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>

1 files changed, 89 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index c49fc1e7895d..e6823a0cf642 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/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