EHCI: centralize controller suspend/resume

This patch (as1563) removes a lot of duplicated code by moving the
EHCI controller suspend/resume routines into the core driver, where
the various platform drivers can invoke them as needed.

Not only does this simplify these platform drivers, this also makes it
easier for other platform drivers to add suspend/resume support in the
future.

Note: The patch does not touch the ehci-fsl.c file, because its
approach to suspend and resume is so different from all the others.
It will have to be handled specially by its maintainer.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-au1xxx.c

@@ -158,28 +158,10 @@ static int ehci_hcd_au1xxx_drv_remove(struct platform_device *pdev)
 static int ehci_hcd_au1xxx_drv_suspend(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
-	unsigned long flags;
-	int rc = 0;
-
-	if (time_before(jiffies, ehci->next_statechange))
-		msleep(10);
-
-	/* Root hub was already suspended. Disable irq emission and
-	 * mark HW unaccessible.  The PM and USB cores make sure that
-	 * the root hub is either suspended or stopped.
-	 */
-	ehci_prepare_ports_for_controller_suspend(ehci, device_may_wakeup(dev));
-	spin_lock_irqsave(&ehci->lock, flags);
-	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
-	(void)ehci_readl(ehci, &ehci->regs->intr_enable);
-
-	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-	spin_unlock_irqrestore(&ehci->lock, flags);
-
-	// could save FLADJ in case of Vaux power loss
-	// ... we'd only use it to handle clock skew
+	bool do_wakeup = device_may_wakeup(dev);
+	int rc;
 
+	rc = ehci_suspend(hcd, do_wakeup);
 	alchemy_usb_control(ALCHEMY_USB_EHCI0, 0);
 
 	return rc;
@@ -188,56 +170,9 @@ static int ehci_hcd_au1xxx_drv_suspend(struct device *dev)
 static int ehci_hcd_au1xxx_drv_resume(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
 
 	alchemy_usb_control(ALCHEMY_USB_EHCI0, 1);
-
-	// maybe restore FLADJ
-
-	if (time_before(jiffies, ehci->next_statechange))
-		msleep(100);
-
-	/* Mark hardware accessible again as we are out of D3 state by now */
-	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-
-	/* If CF is still set, we maintained PCI Vaux power.
-	 * Just undo the effect of ehci_pci_suspend().
-	 */
-	if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF) {
-		int	mask = INTR_MASK;
-
-		ehci_prepare_ports_for_controller_resume(ehci);
-		if (!hcd->self.root_hub->do_remote_wakeup)
-			mask &= ~STS_PCD;
-		ehci_writel(ehci, mask, &ehci->regs->intr_enable);
-		ehci_readl(ehci, &ehci->regs->intr_enable);
-		return 0;
-	}
-
-	ehci_dbg(ehci, "lost power, restarting\n");
-	usb_root_hub_lost_power(hcd->self.root_hub);
-
-	/* Else reset, to cope with power loss or flush-to-storage
-	 * style "resume" having let BIOS kick in during reboot.
-	 */
-	(void) ehci_halt(ehci);
-	(void) ehci_reset(ehci);
-
-	/* emptying the schedule aborts any urbs */
-	spin_lock_irq(&ehci->lock);
-	if (ehci->reclaim)
-		end_unlink_async(ehci);
-	ehci_work(ehci);
-	spin_unlock_irq(&ehci->lock);
-
-	ehci_writel(ehci, ehci->command, &ehci->regs->command);
-	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
-	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
-
-	/* here we "know" root ports should always stay powered */
-	ehci_port_power(ehci, 1);
-
-	ehci->rh_state = EHCI_RH_SUSPENDED;
+	ehci_resume(hcd, false);
 
 	return 0;
 }

drivers/usb/host/ehci-hcd.c

@@ -1242,6 +1242,95 @@ static int ehci_get_frame (struct usb_hcd *hcd)
 }
 
 /*-------------------------------------------------------------------------*/
+
+#ifdef	CONFIG_PM
+
+/* suspend/resume, section 4.3 */
+
+/* These routines handle the generic parts of controller suspend/resume */
+
+static int __maybe_unused ehci_suspend(struct usb_hcd *hcd, bool do_wakeup)
+{
+	struct ehci_hcd		*ehci = hcd_to_ehci(hcd);
+
+	if (time_before(jiffies, ehci->next_statechange))
+		msleep(10);
+
+	/*
+	 * Root hub was already suspended.  Disable IRQ emission and
+	 * mark HW unaccessible.  The PM and USB cores make sure that
+	 * the root hub is either suspended or stopped.
+	 */
+	ehci_prepare_ports_for_controller_suspend(ehci, do_wakeup);
+
+	spin_lock_irq(&ehci->lock);
+	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
+	(void) ehci_readl(ehci, &ehci->regs->intr_enable);
+
+	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+	spin_unlock_irq(&ehci->lock);
+
+	return 0;
+}
+
+/* Returns 0 if power was preserved, 1 if power was lost */
+static int __maybe_unused ehci_resume(struct usb_hcd *hcd, bool hibernated)
+{
+	struct ehci_hcd		*ehci = hcd_to_ehci(hcd);
+
+	if (time_before(jiffies, ehci->next_statechange))
+		msleep(100);
+
+	/* Mark hardware accessible again as we are back to full power by now */
+	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+
+	/*
+	 * If CF is still set and we aren't resuming from hibernation
+	 * then we maintained suspend power.
+	 * Just undo the effect of ehci_suspend().
+	 */
+	if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF &&
+			!hibernated) {
+		int	mask = INTR_MASK;
+
+		ehci_prepare_ports_for_controller_resume(ehci);
+		if (!hcd->self.root_hub->do_remote_wakeup)
+			mask &= ~STS_PCD;
+		ehci_writel(ehci, mask, &ehci->regs->intr_enable);
+		ehci_readl(ehci, &ehci->regs->intr_enable);
+		return 0;
+	}
+
+	/*
+	 * Else reset, to cope with power loss or resume from hibernation
+	 * having let the firmware kick in during reboot.
+	 */
+	usb_root_hub_lost_power(hcd->self.root_hub);
+	(void) ehci_halt(ehci);
+	(void) ehci_reset(ehci);
+
+	/* emptying the schedule aborts any urbs */
+	spin_lock_irq(&ehci->lock);
+	if (ehci->reclaim)
+		end_unlink_async(ehci);
+	ehci_work(ehci);
+	spin_unlock_irq(&ehci->lock);
+
+	ehci_writel(ehci, ehci->command, &ehci->regs->command);
+	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
+	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
+
+	/* here we "know" root ports should always stay powered */
+	ehci_port_power(ehci, 1);
+
+	ehci->rh_state = EHCI_RH_SUSPENDED;
+	return 1;
+}
+
+#endif
+
+/*-------------------------------------------------------------------------*/
+
 /*
  * The EHCI in ChipIdea HDRC cannot be a separate module or device,
  * because its registers (and irq) are shared between host/gadget/otg

drivers/usb/host/ehci-hub.c

@@ -107,7 +107,7 @@ static void ehci_handover_companion_ports(struct ehci_hcd *ehci)
 	ehci->owned_ports = 0;
 }
 
-static int __maybe_unused ehci_port_change(struct ehci_hcd *ehci)
+static int ehci_port_change(struct ehci_hcd *ehci)
 {
 	int i = HCS_N_PORTS(ehci->hcs_params);
 
@@ -128,7 +128,7 @@ static int __maybe_unused ehci_port_change(struct ehci_hcd *ehci)
 	return 0;
 }
 
-static __maybe_unused void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci,
+static void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci,
 		bool suspending, bool do_wakeup)
 {
 	int		port;

drivers/usb/host/ehci-msm.c

@@ -198,32 +198,19 @@ static int __devexit ehci_msm_remove(struct platform_device *pdev)
 static int ehci_msm_pm_suspend(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	bool wakeup = device_may_wakeup(dev);
+	bool do_wakeup = device_may_wakeup(dev);
 
 	dev_dbg(dev, "ehci-msm PM suspend\n");
 
-	/*
-	 * EHCI helper function has also the same check before manipulating
-	 * port wakeup flags.  We do check here the same condition before
-	 * calling the same helper function to avoid bringing hardware
-	 * from Low power mode when there is no need for adjusting port
-	 * wakeup flags.
-	 */
-	if (hcd->self.root_hub->do_remote_wakeup && !wakeup) {
-		pm_runtime_resume(dev);
-		ehci_prepare_ports_for_controller_suspend(hcd_to_ehci(hcd),
-				wakeup);
-	}
-
-	return 0;
+	return ehci_suspend(hcd, do_wakeup);
 }
 
 static int ehci_msm_pm_resume(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 
 	dev_dbg(dev, "ehci-msm PM resume\n");
-	ehci_prepare_ports_for_controller_resume(hcd_to_ehci(hcd));
+	ehci_resume(hcd, false);
 
 	return 0;
 }

drivers/usb/host/ehci-pci.c

@@ -331,29 +331,7 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
 
 static int ehci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
 {
-	struct ehci_hcd		*ehci = hcd_to_ehci(hcd);
-	unsigned long		flags;
-	int			rc = 0;
-
-	if (time_before(jiffies, ehci->next_statechange))
-		msleep(10);
-
-	/* Root hub was already suspended. Disable irq emission and
-	 * mark HW unaccessible.  The PM and USB cores make sure that
-	 * the root hub is either suspended or stopped.
-	 */
-	ehci_prepare_ports_for_controller_suspend(ehci, do_wakeup);
-	spin_lock_irqsave (&ehci->lock, flags);
-	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
-	(void)ehci_readl(ehci, &ehci->regs->intr_enable);
-
-	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-	spin_unlock_irqrestore (&ehci->lock, flags);
-
-	// could save FLADJ in case of Vaux power loss
-	// ... we'd only use it to handle clock skew
-
-	return rc;
+	return ehci_suspend(hcd, do_wakeup);
 }
 
 static bool usb_is_intel_switchable_ehci(struct pci_dev *pdev)
@@ -402,54 +380,8 @@ static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 	if (usb_is_intel_switchable_ehci(pdev))
 		ehci_enable_xhci_companion();
 
-	// maybe restore FLADJ
-
-	if (time_before(jiffies, ehci->next_statechange))
-		msleep(100);
-
-	/* Mark hardware accessible again as we are out of D3 state by now */
-	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-
-	/* If CF is still set and we aren't resuming from hibernation
-	 * then we maintained PCI Vaux power.
-	 * Just undo the effect of ehci_pci_suspend().
-	 */
-	if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF &&
-				!hibernated) {
-		int	mask = INTR_MASK;
-
-		ehci_prepare_ports_for_controller_resume(ehci);
-		if (!hcd->self.root_hub->do_remote_wakeup)
-			mask &= ~STS_PCD;
-		ehci_writel(ehci, mask, &ehci->regs->intr_enable);
-		ehci_readl(ehci, &ehci->regs->intr_enable);
-		return 0;
-	}
-
-	usb_root_hub_lost_power(hcd->self.root_hub);
-
-	/* Else reset, to cope with power loss or flush-to-storage
-	 * style "resume" having let BIOS kick in during reboot.
-	 */
-	(void) ehci_halt(ehci);
-	(void) ehci_reset(ehci);
-	(void) ehci_pci_reinit(ehci, pdev);
-
-	/* emptying the schedule aborts any urbs */
-	spin_lock_irq(&ehci->lock);
-	if (ehci->reclaim)
-		end_unlink_async(ehci);
-	ehci_work(ehci);
-	spin_unlock_irq(&ehci->lock);
-
-	ehci_writel(ehci, ehci->command, &ehci->regs->command);
-	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
-	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
-
-	/* here we "know" root ports should always stay powered */
-	ehci_port_power(ehci, 1);
-
-	ehci->rh_state = EHCI_RH_SUSPENDED;
+	if (ehci_resume(hcd, hibernated) != 0)
+		(void) ehci_pci_reinit(ehci, pdev);
 	return 0;
 }
 #endif

drivers/usb/host/ehci-platform.c

@@ -153,17 +153,16 @@ static int __devexit ehci_platform_remove(struct platform_device *dev)
 static int ehci_platform_suspend(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	bool wakeup = device_may_wakeup(dev);
+	bool do_wakeup = device_may_wakeup(dev);
 
-	ehci_prepare_ports_for_controller_suspend(hcd_to_ehci(hcd), wakeup);
-	return 0;
+	return ehci_suspend(hcd, do_wakeup);
 }
 
 static int ehci_platform_resume(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 
-	ehci_prepare_ports_for_controller_resume(hcd_to_ehci(hcd));
+	ehci_resume(hcd, false);
 	return 0;
 }