iMX51 一步一个脚印 --iMX51 WINCE6.0 GPIO设置

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iMX51的功能十分强大，对于从三星平台转移过来的人说那近4千多页的看着实在是头疼，看了看实在是没办法下手，按照常规的学习方法先从IO入手，看了近一周才看出了个眉目。参考上一篇文章这才对IO设置有了一个基本的认识。下边就以PWRBUTTON为例：

#define BSP_PWRBTN_IOMUX_PIN                    DDK_IOMUX_PIN_EIM_A27#define BSP_PWRBTN_IOMUX_PAD                    DDK_IOMUX_PAD_EIM_A27#define BSP_PWRBTN_GPIO_PORT                    DDK_GPIO_PORT2#define BSP_PWRBTN_GPIO_PIN                     21#define BSP_PWRBTN_GPIO_IRQ                     IRQ_GPIO2_PIN21

    // Configure GPIO signal for power button events    DDKIomuxSetPinMux(BSP_PWRBTN_IOMUX_PIN, DDK_IOMUX_PIN_MUXMODE_ALT1, DDK_IOMUX_PIN_SION_REGULAR);    DDKIomuxSetPadConfig(BSP_PWRBTN_IOMUX_PAD, DDK_IOMUX_PAD_SLEW_NULL, DDK_IOMUX_PAD_DRIVE_NULL, DDK_IOMUX_PAD_OPENDRAIN_NULL, DDK_IOMUX_PAD_PULL_NONE, DDK_IOMUX_PAD_HYSTERESIS_ENABLE, DDK_IOMUX_PAD_INMODE_NULL, DDK_IOMUX_PAD_OUTVOLT_NULL);    DDKGpioSetConfig(BSP_PWRBTN_GPIO_PORT, BSP_PWRBTN_GPIO_PIN, DDK_GPIO_DIR_IN, DDK_GPIO_INTR_HIGH_LEV);     DDKGpioClearIntrPin(BSP_PWRBTN_GPIO_PORT, BSP_PWRBTN_GPIO_PIN);

板子上PWRBUTTON键是用的CPU IO口为GPIO2[21]. .

以上几个函数的原型为：

//  Function: DDKIomuxSetPinMux////  Sets the IOMUX configuration for the specified IOMUX pin.////  Parameters://      pin//          [in] Functional pin name used to select the IOMUX output/input//               path that will be configured.////      muxmode//          [in] MUX_MODE configuration.////      sion//          [in] SION configuration.////  Returns://      Returns TRUE if successful, otherwise returns FALSE.////-----------------------------------------------------------------------------BOOL DDKIomuxSetPinMux(DDK_IOMUX_PIN pin, DDK_IOMUX_PIN_MUXMODE muxmode,     DDK_IOMUX_PIN_SION sion){    // No need to use interlocked access since each pad has a separate register    OUTREG32(&g_pIOMUX->SW_MUX_CTL[pin], (muxmode | sion));    return TRUE;}

DDKIomuxSetPinMux(BSP_PWRBTN_IOMUX_PIN, DDK_IOMUX_PIN_MUXMODE_ALT1, DDK_IOMUX_PIN_SION_REGULAR);

设置EIM_A27引脚做为GPIO使用GPIO2[21]. DDK_IOMUX_PIN_MUXMODE_ALT1对应的设置为GPIO2[21].

函数原型为：

//  Function: DDKIomuxSetPadConfig////  Sets the IOMUX pad configuration for the specified IOMUX pad.////  Parameters://      pad//          [in] Functional pad name used to select the pad that will be //          configured.////      slew//          [in] Slew rate configuration.////      drive//          [in] Drive strength configuration.////      openDrain//          [in] Open drain configuration.////      pull//          [in] Pull-up/pull-down/keeper configuration.////      hysteresis//          [in] Hysteresis configuration.////      inputMode//          [in] Input mode (CMOS/DDR) configuration.////      outputVolt//          [in] Output voltage configuration.////  Returns://      Returns TRUE if successful, otherwise returns FALSE.////-----------------------------------------------------------------------------BOOL DDKIomuxSetPadConfig(DDK_IOMUX_PAD pad, DDK_IOMUX_PAD_SLEW slew,     DDK_IOMUX_PAD_DRIVE drive, DDK_IOMUX_PAD_OPENDRAIN openDrain,     DDK_IOMUX_PAD_PULL pull, DDK_IOMUX_PAD_HYSTERESIS hysteresis,     DDK_IOMUX_PAD_INMODE inputMode, DDK_IOMUX_PAD_OUTVOLT_HLVOLT outputVolt){    // No need to use interlocked access since each pad has a separate register    OUTREG32(&g_pIOMUX->SW_PAD_CTL[pad], (slew | drive | openDrain | pull | hysteresis |                   inputMode | outputVolt));    return TRUE;}

DDKIomuxSetPadConfig(BSP_PWRBTN_IOMUX_PAD, DDK_IOMUX_PAD_SLEW_NULL, DDK_IOMUX_PAD_DRIVE_NULL, DDK_IOMUX_PAD_OPENDRAIN_NULL, DDK_IOMUX_PAD_PULL_NONE, DDK_IOMUX_PAD_HYSTERESIS_ENABLE, DDK_IOMUX_PAD_INMODE_NULL, DDK_IOMUX_PAD_OUTVOLT_NULL);

设置PAD寄存器：HYS [8]: 1, PKE[7]:0

通过这2个寄存器的配置，就可以对IO进行操作了。

以下是常用的操作函数：

BOOL DDKGpioSetConfig(DDK_GPIO_PORT port, UINT32 pin, DDK_GPIO_DIR dir, DDK_GPIO_INTR intr);BOOL DDKGpioWriteData(DDK_GPIO_PORT port, UINT32 portMask, UINT32 data);BOOL DDKGpioWriteDataPin(DDK_GPIO_PORT port, UINT32 pin, UINT32 data);BOOL DDKGpioReadData(DDK_GPIO_PORT port, UINT32 portMask, UINT32 *pData);BOOL DDKGpioReadDataPin(DDK_GPIO_PORT port, UINT32 pin, UINT32 *pData);BOOL DDKGpioReadIntr(DDK_GPIO_PORT port, UINT32 portMask, UINT32 *pStatus);BOOL DDKGpioReadIntrPin(DDK_GPIO_PORT port, UINT32 pin, UINT32 *pStatus);BOOL DDKGpioClearIntrPin(DDK_GPIO_PORT port, UINT32 pin);