XILINX GPIO驱动分析

High Level – level 1 hardware driver api

Low Level – level 0 hardware driver api

XGPIO.H

#include "xil_types.h"

#include "xil_assert.h"

#include "xstatus.h"

#include "xgpio_l.h"

Define:

XGpio_CfgInitialize

XGpio_SetDataDirection

XGPIO.C

    #include "xgpio.h"

#include "xstatus.h"

Implement:

XGpio_CfgInitialize

XGpio_SetDataDirection

<==上面API：

#include "xgpio_l.h" (xgpio low level)

XGPIO_L.H:

    #include "xil_types.h"

#include "xil_assert.h"

#include "xil_io.h"

#define XGPIO_DATA_OFFSET    0x0 /**< Data register for 1st channel */

#define XGPIO_TRI_OFFSET    0x1 /**< I/O direction reg for 1st channel */

#define XGPIO_DATA2_OFFSET    0x2 /**< Data register for 2nd channel */

#define XGPIO_TRI2_OFFSET    0x3 /**< I/O direction reg for 2nd channel */

 

#define XGPIO_GIE_OFFSET    0x47 /**< Global interrupt enable register */

#define XGPIO_ISR_OFFSET    0x48 /**< Interrupt status register */

#define XGPIO_IER_OFFSET    0x4A /**< Interrupt enable register */

#define XGpio_ReadReg     Xil_In32 ==> (xil_io.c)

XGPIO_L.C文件不存在，因为LOW LEVEL的驱动全是MACRO写的，不需要C文件实现。

< == 上面API：

#include "xil_io.h"

XIL_IO.H：

#include "xil_types.h"

#include "xpseudo_asm.h"

#include "xil_printf.h"

DEFINE:

    u8 Xil_In8(u32 Addr);

u16 Xil_In16(u32 Addr);

u32 Xil_In32(u32 Addr);

XIL_IO.C

    #include "xil_io.h"

#include "xil_types.h"

#include "xil_assert.h"

#include "xpseudo_asm.h"

#include "xreg_cortexa9.h"

Implement:

u8 Xil_In8(u32 Addr);

u16 Xil_In16(u32 Addr);

u32 Xil_In32(u32 Addr);

<= =上层API：

H:

#include "xpseudo_asm.h"

C:

#include "xpseudo_asm.h"

#include "xreg_cortexa9.h"

XPSEUDO_ASM.H 没有C文件

#include "xreg_cortexa9.h"

    #include "xpseudo_asm_gcc.h"

XREG_CORTEXA9.H 没有C文件

    /* GPRs */

#define XREG_GPR0                r0

#define XREG_GPR1                r1

#define XREG_GPR2                r2

#define XREG_GPR14                r14

#define XREG_GPR15                r15

#define XREG_CPSR                cpsr

XPSEUDO_ASM_GCC.H：没有C文件

/* pseudo assembler instructions */

#define mfcpsr()    ({unsigned int rval; \

             __asm__ __volatile__(\

             "mrs    %0, cpsr\n"\

             : "=r" (rval)\

             );\

             rval;\

             })

 

/* Memory Operations */

#define ldr(adr)    ({unsigned long rval; \

             __asm__ __volatile__(\

             "ldr    %0,[%1]"\

             : "=r" (rval) : "r" (adr)\

             );\

             rval;\

             })

 

下图是各个文件与其对应的功能图：

下图是GPIO模块驱动API的层次结构图：