ENGR00126584 usb gadget driver: Clarify some usb handling routines

1. When the usb is not in use, the usb can be put into low power mode
(usb related clock are off, and phcd = 1)
2. When the usb is in low power mode, the usb wakeup irq can be triggered,
and let the usb return to normal mode
3. The flag device_can_wakeup(struct device *dev) is standing for the device
has(and will use) the abilities for waking up the whole system, not means
the device has the abilities for waking up itself.
4. During the pm process, wakeup is only needed to enable when the user
needs usb device to wakeup the whole system.
5. The initialization changes a little, for evk board is not connected to pc
as an example:
Loading the driver:
1. Clear phcd and Open clock 
2. init usb registers 
3. vbus is not valid, and go to low power mode
connect usb line to pc:
1. Wakeup irq happens 
2. usb goes to normal mode
3. vbus irq happens(at the same interrupt)
4. set run_stop bit
5. enumeration begins

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Huhui <b29976@freescale.com>

1 files changed, 68 insertions, 51 deletions

diff --git a/drivers/usb/gadget/arcotg_udc.c b/drivers/usb/gadget/arcotg_udc.c
index 9947da5fa035..161557f4b2a9 100644
--- a/drivers/usb/gadget/arcotg_udc.c
+++ b/drivers/usb/gadget/arcotg_udc.c
@@ -112,9 +112,6 @@ dr_wake_up_enable(struct fsl_udc *udc, bool enable)
 	struct fsl_usb2_platform_data *pdata;
 	pdata = udc->pdata;
 
-	if (enable && (!device_may_wakeup(udc_controller->gadget.dev.parent)))
-		return;
-
 	if (pdata->wake_up_enable)
 		pdata->wake_up_enable(pdata, enable);
 }
@@ -304,10 +301,6 @@ static void nuke(struct fsl_ep *ep, int status)
 static void dr_phy_low_power_mode(struct fsl_udc *udc, bool enable)
 {
 	u32 temp;
-
-	if (!device_may_wakeup(udc_controller->gadget.dev.parent))
-		return;
-
 	if (enable) {
 		temp = fsl_readl(&dr_regs->portsc1);
 		temp |= PORTSCX_PHY_LOW_POWER_SPD;
@@ -321,6 +314,7 @@ static void dr_phy_low_power_mode(struct fsl_udc *udc, bool enable)
 
 		/* Due to mx35/mx25's phy's bug */
 		reset_phy();
+
 		temp = fsl_readl(&dr_regs->portsc1);
 		temp &= ~PORTSCX_PHY_LOW_POWER_SPD;
 		fsl_writel(temp, &dr_regs->portsc1);
@@ -448,23 +442,20 @@ static void dr_controller_run(struct fsl_udc *udc)
 
 	fsl_writel(temp, &dr_regs->usbintr);
 
-	if (device_may_wakeup(udc_controller->gadget.dev.parent)) {
-		/* enable BSV irq */
-		temp = fsl_readl(&dr_regs->otgsc);
-		temp |= OTGSC_B_SESSION_VALID_IRQ_EN;
-		fsl_writel(temp, &dr_regs->otgsc);
-	}
+	/* enable BSV irq */
+	temp = fsl_readl(&dr_regs->otgsc);
+	temp |= OTGSC_B_SESSION_VALID_IRQ_EN;
+	fsl_writel(temp, &dr_regs->otgsc);
 
 	/* If vbus not on and used low power mode */
-	if (!(fsl_readl(&dr_regs->otgsc) & OTGSC_B_SESSION_VALID)
-	    && device_may_wakeup(udc_controller->gadget.dev.parent)) {
-		/* enable wake up */
-		dr_wake_up_enable(udc, true);
+	if (!(temp & OTGSC_B_SESSION_VALID)) {
 		/* Set stopped before low power mode */
 		udc->stopped = 1;
+		/* enable wake up */
+		dr_wake_up_enable(udc, true);
 		/* close PHY clock */
 		dr_phy_low_power_mode(udc, true);
-		printk(KERN_INFO "udc enter low power mode \n");
+		printk(KERN_INFO "%s: udc enter low power mode \n", __func__);
 	} else {
 #ifdef CONFIG_ARCH_MX37
 		/*
@@ -476,11 +467,11 @@ static void dr_controller_run(struct fsl_udc *udc)
 #endif
 		/* Clear stopped bit */
 		udc->stopped = 0;
-		/* Set controller to Run */
+
+		/* The usb line has already been connected to pc */
 		temp = fsl_readl(&dr_regs->usbcmd);
 		temp |= USB_CMD_RUN_STOP;
 		fsl_writel(temp, &dr_regs->usbcmd);
-		printk(KERN_INFO "udc run \n");
 	}
 
 	return;
@@ -2056,9 +2047,6 @@ bool try_wake_up_udc(struct fsl_udc *udc)
 
 	/* when udc is stopped, only handle wake up irq */
 	if (udc->stopped) {
-		if (!device_may_wakeup(&(udc->pdata->pdev->dev)))
-			return false;
-
 		dr_phy_low_power_mode(udc_controller, false);
 
 		/* check to see if wake up irq */
@@ -2070,9 +2058,6 @@ bool try_wake_up_udc(struct fsl_udc *udc)
 		}
 	}
 
-	if (!device_may_wakeup(udc_controller->gadget.dev.parent))
-		return true;
-
 	/* check if Vbus change irq */
 	irq_src = fsl_readl(&dr_regs->otgsc);
 	if (irq_src & OTGSC_B_SESSION_VALID_IRQ_STS) {
@@ -2083,13 +2068,13 @@ bool try_wake_up_udc(struct fsl_udc *udc)
 		if (irq_src & OTGSC_B_SESSION_VALID) {
 			udc->stopped = 0;
 			fsl_writel(tmp | USB_CMD_RUN_STOP, &dr_regs->usbcmd);
-			printk(KERN_INFO "udc out low power mode\n");
+			printk(KERN_INFO "%s: udc out low power mode\n", __func__);
 		} else {
-			printk(KERN_INFO "udc enter low power mode \n");
+			printk(KERN_INFO "%s: udc enter low power mode \n", __func__);
 			fsl_writel(tmp & ~USB_CMD_RUN_STOP, &dr_regs->usbcmd);
+			udc->stopped = 1;
 			/* enable wake up */
 			dr_wake_up_enable(udc, true);
-			udc->stopped = 1;
 			/* close USB PHY clock */
 			dr_phy_low_power_mode(udc, true);
 			return false;
@@ -2098,7 +2083,6 @@ bool try_wake_up_udc(struct fsl_udc *udc)
 
 	return true;
 }
-
 /*
  * USB device controller interrupt handler
  */
@@ -2109,6 +2093,11 @@ static irqreturn_t fsl_udc_irq(int irq, void *_udc)
 	irqreturn_t status = IRQ_NONE;
 	unsigned long flags;
 
+	/* only handle device interrupt event */
+	if (!(fsl_readl(&dr_regs->otgsc) & OTGSC_STS_USB_ID)) {
+		return IRQ_NONE;
+	}
+
 	if (try_wake_up_udc(udc) == false)
 		return IRQ_NONE;
 
@@ -2117,7 +2106,7 @@ static irqreturn_t fsl_udc_irq(int irq, void *_udc)
 	/* Clear notification bits */
 	fsl_writel(irq_src, &dr_regs->usbsts);
 
-	/* VDBG("irq_src [0x%8x]", irq_src); */
+	VDBG("0x%x\n", irq_src);
 
 	/* Need to resume? */
 	if (udc->usb_state == USB_STATE_SUSPENDED)
@@ -2162,6 +2151,7 @@ static irqreturn_t fsl_udc_irq(int irq, void *_udc)
 
 	/* Sleep Enable (Suspend) */
 	if (irq_src & USB_STS_SUSPEND) {
+		VDBG("suspend int");
 		suspend_irq(udc);
 		status = IRQ_HANDLED;
 	}
@@ -2182,7 +2172,6 @@ int usb_gadget_register_driver(struct usb_gadget_driver *driver)
 {
 	int retval = -ENODEV;
 	unsigned long flags = 0;
-	u32 portsc;
 
 	if (!udc_controller)
 		return -ENODEV;
@@ -2205,12 +2194,11 @@ int usb_gadget_register_driver(struct usb_gadget_driver *driver)
 	udc_controller->gadget.dev.driver = &driver->driver;
 	spin_unlock_irqrestore(&udc_controller->lock, flags);
 
-	if (udc_controller->pdata->usb_clock_for_pm)
-		udc_controller->pdata->usb_clock_for_pm(true);
-
-	portsc = fsl_readl(&dr_regs->portsc1);
-	portsc &= ~PORTSCX_PHY_LOW_POWER_SPD;
-	fsl_writel(portsc, &dr_regs->portsc1);
+	/* It doesn't need to switch usb from low power mode to normal mode
+	 * at otg mode
+	 */
+	if (!udc_controller->transceiver)
+		dr_phy_low_power_mode(udc_controller, false);
 
 	/* bind udc driver to gadget driver */
 	retval = driver->bind(&udc_controller->gadget);
@@ -2265,7 +2253,6 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 {
 	struct fsl_ep *loop_ep;
 	unsigned long flags;
-	u32 portsc;
 
 	if (!udc_controller)
 		return -ENODEV;
@@ -2305,12 +2292,7 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 
 	dr_wake_up_enable(udc_controller, false);
 
-	portsc = fsl_readl(&dr_regs->portsc1);
-	portsc |= PORTSCX_PHY_LOW_POWER_SPD;
-	fsl_writel(portsc, &dr_regs->portsc1);
-
-	if (udc_controller->pdata->usb_clock_for_pm)
-		udc_controller->pdata->usb_clock_for_pm(false);
+	dr_phy_low_power_mode(udc_controller, true);
 
 	printk(KERN_INFO "unregistered gadget driver '%s'\r\n",
 	       driver->driver.name);
@@ -2917,7 +2899,6 @@ err1a:
  */
 static int __exit fsl_udc_remove(struct platform_device *pdev)
 {
-	struct resource *res;
 	struct fsl_usb2_platform_data *pdata = pdev->dev.platform_data;
 
 	DECLARE_COMPLETION(done);
@@ -2949,8 +2930,11 @@ static int __exit fsl_udc_remove(struct platform_device *pdev)
 	iounmap((u8 __iomem *)dr_regs);
 
 #ifndef CONFIG_USB_OTG
+{
+	struct resource *res;
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(res->start, resource_size(res));
+}
 #endif
 
 	device_unregister(&udc_controller->gadget.dev);
@@ -2975,6 +2959,18 @@ static int udc_suspend(struct fsl_udc *udc)
 	if (udc_controller->pdata->usb_clock_for_pm)
 		udc_controller->pdata->usb_clock_for_pm(true);
 
+	/*
+	 * When it is the PM suspend routine and the device has no
+	 * abilities to wakeup system, it should not set wakeup enable.
+	 * Otherwise, the system will wakeup even the user only wants to
+	 * charge using usb
+	 */
+	if (!device_may_wakeup(udc_controller->gadget.dev.parent) &&
+		udc_controller->gadget.dev.parent->power.status
+			== DPM_SUSPENDING){
+		dr_wake_up_enable(udc, false);
+	}
+
 	mode = fsl_readl(&dr_regs->usbmode) & USB_MODE_CTRL_MODE_MASK;
 	usbcmd = fsl_readl(&dr_regs->usbcmd);
 
@@ -2997,17 +2993,20 @@ static int udc_suspend(struct fsl_udc *udc)
 	}
 
 	udc->stopped = 1;
+
+	/* stop the controller */
+	usbcmd = fsl_readl(&dr_regs->usbcmd) & ~USB_CMD_RUN_STOP;
+	fsl_writel(usbcmd, &dr_regs->usbcmd);
+
 	/* if the suspend is not for switch to host in otg mode */
 	if ((!(udc->gadget.is_otg)) ||
 			(fsl_readl(&dr_regs->otgsc) & OTGSC_STS_USB_ID)) {
-		dr_wake_up_enable(udc, true);
+		if (device_may_wakeup(udc_controller->gadget.dev.parent)) {
+			dr_wake_up_enable(udc, true);
+		}
 		dr_phy_low_power_mode(udc, true);
 	}
 
-	/* stop the controller */
-	usbcmd = fsl_readl(&dr_regs->usbcmd) & ~USB_CMD_RUN_STOP;
-	fsl_writel(usbcmd, &dr_regs->usbcmd);
-
 	printk(KERN_INFO "USB Gadget suspended\n");
 out:
 	if (udc_controller->pdata->usb_clock_for_pm)
@@ -3044,6 +3043,24 @@ static int fsl_udc_resume(struct platform_device *pdev)
 	 * don't resume it now.
 	 */
 	if (udc_controller->already_stopped) {
+		/*
+		 * If it is PM resume routine, the udc is at low power mode,
+		 * and the udc has no abilities to wakeup system, it should
+		 * set the abilities to wakeup itself. Otherwise, the usb
+		 * subsystem will not leave from low power mode.
+		 */
+		if (!device_may_wakeup(udc_controller->gadget.dev.parent) &&
+			udc_controller->gadget.dev.parent->power.status
+			== DPM_RESUMING){
+			if (udc_controller->pdata->usb_clock_for_pm)
+				udc_controller->pdata->usb_clock_for_pm(true);
+			dr_wake_up_enable(udc_controller, true);
+			if (fsl_readl(&dr_regs->otgsc) & OTGSC_STS_USB_ID) {
+				if (udc_controller->pdata->usb_clock_for_pm)
+					udc_controller->pdata->usb_clock_for_pm(false);
+			}
+		}
+
 		udc_controller->already_stopped = 0;
 		pr_debug("gadget was already stopped, leaving early\n");
 		return 0;