drivers/usb/dwc2/core_intr.c - linux - Git at Google

 /*
  * core_intr.c - DesignWare HS OTG Controller common interrupt handling
  *
  * Copyright (C) 2004-2013 Synopsys, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions, and the following disclaimer,
  *    without modification.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The names of the above-listed copyright holders may not be used
  *    to endorse or promote products derived from this software without
  *    specific prior written permission.
  *
  * ALTERNATIVELY, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") as published by the Free Software
  * Foundation; either version 2 of the License, or (at your option) any
  * later version.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS 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.
  */

 /*
  * This file contains the common interrupt handlers
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/usb.h>

 #include <linux/usb/hcd.h>
 #include <linux/usb/ch11.h>

 #include "core.h"
 #include "hcd.h"

 static const char *dwc2_op_state_str(struct dwc2_hsotg *hsotg)
 {
 	switch (hsotg->op_state) {
 	case OTG_STATE_A_HOST:
 		return "a_host";
 	case OTG_STATE_A_SUSPEND:
 		return "a_suspend";
 	case OTG_STATE_A_PERIPHERAL:
 		return "a_peripheral";
 	case OTG_STATE_B_PERIPHERAL:
 		return "b_peripheral";
 	case OTG_STATE_B_HOST:
 		return "b_host";
 	default:
 		return "unknown";
 	}
 }

 /**
  * dwc2_handle_usb_port_intr - handles OTG PRTINT interrupts.
  * When the PRTINT interrupt fires, there are certain status bits in the Host
  * Port that needs to get cleared.
  *
  * @hsotg: Programming view of DWC_otg controller
  */
 static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 hprt0 = readl(hsotg->regs + HPRT0);

 	if (hprt0 & HPRT0_ENACHG) {
 		hprt0 &= ~HPRT0_ENA;
 		writel(hprt0, hsotg->regs + HPRT0);
 	}

 	/* Clear interrupt */
 	writel(GINTSTS_PRTINT, hsotg->regs + GINTSTS);
 }

 /**
  * dwc2_handle_mode_mismatch_intr() - Logs a mode mismatch warning message
  *
  * @hsotg: Programming view of DWC_otg controller
  */
 static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
 {
 	dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
 		 dwc2_is_host_mode(hsotg) ? "Host" : "Device");

 	/* Clear interrupt */
 	writel(GINTSTS_MODEMIS, hsotg->regs + GINTSTS);
 }

 /**
  * dwc2_handle_otg_intr() - Handles the OTG Interrupts. It reads the OTG
  * Interrupt Register (GOTGINT) to determine what interrupt has occurred.
  *
  * @hsotg: Programming view of DWC_otg controller
  */
 static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 gotgint;
 	u32 gotgctl;
 	u32 gintmsk;

 	gotgint = readl(hsotg->regs + GOTGINT);
 	gotgctl = readl(hsotg->regs + GOTGCTL);
 	dev_dbg(hsotg->dev, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint,
 		dwc2_op_state_str(hsotg));

 	if (gotgint & GOTGINT_SES_END_DET) {
 		dev_dbg(hsotg->dev,
 			" ++OTG Interrupt: Session End Detected++ (%s)\n",
 			dwc2_op_state_str(hsotg));
 		gotgctl = readl(hsotg->regs + GOTGCTL);

 		if (dwc2_is_device_mode(hsotg))
 			s3c_hsotg_disconnect(hsotg);

 		if (hsotg->op_state == OTG_STATE_B_HOST) {
 			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
 		} else {
 			/*
 			 * If not B_HOST and Device HNP still set, HNP did
 			 * not succeed!
 			 */
 			if (gotgctl & GOTGCTL_DEVHNPEN) {
 				dev_dbg(hsotg->dev, "Session End Detected\n");
 				dev_err(hsotg->dev,
 					"Device Not Connected/Responding!\n");
 			}

 			/*
 			 * If Session End Detected the B-Cable has been
 			 * disconnected
 			 */
 			/* Reset to a clean state */
 			hsotg->lx_state = DWC2_L0;
 		}

 		gotgctl = readl(hsotg->regs + GOTGCTL);
 		gotgctl &= ~GOTGCTL_DEVHNPEN;
 		writel(gotgctl, hsotg->regs + GOTGCTL);
 	}

 	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
 		dev_dbg(hsotg->dev,
 			" ++OTG Interrupt: Session Request Success Status Change++\n");
 		gotgctl = readl(hsotg->regs + GOTGCTL);
 		if (gotgctl & GOTGCTL_SESREQSCS) {
 			if (hsotg->core_params->phy_type ==
 					DWC2_PHY_TYPE_PARAM_FS
 			    && hsotg->core_params->i2c_enable > 0) {
 				hsotg->srp_success = 1;
 			} else {
 				/* Clear Session Request */
 				gotgctl = readl(hsotg->regs + GOTGCTL);
 				gotgctl &= ~GOTGCTL_SESREQ;
 				writel(gotgctl, hsotg->regs + GOTGCTL);
 			}
 		}
 	}

 	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
 		/*
 		 * Print statements during the HNP interrupt handling
 		 * can cause it to fail
 		 */
 		gotgctl = readl(hsotg->regs + GOTGCTL);
 		/*
 		 * WA for 3.00a- HW is not setting cur_mode, even sometimes
 		 * this does not help
 		 */
 		if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
 			udelay(100);
 		if (gotgctl & GOTGCTL_HSTNEGSCS) {
 			if (dwc2_is_host_mode(hsotg)) {
 				hsotg->op_state = OTG_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 = readl(hsotg->regs + GINTMSK);
 				gintmsk &= ~GINTSTS_SOF;
 				writel(gintmsk, hsotg->regs + GINTMSK);

 				/*
 				 * Call callback function with spin lock
 				 * released
 				 */
 				spin_unlock(&hsotg->lock);

 				/* Initialize the Core for Host mode */
 				dwc2_hcd_start(hsotg);
 				spin_lock(&hsotg->lock);
 				hsotg->op_state = OTG_STATE_B_HOST;
 			}
 		} else {
 			gotgctl = readl(hsotg->regs + GOTGCTL);
 			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
 			writel(gotgctl, hsotg->regs + GOTGCTL);
 			dev_dbg(hsotg->dev, "HNP Failed\n");
 			dev_err(hsotg->dev,
 				"Device Not Connected/Responding\n");
 		}
 	}

 	if (gotgint & GOTGINT_HST_NEG_DET) {
 		/*
 		 * 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.
 		 */
 		dev_dbg(hsotg->dev,
 			" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
 			(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
 		if (dwc2_is_device_mode(hsotg)) {
 			dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
 				hsotg->op_state);
 			spin_unlock(&hsotg->lock);
 			dwc2_hcd_disconnect(hsotg);
 			spin_lock(&hsotg->lock);
 			hsotg->op_state = OTG_STATE_A_PERIPHERAL;
 		} else {
 			/* Need to disable SOF interrupt immediately */
 			gintmsk = readl(hsotg->regs + GINTMSK);
 			gintmsk &= ~GINTSTS_SOF;
 			writel(gintmsk, hsotg->regs + GINTMSK);
 			spin_unlock(&hsotg->lock);
 			dwc2_hcd_start(hsotg);
 			spin_lock(&hsotg->lock);
 			hsotg->op_state = OTG_STATE_A_HOST;
 		}
 	}

 	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
 		dev_dbg(hsotg->dev,
 			" ++OTG Interrupt: A-Device Timeout Change++\n");
 	if (gotgint & GOTGINT_DBNCE_DONE)
 		dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");

 	/* Clear GOTGINT */
 	writel(gotgint, hsotg->regs + GOTGINT);
 }

 /**
  * dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
  * Change Interrupt
  *
  * @hsotg: Programming view of DWC_otg controller
  *
  * Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
  * Device to Host Mode transition or a Host to Device Mode transition. This only
  * occurs when the cable is connected/removed from the PHY connector.
  */
 static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 gintmsk = readl(hsotg->regs + GINTMSK);

 	/* Need to disable SOF interrupt immediately */
 	gintmsk &= ~GINTSTS_SOF;
 	writel(gintmsk, hsotg->regs + GINTMSK);

 	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++  (%s)\n",
 		dwc2_is_host_mode(hsotg) ? "Host" : "Device");

 	/*
 	 * Need to schedule a work, as there are possible DELAY function calls.
 	 * Release lock before scheduling workq as it holds spinlock during
 	 * scheduling.
 	 */
 	if (hsotg->wq_otg) {
 		spin_unlock(&hsotg->lock);
 		queue_work(hsotg->wq_otg, &hsotg->wf_otg);
 		spin_lock(&hsotg->lock);
 	}

 	/* Clear interrupt */
 	writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
 }

 /**
  * dwc2_handle_session_req_intr() - 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
  *
  * @hsotg: Programming view of DWC_otg controller
  *
  * This handler responds by turning on bus power. If the DWC_otg controller is
  * in low power mode, this handler brings the controller out of low power mode
  * before turning on bus power.
  */
 static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
 {
 	dev_dbg(hsotg->dev, "++Session Request Interrupt++\n");

 	/* Clear interrupt */
 	writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);

 	/*
 	 * Report disconnect if there is any previous session established
 	 */
 	if (dwc2_is_device_mode(hsotg))
 		s3c_hsotg_disconnect(hsotg);
 }

 /*
  * 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.
  */
 static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
 {
 	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);

 	if (dwc2_is_device_mode(hsotg)) {
 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", readl(hsotg->regs + DSTS));
 		if (hsotg->lx_state == DWC2_L2) {
 			u32 dctl = readl(hsotg->regs + DCTL);

 			/* Clear Remote Wakeup Signaling */
 			dctl &= ~DCTL_RMTWKUPSIG;
 			writel(dctl, hsotg->regs + DCTL);
 		}
 		/* Change to L0 state */
 		hsotg->lx_state = DWC2_L0;
 	} else {
 		if (hsotg->lx_state != DWC2_L1) {
 			u32 pcgcctl = readl(hsotg->regs + PCGCTL);

 			/* Restart the Phy Clock */
 			pcgcctl &= ~PCGCTL_STOPPCLK;
 			writel(pcgcctl, hsotg->regs + PCGCTL);
 			mod_timer(&hsotg->wkp_timer,
 				  jiffies + msecs_to_jiffies(71));
 		} else {
 			/* Change to L0 state */
 			hsotg->lx_state = DWC2_L0;
 		}
 	}

 	/* Clear interrupt */
 	writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
 }

 /*
  * This interrupt indicates that a device has been disconnected from the
  * root port
  */
 static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
 {
 	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
 		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
 		dwc2_op_state_str(hsotg));

 	/* Change to L3 (OFF) state */
 	hsotg->lx_state = DWC2_L3;

 	writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
 }

 /*
  * 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.
  */
 static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 dsts;

 	dev_dbg(hsotg->dev, "USB SUSPEND\n");

 	if (dwc2_is_device_mode(hsotg)) {
 		/*
 		 * Check the Device status register to determine if the Suspend
 		 * state is active
 		 */
 		dsts = readl(hsotg->regs + DSTS);
 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
 		dev_dbg(hsotg->dev,
 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
 			!!(dsts & DSTS_SUSPSTS),
 			hsotg->hw_params.power_optimized);
 	} else {
 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");

 			/* Clear the a_peripheral flag, back to a_host */
 			spin_unlock(&hsotg->lock);
 			dwc2_hcd_start(hsotg);
 			spin_lock(&hsotg->lock);
 			hsotg->op_state = OTG_STATE_A_HOST;
 		}
 	}

 	/* Change to L2 (suspend) state */
 	hsotg->lx_state = DWC2_L2;

 	/* Clear interrupt */
 	writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
 }

 #define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
 			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
 			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
 			 GINTSTS_USBSUSP | GINTSTS_PRTINT)

 /*
  * This function returns the Core Interrupt register
  */
 static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 gintsts;
 	u32 gintmsk;
 	u32 gahbcfg;
 	u32 gintmsk_common = GINTMSK_COMMON;

 	gintsts = readl(hsotg->regs + GINTSTS);
 	gintmsk = readl(hsotg->regs + GINTMSK);
 	gahbcfg = readl(hsotg->regs + GAHBCFG);

 	/* If any common interrupts set */
 	if (gintsts & gintmsk_common)
 		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
 			gintsts, gintmsk);

 	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
 		return gintsts & gintmsk & gintmsk_common;
 	else
 		return 0;
 }

 /*
  * 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
  * - OTG Interrupt
  * - Connector ID Status Change Interrupt
  * - Disconnect Interrupt
  * - Session Request Interrupt
  * - Resume / Remote Wakeup Detected Interrupt
  * - Suspend Interrupt
  */
 irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
 {
 	struct dwc2_hsotg *hsotg = dev;
 	u32 gintsts;
 	irqreturn_t retval = IRQ_NONE;

 	spin_lock(&hsotg->lock);

 	if (!dwc2_is_controller_alive(hsotg)) {
 		dev_warn(hsotg->dev, "Controller is dead\n");
 		goto out;
 	}

 	gintsts = dwc2_read_common_intr(hsotg);
 	if (gintsts & ~GINTSTS_PRTINT)
 		retval = IRQ_HANDLED;

 	if (gintsts & GINTSTS_MODEMIS)
 		dwc2_handle_mode_mismatch_intr(hsotg);
 	if (gintsts & GINTSTS_OTGINT)
 		dwc2_handle_otg_intr(hsotg);
 	if (gintsts & GINTSTS_CONIDSTSCHNG)
 		dwc2_handle_conn_id_status_change_intr(hsotg);
 	if (gintsts & GINTSTS_DISCONNINT)
 		dwc2_handle_disconnect_intr(hsotg);
 	if (gintsts & GINTSTS_SESSREQINT)
 		dwc2_handle_session_req_intr(hsotg);
 	if (gintsts & GINTSTS_WKUPINT)
 		dwc2_handle_wakeup_detected_intr(hsotg);
 	if (gintsts & GINTSTS_USBSUSP)
 		dwc2_handle_usb_suspend_intr(hsotg);

 	if (gintsts & GINTSTS_PRTINT) {
 		/*
 		 * The port interrupt occurs while in device mode with HPRT0
 		 * Port Enable/Disable
 		 */
 		if (dwc2_is_device_mode(hsotg)) {
 			dev_dbg(hsotg->dev,
 				" --Port interrupt received in Device mode--\n");
 			dwc2_handle_usb_port_intr(hsotg);
 			retval = IRQ_HANDLED;
 		}
 	}

 out:
 	spin_unlock(&hsotg->lock);
 	return retval;
 }
 EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);
	/*
	* core_intr.c - DesignWare HS OTG Controller common interrupt handling
	*
	* Copyright (C) 2004-2013 Synopsys, Inc.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions, and the following disclaimer,
	* without modification.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. The names of the above-listed copyright holders may not be used
	* to endorse or promote products derived from this software without
	* specific prior written permission.
	*
	* ALTERNATIVELY, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") as published by the Free Software
	* Foundation; either version 2 of the License, or (at your option) any
	* later version.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
	* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS 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.
	*/

	/*
	* This file contains the common interrupt handlers
	*/
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/spinlock.h>
	#include <linux/interrupt.h>
	#include <linux/dma-mapping.h>
	#include <linux/io.h>
	#include <linux/slab.h>
	#include <linux/usb.h>

	#include <linux/usb/hcd.h>
	#include <linux/usb/ch11.h>

	#include "core.h"
	#include "hcd.h"

	static const char dwc2_op_state_str(struct dwc2_hsotg hsotg)
	{
	switch (hsotg->op_state) {
	case OTG_STATE_A_HOST:
	return "a_host";
	case OTG_STATE_A_SUSPEND:
	return "a_suspend";
	case OTG_STATE_A_PERIPHERAL:
	return "a_peripheral";
	case OTG_STATE_B_PERIPHERAL:
	return "b_peripheral";
	case OTG_STATE_B_HOST:
	return "b_host";
	default:
	return "unknown";
	}
	}

	/**
	* dwc2_handle_usb_port_intr - handles OTG PRTINT interrupts.
	* When the PRTINT interrupt fires, there are certain status bits in the Host
	* Port that needs to get cleared.
	*
	* @hsotg: Programming view of DWC_otg controller
	*/
	static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
	{
	u32 hprt0 = readl(hsotg->regs + HPRT0);

	if (hprt0 & HPRT0_ENACHG) {
	hprt0 &= ~HPRT0_ENA;
	writel(hprt0, hsotg->regs + HPRT0);
	}

	/* Clear interrupt */
	writel(GINTSTS_PRTINT, hsotg->regs + GINTSTS);
	}

	/**
	* dwc2_handle_mode_mismatch_intr() - Logs a mode mismatch warning message
	*
	* @hsotg: Programming view of DWC_otg controller
	*/
	static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
	{
	dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
	dwc2_is_host_mode(hsotg) ? "Host" : "Device");

	/* Clear interrupt */
	writel(GINTSTS_MODEMIS, hsotg->regs + GINTSTS);
	}

	/**
	* dwc2_handle_otg_intr() - Handles the OTG Interrupts. It reads the OTG
	* Interrupt Register (GOTGINT) to determine what interrupt has occurred.
	*
	* @hsotg: Programming view of DWC_otg controller
	*/
	static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
	{
	u32 gotgint;
	u32 gotgctl;
	u32 gintmsk;

	gotgint = readl(hsotg->regs + GOTGINT);
	gotgctl = readl(hsotg->regs + GOTGCTL);
	dev_dbg(hsotg->dev, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint,
	dwc2_op_state_str(hsotg));

	if (gotgint & GOTGINT_SES_END_DET) {
	dev_dbg(hsotg->dev,
	" ++OTG Interrupt: Session End Detected++ (%s)\n",
	dwc2_op_state_str(hsotg));
	gotgctl = readl(hsotg->regs + GOTGCTL);

	if (dwc2_is_device_mode(hsotg))
	s3c_hsotg_disconnect(hsotg);

	if (hsotg->op_state == OTG_STATE_B_HOST) {
	hsotg->op_state = OTG_STATE_B_PERIPHERAL;
	} else {
	/*
	* If not B_HOST and Device HNP still set, HNP did
	* not succeed!
	*/
	if (gotgctl & GOTGCTL_DEVHNPEN) {
	dev_dbg(hsotg->dev, "Session End Detected\n");
	dev_err(hsotg->dev,
	"Device Not Connected/Responding!\n");
	}

	/*
	* If Session End Detected the B-Cable has been
	* disconnected
	*/
	/* Reset to a clean state */
	hsotg->lx_state = DWC2_L0;
	}

	gotgctl = readl(hsotg->regs + GOTGCTL);
	gotgctl &= ~GOTGCTL_DEVHNPEN;
	writel(gotgctl, hsotg->regs + GOTGCTL);
	}

	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
	dev_dbg(hsotg->dev,
	" ++OTG Interrupt: Session Request Success Status Change++\n");
	gotgctl = readl(hsotg->regs + GOTGCTL);
	if (gotgctl & GOTGCTL_SESREQSCS) {
	if (hsotg->core_params->phy_type ==
	DWC2_PHY_TYPE_PARAM_FS
	&& hsotg->core_params->i2c_enable > 0) {
	hsotg->srp_success = 1;
	} else {
	/* Clear Session Request */
	gotgctl = readl(hsotg->regs + GOTGCTL);
	gotgctl &= ~GOTGCTL_SESREQ;
	writel(gotgctl, hsotg->regs + GOTGCTL);
	}
	}
	}

	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
	/*
	* Print statements during the HNP interrupt handling
	* can cause it to fail
	*/
	gotgctl = readl(hsotg->regs + GOTGCTL);
	/*
	* WA for 3.00a- HW is not setting cur_mode, even sometimes
	* this does not help
	*/
	if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
	udelay(100);
	if (gotgctl & GOTGCTL_HSTNEGSCS) {
	if (dwc2_is_host_mode(hsotg)) {
	hsotg->op_state = OTG_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 = readl(hsotg->regs + GINTMSK);
	gintmsk &= ~GINTSTS_SOF;
	writel(gintmsk, hsotg->regs + GINTMSK);

	/*
	* Call callback function with spin lock
	* released
	*/
	spin_unlock(&hsotg->lock);

	/* Initialize the Core for Host mode */
	dwc2_hcd_start(hsotg);
	spin_lock(&hsotg->lock);
	hsotg->op_state = OTG_STATE_B_HOST;
	}
	} else {
	gotgctl = readl(hsotg->regs + GOTGCTL);
	gotgctl &= ~(GOTGCTL_HNPREQ \| GOTGCTL_DEVHNPEN);
	writel(gotgctl, hsotg->regs + GOTGCTL);
	dev_dbg(hsotg->dev, "HNP Failed\n");
	dev_err(hsotg->dev,
	"Device Not Connected/Responding\n");
	}
	}

	if (gotgint & GOTGINT_HST_NEG_DET) {
	/*
	* 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.
	*/
	dev_dbg(hsotg->dev,
	" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
	(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
	if (dwc2_is_device_mode(hsotg)) {
	dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
	hsotg->op_state);
	spin_unlock(&hsotg->lock);
	dwc2_hcd_disconnect(hsotg);
	spin_lock(&hsotg->lock);
	hsotg->op_state = OTG_STATE_A_PERIPHERAL;
	} else {
	/* Need to disable SOF interrupt immediately */
	gintmsk = readl(hsotg->regs + GINTMSK);
	gintmsk &= ~GINTSTS_SOF;
	writel(gintmsk, hsotg->regs + GINTMSK);
	spin_unlock(&hsotg->lock);
	dwc2_hcd_start(hsotg);
	spin_lock(&hsotg->lock);
	hsotg->op_state = OTG_STATE_A_HOST;
	}
	}

	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
	dev_dbg(hsotg->dev,
	" ++OTG Interrupt: A-Device Timeout Change++\n");
	if (gotgint & GOTGINT_DBNCE_DONE)
	dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");

	/* Clear GOTGINT */
	writel(gotgint, hsotg->regs + GOTGINT);
	}

	/**
	* dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
	* Change Interrupt
	*
	* @hsotg: Programming view of DWC_otg controller
	*
	* Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
	* Device to Host Mode transition or a Host to Device Mode transition. This only
	* occurs when the cable is connected/removed from the PHY connector.
	*/
	static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
	{
	u32 gintmsk = readl(hsotg->regs + GINTMSK);

	/* Need to disable SOF interrupt immediately */
	gintmsk &= ~GINTSTS_SOF;
	writel(gintmsk, hsotg->regs + GINTMSK);

	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++ (%s)\n",
	dwc2_is_host_mode(hsotg) ? "Host" : "Device");

	/*
	* Need to schedule a work, as there are possible DELAY function calls.
	* Release lock before scheduling workq as it holds spinlock during
	* scheduling.
	*/
	if (hsotg->wq_otg) {
	spin_unlock(&hsotg->lock);
	queue_work(hsotg->wq_otg, &hsotg->wf_otg);
	spin_lock(&hsotg->lock);
	}

	/* Clear interrupt */
	writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
	}

	/**
	* dwc2_handle_session_req_intr() - 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
	*
	* @hsotg: Programming view of DWC_otg controller
	*
	* This handler responds by turning on bus power. If the DWC_otg controller is
	* in low power mode, this handler brings the controller out of low power mode
	* before turning on bus power.
	*/
	static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
	{
	dev_dbg(hsotg->dev, "++Session Request Interrupt++\n");

	/* Clear interrupt */
	writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);

	/*
	* Report disconnect if there is any previous session established
	*/
	if (dwc2_is_device_mode(hsotg))
	s3c_hsotg_disconnect(hsotg);
	}

	/*
	* 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.
	*/
	static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
	{
	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);

	if (dwc2_is_device_mode(hsotg)) {
	dev_dbg(hsotg->dev, "DSTS=0x%0x\n", readl(hsotg->regs + DSTS));
	if (hsotg->lx_state == DWC2_L2) {
	u32 dctl = readl(hsotg->regs + DCTL);

	/* Clear Remote Wakeup Signaling */
	dctl &= ~DCTL_RMTWKUPSIG;
	writel(dctl, hsotg->regs + DCTL);
	}
	/* Change to L0 state */
	hsotg->lx_state = DWC2_L0;
	} else {
	if (hsotg->lx_state != DWC2_L1) {
	u32 pcgcctl = readl(hsotg->regs + PCGCTL);

	/* Restart the Phy Clock */
	pcgcctl &= ~PCGCTL_STOPPCLK;
	writel(pcgcctl, hsotg->regs + PCGCTL);
	mod_timer(&hsotg->wkp_timer,
	jiffies + msecs_to_jiffies(71));
	} else {
	/* Change to L0 state */
	hsotg->lx_state = DWC2_L0;
	}
	}

	/* Clear interrupt */
	writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
	}

	/*
	* This interrupt indicates that a device has been disconnected from the
	* root port
	*/
	static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
	{
	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
	dwc2_is_host_mode(hsotg) ? "Host" : "Device",
	dwc2_op_state_str(hsotg));

	/* Change to L3 (OFF) state */
	hsotg->lx_state = DWC2_L3;

	writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
	}

	/*
	* 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.
	*/
	static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
	{
	u32 dsts;

	dev_dbg(hsotg->dev, "USB SUSPEND\n");

	if (dwc2_is_device_mode(hsotg)) {
	/*
	* Check the Device status register to determine if the Suspend
	* state is active
	*/
	dsts = readl(hsotg->regs + DSTS);
	dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
	dev_dbg(hsotg->dev,
	"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
	!!(dsts & DSTS_SUSPSTS),
	hsotg->hw_params.power_optimized);
	} else {
	if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
	dev_dbg(hsotg->dev, "a_peripheral->a_host\n");

	/* Clear the a_peripheral flag, back to a_host */
	spin_unlock(&hsotg->lock);
	dwc2_hcd_start(hsotg);
	spin_lock(&hsotg->lock);
	hsotg->op_state = OTG_STATE_A_HOST;
	}
	}

	/* Change to L2 (suspend) state */
	hsotg->lx_state = DWC2_L2;

	/* Clear interrupt */
	writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
	}

	#define GINTMSK_COMMON (GINTSTS_WKUPINT \| GINTSTS_SESSREQINT \| \
	GINTSTS_CONIDSTSCHNG \| GINTSTS_OTGINT \| \
	GINTSTS_MODEMIS \| GINTSTS_DISCONNINT \| \
	GINTSTS_USBSUSP \| GINTSTS_PRTINT)

	/*
	* This function returns the Core Interrupt register
	*/
	static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
	{
	u32 gintsts;
	u32 gintmsk;
	u32 gahbcfg;
	u32 gintmsk_common = GINTMSK_COMMON;

	gintsts = readl(hsotg->regs + GINTSTS);
	gintmsk = readl(hsotg->regs + GINTMSK);
	gahbcfg = readl(hsotg->regs + GAHBCFG);

	/* If any common interrupts set */
	if (gintsts & gintmsk_common)
	dev_dbg(hsotg->dev, "gintsts=%08x gintmsk=%08x\n",
	gintsts, gintmsk);

	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
	return gintsts & gintmsk & gintmsk_common;
	else
	return 0;
	}

	/*
	* 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
	* - OTG Interrupt
	* - Connector ID Status Change Interrupt
	* - Disconnect Interrupt
	* - Session Request Interrupt
	* - Resume / Remote Wakeup Detected Interrupt
	* - Suspend Interrupt
	*/
	irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
	{
	struct dwc2_hsotg *hsotg = dev;
	u32 gintsts;
	irqreturn_t retval = IRQ_NONE;

	spin_lock(&hsotg->lock);

	if (!dwc2_is_controller_alive(hsotg)) {
	dev_warn(hsotg->dev, "Controller is dead\n");
	goto out;
	}

	gintsts = dwc2_read_common_intr(hsotg);
	if (gintsts & ~GINTSTS_PRTINT)
	retval = IRQ_HANDLED;

	if (gintsts & GINTSTS_MODEMIS)
	dwc2_handle_mode_mismatch_intr(hsotg);
	if (gintsts & GINTSTS_OTGINT)
	dwc2_handle_otg_intr(hsotg);
	if (gintsts & GINTSTS_CONIDSTSCHNG)
	dwc2_handle_conn_id_status_change_intr(hsotg);
	if (gintsts & GINTSTS_DISCONNINT)
	dwc2_handle_disconnect_intr(hsotg);
	if (gintsts & GINTSTS_SESSREQINT)
	dwc2_handle_session_req_intr(hsotg);
	if (gintsts & GINTSTS_WKUPINT)
	dwc2_handle_wakeup_detected_intr(hsotg);
	if (gintsts & GINTSTS_USBSUSP)
	dwc2_handle_usb_suspend_intr(hsotg);

	if (gintsts & GINTSTS_PRTINT) {
	/*
	* The port interrupt occurs while in device mode with HPRT0
	* Port Enable/Disable
	*/
	if (dwc2_is_device_mode(hsotg)) {
	dev_dbg(hsotg->dev,
	" --Port interrupt received in Device mode--\n");
	dwc2_handle_usb_port_intr(hsotg);
	retval = IRQ_HANDLED;
	}
	}

	out:
	spin_unlock(&hsotg->lock);
	return retval;
	}
	EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);