Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 631 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
new file mode 100644
index 000000000..f3e37d383
--- /dev/null
+++ b/drivers/usb/dwc3/drd.c
@@ -0,0 +1,631 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drd.c - DesignWare USB3 DRD Controller Dual-role support
+ *
+ * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com
+ *
+ * Authors: Roger Quadros <rogerq@ti.com>
+ */
+
+#include <linux/extcon.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#include "debug.h"
+#include "core.h"
+#include "gadget.h"
+
+static void dwc3_otg_disable_events(struct dwc3 *dwc, u32 disable_mask)
+{
+	u32 reg = dwc3_readl(dwc, DWC3_OEVTEN);
+
+	reg &= ~(disable_mask);
+	dwc3_writel(dwc, DWC3_OEVTEN, reg);
+}
+
+static void dwc3_otg_enable_events(struct dwc3 *dwc, u32 enable_mask)
+{
+	u32 reg = dwc3_readl(dwc, DWC3_OEVTEN);
+
+	reg |= (enable_mask);
+	dwc3_writel(dwc, DWC3_OEVTEN, reg);
+}
+
+static void dwc3_otg_clear_events(struct dwc3 *dwc)
+{
+	u32 reg = dwc3_readl(dwc, DWC3_OEVT);
+
+	dwc3_writel(dwc, DWC3_OEVTEN, reg);
+}
+
+#define DWC3_OTG_ALL_EVENTS	(DWC3_OEVTEN_XHCIRUNSTPSETEN | \
+		DWC3_OEVTEN_DEVRUNSTPSETEN | DWC3_OEVTEN_HIBENTRYEN | \
+		DWC3_OEVTEN_CONIDSTSCHNGEN | DWC3_OEVTEN_HRRCONFNOTIFEN | \
+		DWC3_OEVTEN_HRRINITNOTIFEN | DWC3_OEVTEN_ADEVIDLEEN | \
+		DWC3_OEVTEN_ADEVBHOSTENDEN | DWC3_OEVTEN_ADEVHOSTEN | \
+		DWC3_OEVTEN_ADEVHNPCHNGEN | DWC3_OEVTEN_ADEVSRPDETEN | \
+		DWC3_OEVTEN_ADEVSESSENDDETEN | DWC3_OEVTEN_BDEVBHOSTENDEN | \
+		DWC3_OEVTEN_BDEVHNPCHNGEN | DWC3_OEVTEN_BDEVSESSVLDDETEN | \
+		DWC3_OEVTEN_BDEVVBUSCHNGEN)
+
+static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
+{
+	struct dwc3 *dwc = _dwc;
+
+	spin_lock(&dwc->lock);
+	if (dwc->otg_restart_host) {
+		dwc3_otg_host_init(dwc);
+		dwc->otg_restart_host = false;
+	}
+
+	spin_unlock(&dwc->lock);
+
+	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
+{
+	u32 reg;
+	struct dwc3 *dwc = _dwc;
+	irqreturn_t ret = IRQ_NONE;
+
+	reg = dwc3_readl(dwc, DWC3_OEVT);
+	if (reg) {
+		/* ignore non OTG events, we can't disable them in OEVTEN */
+		if (!(reg & DWC3_OTG_ALL_EVENTS)) {
+			dwc3_writel(dwc, DWC3_OEVT, reg);
+			return IRQ_NONE;
+		}
+
+		if (dwc->current_otg_role == DWC3_OTG_ROLE_HOST &&
+		    !(reg & DWC3_OEVT_DEVICEMODE))
+			dwc->otg_restart_host = true;
+		dwc3_writel(dwc, DWC3_OEVT, reg);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	return ret;
+}
+
+static void dwc3_otgregs_init(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/*
+	 * Prevent host/device reset from resetting OTG core.
+	 * If we don't do this then xhci_reset (USBCMD.HCRST) will reset
+	 * the signal outputs sent to the PHY, the OTG FSM logic of the
+	 * core and also the resets to the VBUS filters inside the core.
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCFG);
+	reg |= DWC3_OCFG_SFTRSTMASK;
+	dwc3_writel(dwc, DWC3_OCFG, reg);
+
+	/* Disable hibernation for simplicity */
+	reg = dwc3_readl(dwc, DWC3_GCTL);
+	reg &= ~DWC3_GCTL_GBLHIBERNATIONEN;
+	dwc3_writel(dwc, DWC3_GCTL, reg);
+
+	/*
+	 * Initialize OTG registers as per
+	 * Figure 11-4 OTG Driver Overall Programming Flow
+	 */
+	/* OCFG.SRPCap = 0, OCFG.HNPCap = 0 */
+	reg = dwc3_readl(dwc, DWC3_OCFG);
+	reg &= ~(DWC3_OCFG_SRPCAP | DWC3_OCFG_HNPCAP);
+	dwc3_writel(dwc, DWC3_OCFG, reg);
+	/* OEVT = FFFF */
+	dwc3_otg_clear_events(dwc);
+	/* OEVTEN = 0 */
+	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
+	/* OEVTEN.ConIDStsChngEn = 1. Instead we enable all events */
+	dwc3_otg_enable_events(dwc, DWC3_OTG_ALL_EVENTS);
+	/*
+	 * OCTL.PeriMode = 1, OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0,
+	 * OCTL.HNPReq = 0
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg |= DWC3_OCTL_PERIMODE;
+	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN |
+		 DWC3_OCTL_HNPREQ);
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+}
+
+static int dwc3_otg_get_irq(struct dwc3 *dwc)
+{
+	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
+	int irq;
+
+	irq = platform_get_irq_byname_optional(dwc3_pdev, "otg");
+	if (irq > 0)
+		goto out;
+
+	if (irq == -EPROBE_DEFER)
+		goto out;
+
+	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
+	if (irq > 0)
+		goto out;
+
+	if (irq == -EPROBE_DEFER)
+		goto out;
+
+	irq = platform_get_irq(dwc3_pdev, 0);
+	if (irq > 0)
+		goto out;
+
+	if (!irq)
+		irq = -EINVAL;
+
+out:
+	return irq;
+}
+
+void dwc3_otg_init(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/*
+	 * As per Figure 11-4 OTG Driver Overall Programming Flow,
+	 * block "Initialize GCTL for OTG operation".
+	 */
+	/* GCTL.PrtCapDir=2'b11 */
+	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG, true);
+	/* GUSB2PHYCFG0.SusPHY=0 */
+	reg = dwc3_readl(dwc, DWC3_GUSB2PHYCFG(0));
+	reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+	dwc3_writel(dwc, DWC3_GUSB2PHYCFG(0), reg);
+
+	/* Initialize OTG registers */
+	dwc3_otgregs_init(dwc);
+}
+
+void dwc3_otg_exit(struct dwc3 *dwc)
+{
+	/* disable all OTG IRQs */
+	dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
+	/* clear all events */
+	dwc3_otg_clear_events(dwc);
+}
+
+/* should be called before Host controller driver is started */
+void dwc3_otg_host_init(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/* As per Figure 11-10 A-Device Flow Diagram */
+	/* OCFG.HNPCap = 0, OCFG.SRPCap = 0. Already 0 */
+
+	/*
+	 * OCTL.PeriMode=0, OCTL.TermSelDLPulse = 0,
+	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg &= ~(DWC3_OCTL_PERIMODE | DWC3_OCTL_TERMSELIDPULSE |
+			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+
+	/*
+	 * OCFG.DisPrtPwrCutoff = 0/1
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCFG);
+	reg &= ~DWC3_OCFG_DISPWRCUTTOFF;
+	dwc3_writel(dwc, DWC3_OCFG, reg);
+
+	/*
+	 * OCFG.SRPCap = 1, OCFG.HNPCap = GHWPARAMS6.HNP_CAP
+	 * We don't want SRP/HNP for simple dual-role so leave
+	 * these disabled.
+	 */
+
+	/*
+	 * OEVTEN.OTGADevHostEvntEn = 1
+	 * OEVTEN.OTGADevSessEndDetEvntEn = 1
+	 * We don't want HNP/role-swap so leave these disabled.
+	 */
+
+	/* GUSB2PHYCFG.ULPIAutoRes = 1/0, GUSB2PHYCFG.SusPHY = 1 */
+	if (!dwc->dis_u2_susphy_quirk) {
+		reg = dwc3_readl(dwc, DWC3_GUSB2PHYCFG(0));
+		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
+		dwc3_writel(dwc, DWC3_GUSB2PHYCFG(0), reg);
+	}
+
+	/* Set Port Power to enable VBUS: OCTL.PrtPwrCtl = 1 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg |= DWC3_OCTL_PRTPWRCTL;
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+}
+
+/* should be called after Host controller driver is stopped */
+static void dwc3_otg_host_exit(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/*
+	 * Exit from A-device flow as per
+	 * Figure 11-4 OTG Driver Overall Programming Flow
+	 */
+
+	/*
+	 * OEVTEN.OTGADevBHostEndEvntEn=0, OEVTEN.OTGADevHNPChngEvntEn=0
+	 * OEVTEN.OTGADevSessEndDetEvntEn=0,
+	 * OEVTEN.OTGADevHostEvntEn = 0
+	 * But we don't disable any OTG events
+	 */
+
+	/* OCTL.HstSetHNPEn = 0, OCTL.PrtPwrCtl=0 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg &= ~(DWC3_OCTL_HSTSETHNPEN | DWC3_OCTL_PRTPWRCTL);
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+}
+
+/* should be called before the gadget controller driver is started */
+static void dwc3_otg_device_init(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/* As per Figure 11-20 B-Device Flow Diagram */
+
+	/*
+	 * OCFG.HNPCap = GHWPARAMS6.HNP_CAP, OCFG.SRPCap = 1
+	 * but we keep them 0 for simple dual-role operation.
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCFG);
+	/* OCFG.OTGSftRstMsk = 0/1 */
+	reg |= DWC3_OCFG_SFTRSTMASK;
+	dwc3_writel(dwc, DWC3_OCFG, reg);
+	/*
+	 * OCTL.PeriMode = 1
+	 * OCTL.TermSelDLPulse = 0/1, OCTL.HNPReq = 0
+	 * OCTL.DevSetHNPEn = 0, OCTL.HstSetHNPEn = 0
+	 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg |= DWC3_OCTL_PERIMODE;
+	reg &= ~(DWC3_OCTL_TERMSELIDPULSE | DWC3_OCTL_HNPREQ |
+			DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HSTSETHNPEN);
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+	/* OEVTEN.OTGBDevSesVldDetEvntEn = 1 */
+	dwc3_otg_enable_events(dwc, DWC3_OEVTEN_BDEVSESSVLDDETEN);
+	/* GUSB2PHYCFG.ULPIAutoRes = 0, GUSB2PHYCFG0.SusPHY = 1 */
+	if (!dwc->dis_u2_susphy_quirk) {
+		reg = dwc3_readl(dwc, DWC3_GUSB2PHYCFG(0));
+		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
+		dwc3_writel(dwc, DWC3_GUSB2PHYCFG(0), reg);
+	}
+	/* GCTL.GblHibernationEn = 0. Already 0. */
+}
+
+/* should be called after the gadget controller driver is stopped */
+static void dwc3_otg_device_exit(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	/*
+	 * Exit from B-device flow as per
+	 * Figure 11-4 OTG Driver Overall Programming Flow
+	 */
+
+	/*
+	 * OEVTEN.OTGBDevHNPChngEvntEn = 0
+	 * OEVTEN.OTGBDevVBusChngEvntEn = 0
+	 * OEVTEN.OTGBDevBHostEndEvntEn = 0
+	 */
+	dwc3_otg_disable_events(dwc, DWC3_OEVTEN_BDEVHNPCHNGEN |
+				DWC3_OEVTEN_BDEVVBUSCHNGEN |
+				DWC3_OEVTEN_BDEVBHOSTENDEN);
+
+	/* OCTL.DevSetHNPEn = 0, OCTL.HNPReq = 0, OCTL.PeriMode=1 */
+	reg = dwc3_readl(dwc, DWC3_OCTL);
+	reg &= ~(DWC3_OCTL_DEVSETHNPEN | DWC3_OCTL_HNPREQ);
+	reg |= DWC3_OCTL_PERIMODE;
+	dwc3_writel(dwc, DWC3_OCTL, reg);
+}
+
+void dwc3_otg_update(struct dwc3 *dwc, bool ignore_idstatus)
+{
+	int ret;
+	u32 reg;
+	int id;
+	unsigned long flags;
+	int i;
+
+	if (dwc->dr_mode != USB_DR_MODE_OTG)
+		return;
+
+	/* don't do anything if debug user changed role to not OTG */
+	if (dwc->current_dr_role != DWC3_GCTL_PRTCAP_OTG)
+		return;
+
+	if (!ignore_idstatus) {
+		reg = dwc3_readl(dwc, DWC3_OSTS);
+		id = !!(reg & DWC3_OSTS_CONIDSTS);
+
+		dwc->desired_otg_role = id ? DWC3_OTG_ROLE_DEVICE :
+					DWC3_OTG_ROLE_HOST;
+	}
+
+	if (dwc->desired_otg_role == dwc->current_otg_role)
+		return;
+
+	switch (dwc->current_otg_role) {
+	case DWC3_OTG_ROLE_HOST:
+		dwc3_host_exit(dwc);
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_otg_host_exit(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		break;
+	case DWC3_OTG_ROLE_DEVICE:
+		dwc3_gadget_exit(dwc);
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_event_buffers_cleanup(dwc);
+		dwc3_otg_device_exit(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		break;
+	default:
+		break;
+	}
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	dwc->current_otg_role = dwc->desired_otg_role;
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	switch (dwc->desired_otg_role) {
+	case DWC3_OTG_ROLE_HOST:
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_otgregs_init(dwc);
+		dwc3_otg_host_init(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		dwc3_pre_set_role(dwc, USB_ROLE_HOST);
+		ret = dwc3_host_init(dwc);
+		if (ret) {
+			dev_err(dwc->dev, "failed to initialize host\n");
+		} else {
+			if (dwc->usb2_phy)
+				otg_set_vbus(dwc->usb2_phy->otg, true);
+			for (i = 0; i < dwc->num_usb2_ports; i++) {
+				if (dwc->usb2_generic_phy[i]) {
+					phy_set_mode(dwc->usb2_generic_phy[i],
+						     PHY_MODE_USB_HOST);
+				}
+			}
+		}
+		break;
+	case DWC3_OTG_ROLE_DEVICE:
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc3_otgregs_init(dwc);
+		dwc3_otg_device_init(dwc);
+		dwc3_event_buffers_setup(dwc);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+
+		if (dwc->usb2_phy)
+			otg_set_vbus(dwc->usb2_phy->otg, false);
+		if (dwc->usb2_generic_phy[0])
+			phy_set_mode(dwc->usb2_generic_phy[0], PHY_MODE_USB_DEVICE);
+		dwc3_pre_set_role(dwc, USB_ROLE_DEVICE);
+		ret = dwc3_gadget_init(dwc);
+		if (ret)
+			dev_err(dwc->dev, "failed to initialize peripheral\n");
+		break;
+	default:
+		break;
+	}
+}
+
+static void dwc3_drd_update(struct dwc3 *dwc)
+{
+	int id;
+
+	if (dwc->edev) {
+		id = extcon_get_state(dwc->edev, EXTCON_USB_HOST);
+		if (id < 0)
+			id = 0;
+		dwc3_set_mode(dwc, id ?
+			      DWC3_GCTL_PRTCAP_HOST :
+			      DWC3_GCTL_PRTCAP_DEVICE);
+	}
+}
+
+static int dwc3_drd_notifier(struct notifier_block *nb,
+			     unsigned long event, void *ptr)
+{
+	struct dwc3 *dwc = container_of(nb, struct dwc3, edev_nb);
+	u32 mode = event ? DWC3_GCTL_PRTCAP_HOST : DWC3_GCTL_PRTCAP_DEVICE;
+	enum usb_role role = mode == DWC3_GCTL_PRTCAP_HOST ?
+				     USB_ROLE_HOST : USB_ROLE_DEVICE;
+
+	dwc3_pre_set_role(dwc, role);
+	dwc3_set_mode(dwc, mode);
+
+	return NOTIFY_DONE;
+}
+
+#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
+#define ROLE_SWITCH 1
+static int dwc3_usb_role_switch_set(struct usb_role_switch *sw,
+				    enum usb_role role)
+{
+	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
+	u32 mode;
+
+	switch (role) {
+	case USB_ROLE_HOST:
+		mode = DWC3_GCTL_PRTCAP_HOST;
+		break;
+	case USB_ROLE_DEVICE:
+		mode = DWC3_GCTL_PRTCAP_DEVICE;
+		break;
+	default:
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			mode = DWC3_GCTL_PRTCAP_HOST;
+		else
+			mode = DWC3_GCTL_PRTCAP_DEVICE;
+		break;
+	}
+
+	dwc3_pre_set_role(dwc, role);
+	dwc3_set_mode(dwc, mode);
+	return 0;
+}
+
+static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
+{
+	struct dwc3 *dwc = usb_role_switch_get_drvdata(sw);
+	unsigned long flags;
+	enum usb_role role;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_HOST:
+		role = USB_ROLE_HOST;
+		break;
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		role = USB_ROLE_DEVICE;
+		break;
+	case DWC3_GCTL_PRTCAP_OTG:
+		role = dwc->current_otg_role;
+		break;
+	default:
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			role = USB_ROLE_HOST;
+		else
+			role = USB_ROLE_DEVICE;
+		break;
+	}
+	spin_unlock_irqrestore(&dwc->lock, flags);
+	return role;
+}
+
+static int dwc3_setup_role_switch(struct dwc3 *dwc)
+{
+	struct usb_role_switch_desc dwc3_role_switch = {NULL};
+	u32 mode;
+
+	dwc->role_switch_default_mode = usb_get_role_switch_default_mode(dwc->dev);
+	if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) {
+		mode = DWC3_GCTL_PRTCAP_HOST;
+	} else {
+		dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
+		mode = DWC3_GCTL_PRTCAP_DEVICE;
+	}
+	dwc3_set_mode(dwc, mode);
+
+	dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
+	dwc3_role_switch.set = dwc3_usb_role_switch_set;
+	dwc3_role_switch.get = dwc3_usb_role_switch_get;
+	dwc3_role_switch.driver_data = dwc;
+	dwc3_role_switch.allow_userspace_control = true;
+	dwc->role_sw = usb_role_switch_register(dwc->dev, &dwc3_role_switch);
+	if (IS_ERR(dwc->role_sw))
+		return PTR_ERR(dwc->role_sw);
+
+	if (dwc->dev->of_node) {
+		/* populate connector entry */
+		int ret = devm_of_platform_populate(dwc->dev);
+
+		if (ret) {
+			usb_role_switch_unregister(dwc->role_sw);
+			dwc->role_sw = NULL;
+			dev_err(dwc->dev, "DWC3 platform devices creation failed: %i\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+#else
+#define ROLE_SWITCH 0
+#define dwc3_setup_role_switch(x) 0
+#endif
+
+int dwc3_drd_init(struct dwc3 *dwc)
+{
+	int ret, irq;
+
+	if (ROLE_SWITCH &&
+	    device_property_read_bool(dwc->dev, "usb-role-switch"))
+		return dwc3_setup_role_switch(dwc);
+
+	if (dwc->edev) {
+		dwc->edev_nb.notifier_call = dwc3_drd_notifier;
+		ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
+					       &dwc->edev_nb);
+		if (ret < 0) {
+			dev_err(dwc->dev, "couldn't register cable notifier\n");
+			return ret;
+		}
+
+		dwc3_drd_update(dwc);
+	} else {
+		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_OTG, true);
+
+		/* use OTG block to get ID event */
+		irq = dwc3_otg_get_irq(dwc);
+		if (irq < 0)
+			return irq;
+
+		dwc->otg_irq = irq;
+
+		/* disable all OTG IRQs */
+		dwc3_otg_disable_events(dwc, DWC3_OTG_ALL_EVENTS);
+		/* clear all events */
+		dwc3_otg_clear_events(dwc);
+
+		ret = request_threaded_irq(dwc->otg_irq, dwc3_otg_irq,
+					   dwc3_otg_thread_irq,
+					   IRQF_SHARED, "dwc3-otg", dwc);
+		if (ret) {
+			dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
+				dwc->otg_irq, ret);
+			ret = -ENODEV;
+			return ret;
+		}
+
+		dwc3_otg_init(dwc);
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
+	}
+
+	return 0;
+}
+
+void dwc3_drd_exit(struct dwc3 *dwc)
+{
+	unsigned long flags;
+
+	if (dwc->role_sw)
+		usb_role_switch_unregister(dwc->role_sw);
+
+	if (dwc->edev)
+		extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
+					   &dwc->edev_nb);
+
+	cancel_work_sync(&dwc->drd_work);
+
+	/* debug user might have changed role, clean based on current role */
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_HOST:
+		dwc3_host_exit(dwc);
+		break;
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		dwc3_gadget_exit(dwc);
+		dwc3_event_buffers_cleanup(dwc);
+		break;
+	case DWC3_GCTL_PRTCAP_OTG:
+		dwc3_otg_exit(dwc);
+		spin_lock_irqsave(&dwc->lock, flags);
+		dwc->desired_otg_role = DWC3_OTG_ROLE_IDLE;
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		dwc3_otg_update(dwc, 1);
+		break;
+	default:
+		break;
+	}
+
+	if (dwc->otg_irq)
+		free_irq(dwc->otg_irq, dwc);
+}