drivers/usb/cdns3/core.c - kernel/msm-5.4 - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Cadence USBSS DRD Driver.
  *
  * Copyright (C) 2018-2019 Cadence.
  * Copyright (C) 2017-2018 NXP
  * Copyright (C) 2019 Texas Instruments
  *
  * Author: Peter Chen <peter.chen@nxp.com>
  *         Pawel Laszczak <pawell@cadence.com>
  *         Roger Quadros <rogerq@ti.com>
  */

 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>

 #include "gadget.h"
 #include "core.h"
 #include "host-export.h"
 #include "gadget-export.h"
 #include "drd.h"

 static int cdns3_idle_init(struct cdns3 *cdns);

 static inline
 struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
 {
 	WARN_ON(!cdns->roles[cdns->role]);
 	return cdns->roles[cdns->role];
 }

 static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
 {
 	int ret;

 	if (WARN_ON(role > USB_ROLE_DEVICE))
 		return 0;

 	mutex_lock(&cdns->mutex);
 	cdns->role = role;
 	mutex_unlock(&cdns->mutex);

 	if (!cdns->roles[role])
 		return -ENXIO;

 	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
 		return 0;

 	mutex_lock(&cdns->mutex);
 	ret = cdns->roles[role]->start(cdns);
 	if (!ret)
 		cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
 	mutex_unlock(&cdns->mutex);

 	return ret;
 }

 static void cdns3_role_stop(struct cdns3 *cdns)
 {
 	enum usb_role role = cdns->role;

 	if (WARN_ON(role > USB_ROLE_DEVICE))
 		return;

 	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
 		return;

 	mutex_lock(&cdns->mutex);
 	cdns->roles[role]->stop(cdns);
 	cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
 	mutex_unlock(&cdns->mutex);
 }

 static void cdns3_exit_roles(struct cdns3 *cdns)
 {
 	cdns3_role_stop(cdns);
 	cdns3_drd_exit(cdns);
 }

 static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns);

 /**
  * cdns3_core_init_role - initialize role of operation
  * @cdns: Pointer to cdns3 structure
  *
  * Returns 0 on success otherwise negative errno
  */
 static int cdns3_core_init_role(struct cdns3 *cdns)
 {
 	struct device *dev = cdns->dev;
 	enum usb_dr_mode best_dr_mode;
 	enum usb_dr_mode dr_mode;
 	int ret = 0;

 	dr_mode = usb_get_dr_mode(dev);
 	cdns->role = USB_ROLE_NONE;

 	/*
 	 * If driver can't read mode by means of usb_get_dr_mode function then
 	 * chooses mode according with Kernel configuration. This setting
 	 * can be restricted later depending on strap pin configuration.
 	 */
 	if (dr_mode == USB_DR_MODE_UNKNOWN) {
 		if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
 		    IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
 			dr_mode = USB_DR_MODE_OTG;
 		else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
 			dr_mode = USB_DR_MODE_HOST;
 		else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
 			dr_mode = USB_DR_MODE_PERIPHERAL;
 	}

 	/*
 	 * At this point cdns->dr_mode contains strap configuration.
 	 * Driver try update this setting considering kernel configuration
 	 */
 	best_dr_mode = cdns->dr_mode;

 	ret = cdns3_idle_init(cdns);
 	if (ret)
 		return ret;

 	if (dr_mode == USB_DR_MODE_OTG) {
 		best_dr_mode = cdns->dr_mode;
 	} else if (cdns->dr_mode == USB_DR_MODE_OTG) {
 		best_dr_mode = dr_mode;
 	} else if (cdns->dr_mode != dr_mode) {
 		dev_err(dev, "Incorrect DRD configuration\n");
 		return -EINVAL;
 	}

 	dr_mode = best_dr_mode;

 	if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
 		ret = cdns3_host_init(cdns);
 		if (ret) {
 			dev_err(dev, "Host initialization failed with %d\n",
 				ret);
 			goto err;
 		}
 	}

 	if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
 		ret = cdns3_gadget_init(cdns);
 		if (ret) {
 			dev_err(dev, "Device initialization failed with %d\n",
 				ret);
 			goto err;
 		}
 	}

 	cdns->dr_mode = dr_mode;

 	ret = cdns3_drd_update_mode(cdns);
 	if (ret)
 		goto err;

 	/* Initialize idle role to start with */
 	ret = cdns3_role_start(cdns, USB_ROLE_NONE);
 	if (ret)
 		goto err;

 	switch (cdns->dr_mode) {
 	case USB_DR_MODE_UNKNOWN:
 	case USB_DR_MODE_OTG:
 		ret = cdns3_hw_role_switch(cdns);
 		if (ret)
 			goto err;
 		break;
 	case USB_DR_MODE_PERIPHERAL:
 		ret = cdns3_role_start(cdns, USB_ROLE_DEVICE);
 		if (ret)
 			goto err;
 		break;
 	case USB_DR_MODE_HOST:
 		ret = cdns3_role_start(cdns, USB_ROLE_HOST);
 		if (ret)
 			goto err;
 		break;
 	}

 	return ret;
 err:
 	cdns3_exit_roles(cdns);
 	return ret;
 }

 /**
  * cdsn3_hw_role_state_machine  - role switch state machine based on hw events.
  * @cdns: Pointer to controller structure.
  *
  * Returns next role to be entered based on hw events.
  */
 static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
 {
 	enum usb_role role;
 	int id, vbus;

 	if (cdns->dr_mode != USB_DR_MODE_OTG)
 		goto not_otg;

 	id = cdns3_get_id(cdns);
 	vbus = cdns3_get_vbus(cdns);

 	/*
 	 * Role change state machine
 	 * Inputs: ID, VBUS
 	 * Previous state: cdns->role
 	 * Next state: role
 	 */
 	role = cdns->role;

 	switch (role) {
 	case USB_ROLE_NONE:
 		/*
 		 * Driver treats USB_ROLE_NONE synonymous to IDLE state from
 		 * controller specification.
 		 */
 		if (!id)
 			role = USB_ROLE_HOST;
 		else if (vbus)
 			role = USB_ROLE_DEVICE;
 		break;
 	case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
 		if (id)
 			role = USB_ROLE_NONE;
 		break;
 	case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
 		if (!vbus)
 			role = USB_ROLE_NONE;
 		break;
 	}

 	dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);

 	return role;

 not_otg:
 	if (cdns3_is_host(cdns))
 		role = USB_ROLE_HOST;
 	if (cdns3_is_device(cdns))
 		role = USB_ROLE_DEVICE;

 	return role;
 }

 static int cdns3_idle_role_start(struct cdns3 *cdns)
 {
 	return 0;
 }

 static void cdns3_idle_role_stop(struct cdns3 *cdns)
 {
 	/* Program Lane swap and bring PHY out of RESET */
 	phy_reset(cdns->usb3_phy);
 }

 static int cdns3_idle_init(struct cdns3 *cdns)
 {
 	struct cdns3_role_driver *rdrv;

 	rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
 	if (!rdrv)
 		return -ENOMEM;

 	rdrv->start = cdns3_idle_role_start;
 	rdrv->stop = cdns3_idle_role_stop;
 	rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
 	rdrv->suspend = NULL;
 	rdrv->resume = NULL;
 	rdrv->name = "idle";

 	cdns->roles[USB_ROLE_NONE] = rdrv;

 	return 0;
 }

 /**
  * cdns3_hw_role_switch - switch roles based on HW state
  * @cdns3: controller
  */
 int cdns3_hw_role_switch(struct cdns3 *cdns)
 {
 	enum usb_role real_role, current_role;
 	int ret = 0;

 	/* Do nothing if role based on syfs. */
 	if (cdns->role_override)
 		return 0;

 	pm_runtime_get_sync(cdns->dev);

 	current_role = cdns->role;
 	real_role = cdsn3_hw_role_state_machine(cdns);

 	/* Do nothing if nothing changed */
 	if (current_role == real_role)
 		goto exit;

 	cdns3_role_stop(cdns);

 	dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);

 	ret = cdns3_role_start(cdns, real_role);
 	if (ret) {
 		/* Back to current role */
 		dev_err(cdns->dev, "set %d has failed, back to %d\n",
 			real_role, current_role);
 		ret = cdns3_role_start(cdns, current_role);
 		if (ret)
 			dev_err(cdns->dev, "back to %d failed too\n",
 				current_role);
 	}
 exit:
 	pm_runtime_put_sync(cdns->dev);
 	return ret;
 }

 /**
  * cdsn3_role_get - get current role of controller.
  *
  * @dev: Pointer to device structure
  *
  * Returns role
  */
 static enum usb_role cdns3_role_get(struct device *dev)
 {
 	struct cdns3 *cdns = dev_get_drvdata(dev);

 	return cdns->role;
 }

 /**
  * cdns3_role_set - set current role of controller.
  *
  * @dev: pointer to device object
  * @role - the previous role
  * Handles below events:
  * - Role switch for dual-role devices
  * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
  */
 static int cdns3_role_set(struct device *dev, enum usb_role role)
 {
 	struct cdns3 *cdns = dev_get_drvdata(dev);
 	int ret = 0;

 	pm_runtime_get_sync(cdns->dev);

 	/*
 	 * FIXME: switch role framework should be extended to meet
 	 * requirements. Driver assumes that role can be controlled
 	 * by SW or HW. Temporary workaround is to use USB_ROLE_NONE to
 	 * switch from SW to HW control.
 	 *
 	 * For dr_mode == USB_DR_MODE_OTG:
 	 *	if user sets USB_ROLE_HOST or USB_ROLE_DEVICE then driver
 	 *	sets role_override flag and forces that role.
 	 *	if user sets USB_ROLE_NONE, driver clears role_override and lets
 	 *	HW state machine take over.
 	 *
 	 * For dr_mode != USB_DR_MODE_OTG:
 	 *	Assumptions:
 	 *	1. Restricted user control between NONE and dr_mode.
 	 *	2. Driver doesn't need to rely on role_override flag.
 	 *	3. Driver needs to ensure that HW state machine is never called
 	 *	   if dr_mode != USB_DR_MODE_OTG.
 	 */
 	if (role == USB_ROLE_NONE)
 		cdns->role_override = 0;
 	else
 		cdns->role_override = 1;

 	/*
 	 * HW state might have changed so driver need to trigger
 	 * HW state machine if dr_mode == USB_DR_MODE_OTG.
 	 */
 	if (!cdns->role_override && cdns->dr_mode == USB_DR_MODE_OTG) {
 		cdns3_hw_role_switch(cdns);
 		goto pm_put;
 	}

 	if (cdns->role == role)
 		goto pm_put;

 	if (cdns->dr_mode == USB_DR_MODE_HOST) {
 		switch (role) {
 		case USB_ROLE_NONE:
 		case USB_ROLE_HOST:
 			break;
 		default:
 			ret = -EPERM;
 			goto pm_put;
 		}
 	}

 	if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
 		switch (role) {
 		case USB_ROLE_NONE:
 		case USB_ROLE_DEVICE:
 			break;
 		default:
 			ret = -EPERM;
 			goto pm_put;
 		}
 	}

 	cdns3_role_stop(cdns);
 	ret = cdns3_role_start(cdns, role);
 	if (ret) {
 		dev_err(cdns->dev, "set role %d has failed\n", role);
 		ret = -EPERM;
 	}

 pm_put:
 	pm_runtime_put_sync(cdns->dev);
 	return ret;
 }

 static const struct usb_role_switch_desc cdns3_switch_desc = {
 	.set = cdns3_role_set,
 	.get = cdns3_role_get,
 	.allow_userspace_control = true,
 };

 /**
  * cdns3_probe - probe for cdns3 core device
  * @pdev: Pointer to cdns3 core platform device
  *
  * Returns 0 on success otherwise negative errno
  */
 static int cdns3_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct resource	*res;
 	struct cdns3 *cdns;
 	void __iomem *regs;
 	int ret;

 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 	if (ret) {
 		dev_err(dev, "error setting dma mask: %d\n", ret);
 		return -ENODEV;
 	}

 	cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
 	if (!cdns)
 		return -ENOMEM;

 	cdns->dev = dev;

 	platform_set_drvdata(pdev, cdns);

 	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "host");
 	if (!res) {
 		dev_err(dev, "missing host IRQ\n");
 		return -ENODEV;
 	}

 	cdns->xhci_res[0] = *res;

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xhci");
 	if (!res) {
 		dev_err(dev, "couldn't get xhci resource\n");
 		return -ENXIO;
 	}

 	cdns->xhci_res[1] = *res;

 	cdns->dev_irq = platform_get_irq_byname(pdev, "peripheral");
 	if (cdns->dev_irq == -EPROBE_DEFER)
 		return cdns->dev_irq;

 	if (cdns->dev_irq < 0)
 		dev_err(dev, "couldn't get peripheral irq\n");

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dev");
 	regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);
 	cdns->dev_regs	= regs;

 	cdns->otg_irq = platform_get_irq_byname(pdev, "otg");
 	if (cdns->otg_irq == -EPROBE_DEFER)
 		return cdns->otg_irq;

 	if (cdns->otg_irq < 0) {
 		dev_err(dev, "couldn't get otg irq\n");
 		return cdns->otg_irq;
 	}

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg");
 	if (!res) {
 		dev_err(dev, "couldn't get otg resource\n");
 		return -ENXIO;
 	}

 	cdns->otg_res = *res;

 	mutex_init(&cdns->mutex);

 	cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy");
 	if (IS_ERR(cdns->usb2_phy))
 		return PTR_ERR(cdns->usb2_phy);

 	ret = phy_init(cdns->usb2_phy);
 	if (ret)
 		return ret;

 	cdns->usb3_phy = devm_phy_optional_get(dev, "cdns3,usb3-phy");
 	if (IS_ERR(cdns->usb3_phy))
 		return PTR_ERR(cdns->usb3_phy);

 	ret = phy_init(cdns->usb3_phy);
 	if (ret)
 		goto err1;

 	ret = phy_power_on(cdns->usb2_phy);
 	if (ret)
 		goto err2;

 	ret = phy_power_on(cdns->usb3_phy);
 	if (ret)
 		goto err3;

 	cdns->role_sw = usb_role_switch_register(dev, &cdns3_switch_desc);
 	if (IS_ERR(cdns->role_sw)) {
 		ret = PTR_ERR(cdns->role_sw);
 		dev_warn(dev, "Unable to register Role Switch\n");
 		goto err4;
 	}

 	ret = cdns3_drd_init(cdns);
 	if (ret)
 		goto err5;

 	ret = cdns3_core_init_role(cdns);
 	if (ret)
 		goto err5;

 	device_set_wakeup_capable(dev, true);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);

 	/*
 	 * The controller needs less time between bus and controller suspend,
 	 * and we also needs a small delay to avoid frequently entering low
 	 * power mode.
 	 */
 	pm_runtime_set_autosuspend_delay(dev, 20);
 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_use_autosuspend(dev);
 	dev_dbg(dev, "Cadence USB3 core: probe succeed\n");

 	return 0;
 err5:
 	cdns3_drd_exit(cdns);
 	usb_role_switch_unregister(cdns->role_sw);
 err4:
 	phy_power_off(cdns->usb3_phy);

 err3:
 	phy_power_off(cdns->usb2_phy);
 err2:
 	phy_exit(cdns->usb3_phy);
 err1:
 	phy_exit(cdns->usb2_phy);

 	return ret;
 }

 /**
  * cdns3_remove - unbind drd driver and clean up
  * @pdev: Pointer to Linux platform device
  *
  * Returns 0 on success otherwise negative errno
  */
 static int cdns3_remove(struct platform_device *pdev)
 {
 	struct cdns3 *cdns = platform_get_drvdata(pdev);

 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 	cdns3_exit_roles(cdns);
 	usb_role_switch_unregister(cdns->role_sw);
 	phy_power_off(cdns->usb2_phy);
 	phy_power_off(cdns->usb3_phy);
 	phy_exit(cdns->usb2_phy);
 	phy_exit(cdns->usb3_phy);
 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP

 static int cdns3_suspend(struct device *dev)
 {
 	struct cdns3 *cdns = dev_get_drvdata(dev);
 	unsigned long flags;

 	if (cdns->role == USB_ROLE_HOST)
 		return 0;

 	if (pm_runtime_status_suspended(dev))
 		pm_runtime_resume(dev);

 	if (cdns->roles[cdns->role]->suspend) {
 		spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 		cdns->roles[cdns->role]->suspend(cdns, false);
 		spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 	}

 	return 0;
 }

 static int cdns3_resume(struct device *dev)
 {
 	struct cdns3 *cdns = dev_get_drvdata(dev);
 	unsigned long flags;

 	if (cdns->role == USB_ROLE_HOST)
 		return 0;

 	if (cdns->roles[cdns->role]->resume) {
 		spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 		cdns->roles[cdns->role]->resume(cdns, false);
 		spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 	}

 	pm_runtime_disable(dev);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);

 	return 0;
 }
 #endif

 static const struct dev_pm_ops cdns3_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
 };

 #ifdef CONFIG_OF
 static const struct of_device_id of_cdns3_match[] = {
 	{ .compatible = "cdns,usb3" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, of_cdns3_match);
 #endif

 static struct platform_driver cdns3_driver = {
 	.probe		= cdns3_probe,
 	.remove		= cdns3_remove,
 	.driver		= {
 		.name	= "cdns-usb3",
 		.of_match_table	= of_match_ptr(of_cdns3_match),
 		.pm	= &cdns3_pm_ops,
 	},
 };

 module_platform_driver(cdns3_driver);

 MODULE_ALIAS("platform:cdns3");
 MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Cadence USBSS DRD Driver.
	*
	* Copyright (C) 2018-2019 Cadence.
	* Copyright (C) 2017-2018 NXP
	* Copyright (C) 2019 Texas Instruments
	*
	* Author: Peter Chen <peter.chen@nxp.com>
	* Pawel Laszczak <pawell@cadence.com>
	* Roger Quadros <rogerq@ti.com>
	*/

	#include <linux/dma-mapping.h>
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/pm_runtime.h>

	#include "gadget.h"
	#include "core.h"
	#include "host-export.h"
	#include "gadget-export.h"
	#include "drd.h"

	static int cdns3_idle_init(struct cdns3 *cdns);

	static inline
	struct cdns3_role_driver cdns3_get_current_role_driver(struct cdns3 cdns)
	{
	WARN_ON(!cdns->roles[cdns->role]);
	return cdns->roles[cdns->role];
	}

	static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
	{
	int ret;

	if (WARN_ON(role > USB_ROLE_DEVICE))
	return 0;

	mutex_lock(&cdns->mutex);
	cdns->role = role;
	mutex_unlock(&cdns->mutex);

	if (!cdns->roles[role])
	return -ENXIO;

	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
	return 0;

	mutex_lock(&cdns->mutex);
	ret = cdns->roles[role]->start(cdns);
	if (!ret)
	cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
	mutex_unlock(&cdns->mutex);

	return ret;
	}

	static void cdns3_role_stop(struct cdns3 *cdns)
	{
	enum usb_role role = cdns->role;

	if (WARN_ON(role > USB_ROLE_DEVICE))
	return;

	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
	return;

	mutex_lock(&cdns->mutex);
	cdns->roles[role]->stop(cdns);
	cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
	mutex_unlock(&cdns->mutex);
	}

	static void cdns3_exit_roles(struct cdns3 *cdns)
	{
	cdns3_role_stop(cdns);
	cdns3_drd_exit(cdns);
	}

	static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns);

	/**
	* cdns3_core_init_role - initialize role of operation
	* @cdns: Pointer to cdns3 structure
	*
	* Returns 0 on success otherwise negative errno
	*/
	static int cdns3_core_init_role(struct cdns3 *cdns)
	{
	struct device *dev = cdns->dev;
	enum usb_dr_mode best_dr_mode;
	enum usb_dr_mode dr_mode;
	int ret = 0;

	dr_mode = usb_get_dr_mode(dev);
	cdns->role = USB_ROLE_NONE;

	/*
	* If driver can't read mode by means of usb_get_dr_mode function then
	* chooses mode according with Kernel configuration. This setting
	* can be restricted later depending on strap pin configuration.
	*/
	if (dr_mode == USB_DR_MODE_UNKNOWN) {
	if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
	IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
	dr_mode = USB_DR_MODE_OTG;
	else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
	dr_mode = USB_DR_MODE_HOST;
	else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
	dr_mode = USB_DR_MODE_PERIPHERAL;
	}

	/*
	* At this point cdns->dr_mode contains strap configuration.
	* Driver try update this setting considering kernel configuration
	*/
	best_dr_mode = cdns->dr_mode;

	ret = cdns3_idle_init(cdns);
	if (ret)
	return ret;

	if (dr_mode == USB_DR_MODE_OTG) {
	best_dr_mode = cdns->dr_mode;
	} else if (cdns->dr_mode == USB_DR_MODE_OTG) {
	best_dr_mode = dr_mode;
	} else if (cdns->dr_mode != dr_mode) {
	dev_err(dev, "Incorrect DRD configuration\n");
	return -EINVAL;
	}

	dr_mode = best_dr_mode;

	if (dr_mode == USB_DR_MODE_OTG \|\| dr_mode == USB_DR_MODE_HOST) {
	ret = cdns3_host_init(cdns);
	if (ret) {
	dev_err(dev, "Host initialization failed with %d\n",
	ret);
	goto err;
	}
	}

	if (dr_mode == USB_DR_MODE_OTG \|\| dr_mode == USB_DR_MODE_PERIPHERAL) {
	ret = cdns3_gadget_init(cdns);
	if (ret) {
	dev_err(dev, "Device initialization failed with %d\n",
	ret);
	goto err;
	}
	}

	cdns->dr_mode = dr_mode;

	ret = cdns3_drd_update_mode(cdns);
	if (ret)
	goto err;

	/* Initialize idle role to start with */
	ret = cdns3_role_start(cdns, USB_ROLE_NONE);
	if (ret)
	goto err;

	switch (cdns->dr_mode) {
	case USB_DR_MODE_UNKNOWN:
	case USB_DR_MODE_OTG:
	ret = cdns3_hw_role_switch(cdns);
	if (ret)
	goto err;
	break;
	case USB_DR_MODE_PERIPHERAL:
	ret = cdns3_role_start(cdns, USB_ROLE_DEVICE);
	if (ret)
	goto err;
	break;
	case USB_DR_MODE_HOST:
	ret = cdns3_role_start(cdns, USB_ROLE_HOST);
	if (ret)
	goto err;
	break;
	}

	return ret;
	err:
	cdns3_exit_roles(cdns);
	return ret;
	}

	/**
	* cdsn3_hw_role_state_machine - role switch state machine based on hw events.
	* @cdns: Pointer to controller structure.
	*
	* Returns next role to be entered based on hw events.
	*/
	static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
	{
	enum usb_role role;
	int id, vbus;

	if (cdns->dr_mode != USB_DR_MODE_OTG)
	goto not_otg;

	id = cdns3_get_id(cdns);
	vbus = cdns3_get_vbus(cdns);

	/*
	* Role change state machine
	* Inputs: ID, VBUS
	* Previous state: cdns->role
	* Next state: role
	*/
	role = cdns->role;

	switch (role) {
	case USB_ROLE_NONE:
	/*
	* Driver treats USB_ROLE_NONE synonymous to IDLE state from
	* controller specification.
	*/
	if (!id)
	role = USB_ROLE_HOST;
	else if (vbus)
	role = USB_ROLE_DEVICE;
	break;
	case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
	if (id)
	role = USB_ROLE_NONE;
	break;
	case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
	if (!vbus)
	role = USB_ROLE_NONE;
	break;
	}

	dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);

	return role;

	not_otg:
	if (cdns3_is_host(cdns))
	role = USB_ROLE_HOST;
	if (cdns3_is_device(cdns))
	role = USB_ROLE_DEVICE;

	return role;
	}

	static int cdns3_idle_role_start(struct cdns3 *cdns)
	{
	return 0;
	}

	static void cdns3_idle_role_stop(struct cdns3 *cdns)
	{
	/* Program Lane swap and bring PHY out of RESET */
	phy_reset(cdns->usb3_phy);
	}

	static int cdns3_idle_init(struct cdns3 *cdns)
	{
	struct cdns3_role_driver *rdrv;

	rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
	if (!rdrv)
	return -ENOMEM;

	rdrv->start = cdns3_idle_role_start;
	rdrv->stop = cdns3_idle_role_stop;
	rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
	rdrv->suspend = NULL;
	rdrv->resume = NULL;
	rdrv->name = "idle";

	cdns->roles[USB_ROLE_NONE] = rdrv;

	return 0;
	}

	/**
	* cdns3_hw_role_switch - switch roles based on HW state
	* @cdns3: controller
	*/
	int cdns3_hw_role_switch(struct cdns3 *cdns)
	{
	enum usb_role real_role, current_role;
	int ret = 0;

	/* Do nothing if role based on syfs. */
	if (cdns->role_override)
	return 0;

	pm_runtime_get_sync(cdns->dev);

	current_role = cdns->role;
	real_role = cdsn3_hw_role_state_machine(cdns);

	/* Do nothing if nothing changed */
	if (current_role == real_role)
	goto exit;

	cdns3_role_stop(cdns);

	dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);

	ret = cdns3_role_start(cdns, real_role);
	if (ret) {
	/* Back to current role */
	dev_err(cdns->dev, "set %d has failed, back to %d\n",
	real_role, current_role);
	ret = cdns3_role_start(cdns, current_role);
	if (ret)
	dev_err(cdns->dev, "back to %d failed too\n",
	current_role);
	}
	exit:
	pm_runtime_put_sync(cdns->dev);
	return ret;
	}

	/**
	* cdsn3_role_get - get current role of controller.
	*
	* @dev: Pointer to device structure
	*
	* Returns role
	*/
	static enum usb_role cdns3_role_get(struct device *dev)
	{
	struct cdns3 *cdns = dev_get_drvdata(dev);

	return cdns->role;
	}

	/**
	* cdns3_role_set - set current role of controller.
	*
	* @dev: pointer to device object
	* @role - the previous role
	* Handles below events:
	* - Role switch for dual-role devices
	* - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
	*/
	static int cdns3_role_set(struct device *dev, enum usb_role role)
	{
	struct cdns3 *cdns = dev_get_drvdata(dev);
	int ret = 0;

	pm_runtime_get_sync(cdns->dev);

	/*
	* FIXME: switch role framework should be extended to meet
	* requirements. Driver assumes that role can be controlled
	* by SW or HW. Temporary workaround is to use USB_ROLE_NONE to
	* switch from SW to HW control.
	*
	* For dr_mode == USB_DR_MODE_OTG:
	* if user sets USB_ROLE_HOST or USB_ROLE_DEVICE then driver
	* sets role_override flag and forces that role.
	* if user sets USB_ROLE_NONE, driver clears role_override and lets
	* HW state machine take over.
	*
	* For dr_mode != USB_DR_MODE_OTG:
	* Assumptions:
	* 1. Restricted user control between NONE and dr_mode.
	* 2. Driver doesn't need to rely on role_override flag.
	* 3. Driver needs to ensure that HW state machine is never called
	* if dr_mode != USB_DR_MODE_OTG.
	*/
	if (role == USB_ROLE_NONE)
	cdns->role_override = 0;
	else
	cdns->role_override = 1;

	/*
	* HW state might have changed so driver need to trigger
	* HW state machine if dr_mode == USB_DR_MODE_OTG.
	*/
	if (!cdns->role_override && cdns->dr_mode == USB_DR_MODE_OTG) {
	cdns3_hw_role_switch(cdns);
	goto pm_put;
	}

	if (cdns->role == role)
	goto pm_put;

	if (cdns->dr_mode == USB_DR_MODE_HOST) {
	switch (role) {
	case USB_ROLE_NONE:
	case USB_ROLE_HOST:
	break;
	default:
	ret = -EPERM;
	goto pm_put;
	}
	}

	if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
	switch (role) {
	case USB_ROLE_NONE:
	case USB_ROLE_DEVICE:
	break;
	default:
	ret = -EPERM;
	goto pm_put;
	}
	}

	cdns3_role_stop(cdns);
	ret = cdns3_role_start(cdns, role);
	if (ret) {
	dev_err(cdns->dev, "set role %d has failed\n", role);
	ret = -EPERM;
	}

	pm_put:
	pm_runtime_put_sync(cdns->dev);
	return ret;
	}

	static const struct usb_role_switch_desc cdns3_switch_desc = {
	.set = cdns3_role_set,
	.get = cdns3_role_get,
	.allow_userspace_control = true,
	};

	/**
	* cdns3_probe - probe for cdns3 core device
	* @pdev: Pointer to cdns3 core platform device
	*
	* Returns 0 on success otherwise negative errno
	*/
	static int cdns3_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct cdns3 *cdns;
	void __iomem *regs;
	int ret;

	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
	if (ret) {
	dev_err(dev, "error setting dma mask: %d\n", ret);
	return -ENODEV;
	}

	cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
	if (!cdns)
	return -ENOMEM;

	cdns->dev = dev;

	platform_set_drvdata(pdev, cdns);

	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "host");
	if (!res) {
	dev_err(dev, "missing host IRQ\n");
	return -ENODEV;
	}

	cdns->xhci_res[0] = *res;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xhci");
	if (!res) {
	dev_err(dev, "couldn't get xhci resource\n");
	return -ENXIO;
	}

	cdns->xhci_res[1] = *res;

	cdns->dev_irq = platform_get_irq_byname(pdev, "peripheral");
	if (cdns->dev_irq == -EPROBE_DEFER)
	return cdns->dev_irq;

	if (cdns->dev_irq < 0)
	dev_err(dev, "couldn't get peripheral irq\n");

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dev");
	regs = devm_ioremap_resource(dev, res);
	if (IS_ERR(regs))
	return PTR_ERR(regs);
	cdns->dev_regs = regs;

	cdns->otg_irq = platform_get_irq_byname(pdev, "otg");
	if (cdns->otg_irq == -EPROBE_DEFER)
	return cdns->otg_irq;

	if (cdns->otg_irq < 0) {
	dev_err(dev, "couldn't get otg irq\n");
	return cdns->otg_irq;
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg");
	if (!res) {
	dev_err(dev, "couldn't get otg resource\n");
	return -ENXIO;
	}

	cdns->otg_res = *res;

	mutex_init(&cdns->mutex);

	cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy");
	if (IS_ERR(cdns->usb2_phy))
	return PTR_ERR(cdns->usb2_phy);

	ret = phy_init(cdns->usb2_phy);
	if (ret)
	return ret;

	cdns->usb3_phy = devm_phy_optional_get(dev, "cdns3,usb3-phy");
	if (IS_ERR(cdns->usb3_phy))
	return PTR_ERR(cdns->usb3_phy);

	ret = phy_init(cdns->usb3_phy);
	if (ret)
	goto err1;

	ret = phy_power_on(cdns->usb2_phy);
	if (ret)
	goto err2;

	ret = phy_power_on(cdns->usb3_phy);
	if (ret)
	goto err3;

	cdns->role_sw = usb_role_switch_register(dev, &cdns3_switch_desc);
	if (IS_ERR(cdns->role_sw)) {
	ret = PTR_ERR(cdns->role_sw);
	dev_warn(dev, "Unable to register Role Switch\n");
	goto err4;
	}

	ret = cdns3_drd_init(cdns);
	if (ret)
	goto err5;

	ret = cdns3_core_init_role(cdns);
	if (ret)
	goto err5;

	device_set_wakeup_capable(dev, true);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	/*
	* The controller needs less time between bus and controller suspend,
	* and we also needs a small delay to avoid frequently entering low
	* power mode.
	*/
	pm_runtime_set_autosuspend_delay(dev, 20);
	pm_runtime_mark_last_busy(dev);
	pm_runtime_use_autosuspend(dev);
	dev_dbg(dev, "Cadence USB3 core: probe succeed\n");

	return 0;
	err5:
	cdns3_drd_exit(cdns);
	usb_role_switch_unregister(cdns->role_sw);
	err4:
	phy_power_off(cdns->usb3_phy);

	err3:
	phy_power_off(cdns->usb2_phy);
	err2:
	phy_exit(cdns->usb3_phy);
	err1:
	phy_exit(cdns->usb2_phy);

	return ret;
	}

	/**
	* cdns3_remove - unbind drd driver and clean up
	* @pdev: Pointer to Linux platform device
	*
	* Returns 0 on success otherwise negative errno
	*/
	static int cdns3_remove(struct platform_device *pdev)
	{
	struct cdns3 *cdns = platform_get_drvdata(pdev);

	pm_runtime_get_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
	cdns3_exit_roles(cdns);
	usb_role_switch_unregister(cdns->role_sw);
	phy_power_off(cdns->usb2_phy);
	phy_power_off(cdns->usb3_phy);
	phy_exit(cdns->usb2_phy);
	phy_exit(cdns->usb3_phy);
	return 0;
	}

	#ifdef CONFIG_PM_SLEEP

	static int cdns3_suspend(struct device *dev)
	{
	struct cdns3 *cdns = dev_get_drvdata(dev);
	unsigned long flags;

	if (cdns->role == USB_ROLE_HOST)
	return 0;

	if (pm_runtime_status_suspended(dev))
	pm_runtime_resume(dev);

	if (cdns->roles[cdns->role]->suspend) {
	spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
	cdns->roles[cdns->role]->suspend(cdns, false);
	spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
	}

	return 0;
	}

	static int cdns3_resume(struct device *dev)
	{
	struct cdns3 *cdns = dev_get_drvdata(dev);
	unsigned long flags;

	if (cdns->role == USB_ROLE_HOST)
	return 0;

	if (cdns->roles[cdns->role]->resume) {
	spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
	cdns->roles[cdns->role]->resume(cdns, false);
	spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
	}

	pm_runtime_disable(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	return 0;
	}
	#endif

	static const struct dev_pm_ops cdns3_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
	};

	#ifdef CONFIG_OF
	static const struct of_device_id of_cdns3_match[] = {
	{ .compatible = "cdns,usb3" },
	{ },
	};
	MODULE_DEVICE_TABLE(of, of_cdns3_match);
	#endif

	static struct platform_driver cdns3_driver = {
	.probe = cdns3_probe,
	.remove = cdns3_remove,
	.driver = {
	.name = "cdns-usb3",
	.of_match_table = of_match_ptr(of_cdns3_match),
	.pm = &cdns3_pm_ops,
	},
	};

	module_platform_driver(cdns3_driver);

	MODULE_ALIAS("platform:cdns3");
	MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");