embeddedsw/XilinxProcessorIPLib/drivers/usbps/src/xusbps_hw.c

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/**
 *
 * @file xusbps_hw.c
 *
 * The implementation of the XUsbPs interface reset functionality
 *
 * <pre>
 * MODIFICATION HISTORY:
 *
 * Ver   Who  Date     Changes
 * ----- ---- -------- -----------------------------------------------
 * 1.05a kpc  10/10/10 first version
 * </pre>
 *
 *****************************************************************************/

/***************************** Include Files ********************************/

#include "xstatus.h"
#include "xusbps.h"
#include "xparameters.h"


/************************** Constant Definitions ****************************/
#define XUSBPS_RESET_TIMEOUT 0xFFFFF
/**************************** Type Definitions ******************************/

/***************** Macros (Inline Functions) Definitions ********************/

/************************** Variable Definitions ****************************/


/************************** Function Prototypes *****************************/


/*****************************************************************************/
/**
* This function perform the reset sequence to the given usbps interface by 
* configuring the appropriate control bits in the usbps specifc registers.
* the usbps reset sequence involves the below steps
* 	Disbale the interrupts
*	Clear the status registers
*	Apply the reset command and wait for reset complete status
*	Update the relevant control registers with reset values
* @param   BaseAddress of the interface
*
* @return   N/A.
*
* @note     None.
*
******************************************************************************/
void XUsbPs_ResetHw(u32 BaseAddress)
{
	u32 RegVal;
	u32 Timeout = 0;
	
	/* Host and device mode */
	/* Disable the interrupts */
	XUsbPs_WriteReg(BaseAddress,XUSBPS_IER_OFFSET,0x0);
	/* Clear the interuupt status */
	RegVal = XUsbPs_ReadReg(BaseAddress,XUSBPS_ISR_OFFSET);
	XUsbPs_WriteReg(BaseAddress,XUSBPS_ISR_OFFSET,RegVal);

	/* Perform the reset operation using USB CMD register */	
	RegVal = XUsbPs_ReadReg(BaseAddress,XUSBPS_CMD_OFFSET);
	RegVal = RegVal | XUSBPS_CMD_RST_MASK;
	XUsbPs_WriteReg(BaseAddress,XUSBPS_CMD_OFFSET,RegVal);
	RegVal = XUsbPs_ReadReg(BaseAddress,XUSBPS_CMD_OFFSET);
	/* Wait till the reset operation returns success */
	/*
	* FIX ME: right now no indication to the caller or user about
	* timeout overflow
	*/
	while ((RegVal & XUSBPS_CMD_RST_MASK) && (Timeout < XUSBPS_RESET_TIMEOUT))
	{
		RegVal = XUsbPs_ReadReg(BaseAddress,XUSBPS_CMD_OFFSET);	
		Timeout++;
	}
	/* Update periodic list base address register with reset value */		
	XUsbPs_WriteReg(BaseAddress,XUSBPS_LISTBASE_OFFSET,0x0);	
	/* Update async/endpoint list base address register with reset value */		
	XUsbPs_WriteReg(BaseAddress,XUSBPS_ASYNCLISTADDR_OFFSET,0x0);		
	
}