EHCI: update PM methods in ehci-tegra.c

This patch (as1547) rearranges the Power Management parts of the
ehci-tegra driver to match the conventions used in other EHCI platform
drivers.  In particular, the controller should not be powered down by
the root hub's suspend routine; the controller's power level should be
managed by the controller's own PM methods.

The end result of the patch is that the standard ehci_bus_suspend()
and ehci_bus_resume() methods can be used instead of special-purpose
routines.  The driver now uses the standard dev_pm_ops methods instead
of legacy power management.  Since there is no supported wakeup
mechanism for the controller, runtime suspend is forbidden by default
(this can be overridden via sysfs, if desired).

These adjustments are needed in order to make ehci-tegra compatible
with recent changes to the USB core.  The core now checks the root
hub's status following bus suspend; if the controller is automatically
powered down during bus suspend then the check will fail and the root
hub will be resumed immediately.  Doing the controller power-down in a
separate method avoids this problem.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-tegra.c

@@ -24,6 +24,7 @@
 #include <linux/gpio.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
+#include <linux/pm_runtime.h>
 
 #include <mach/usb_phy.h>
 #include <mach/iomap.h>
@@ -37,9 +38,7 @@ struct tegra_ehci_hcd {
 	struct clk *emc_clk;
 	struct usb_phy *transceiver;
 	int host_resumed;
-	int bus_suspended;
 	int port_resuming;
-	int power_down_on_bus_suspend;
 	enum tegra_usb_phy_port_speed port_speed;
 };
 
@@ -273,120 +272,6 @@ static void tegra_ehci_restart(struct usb_hcd *hcd)
 	up_write(&ehci_cf_port_reset_rwsem);
 }
 
-static int tegra_usb_suspend(struct usb_hcd *hcd)
-{
-	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
-	struct ehci_regs __iomem *hw = tegra->ehci->regs;
-	unsigned long flags;
-
-	spin_lock_irqsave(&tegra->ehci->lock, flags);
-
-	tegra->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;
-	ehci_halt(tegra->ehci);
-	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-
-	spin_unlock_irqrestore(&tegra->ehci->lock, flags);
-
-	tegra_ehci_power_down(hcd);
-	return 0;
-}
-
-static int tegra_usb_resume(struct usb_hcd *hcd)
-{
-	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
-	struct ehci_hcd	*ehci = hcd_to_ehci(hcd);
-	struct ehci_regs __iomem *hw = ehci->regs;
-	unsigned long val;
-
-	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-	tegra_ehci_power_up(hcd);
-
-	if (tegra->port_speed > TEGRA_USB_PHY_PORT_SPEED_HIGH) {
-		/* Wait for the phy to detect new devices
-		 * before we restart the controller */
-		msleep(10);
-		goto restart;
-	}
-
-	/* Force the phy to keep data lines in suspend state */
-	tegra_ehci_phy_restore_start(tegra->phy, tegra->port_speed);
-
-	/* Enable host mode */
-	tdi_reset(ehci);
-
-	/* Enable Port Power */
-	val = readl(&hw->port_status[0]);
-	val |= PORT_POWER;
-	writel(val, &hw->port_status[0]);
-	udelay(10);
-
-	/* Check if the phy resume from LP0. When the phy resume from LP0
-	 * USB register will be reset. */
-	if (!readl(&hw->async_next)) {
-		/* Program the field PTC based on the saved speed mode */
-		val = readl(&hw->port_status[0]);
-		val &= ~PORT_TEST(~0);
-		if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_HIGH)
-			val |= PORT_TEST_FORCE;
-		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_FULL)
-			val |= PORT_TEST(6);
-		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_LOW)
-			val |= PORT_TEST(7);
-		writel(val, &hw->port_status[0]);
-		udelay(10);
-
-		/* Disable test mode by setting PTC field to NORMAL_OP */
-		val = readl(&hw->port_status[0]);
-		val &= ~PORT_TEST(~0);
-		writel(val, &hw->port_status[0]);
-		udelay(10);
-	}
-
-	/* Poll until CCS is enabled */
-	if (handshake(ehci, &hw->port_status[0], PORT_CONNECT,
-						 PORT_CONNECT, 2000)) {
-		pr_err("%s: timeout waiting for PORT_CONNECT\n", __func__);
-		goto restart;
-	}
-
-	/* Poll until PE is enabled */
-	if (handshake(ehci, &hw->port_status[0], PORT_PE,
-						 PORT_PE, 2000)) {
-		pr_err("%s: timeout waiting for USB_PORTSC1_PE\n", __func__);
-		goto restart;
-	}
-
-	/* Clear the PCI status, to avoid an interrupt taken upon resume */
-	val = readl(&hw->status);
-	val |= STS_PCD;
-	writel(val, &hw->status);
-
-	/* Put controller in suspend mode by writing 1 to SUSP bit of PORTSC */
-	val = readl(&hw->port_status[0]);
-	if ((val & PORT_POWER) && (val & PORT_PE)) {
-		val |= PORT_SUSPEND;
-		writel(val, &hw->port_status[0]);
-
-		/* Wait until port suspend completes */
-		if (handshake(ehci, &hw->port_status[0], PORT_SUSPEND,
-							 PORT_SUSPEND, 1000)) {
-			pr_err("%s: timeout waiting for PORT_SUSPEND\n",
-								__func__);
-			goto restart;
-		}
-	}
-
-	tegra_ehci_phy_restore_end(tegra->phy);
-	return 0;
-
-restart:
-	if (tegra->port_speed <= TEGRA_USB_PHY_PORT_SPEED_HIGH)
-		tegra_ehci_phy_restore_end(tegra->phy);
-
-	tegra_ehci_restart(hcd);
-	return 0;
-}
-
 static void tegra_ehci_shutdown(struct usb_hcd *hcd)
 {
 	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
@@ -434,36 +319,6 @@ static int tegra_ehci_setup(struct usb_hcd *hcd)
 	return retval;
 }
 
-#ifdef CONFIG_PM
-static int tegra_ehci_bus_suspend(struct usb_hcd *hcd)
-{
-	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
-	int error_status = 0;
-
-	error_status = ehci_bus_suspend(hcd);
-	if (!error_status && tegra->power_down_on_bus_suspend) {
-		tegra_usb_suspend(hcd);
-		tegra->bus_suspended = 1;
-	}
-
-	return error_status;
-}
-
-static int tegra_ehci_bus_resume(struct usb_hcd *hcd)
-{
-	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
-
-	if (tegra->bus_suspended && tegra->power_down_on_bus_suspend) {
-		tegra_usb_resume(hcd);
-		tegra->bus_suspended = 0;
-	}
-
-	tegra_usb_phy_preresume(tegra->phy);
-	tegra->port_resuming = 1;
-	return ehci_bus_resume(hcd);
-}
-#endif
-
 struct temp_buffer {
 	void *kmalloc_ptr;
 	void *old_xfer_buffer;
@@ -574,8 +429,8 @@ static const struct hc_driver tegra_ehci_hc_driver = {
 	.hub_control		= tegra_ehci_hub_control,
 	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
 #ifdef CONFIG_PM
-	.bus_suspend		= tegra_ehci_bus_suspend,
-	.bus_resume		= tegra_ehci_bus_resume,
+	.bus_suspend		= ehci_bus_suspend,
+	.bus_resume		= ehci_bus_resume,
 #endif
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
@@ -608,6 +463,183 @@ static int setup_vbus_gpio(struct platform_device *pdev)
 	return err;
 }
 
+#ifdef CONFIG_PM
+
+static int controller_suspend(struct device *dev)
+{
+	struct tegra_ehci_hcd *tegra =
+			platform_get_drvdata(to_platform_device(dev));
+	struct ehci_hcd	*ehci = tegra->ehci;
+	struct usb_hcd *hcd = ehci_to_hcd(ehci);
+	struct ehci_regs __iomem *hw = ehci->regs;
+	unsigned long flags;
+
+	if (time_before(jiffies, ehci->next_statechange))
+		msleep(10);
+
+	spin_lock_irqsave(&ehci->lock, flags);
+
+	tegra->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;
+	ehci_halt(ehci);
+	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+
+	spin_unlock_irqrestore(&ehci->lock, flags);
+
+	tegra_ehci_power_down(hcd);
+	return 0;
+}
+
+static int controller_resume(struct device *dev)
+{
+	struct tegra_ehci_hcd *tegra =
+			platform_get_drvdata(to_platform_device(dev));
+	struct ehci_hcd	*ehci = tegra->ehci;
+	struct usb_hcd *hcd = ehci_to_hcd(ehci);
+	struct ehci_regs __iomem *hw = ehci->regs;
+	unsigned long val;
+
+	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+	tegra_ehci_power_up(hcd);
+
+	if (tegra->port_speed > TEGRA_USB_PHY_PORT_SPEED_HIGH) {
+		/* Wait for the phy to detect new devices
+		 * before we restart the controller */
+		msleep(10);
+		goto restart;
+	}
+
+	/* Force the phy to keep data lines in suspend state */
+	tegra_ehci_phy_restore_start(tegra->phy, tegra->port_speed);
+
+	/* Enable host mode */
+	tdi_reset(ehci);
+
+	/* Enable Port Power */
+	val = readl(&hw->port_status[0]);
+	val |= PORT_POWER;
+	writel(val, &hw->port_status[0]);
+	udelay(10);
+
+	/* Check if the phy resume from LP0. When the phy resume from LP0
+	 * USB register will be reset. */
+	if (!readl(&hw->async_next)) {
+		/* Program the field PTC based on the saved speed mode */
+		val = readl(&hw->port_status[0]);
+		val &= ~PORT_TEST(~0);
+		if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_HIGH)
+			val |= PORT_TEST_FORCE;
+		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_FULL)
+			val |= PORT_TEST(6);
+		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_LOW)
+			val |= PORT_TEST(7);
+		writel(val, &hw->port_status[0]);
+		udelay(10);
+
+		/* Disable test mode by setting PTC field to NORMAL_OP */
+		val = readl(&hw->port_status[0]);
+		val &= ~PORT_TEST(~0);
+		writel(val, &hw->port_status[0]);
+		udelay(10);
+	}
+
+	/* Poll until CCS is enabled */
+	if (handshake(ehci, &hw->port_status[0], PORT_CONNECT,
+						 PORT_CONNECT, 2000)) {
+		pr_err("%s: timeout waiting for PORT_CONNECT\n", __func__);
+		goto restart;
+	}
+
+	/* Poll until PE is enabled */
+	if (handshake(ehci, &hw->port_status[0], PORT_PE,
+						 PORT_PE, 2000)) {
+		pr_err("%s: timeout waiting for USB_PORTSC1_PE\n", __func__);
+		goto restart;
+	}
+
+	/* Clear the PCI status, to avoid an interrupt taken upon resume */
+	val = readl(&hw->status);
+	val |= STS_PCD;
+	writel(val, &hw->status);
+
+	/* Put controller in suspend mode by writing 1 to SUSP bit of PORTSC */
+	val = readl(&hw->port_status[0]);
+	if ((val & PORT_POWER) && (val & PORT_PE)) {
+		val |= PORT_SUSPEND;
+		writel(val, &hw->port_status[0]);
+
+		/* Wait until port suspend completes */
+		if (handshake(ehci, &hw->port_status[0], PORT_SUSPEND,
+							 PORT_SUSPEND, 1000)) {
+			pr_err("%s: timeout waiting for PORT_SUSPEND\n",
+								__func__);
+			goto restart;
+		}
+	}
+
+	tegra_ehci_phy_restore_end(tegra->phy);
+	goto done;
+
+ restart:
+	if (tegra->port_speed <= TEGRA_USB_PHY_PORT_SPEED_HIGH)
+		tegra_ehci_phy_restore_end(tegra->phy);
+
+	tegra_ehci_restart(hcd);
+
+ done:
+	tegra_usb_phy_preresume(tegra->phy);
+	tegra->port_resuming = 1;
+	return 0;
+}
+
+static int tegra_ehci_suspend(struct device *dev)
+{
+	struct tegra_ehci_hcd *tegra =
+			platform_get_drvdata(to_platform_device(dev));
+	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+	int rc = 0;
+
+	/*
+	 * When system sleep is supported and USB controller wakeup is
+	 * implemented: If the controller is runtime-suspended and the
+	 * wakeup setting needs to be changed, call pm_runtime_resume().
+	 */
+	if (HCD_HW_ACCESSIBLE(hcd))
+		rc = controller_suspend(dev);
+	return rc;
+}
+
+static int tegra_ehci_resume(struct device *dev)
+{
+	int rc;
+
+	rc = controller_resume(dev);
+	if (rc == 0) {
+		pm_runtime_disable(dev);
+		pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+	}
+	return rc;
+}
+
+static int tegra_ehci_runtime_suspend(struct device *dev)
+{
+	return controller_suspend(dev);
+}
+
+static int tegra_ehci_runtime_resume(struct device *dev)
+{
+	return controller_resume(dev);
+}
+
+static const struct dev_pm_ops tegra_ehci_pm_ops = {
+	.suspend	= tegra_ehci_suspend,
+	.resume		= tegra_ehci_resume,
+	.runtime_suspend = tegra_ehci_runtime_suspend,
+	.runtime_resume	= tegra_ehci_runtime_resume,
+};
+
+#endif
+
 static u64 tegra_ehci_dma_mask = DMA_BIT_MASK(32);
 
 static int tegra_ehci_probe(struct platform_device *pdev)
@@ -722,7 +754,6 @@ static int tegra_ehci_probe(struct platform_device *pdev)
 	}
 
 	tegra->host_resumed = 1;
-	tegra->power_down_on_bus_suspend = pdata->power_down_on_bus_suspend;
 	tegra->ehci = hcd_to_ehci(hcd);
 
 	irq = platform_get_irq(pdev, 0);
@@ -746,6 +777,14 @@ static int tegra_ehci_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+
+	/* Don't skip the pm_runtime_forbid call if wakeup isn't working */
+	/* if (!pdata->power_down_on_bus_suspend) */
+		pm_runtime_forbid(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
 	return err;
 
 fail:
@@ -772,33 +811,6 @@ static int tegra_ehci_probe(struct platform_device *pdev)
 	return err;
 }
 
-#ifdef CONFIG_PM
-static int tegra_ehci_resume(struct platform_device *pdev)
-{
-	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
-	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
-
-	if (tegra->bus_suspended)
-		return 0;
-
-	return tegra_usb_resume(hcd);
-}
-
-static int tegra_ehci_suspend(struct platform_device *pdev, pm_message_t state)
-{
-	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
-	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
-
-	if (tegra->bus_suspended)
-		return 0;
-
-	if (time_before(jiffies, tegra->ehci->next_statechange))
-		msleep(10);
-
-	return tegra_usb_suspend(hcd);
-}
-#endif
-
 static int tegra_ehci_remove(struct platform_device *pdev)
 {
 	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
@@ -807,6 +819,10 @@ static int tegra_ehci_remove(struct platform_device *pdev)
 	if (tegra == NULL || hcd == NULL)
 		return -EINVAL;
 
+	pm_runtime_get_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
 #ifdef CONFIG_USB_OTG_UTILS
 	if (tegra->transceiver) {
 		otg_set_host(tegra->transceiver->otg, NULL);
@@ -847,13 +863,12 @@ static struct of_device_id tegra_ehci_of_match[] __devinitdata = {
 static struct platform_driver tegra_ehci_driver = {
 	.probe		= tegra_ehci_probe,
 	.remove		= tegra_ehci_remove,
-#ifdef CONFIG_PM
-	.suspend	= tegra_ehci_suspend,
-	.resume		= tegra_ehci_resume,
-#endif
 	.shutdown	= tegra_ehci_hcd_shutdown,
 	.driver		= {
 		.name	= "tegra-ehci",
 		.of_match_table = tegra_ehci_of_match,
+#ifdef CONFIG_PM
+		.pm	= &tegra_ehci_pm_ops,
+#endif
 	}
 };