path: root/drivers/usb/gadget/dwc_otg/dwc_otg_cil_intr.c

/* ==========================================================================
 * $File: //dwh/usb_iip/dev/software/otg_ipmate/linux/drivers/dwc_otg_cil_intr.c $
 * $Revision: #7 $
 * $Date: 2005/11/02 $
 * $Change: 553126 $
 *
 * Synopsys HS OTG Linux Software Driver and documentation (hereinafter,
 * "Software") is an Unsupported proprietary work of Synopsys, Inc. unless
 * otherwise expressly agreed to in writing between Synopsys and you.
 * 
 * The Software IS NOT an item of Licensed Software or Licensed Product under
 * any End User Software License Agreement or Agreement for Licensed Product
 * with Synopsys or any supplement thereto. You are permitted to use and
 * redistribute this Software in source and binary forms, with or without
 * modification, provided that redistributions of source code must retain this
 * notice. You may not view, use, disclose, copy or distribute this file or
 * any information contained herein except pursuant to this license grant from
 * Synopsys. If you do not agree with this notice, including the disclaimer
 * below, then you are not authorized to use the Software.
 * 
 * THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS" BASIS
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * ========================================================================== */
     
    
/** @file 
 *
 * The Core Interface Layer provides basic services for accessing and
 * managing the DWC_otg hardware. These services are used by both the
 * Host Controller Driver and the Peripheral Controller Driver.
 *
 * This file contains the Common Interrupt handlers.
 */ 
#include "linux/dwc_otg_plat.h"
#include "dwc_otg_regs.h"
#include "dwc_otg_cil.h"
    
inline const char *op_state_str(dwc_otg_core_if_t * _core_if) 
{
	return (_core_if->op_state == A_HOST ? "a_host" : 
		(_core_if->op_state == A_SUSPEND ? "a_suspend" : 
		(_core_if->op_state == A_PERIPHERAL ? "a_peripheral" : 
		(_core_if->op_state == B_PERIPHERAL ? "b_peripheral" : 
		(_core_if->op_state == B_HOST ? "b_host" : "unknown")))));
}
    
/** This function will log a debug message 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
int32_t dwc_otg_handle_mode_mismatch_intr(dwc_otg_core_if_t * _core_if) 
{
	gintsts_data_t gintsts;
	DWC_WARN("Mode Mismatch Interrupt: currently in %s mode\n",
		  dwc_otg_mode(_core_if) ? "Host" : "Device");
	
	/* Clear interrupt */ 
	gintsts.d32 = 0;
	gintsts.b.modemismatch = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/** Start the HCD.  Helper function for using the HCD callbacks.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void hcd_start(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->hcd_cb && _core_if->hcd_cb->start) {
		_core_if->hcd_cb->start(_core_if->hcd_cb->p);
	}
}

/** Stop the HCD.  Helper function for using the HCD callbacks. 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void hcd_stop(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->hcd_cb && _core_if->hcd_cb->stop) {
		_core_if->hcd_cb->stop(_core_if->hcd_cb->p);
	}
}

/** Disconnect the HCD.  Helper function for using the HCD callbacks.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void hcd_disconnect(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->hcd_cb && _core_if->hcd_cb->disconnect) {
		_core_if->hcd_cb->disconnect(_core_if->hcd_cb->p);
	}
}

/** Inform the HCD the a New Session has begun.  Helper function for
 * using the HCD callbacks.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void hcd_session_start(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->hcd_cb && _core_if->hcd_cb->session_start) {
		_core_if->hcd_cb->session_start(_core_if->hcd_cb->p);
	}
}

/** Start the PCD.  Helper function for using the PCD callbacks.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void pcd_start(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->pcd_cb && _core_if->pcd_cb->start) {
		_core_if->pcd_cb->start(_core_if->pcd_cb->p);
	}
}

/** Stop the PCD.  Helper function for using the PCD callbacks. 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void pcd_stop(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->pcd_cb && _core_if->pcd_cb->stop) {
		_core_if->pcd_cb->stop(_core_if->pcd_cb->p);
	}
}

/** Suspend the PCD.  Helper function for using the PCD callbacks. 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void pcd_suspend(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->pcd_cb && _core_if->pcd_cb->suspend) {
		_core_if->pcd_cb->suspend(_core_if->pcd_cb->p);
	}
}

/** Resume the PCD.  Helper function for using the PCD callbacks. 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
static inline void pcd_resume(dwc_otg_core_if_t * _core_if) 
{
	if (_core_if->pcd_cb && _core_if->pcd_cb->resume_wakeup) {
		_core_if->pcd_cb->resume_wakeup(_core_if->pcd_cb->p);
	}
}

/**
 * This function handles the OTG Interrupts. It reads the OTG
 * Interrupt Register (GOTGINT) to determine what interrupt has
 * occurred.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
int32_t dwc_otg_handle_otg_intr(dwc_otg_core_if_t * _core_if) 
{
	dwc_otg_core_global_regs_t * global_regs = _core_if->core_global_regs;
	gotgint_data_t gotgint;
	gotgctl_data_t gotgctl;
	gintmsk_data_t gintmsk;
	gotgint.d32 = dwc_read_reg32(&global_regs->gotgint);
	gotgctl.d32 = dwc_read_reg32(&global_regs->gotgctl);
	DWC_DEBUGPL(DBG_CIL, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint.d32,
		     op_state_str(_core_if));
	
	//DWC_DEBUGPL(DBG_CIL, "gotgctl=%08x\n", gotgctl.d32 );
	if (gotgint.b.sesenddet) {
		DWC_DEBUGPL(DBG_ANY, " ++OTG Interrupt: " 
			     "Session End Detected++ (%s)\n",
			     op_state_str(_core_if));
		gotgctl.d32 = dwc_read_reg32(&global_regs->gotgctl);
		if (_core_if->op_state == B_HOST) {
			pcd_start(_core_if);
			_core_if->op_state = B_PERIPHERAL;
		} else {
			/* If not B_HOST and Device HNP still set. HNP
			 * Did not succeed!*/ 
			if (gotgctl.b.devhnpen) {
				DWC_DEBUGPL(DBG_ANY, "Session End Detected\n");
				DWC_ERROR("Device Not Connected/Responding!\n");
			}
			/* If Session End Detected the B-Cable has
			 * been disconnected. */ 
			/* Reset PCD and Gadget driver to a
			 * clean state. */ 
			pcd_stop(_core_if);
		}
		gotgctl.d32 = 0;
		gotgctl.b.devhnpen = 1;
		dwc_modify_reg32(&global_regs->gotgctl, gotgctl.d32, 0);
	}
	if (gotgint.b.sesreqsucstschng) {
		DWC_DEBUGPL(DBG_ANY, " ++OTG Interrupt: " 
			     "Session Reqeust Success Status Change++\n");
		gotgctl.d32 = dwc_read_reg32(&global_regs->gotgctl);
		if (gotgctl.b.sesreqscs) {
			if ((_core_if->core_params->phy_type ==
			      DWC_PHY_TYPE_PARAM_FS)
			     && (_core_if->core_params->i2c_enable)) {
				_core_if->srp_success = 1;
			} else {
				pcd_resume(_core_if);
				
				/* Clear Session Request */ 
				gotgctl.d32 = 0;
				gotgctl.b.sesreq = 1;
				dwc_modify_reg32(&global_regs->gotgctl,
						  gotgctl.d32, 0);
			}
		}
	}
	if (gotgint.b.hstnegsucstschng) {
		/* Print statements during the HNP interrupt handling
		 * can cause it to fail.*/ 
		gotgctl.d32 = dwc_read_reg32(&global_regs->gotgctl);
		if (gotgctl.b.hstnegscs) {
			if (dwc_otg_is_host_mode(_core_if)) {
				_core_if->op_state = B_HOST;
				
				/*
				 * Need to disable SOF interrupt immediately.
				 * When switching from device to host, the PCD
				 * interrupt handler won't handle the
				 * interrupt if host mode is already set. The
				 * HCD interrupt handler won't get called if
				 * the HCD state is HALT. This means that the
				 * interrupt does not get handled and Linux
				 * complains loudly.
				 */ 
				gintmsk.d32 = 0;
				gintmsk.b.sofintr = 1;
				dwc_modify_reg32(&global_regs->gintmsk, gintmsk.d32, 0);
				pcd_stop(_core_if);
				
				/*
				 * Initialize the Core for Host mode.
				 */ 
				hcd_start(_core_if);
				_core_if->op_state = B_HOST;
			}
		} else {
			gotgctl.d32 = 0;
			gotgctl.b.hnpreq = 1;
			gotgctl.b.devhnpen = 1;
			dwc_modify_reg32(&global_regs->gotgctl, gotgctl.d32, 0);
			DWC_DEBUGPL(DBG_ANY, "HNP Failed\n");
			DWC_ERROR("Device Not Connected/Responding\n");
		}
	}
	if (gotgint.b.hstnegdet) {
		
		/* The disconnect interrupt is set at the same time as
		 * Host Negotiation Detected.  During the mode
		 * switch all interrupts are cleared so the disconnect
		 * interrupt handler will not get executed.
		 */ 
		DWC_DEBUGPL(DBG_ANY, " ++OTG Interrupt: " 
				"Host Negotiation Detected++ (%s)\n", 
				(dwc_otg_is_host_mode(_core_if) ? "Host" :
				 "Device"));
		if (dwc_otg_is_device_mode(_core_if)) {
			DWC_DEBUGPL(DBG_ANY, "a_suspend->a_peripheral (%d)\n",
				     _core_if->op_state);
			hcd_disconnect(_core_if);
			pcd_start(_core_if);
			_core_if->op_state = A_PERIPHERAL;
		} else {
			
			/*
			 * Need to disable SOF interrupt immediately. When
			 * switching from device to host, the PCD interrupt
			 * handler won't handle the interrupt if host mode is
			 * already set. The HCD interrupt handler won't get
			 * called if the HCD state is HALT. This means that
			 * the interrupt does not get handled and Linux
			 * complains loudly.
			 */ 
			gintmsk.d32 = 0;
			gintmsk.b.sofintr = 1;
			dwc_modify_reg32(&global_regs->gintmsk, gintmsk.d32,
					  0);
			pcd_stop(_core_if);
			hcd_start(_core_if);
			_core_if->op_state = A_HOST;
		}
	}
	if (gotgint.b.adevtoutchng) {
		DWC_DEBUGPL(DBG_ANY, " ++OTG Interrupt: " 
			     "A-Device Timeout Change++\n");
	}
	if (gotgint.b.debdone) {
		DWC_DEBUGPL(DBG_ANY, " ++OTG Interrupt: " 
			     "Debounce Done++\n");
	}
	
	/* Clear GOTGINT */ 
	dwc_write_reg32(&_core_if->core_global_regs->gotgint, gotgint.d32);
	return 1;
}

/**
 * This function handles the Connector ID Status Change Interrupt.  It
 * reads the OTG Interrupt Register (GOTCTL) to determine whether this
 * is a Device to Host Mode transition or a Host Mode to Device
 * Transition.  
 *
 * This only occurs when the cable is connected/removed from the PHY
 * connector.
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
int32_t dwc_otg_handle_conn_id_status_change_intr(dwc_otg_core_if_t *
						      _core_if) 
{
	uint32_t count = 0;
	gintsts_data_t gintsts = {.d32 = 0};
	gintmsk_data_t gintmsk = {.d32 = 0};
	gotgctl_data_t gotgctl = {.d32 = 0};
	
	/*
	 * Need to disable SOF interrupt immediately. If switching from device
	 * to host, the PCD interrupt handler won't handle the interrupt if
	 * host mode is already set. The HCD interrupt handler won't get
	 * called if the HCD state is HALT. This means that the interrupt does
	 * not get handled and Linux complains loudly.
	 */ 
	gintmsk.b.sofintr = 1;
	dwc_modify_reg32(&_core_if->core_global_regs->gintmsk, gintmsk.d32, 0);
	DWC_DEBUGPL(DBG_CIL,
		      " ++Connector ID Status Change Interrupt++  (%s)\n",
		      (dwc_otg_is_host_mode(_core_if) ? "Host" : "Device"));
	gotgctl.d32 = dwc_read_reg32(&_core_if->core_global_regs->gotgctl);
	DWC_DEBUGPL(DBG_CIL, "gotgctl=%0x\n", gotgctl.d32);
	DWC_DEBUGPL(DBG_CIL, "gotgctl.b.conidsts=%d\n", gotgctl.b.conidsts);
	
	/* B-Device connector (Device Mode) */ 
	if (gotgctl.b.conidsts) {
		
		/* Wait for switch to device mode. */ 
		while (!dwc_otg_is_device_mode(_core_if)) {
			DWC_PRINT("Waiting for Peripheral Mode, Mode=%s\n", 
				   (dwc_otg_is_host_mode(_core_if) ? "Host" :
				    "Peripheral"));
			MDELAY(100);
			if (++count > 10000)
				*(uint32_t *) NULL = 0;
		}
		_core_if->op_state = B_PERIPHERAL;
		dwc_otg_core_init(_core_if);
		dwc_otg_enable_global_interrupts(_core_if);
		pcd_start(_core_if);
	} else {
		
		/* A-Device connector (Host Mode) */ 
		while (!dwc_otg_is_host_mode(_core_if)) {
			DWC_PRINT("Waiting for Host Mode, Mode=%s\n", 
				   (dwc_otg_is_host_mode(_core_if) ? "Host" :
				    "Peripheral"));
			MDELAY(100);
			if (++count > 10000)
				*(uint32_t *) NULL = 0;
		}
		_core_if->op_state = A_HOST;
		
		/*
		 * Initialize the Core for Host mode.
		 */ 
		dwc_otg_core_init(_core_if);
		dwc_otg_enable_global_interrupts(_core_if);
		hcd_start(_core_if);
	}
	
	/* Set flag and clear interrupt */ 
	gintsts.b.conidstschng = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/** 
 * This interrupt indicates that a device is initiating the Session
 * Request Protocol to request the host to turn on bus power so a new
 * session can begin. The handler responds by turning on bus power. If
 * the DWC_otg controller is in low power mode, the handler brings the
 * controller out of low power mode before turning on bus power. 
 *
 * @param _core_if Programming view of DWC_otg controller.
 */ 
int32_t dwc_otg_handle_session_req_intr(dwc_otg_core_if_t * _core_if) 
{
	gintsts_data_t gintsts;
	
#ifndef CONFIG_DWC_HOST_ONLY
	hprt0_data_t hprt0;
	DWC_DEBUGPL(DBG_ANY, "++Session Request Interrupt++\n");
	if (dwc_otg_is_device_mode(_core_if)) {
		DWC_PRINT("SRP: Device mode\n");
	} else {
		DWC_PRINT("SRP: Host mode\n");
		
		/* Turn on the port power bit. */ 
		hprt0.d32 = dwc_otg_read_hprt0(_core_if);
		hprt0.b.prtpwr = 1;
		dwc_write_reg32(_core_if->host_if->hprt0, hprt0.d32);
		
		/* Start the Connection timer. So a message can be displayed
		 * if connect does not occur within 10 seconds. */ 
		hcd_session_start(_core_if);
	}
	
#endif	/*  */
	    
	/* Clear interrupt */ 
	gintsts.d32 = 0;
	gintsts.b.sessreqintr = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/** 
 * This interrupt indicates that the DWC_otg controller has detected a
 * resume or remote wakeup sequence. If the DWC_otg controller is in
 * low power mode, the handler must brings the controller out of low
 * power mode. The controller automatically begins resume
 * signaling. The handler schedules a time to stop resume signaling.
 */ 
int32_t dwc_otg_handle_wakeup_detected_intr(dwc_otg_core_if_t * _core_if) 
{
	gintsts_data_t gintsts;
	DWC_DEBUGPL(DBG_ANY,"++Resume and Remote Wakeup Detected Interrupt++\n");
	if (dwc_otg_is_device_mode(_core_if)) {
		dctl_data_t dctl = {.d32 = 0};
		DWC_DEBUGPL(DBG_PCD, "DSTS=0x%0x\n",
				dwc_read_reg32(&_core_if->dev_if->dev_global_regs->dsts));
		
#ifdef PARTIAL_POWER_DOWN
		if (_core_if->hwcfg4.b.power_optimiz) {
			pcgcctl_data_t power = {.d32 = 0};
			power.d32 = dwc_read_reg32(_core_if->pcgcctl);
			DWC_DEBUGPL(DBG_CIL, "PCGCCTL=%0x\n", power.d32);
			power.b.stoppclk = 0;
			dwc_write_reg32(_core_if->pcgcctl, power.d32);
			power.b.pwrclmp = 0;
			dwc_write_reg32(_core_if->pcgcctl, power.d32);
			power.b.rstpdwnmodule = 0;
			dwc_write_reg32(_core_if->pcgcctl, power.d32);
		}
		
#endif	/*  */
		/* Clear the Remote Wakeup Signalling */ 
		dctl.b.rmtwkupsig = 1;
		dwc_modify_reg32(&_core_if->dev_if->dev_global_regs->dctl,
				  dctl.d32, 0);
		if (_core_if->pcd_cb && _core_if->pcd_cb->resume_wakeup) {
			_core_if->pcd_cb->resume_wakeup(_core_if->pcd_cb->p);
		}
	} else {
		
		/*
		 * Clear the Resume after 70ms. (Need 20 ms minimum. Use 70 ms
		 * so that OPT tests pass with all PHYs).
		 */ 
		hprt0_data_t hprt0 = {.d32 = 0};
		pcgcctl_data_t pcgcctl = {.d32 = 0};
		
		/* Restart the Phy Clock */ 
		pcgcctl.b.stoppclk = 1;
		dwc_modify_reg32(_core_if->pcgcctl, pcgcctl.d32, 0);
		UDELAY(10);
		
		/* Now wait for 70 ms. */ 
		hprt0.d32 = dwc_otg_read_hprt0(_core_if);
		DWC_DEBUGPL(DBG_ANY, "Resume: HPRT0=%0x\n", hprt0.d32);
		MDELAY(70);
		hprt0.b.prtres = 0;	/* Resume */
		dwc_write_reg32(_core_if->host_if->hprt0, hprt0.d32);
		DWC_DEBUGPL(DBG_ANY, "Clear Resume: HPRT0=%0x\n",
			     dwc_read_reg32(_core_if->host_if->hprt0));
	}
	
	/* Clear interrupt */ 
	gintsts.d32 = 0;
	gintsts.b.wkupintr = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/** 
 * This interrupt indicates that a device has been disconnected from
 * the root port. 
 */ 
int32_t dwc_otg_handle_disconnect_intr(dwc_otg_core_if_t * _core_if) 
{
	gintsts_data_t gintsts;
	printk(KERN_ERR "  Disconnect Detected Interrupt++ (%s) %s\n", 
		 (dwc_otg_is_host_mode(_core_if) ? "Host" : "Device"),
		 op_state_str(_core_if));
	DWC_DEBUGPL(DBG_ANY, "++Disconnect Detected Interrupt++ (%s) %s\n",
		     (dwc_otg_is_host_mode(_core_if) ? "Host" : "Device"),
		     op_state_str(_core_if));
	
/** @todo Consolidate this if statement. */ 
#ifndef CONFIG_DWC_HOST_ONLY
	if (_core_if->op_state == B_HOST) {
		
		/* If in device mode Disconnect and stop the HCD, then
		 * start the PCD. */ 
		hcd_disconnect(_core_if);
		pcd_start(_core_if);
		_core_if->op_state = B_PERIPHERAL;
	} else if (dwc_otg_is_device_mode(_core_if)) {
		gotgctl_data_t gotgctl = {.d32 = 0};
		gotgctl.d32 = dwc_read_reg32(&_core_if->core_global_regs->gotgctl);
		if (gotgctl.b.hstsethnpen == 1) {
			/* Do nothing, if HNP in process the OTG
			 * interrupt "Host Negotiation Detected"
			 * interrupt will do the mode switch.
			 */ 
		} else if (gotgctl.b.devhnpen == 0) {
			/* If in device mode Disconnect and stop the HCD, then
			 * start the PCD. */ 
			hcd_disconnect(_core_if);
			pcd_start(_core_if);
			_core_if->op_state = B_PERIPHERAL;
		} else {
			DWC_DEBUGPL(DBG_ANY, "!a_peripheral && !devhnpen\n");
		}
	} else {
		if (_core_if->op_state == A_HOST) {
			/* A-Cable still connected but device disconnected. */ 
			hcd_disconnect(_core_if);
		}
	}
	
#endif	/*  */
	gintsts.d32 = 0;
	gintsts.b.disconnect = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/**
 * This interrupt indicates that SUSPEND state has been detected on
 * the USB.
 * 
 * For HNP the USB Suspend interrupt signals the change from
 * "a_peripheral" to "a_host".
 *
 * When power management is enabled the core will be put in low power
 * mode.
 */ 
int32_t dwc_otg_handle_usb_suspend_intr(dwc_otg_core_if_t * _core_if) 
{
	dsts_data_t dsts;
	gintsts_data_t gintsts;
	DWC_DEBUGPL(DBG_ANY, "USB SUSPEND\n");
	if (dwc_otg_is_device_mode(_core_if)) {
		
		/* Check the Device status register to determine if the Suspend
		 * state is active. */ 
		dsts.d32 = dwc_read_reg32(&_core_if->dev_if->dev_global_regs->dsts);
		DWC_DEBUGPL(DBG_PCD, "DSTS=0x%0x\n", dsts.d32);
		DWC_DEBUGPL(DBG_PCD, "DSTS.Suspend Status=%d " 
			     "HWCFG4.power Optimize=%d\n", dsts.b.suspsts,
			     _core_if->hwcfg4.b.power_optimiz);
		
#ifdef PARTIAL_POWER_DOWN
/** @todo Add a module parameter for power management. */ 
		if (dsts.b.suspsts && _core_if->hwcfg4.b.power_optimiz) {
			pcgcctl_data_t power = {.d32 = 0};
			DWC_DEBUGPL(DBG_CIL, "suspend\n");
			power.b.pwrclmp = 1;
			dwc_write_reg32(_core_if->pcgcctl, power.d32);
			power.b.rstpdwnmodule = 1;
			dwc_modify_reg32(_core_if->pcgcctl, 0, power.d32);
			power.b.stoppclk = 1;
			dwc_modify_reg32(_core_if->pcgcctl, 0, power.d32);
		} else {
			DWC_DEBUGPL(DBG_ANY, "disconnect?\n");
		}
		
#endif	/*  */
		/* PCD callback for suspend. */ 
		pcd_suspend(_core_if);
	} else {
		if (_core_if->op_state == A_PERIPHERAL) {
			DWC_DEBUGPL(DBG_ANY, "a_peripheral->a_host\n");
			
			/* Clear the a_peripheral flag, back to a_host. */ 
			pcd_stop(_core_if);
			hcd_start(_core_if);
			_core_if->op_state = A_HOST;
		}
	}
	
	/* Clear interrupt */ 
	gintsts.d32 = 0;
	gintsts.b.usbsuspend = 1;
	dwc_write_reg32(&_core_if->core_global_regs->gintsts, gintsts.d32);
	return 1;
}

/**
 * This function returns the Core Interrupt register.
 */ 
static inline uint32_t dwc_otg_read_common_intr(dwc_otg_core_if_t * _core_if) 
{
	gintsts_data_t gintsts;
	gintmsk_data_t gintmsk;
	gintmsk_data_t gintmsk_common = {.d32 = 0};
	gintmsk_common.b.wkupintr = 1;
	gintmsk_common.b.sessreqintr = 1;
	gintmsk_common.b.conidstschng = 1;
	gintmsk_common.b.otgintr = 1;
	gintmsk_common.b.modemismatch = 1;
	gintmsk_common.b.disconnect = 1;
	gintmsk_common.b.usbsuspend = 1;
	
	/** @todo: The port interrupt occurs while in device 
     * mode. Added code to CIL to clear the interrupt for now! 
     */ 
	gintmsk_common.b.portintr = 1;
	gintsts.d32 = dwc_read_reg32(&_core_if->core_global_regs->gintsts);
	gintmsk.d32 = dwc_read_reg32(&_core_if->core_global_regs->gintmsk);
	
#ifdef CONFIG_DWC_DEBUG
	/* if any common interrupts set */ 
	if (gintsts.d32 & gintmsk_common.d32) {
		DWC_DEBUGPL(DBG_ANY, "gintsts=%08x  gintmsk=%08x\n",
			     gintsts.d32, gintmsk.d32);
	}
	
#endif	/*  */
	return ((gintsts.d32 & gintmsk.d32) & gintmsk_common.d32);
}

/**
 * Common interrupt handler.
 *
 * The common interrupts are those that occur in both Host and Device mode. 
 * This handler handles the following interrupts:
 * - Mode Mismatch Interrupt
 * - Disconnect Interrupt
 * - OTG Interrupt
 * - Connector ID Status Change Interrupt
 * - Session Request Interrupt.
 * - Resume / Remote Wakeup Detected Interrupt.
 * 
 */ 
extern int32_t dwc_otg_handle_common_intr(dwc_otg_core_if_t * _core_if) 
{
	int retval = 0;
	gintsts_data_t gintsts;
	gintsts.d32 = dwc_otg_read_common_intr(_core_if);
	if (gintsts.b.modemismatch) {
		retval |= dwc_otg_handle_mode_mismatch_intr(_core_if);
	}
	if (gintsts.b.otgintr) {
		retval |= dwc_otg_handle_otg_intr(_core_if);
	}
	if (gintsts.b.conidstschng) {
		retval |= dwc_otg_handle_conn_id_status_change_intr(_core_if);
	}
	if (gintsts.b.disconnect) {
		retval |= dwc_otg_handle_disconnect_intr(_core_if);
	}
	if (gintsts.b.sessreqintr) {
		retval |= dwc_otg_handle_session_req_intr(_core_if);
	}
	if (gintsts.b.wkupintr) {
		retval |= dwc_otg_handle_wakeup_detected_intr(_core_if);
	}
	if (gintsts.b.usbsuspend) {
		retval |= dwc_otg_handle_usb_suspend_intr(_core_if);
	}
	if (gintsts.b.portintr && dwc_otg_is_device_mode(_core_if)) {
		/* The port interrupt occurs while in device mode with HPRT0
		 * Port Enable/Disable.
		 */ 
		gintsts.d32 = 0;
		gintsts.b.portintr = 1;
		dwc_write_reg32(&_core_if->core_global_regs->gintsts,
				 gintsts.d32);
		retval |= 1;
	}
	return retval;
}