drivers/usb/cdns3/drd.c - SHIFTPHONES/mainline/linux - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Cadence USBSS DRD Driver.
  *
  * Copyright (C) 2018-2019 Cadence.
  * Copyright (C) 2019 Texas Instruments
  *
  * Author: Pawel Laszczak <pawell@cadence.com>
  *         Roger Quadros <rogerq@ti.com>
  *
  *
  */
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/usb/otg.h>

 #include "gadget.h"
 #include "drd.h"
 #include "core.h"

 /**
  * cdns3_set_mode - change mode of OTG Core
  * @cdns: pointer to context structure
  * @mode: selected mode from cdns_role
  *
  * Returns 0 on success otherwise negative errno
  */
 int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
 {
 	int ret = 0;
 	u32 reg;

 	cdns->current_dr_mode = mode;

 	switch (mode) {
 	case USB_DR_MODE_PERIPHERAL:
 		break;
 	case USB_DR_MODE_HOST:
 		break;
 	case USB_DR_MODE_OTG:
 		dev_dbg(cdns->dev, "Set controller to OTG mode\n");
 		if (cdns->version == CDNS3_CONTROLLER_V1) {
 			reg = readl(&cdns->otg_v1_regs->override);
 			reg |= OVERRIDE_IDPULLUP;
 			writel(reg, &cdns->otg_v1_regs->override);
 		} else {
 			reg = readl(&cdns->otg_v0_regs->ctrl1);
 			reg |= OVERRIDE_IDPULLUP_V0;
 			writel(reg, &cdns->otg_v0_regs->ctrl1);
 		}

 		/*
 		 * Hardware specification says: "ID_VALUE must be valid within
 		 * 50ms after idpullup is set to '1" so driver must wait
 		 * 50ms before reading this pin.
 		 */
 		usleep_range(50000, 60000);
 		break;
 	default:
 		cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;
 		dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
 		return -EINVAL;
 	}

 	return ret;
 }

 int cdns3_get_id(struct cdns3 *cdns)
 {
 	int id;

 	id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
 	dev_dbg(cdns->dev, "OTG ID: %d", id);

 	return id;
 }

 int cdns3_get_vbus(struct cdns3 *cdns)
 {
 	int vbus;

 	vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
 	dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
 	return vbus;
 }

 int cdns3_is_host(struct cdns3 *cdns)
 {
 	if (cdns->current_dr_mode == USB_DR_MODE_HOST)
 		return 1;
 	else if (!cdns3_get_id(cdns))
 		return 1;

 	return 0;
 }

 int cdns3_is_device(struct cdns3 *cdns)
 {
 	if (cdns->current_dr_mode == USB_DR_MODE_PERIPHERAL)
 		return 1;
 	else if (cdns->current_dr_mode == USB_DR_MODE_OTG)
 		if (cdns3_get_id(cdns))
 			return 1;

 	return 0;
 }

 /**
  * cdns3_otg_disable_irq - Disable all OTG interrupts
  * @cdns: Pointer to controller context structure
  */
 static void cdns3_otg_disable_irq(struct cdns3 *cdns)
 {
 	writel(0, &cdns->otg_regs->ien);
 }

 /**
  * cdns3_otg_enable_irq - enable id and sess_valid interrupts
  * @cdns: Pointer to controller context structure
  */
 static void cdns3_otg_enable_irq(struct cdns3 *cdns)
 {
 	writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
 	       OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_regs->ien);
 }

 /**
  * cdns3_drd_switch_host - start/stop host
  * @cdns: Pointer to controller context structure
  * @on: 1 for start, 0 for stop
  *
  * Returns 0 on success otherwise negative errno
  */
 int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
 {
 	int ret;
 	u32 reg = OTGCMD_OTG_DIS;

 	/* switch OTG core */
 	if (on) {
 		writel(OTGCMD_HOST_BUS_REQ | reg, &cdns->otg_regs->cmd);

 		dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
 		ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_XHCI_READY,
 				      OTGSTS_XHCI_READY, 100000);

 		if (ret) {
 			dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
 			return ret;
 		}
 	} else {
 		writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
 		       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
 		       &cdns->otg_regs->cmd);
 		/* Waiting till H_IDLE state.*/
 		cdns3_handshake(&cdns->otg_regs->state,
 				OTGSTATE_HOST_STATE_MASK,
 				0, 2000000);
 	}

 	return 0;
 }

 /**
  * cdns3_drd_switch_gadget - start/stop gadget
  * @cdns: Pointer to controller context structure
  * @on: 1 for start, 0 for stop
  *
  * Returns 0 on success otherwise negative errno
  */
 int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
 {
 	int ret;
 	u32 reg = OTGCMD_OTG_DIS;

 	/* switch OTG core */
 	if (on) {
 		writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);

 		dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");

 		ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_DEV_READY,
 				      OTGSTS_DEV_READY, 100000);

 		if (ret) {
 			dev_err(cdns->dev, "timeout waiting for dev_ready\n");
 			return ret;
 		}
 	} else {
 		/*
 		 * driver should wait at least 10us after disabling Device
 		 * before turning-off Device (DEV_BUS_DROP)
 		 */
 		usleep_range(20, 30);
 		writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
 		       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
 		       &cdns->otg_regs->cmd);
 		/* Waiting till DEV_IDLE state.*/
 		cdns3_handshake(&cdns->otg_regs->state, OTGSTATE_DEV_STATE_MASK,
 				0, 2000000);
 	}

 	return 0;
 }

 /**
  * cdns3_init_otg_mode - initialize drd controller
  * @cdns: Pointer to controller context structure
  *
  * Returns 0 on success otherwise negative errno
  */
 static int cdns3_init_otg_mode(struct cdns3 *cdns)
 {
 	int ret = 0;

 	cdns3_otg_disable_irq(cdns);
 	/* clear all interrupts */
 	writel(~0, &cdns->otg_regs->ivect);

 	ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
 	if (ret)
 		return ret;

 	cdns3_otg_enable_irq(cdns);
 	return ret;
 }

 /**
  * cdns3_drd_update_mode - initialize mode of operation
  * @cdns: Pointer to controller context structure
  *
  * Returns 0 on success otherwise negative errno
  */
 int cdns3_drd_update_mode(struct cdns3 *cdns)
 {
 	int ret = 0;

 	if (cdns->desired_dr_mode == cdns->current_dr_mode)
 		return ret;

 	switch (cdns->desired_dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
 		ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
 		break;
 	case USB_DR_MODE_HOST:
 		ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
 		break;
 	case USB_DR_MODE_OTG:
 		ret = cdns3_init_otg_mode(cdns);
 		break;
 	default:
 		dev_err(cdns->dev, "Unsupported mode of operation %d\n",
 			cdns->dr_mode);
 		return -EINVAL;
 	}

 	return ret;
 }

 /**
  * cdns3_drd_irq - interrupt handler for OTG events
  *
  * @irq: irq number for cdns3 core device
  * @data: structure of cdns3
  *
  * Returns IRQ_HANDLED or IRQ_NONE
  */
 static irqreturn_t cdns3_drd_irq(int irq, void *data)
 {
 	irqreturn_t ret = IRQ_NONE;
 	struct cdns3 *cdns = data;
 	u32 reg;

 	if (cdns->dr_mode != USB_DR_MODE_OTG)
 		return ret;

 	reg = readl(&cdns->otg_regs->ivect);

 	if (!reg)
 		return ret;

 	if (reg & OTGIEN_ID_CHANGE_INT) {
 		dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
 			cdns3_get_id(cdns));

 		ret = IRQ_HANDLED;
 	}

 	if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
 		dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
 			cdns3_get_vbus(cdns));

 		ret = IRQ_HANDLED;
 	}

 	if (ret == IRQ_HANDLED)
 		queue_work(system_freezable_wq, &cdns->role_switch_wq);

 	writel(~0, &cdns->otg_regs->ivect);
 	return ret;
 }

 int cdns3_drd_init(struct cdns3 *cdns)
 {
 	void __iomem *regs;
 	int ret = 0;
 	u32 state;

 	regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);

 	/* Detection of DRD version. Controller has been released
 	 * in two versions. Both are similar, but they have same changes
 	 * in register maps.
 	 * The first register in old version is command register and it's read
 	 * only, so driver should read 0 from it. On the other hand, in v1
 	 * the first register contains device ID number which is not set to 0.
 	 * Driver uses this fact to detect the proper version of
 	 * controller.
 	 */
 	cdns->otg_v0_regs = regs;
 	if (!readl(&cdns->otg_v0_regs->cmd)) {
 		cdns->version  = CDNS3_CONTROLLER_V0;
 		cdns->otg_v1_regs = NULL;
 		cdns->otg_regs = regs;
 		writel(1, &cdns->otg_v0_regs->simulate);
 		dev_info(cdns->dev, "DRD version v0 (%08x)\n",
 			 readl(&cdns->otg_v0_regs->version));
 	} else {
 		cdns->otg_v0_regs = NULL;
 		cdns->otg_v1_regs = regs;
 		cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
 		cdns->version  = CDNS3_CONTROLLER_V1;
 		writel(1, &cdns->otg_v1_regs->simulate);
 		dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
 			 readl(&cdns->otg_v1_regs->did),
 			 readl(&cdns->otg_v1_regs->rid));
 	}

 	state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));

 	/* Update dr_mode according to STRAP configuration. */
 	cdns->dr_mode = USB_DR_MODE_OTG;
 	if (state == OTGSTS_STRAP_HOST) {
 		dev_dbg(cdns->dev, "Controller strapped to HOST\n");
 		cdns->dr_mode = USB_DR_MODE_HOST;
 	} else if (state == OTGSTS_STRAP_GADGET) {
 		dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
 		cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
 	}

 	cdns->desired_dr_mode = cdns->dr_mode;
 	cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;

 	ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
 					cdns3_drd_irq,
 					NULL, IRQF_SHARED,
 					dev_name(cdns->dev), cdns);

 	if (ret) {
 		dev_err(cdns->dev, "couldn't get otg_irq\n");
 		return ret;
 	}

 	state = readl(&cdns->otg_regs->sts);
 	if (OTGSTS_OTG_NRDY(state) != 0) {
 		dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
 		return -ENODEV;
 	}

 	return ret;
 }

 int cdns3_drd_exit(struct cdns3 *cdns)
 {
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Cadence USBSS DRD Driver.
	*
	* Copyright (C) 2018-2019 Cadence.
	* Copyright (C) 2019 Texas Instruments
	*
	* Author: Pawel Laszczak <pawell@cadence.com>
	* Roger Quadros <rogerq@ti.com>
	*
	*
	*/
	#include <linux/kernel.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>
	#include <linux/usb/otg.h>

	#include "gadget.h"
	#include "drd.h"
	#include "core.h"

	/**
	* cdns3_set_mode - change mode of OTG Core
	* @cdns: pointer to context structure
	* @mode: selected mode from cdns_role
	*
	* Returns 0 on success otherwise negative errno
	*/
	int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
	{
	int ret = 0;
	u32 reg;

	cdns->current_dr_mode = mode;

	switch (mode) {
	case USB_DR_MODE_PERIPHERAL:
	break;
	case USB_DR_MODE_HOST:
	break;
	case USB_DR_MODE_OTG:
	dev_dbg(cdns->dev, "Set controller to OTG mode\n");
	if (cdns->version == CDNS3_CONTROLLER_V1) {
	reg = readl(&cdns->otg_v1_regs->override);
	reg \|= OVERRIDE_IDPULLUP;
	writel(reg, &cdns->otg_v1_regs->override);
	} else {
	reg = readl(&cdns->otg_v0_regs->ctrl1);
	reg \|= OVERRIDE_IDPULLUP_V0;
	writel(reg, &cdns->otg_v0_regs->ctrl1);
	}

	/*
	* Hardware specification says: "ID_VALUE must be valid within
	* 50ms after idpullup is set to '1" so driver must wait
	* 50ms before reading this pin.
	*/
	usleep_range(50000, 60000);
	break;
	default:
	cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;
	dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
	return -EINVAL;
	}

	return ret;
	}

	int cdns3_get_id(struct cdns3 *cdns)
	{
	int id;

	id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
	dev_dbg(cdns->dev, "OTG ID: %d", id);

	return id;
	}

	int cdns3_get_vbus(struct cdns3 *cdns)
	{
	int vbus;

	vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
	dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
	return vbus;
	}

	int cdns3_is_host(struct cdns3 *cdns)
	{
	if (cdns->current_dr_mode == USB_DR_MODE_HOST)
	return 1;
	else if (!cdns3_get_id(cdns))
	return 1;

	return 0;
	}

	int cdns3_is_device(struct cdns3 *cdns)
	{
	if (cdns->current_dr_mode == USB_DR_MODE_PERIPHERAL)
	return 1;
	else if (cdns->current_dr_mode == USB_DR_MODE_OTG)
	if (cdns3_get_id(cdns))
	return 1;

	return 0;
	}

	/**
	* cdns3_otg_disable_irq - Disable all OTG interrupts
	* @cdns: Pointer to controller context structure
	*/
	static void cdns3_otg_disable_irq(struct cdns3 *cdns)
	{
	writel(0, &cdns->otg_regs->ien);
	}

	/**
	* cdns3_otg_enable_irq - enable id and sess_valid interrupts
	* @cdns: Pointer to controller context structure
	*/
	static void cdns3_otg_enable_irq(struct cdns3 *cdns)
	{
	writel(OTGIEN_ID_CHANGE_INT \| OTGIEN_VBUSVALID_RISE_INT \|
	OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_regs->ien);
	}

	/**
	* cdns3_drd_switch_host - start/stop host
	* @cdns: Pointer to controller context structure
	* @on: 1 for start, 0 for stop
	*
	* Returns 0 on success otherwise negative errno
	*/
	int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
	{
	int ret;
	u32 reg = OTGCMD_OTG_DIS;

	/* switch OTG core */
	if (on) {
	writel(OTGCMD_HOST_BUS_REQ \| reg, &cdns->otg_regs->cmd);

	dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
	ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_XHCI_READY,
	OTGSTS_XHCI_READY, 100000);

	if (ret) {
	dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
	return ret;
	}
	} else {
	writel(OTGCMD_HOST_BUS_DROP \| OTGCMD_DEV_BUS_DROP \|
	OTGCMD_DEV_POWER_OFF \| OTGCMD_HOST_POWER_OFF,
	&cdns->otg_regs->cmd);
	/* Waiting till H_IDLE state.*/
	cdns3_handshake(&cdns->otg_regs->state,
	OTGSTATE_HOST_STATE_MASK,
	0, 2000000);
	}

	return 0;
	}

	/**
	* cdns3_drd_switch_gadget - start/stop gadget
	* @cdns: Pointer to controller context structure
	* @on: 1 for start, 0 for stop
	*
	* Returns 0 on success otherwise negative errno
	*/
	int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
	{
	int ret;
	u32 reg = OTGCMD_OTG_DIS;

	/* switch OTG core */
	if (on) {
	writel(OTGCMD_DEV_BUS_REQ \| reg, &cdns->otg_regs->cmd);

	dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");

	ret = cdns3_handshake(&cdns->otg_regs->sts, OTGSTS_DEV_READY,
	OTGSTS_DEV_READY, 100000);

	if (ret) {
	dev_err(cdns->dev, "timeout waiting for dev_ready\n");
	return ret;
	}
	} else {
	/*
	* driver should wait at least 10us after disabling Device
	* before turning-off Device (DEV_BUS_DROP)
	*/
	usleep_range(20, 30);
	writel(OTGCMD_HOST_BUS_DROP \| OTGCMD_DEV_BUS_DROP \|
	OTGCMD_DEV_POWER_OFF \| OTGCMD_HOST_POWER_OFF,
	&cdns->otg_regs->cmd);
	/* Waiting till DEV_IDLE state.*/
	cdns3_handshake(&cdns->otg_regs->state, OTGSTATE_DEV_STATE_MASK,
	0, 2000000);
	}

	return 0;
	}

	/**
	* cdns3_init_otg_mode - initialize drd controller
	* @cdns: Pointer to controller context structure
	*
	* Returns 0 on success otherwise negative errno
	*/
	static int cdns3_init_otg_mode(struct cdns3 *cdns)
	{
	int ret = 0;

	cdns3_otg_disable_irq(cdns);
	/* clear all interrupts */
	writel(~0, &cdns->otg_regs->ivect);

	ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
	if (ret)
	return ret;

	cdns3_otg_enable_irq(cdns);
	return ret;
	}

	/**
	* cdns3_drd_update_mode - initialize mode of operation
	* @cdns: Pointer to controller context structure
	*
	* Returns 0 on success otherwise negative errno
	*/
	int cdns3_drd_update_mode(struct cdns3 *cdns)
	{
	int ret = 0;

	if (cdns->desired_dr_mode == cdns->current_dr_mode)
	return ret;

	switch (cdns->desired_dr_mode) {
	case USB_DR_MODE_PERIPHERAL:
	ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
	break;
	case USB_DR_MODE_HOST:
	ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
	break;
	case USB_DR_MODE_OTG:
	ret = cdns3_init_otg_mode(cdns);
	break;
	default:
	dev_err(cdns->dev, "Unsupported mode of operation %d\n",
	cdns->dr_mode);
	return -EINVAL;
	}

	return ret;
	}

	/**
	* cdns3_drd_irq - interrupt handler for OTG events
	*
	* @irq: irq number for cdns3 core device
	* @data: structure of cdns3
	*
	* Returns IRQ_HANDLED or IRQ_NONE
	*/
	static irqreturn_t cdns3_drd_irq(int irq, void *data)
	{
	irqreturn_t ret = IRQ_NONE;
	struct cdns3 *cdns = data;
	u32 reg;

	if (cdns->dr_mode != USB_DR_MODE_OTG)
	return ret;

	reg = readl(&cdns->otg_regs->ivect);

	if (!reg)
	return ret;

	if (reg & OTGIEN_ID_CHANGE_INT) {
	dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
	cdns3_get_id(cdns));

	ret = IRQ_HANDLED;
	}

	if (reg & (OTGIEN_VBUSVALID_RISE_INT \| OTGIEN_VBUSVALID_FALL_INT)) {
	dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
	cdns3_get_vbus(cdns));

	ret = IRQ_HANDLED;
	}

	if (ret == IRQ_HANDLED)
	queue_work(system_freezable_wq, &cdns->role_switch_wq);

	writel(~0, &cdns->otg_regs->ivect);
	return ret;
	}

	int cdns3_drd_init(struct cdns3 *cdns)
	{
	void __iomem *regs;
	int ret = 0;
	u32 state;

	regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
	if (IS_ERR(regs))
	return PTR_ERR(regs);

	/* Detection of DRD version. Controller has been released
	* in two versions. Both are similar, but they have same changes
	* in register maps.
	* The first register in old version is command register and it's read
	* only, so driver should read 0 from it. On the other hand, in v1
	* the first register contains device ID number which is not set to 0.
	* Driver uses this fact to detect the proper version of
	* controller.
	*/
	cdns->otg_v0_regs = regs;
	if (!readl(&cdns->otg_v0_regs->cmd)) {
	cdns->version = CDNS3_CONTROLLER_V0;
	cdns->otg_v1_regs = NULL;
	cdns->otg_regs = regs;
	writel(1, &cdns->otg_v0_regs->simulate);
	dev_info(cdns->dev, "DRD version v0 (%08x)\n",
	readl(&cdns->otg_v0_regs->version));
	} else {
	cdns->otg_v0_regs = NULL;
	cdns->otg_v1_regs = regs;
	cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
	cdns->version = CDNS3_CONTROLLER_V1;
	writel(1, &cdns->otg_v1_regs->simulate);
	dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
	readl(&cdns->otg_v1_regs->did),
	readl(&cdns->otg_v1_regs->rid));
	}

	state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));

	/* Update dr_mode according to STRAP configuration. */
	cdns->dr_mode = USB_DR_MODE_OTG;
	if (state == OTGSTS_STRAP_HOST) {
	dev_dbg(cdns->dev, "Controller strapped to HOST\n");
	cdns->dr_mode = USB_DR_MODE_HOST;
	} else if (state == OTGSTS_STRAP_GADGET) {
	dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
	cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
	}

	cdns->desired_dr_mode = cdns->dr_mode;
	cdns->current_dr_mode = USB_DR_MODE_UNKNOWN;

	ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
	cdns3_drd_irq,
	NULL, IRQF_SHARED,
	dev_name(cdns->dev), cdns);

	if (ret) {
	dev_err(cdns->dev, "couldn't get otg_irq\n");
	return ret;
	}

	state = readl(&cdns->otg_regs->sts);
	if (OTGSTS_OTG_NRDY(state) != 0) {
	dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
	return -ENODEV;
	}

	return ret;
	}

	int cdns3_drd_exit(struct cdns3 *cdns)
	{
	return 0;
	}