[PATCH 3/7][v5]usb:fsl:otg: Add support to add/remove usb host driver

[Ramneek Mehresh]

Add workqueue to add/remove host driver (outside
interrupt context) upon each id change, and to
remove host driver upon otg initialization by changing
have_hcd variable.

Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
Signed-off-by: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
Reviewed-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/host/ehci-fsl.c | 73 ++++++++++++++++++++++++++++++++-------------
 drivers/usb/host/ehci-fsl.h | 16 ++++++++++
 include/linux/usb.h         |  1 +
 3 files changed, 70 insertions(+), 20 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 3b6eb21..a01860d 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -44,6 +44,31 @@
 
 static struct hc_driver __read_mostly fsl_ehci_hc_driver;
 
+static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd)
+{
+	return (struct ehci_fsl *)hcd_to_ehci(hcd)->priv;
+}
+
+static void do_change_hcd(struct work_struct *work)
+{
+	struct ehci_fsl *ehci_fsl = container_of(work, struct ehci_fsl,
+					change_hcd_work);
+	struct usb_hcd *hcd = ehci_fsl->hcd;
+	void __iomem *non_ehci = hcd->regs;
+	int retval;
+
+	if (ehci_fsl->hcd_add && !ehci_fsl->have_hcd) {
+		writel(USBMODE_CM_HOST, non_ehci + FSL_SOC_USB_USBMODE);
+		/* host, gadget and otg share same int line */
+		retval = usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
+		if (retval == 0)
+			ehci_fsl->have_hcd = 1;
+	} else if (!ehci_fsl->hcd_add && ehci_fsl->have_hcd) {
+		usb_remove_hcd(hcd);
+		ehci_fsl->have_hcd = 0;
+	}
+}
+
 /* configure so an HC device and id are always provided */
 /* always called with process context; sleeping is OK */
 
@@ -147,11 +172,15 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
 		goto err2;
 	device_wakeup_enable(hcd->self.controller);
 
-#ifdef CONFIG_USB_OTG
 	if (pdata->operating_mode == FSL_USB2_DR_OTG) {
 		struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+		struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
 
+		ehci_fsl->hcd = hcd;
 		hcd->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
+
+		INIT_WORK(&ehci_fsl->change_hcd_work, do_change_hcd);
+
 		dev_dbg(&pdev->dev, "hcd=0x%p  ehci=0x%p, phy=0x%p\n",
 			hcd, ehci, hcd->usb_phy);
 
@@ -167,8 +196,10 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
 			retval = -ENODEV;
 			goto err2;
 		}
+
+		ehci_fsl->have_hcd = 1;
 	}
-#endif
+
 	return retval;
 
       err2:
@@ -375,15 +406,6 @@ static int ehci_fsl_setup(struct usb_hcd *hcd)
 	return retval;
 }
 
-struct ehci_fsl {
-	struct ehci_hcd	ehci;
-
-#ifdef CONFIG_PM
-	/* Saved USB PHY settings, need to restore after deep sleep. */
-	u32 usb_ctrl;
-#endif
-};
-
 #ifdef CONFIG_PM
 
 #ifdef CONFIG_PPC_MPC512x
@@ -531,24 +553,26 @@ static inline int ehci_fsl_mpc512x_drv_resume(struct device *dev)
 }
 #endif /* CONFIG_PPC_MPC512x */
 
-static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd)
-{
-	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
-
-	return container_of(ehci, struct ehci_fsl, ehci);
-}
-
 static int ehci_fsl_drv_suspend(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
 	void __iomem *non_ehci = hcd->regs;
+	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+	struct usb_bus *host = &hcd->self;
 
 	if (of_device_is_compatible(dev->parent->of_node,
 				    "fsl,mpc5121-usb2-dr")) {
 		return ehci_fsl_mpc512x_drv_suspend(dev);
 	}
 
+	if (host->is_otg) {
+		/* remove hcd */
+		ehci_fsl->hcd_add = 0;
+		schedule_work(&ehci_fsl->change_hcd_work);
+		host->is_otg = 0;
+		return 0;
+	}
+
 	ehci_prepare_ports_for_controller_suspend(hcd_to_ehci(hcd),
 			device_may_wakeup(dev));
 	if (!fsl_deep_sleep())
@@ -561,15 +585,24 @@ static int ehci_fsl_drv_suspend(struct device *dev)
 static int ehci_fsl_drv_resume(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
-	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
 	void __iomem *non_ehci = hcd->regs;
+	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+	struct usb_bus *host = &hcd->self;
 
 	if (of_device_is_compatible(dev->parent->of_node,
 				    "fsl,mpc5121-usb2-dr")) {
 		return ehci_fsl_mpc512x_drv_resume(dev);
 	}
 
+	if (host->is_otg) {
+		/* add hcd */
+		ehci_fsl->hcd_add = 1;
+		schedule_work(&ehci_fsl->change_hcd_work);
+		host->is_otg = 0;
+		return 0;
+	}
+
 	ehci_prepare_ports_for_controller_resume(ehci);
 	if (!fsl_deep_sleep())
 		return 0;
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index 1a8a60a..64538eb 100644
--- a/drivers/usb/host/ehci-fsl.h
+++ b/drivers/usb/host/ehci-fsl.h
@@ -63,4 +63,20 @@
 #define UTMI_PHY_EN             (1<<9)
 #define ULPI_PHY_CLK_SEL        (1<<10)
 #define PHY_CLK_VALID		(1<<17)
+
+struct ehci_fsl {
+	/* Save USB CTRL, need to restore after deep sleep. */
+	u32 usb_ctrl;
+	struct usb_hcd *hcd;
+	struct work_struct change_hcd_work;
+	/*
+	 * store current hcd state for otg;
+	 * have_hcd is true when host drv al already part of otg framework,
+	 * otherwise false;
+	 * hcd_add is true when otg framework wants to add host
+	 * drv as part of otg;flase when it wants to remove it
+	 */
+	unsigned have_hcd:1;
+	unsigned hcd_add:1;
+};
 #endif				/* _EHCI_FSL_H */
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 89533ba..b7eb033 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -359,6 +359,7 @@ struct usb_bus {
 					 * for control transfers?
 					 */
 	u8 otg_port;			/* 0, or number of OTG/HNP port */
+	unsigned is_otg:1;		/* true when host is also otg */
 	unsigned is_b_host:1;		/* true during some HNP roleswitches */
 	unsigned b_hnp_enable:1;	/* OTG: did A-Host enable HNP? */
 	unsigned no_stop_on_short:1;    /*
-- 
1.8.3.1

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