usb_pwr.c

Handling Suspend Mode on a USB Mouse

/******************** (C) COPYRIGHT 2006 STMicroelectronics ********************
* File Name          : usb_pwr.c
* Author             : MCD Application Team
* Date First Issued  : 10/01/2006 : V1.0
* Description        : Connection/disconnection & power management
********************************************************************************
* History:
* 10/01/2006 : V1.0
********************************************************************************
* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/
/* Includes ------------------------------------------------------------------*/
#include "91x_lib.h"
#include "usb_lib.h"
#include "usb_conf.h"
#include "usb_pwr.h"
#include "hw_config.h"
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
volatile bool fCellSuspended;
volatile u8 bDeviceState=UNCONNECTED; /* USB device status */
volatile bool fSuspendEnabled=TRUE;  /* true when suspend is possible */

struct {
	volatile RESUME_STATE eState;
	volatile u8 bESOFcnt;
} ResumeS;
/* Extern variables ----------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Extern function prototypes ------------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name  : PowerOn
* Description    :
* Input          : None.
* Output         : None.
* Return         : USB_SUCCESS.
*******************************************************************************/
RESULT PowerOn(void)
{
 u16 wRegVal;

	/*** cable plugged-in ? ***/
	/*while(!CablePluggedIn());*/
        USB_Cable_Config(ENABLE);
		
	/*** CNTR_PWDN = 0 ***/
	wRegVal = CNTR_FRES;
	_SetCNTR(wRegVal);

	/*** CNTR_FRES = 0 ***/
    wInterrupt_Mask = 0;
    _SetCNTR(wInterrupt_Mask);
	/*** Clear pending interrupts ***/
    _SetISTR(0);
	/*** Set interrupt mask ***/
    wInterrupt_Mask = CNTR_RESETM | CNTR_SUSPM | CNTR_WKUPM;
    _SetCNTR(wInterrupt_Mask);

	return USB_SUCCESS;
}
/*******************************************************************************
* Function Name  : PowerOff
* Description    : handles switch-off conditions
* Input          : None.
* Output         : None.
* Return         : USB_SUCCESS.
*******************************************************************************/
RESULT PowerOff()
{
     /* disable all ints and force USB reset */
     _SetCNTR(CNTR_FRES);
     /* clear interrupt status register */
     _SetISTR(0);
     /* Disable the Pull-Up*/
     USB_Cable_Config(DISABLE);
    /* switch-off device */
    _SetCNTR(CNTR_FRES+CNTR_PDWN);
    /* sw variables reset */
	/* ... */

	return USB_SUCCESS;
}
/*******************************************************************************
* Function Name  : Suspend
* Description    : sets suspend mode operating conditions
* Input          : None.
* Output         : None.
* Return         : USB_SUCCESS.
*******************************************************************************/
void Suspend(void)
{
 u16 wCNTR;
    fCellSuspended= TRUE;
	/* suspend preparation */
	/* ... */

	/* macrocell enters suspend mode */
    wCNTR = _GetCNTR();
    wCNTR |= CNTR_FSUSP;
    _SetCNTR(wCNTR);

/* ------------------ ONLY WITH BUS-POWERED DEVICES ---------------------- */
	/* power reduction */
	/* ... on connected devices */

    /* force low-power mode in the macrocell */
    wCNTR = _GetCNTR();
    wCNTR |= CNTR_LPMODE;
    _SetCNTR(wCNTR);

    /* switch-off the clocks */
    /* ... */


}
/*******************************************************************************
* Function Name  : Resume_Init
* Description    : Handles wake-up restoring normal operations
* Input          : None.
* Output         : None.
* Return         : USB_SUCCESS.
*******************************************************************************/
void Resume_Init(void)
{
  u16 wCNTR;

    fCellSuspended= FALSE;

/* ------------------ ONLY WITH BUS-POWERED DEVICES ---------------------- */
    /* restart the clocks */
    /* ...  */

    /* CNTR_LPMODE = 0 */
    wCNTR = _GetCNTR();
    wCNTR &= (~CNTR_LPMODE);
    _SetCNTR(wCNTR);

	/* restore full power */
	/* ... on connected devices */

   	/* reset FSUSP bit */
   	_SetCNTR(IMR_MSK);

	/* reverse suspend preparation */
	/* ... */

}
/*******************************************************************************
* Function Name  : Resume
* Description    : This is the state machine handling resume operations and
*                 timing sequence. The control is based on the Resume structure
*                 variables and on the ESOF interrupt calling this subroutine
*                 without changing machine state.
* Input          : a state machine value (RESUME_STATE)
*                  RESUME_ESOF doesn't change ResumeS.eState allowing
*                  decrementing of the ESOF counter in different states.
* Output         : None.
* Return         : None.
*******************************************************************************/
void Resume(RESUME_STATE eResumeSetVal)
{
 u16 wCNTR;
 u16 wRegVal;

	if(eResumeSetVal != RESUME_ESOF)
			ResumeS.eState = eResumeSetVal;

	switch(ResumeS.eState)
	{
		case RESUME_EXTERNAL:
		Resume_Init();
	  wRegVal = GetFNR();
    		if(wRegVal & FNR_RXDP) //10 & 11 false conditions
     		{
    	     		Suspend();
     		}
		    ResumeS.eState = RESUME_OFF;
			break;
		case RESUME_INTERNAL:
			Resume_Init();
		    ResumeS.eState = RESUME_START;
			break;
		case RESUME_LATER:
			ResumeS.bESOFcnt = 2;
		    ResumeS.eState = RESUME_WAIT;
			break;
		case RESUME_WAIT:
			ResumeS.bESOFcnt--;
			if(ResumeS.bESOFcnt == 0)
			    ResumeS.eState = RESUME_START;
			break;
		case RESUME_START:
		    wCNTR = _GetCNTR();
		    wCNTR |= CNTR_RESUME;
		    _SetCNTR(wCNTR);
		    ResumeS.eState = RESUME_ON;
		    ResumeS.bESOFcnt = 10;
			break;
		case RESUME_ON:
			ResumeS.bESOFcnt--;
			if(ResumeS.bESOFcnt == 0)
			{
			    wCNTR = _GetCNTR();
			    wCNTR &= (~CNTR_RESUME);
			    _SetCNTR(wCNTR);
			    ResumeS.eState = RESUME_OFF;
			}
			break;
		case RESUME_OFF:
		case RESUME_ESOF:
		default:
		    ResumeS.eState = RESUME_OFF;
			break;
	}
}
/******************* (C) COPYRIGHT 2006 STMicroelectronics *****END OF FILE****/