAY                   8c100000              00100000              RESERVED         DISPLAY                    8c 060000              001a 0000              RESERVED     5.   在（4）中修改了DISPLAY显示缓冲区的开始地址,因此要在“s2410.h”中做相应的修改： …\WINCE420\PLATFORM\SMDK2410\INC\s2410.h #define DMA_BUFFER_BASE                    0xAC000000 #define DMA_PHYSICAL_BASE                0x30000000 //#define FRAMEBUF_BASE                      (DMA_BUFFER_BASE + 0x00100000) //#define FRAMEBUF_DMA_BASE             (DMA_PHYSICAL_BASE + 0x00100000) #define FRAMEBUF_BASE                        (DMA_BUFFER_BASE + 0x00060000) #define FRAMEBUF_DMA_BASE               (DMA_PHYSICAL_BASE + 0x00060000) 6.  在（4）中修改了DISPLAY显示缓冲区的大小, 因此要在“s3c2410disp.cpp”中做相应的修改：        …\WINCE420\PLATFORM\SMDK2410\DRIVERS\DISPLAY\S3C2410LCD\s3c2410disp.cpp 红色部分为修改后的内容： void S3C2410DISP::InitializeHardware (void) {        *********        m_VirtualFrameBuffer = (DWORD)VirtualAlloc(0, (0x1A0000), MEM_RESERVE, PAGE_NOACCESS);        if (m_VirtualFrameBuffer == NULL)        {            RETAILMSG(0,(TEXT("m_VirtualFrameBuffer is not allocated\n\r")));               return;        }        else if (!VirtualCopy((PVOID)m_VirtualFrameBuffer, (PVOID)gdwLCDVirtualFrameBase, (0x1A0000), PAGE_READWRITE | PAGE_NOCACHE))        {            RETAILMSG(0, (TEXT("m_VirtualFrameBuffer is not mapped\n\r")));            VirtualFree((PVOID)m_VirtualFrameBuffer, 0, MEM_RELEASE);            return;        }        ********* }   7.      完！