[tegra-udc] Fix remove mutex call from spin_locks.

Regulator current limit uses mutex, which is called from the irq after acquiring
the spin locks. Similarly when vbus is detected phy clock enable is called,
which uses mutex inside the spin locks. This is fixed by calling these apis
under work when called from interrupt context.

Bug 711837

Change-Id: Ib926ad33d3d3674353447b3d94ff63f9eecf6f65
Reviewed-on: http://git-master/r/4339
Tested-by: Hanumanth Venkateswa Moganty <vmoganty@nvidia.com>
Reviewed-by: Ramachandrudu Kandhala <rkandhala@nvidia.com>
Tested-by: Ramachandrudu Kandhala <rkandhala@nvidia.com>
Reviewed-by: Frank Cheng <fcheng@nvidia.com>
Reviewed-by: Gary King <gking@nvidia.com>

2 files changed, 94 insertions, 56 deletions

diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c
index d5bd426dfb5e..52b006e972f6 100644..100755
--- a/drivers/usb/gadget/fsl_udc_core.c
+++ b/drivers/usb/gadget/fsl_udc_core.c
@@ -72,6 +72,11 @@ static struct usb_dr_device *dr_regs;
 static struct usb_sys_interface *usb_sys_regs;
 #endif
 
+/*
+ * Default current limit after VBUS detection is 100mA, this limit will be
+ * changed to the limit specified in the descriptor after set configuration.
+ */
+#define USB_DEFAULT_CURRENT_LIMIT_MA 100
 /* Charger current limit=1800mA, as per the USB charger spec */
 #define USB_CHARGING_CURRENT_LIMIT_MA 1800
 /* 1 sec wait time for charger detection after vbus is detected */
@@ -1185,12 +1190,16 @@ static int fsl_vbus_session(struct usb_gadget *gadget, int is_active)
 	spin_lock_irqsave(&udc->lock, flags);
 	VDBG("VBUS %s", is_active ? "on" : "off");
 	udc->vbus_active = (is_active != 0);
+#ifdef CONFIG_ARCH_TEGRA
+	schedule_work(&udc->vbus_work);
+#else
 	if (can_pullup(udc))
 		fsl_writel((fsl_readl(&dr_regs->usbcmd) | USB_CMD_RUN_STOP),
 				&dr_regs->usbcmd);
 	else
 		fsl_writel((fsl_readl(&dr_regs->usbcmd) & ~USB_CMD_RUN_STOP),
 				&dr_regs->usbcmd);
+#endif
 	spin_unlock_irqrestore(&udc->lock, flags);
 	return 0;
 }
@@ -1209,8 +1218,10 @@ static int fsl_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 	udc = container_of(gadget, struct fsl_udc, gadget);
 	/* check udc regulator is avalable for drawing the vbus current */
 	if (udc->vbus_regulator) {
-		/* set the current limit in uA and return */
-		return regulator_set_current_limit(udc->vbus_regulator, 0, mA*1000);
+		/* set the current limit and schedule work */
+		udc->current_limit_ma = mA;
+		schedule_work(&udc->irq_work);
+		return 0;
 	}
 
 	if (udc->transceiver)
@@ -1999,6 +2010,32 @@ static void fsl_udc_restart(struct fsl_udc *udc)
 	udc->ep0_state = WAIT_FOR_SETUP;
 	udc->ep0_dir = 0;
 }
+
+/*
+ * Work thread function for handling the USB clocks and D+ line pull up/down.
+ */
+static void fsl_udc_vbus_work(struct work_struct* vbus_work)
+{
+	struct fsl_udc *udc = container_of (vbus_work, struct fsl_udc, vbus_work);
+
+	if(udc->vbus_active) {
+		platform_udc_clk_resume();
+		fsl_udc_restart(udc);
+	} else {
+		spin_lock(&udc->lock);
+		reset_queues(udc);
+		spin_unlock(&udc->lock);
+		dr_controller_stop(udc);
+		platform_udc_clk_suspend();
+	}
+
+	if (can_pullup(udc))
+		fsl_writel((fsl_readl(&dr_regs->usbcmd) | USB_CMD_RUN_STOP),
+				&dr_regs->usbcmd);
+	else
+		fsl_writel((fsl_readl(&dr_regs->usbcmd) & ~USB_CMD_RUN_STOP),
+				&dr_regs->usbcmd);
+}
 #endif
 
 
@@ -2014,72 +2051,68 @@ static void fsl_udc_restart(struct fsl_udc *udc)
 static void fsl_udc_irq_work(struct work_struct* irq_work)
 {
 	struct fsl_udc *udc = container_of (irq_work, struct fsl_udc, irq_work);
-	u32 temp;
+	bool cable_connected = false;
+	bool cable_disconnected = false;
 
 	/* check OTG tranceiver is available or not */
 	if (udc->transceiver) {
-		if (udc->transceiver->state == OTG_STATE_B_PERIPHERAL) {
-			if (!udc->vbus_active) {
-				/* set vbus active  and enable the usb clocks */
-				udc->vbus_active = 1;
-				platform_udc_clk_resume();
-				fsl_udc_restart(udc);
-				/* Schedule work to wait for 100msec and check for
-				 * charger if setup packet is not received */
-				schedule_delayed_work(&udc->work,
-					USB_CHARGER_DETECTION_WAIT_TIME_MS);
-			}
-		} else if (udc->transceiver->state == OTG_STATE_A_SUSPEND) {
-			if (udc->vbus_active) {
-				/* If cable disconnected, cancel any delayed work */
-				cancel_delayed_work(&udc->work);
-				spin_lock(&udc->lock);
-				/* Reset all internal Queues and inform client driver */
-				reset_queues(udc);
-				spin_unlock(&udc->lock);
-				/* stop the controller and turn off the clocks */
-				dr_controller_stop(udc);
-				platform_udc_clk_suspend();
-				udc->vbus_active = 0;
-				udc->usb_state = USB_STATE_DEFAULT;
-				udc->transceiver->state = OTG_STATE_UNDEFINED;
-				if (udc->vbus_regulator) {
-					/* set the current limit to 0mA */
-					regulator_set_current_limit(udc->vbus_regulator, 0, 0);
-				}
-			}
+		if ((udc->transceiver->state == OTG_STATE_B_PERIPHERAL) &&
+			(!udc->vbus_active)) {
+			cable_connected = true;
+		} else if ((udc->transceiver->state == OTG_STATE_A_SUSPEND) &&
+			(udc->vbus_active)) {
+			cable_disconnected = true;
 		}
 	}else {
-		/* VBUS A session detection interrupts. When the interrupt is received,
-		 * mark the vbus active shadow.
-		 */
+		u32 temp = 0;
+		/* Check VBUS status register for cable connection */
 		temp = fsl_readl(&usb_sys_regs->vbus_wakeup);
 		if (temp & USB_SYS_VBUS_STATUS) {
-			udc->vbus_active = 1;
-			platform_udc_clk_resume();
-			/* Schedule work to wait for 100msec and check for
-			 * charger if setup packet is not received */
-			schedule_delayed_work(&udc->work,
-				USB_CHARGER_DETECTION_WAIT_TIME_MS);
-			/* printk("USB cable connected\n"); */
+			if (!udc->vbus_active) {
+				cable_connected = true;
+			}
 		} else {
-			/* If cable disconnected, cancel any delayed work */
-			cancel_delayed_work(&udc->work);
-			spin_lock(&udc->lock);
-			reset_queues(udc);
-			spin_unlock(&udc->lock);
-			udc->vbus_active = 0;
-			udc->usb_state = USB_STATE_DEFAULT;
-			platform_udc_clk_suspend();
-			if (udc->vbus_regulator) {
-				/* set the current limit to 0mA */
-				regulator_set_current_limit(udc->vbus_regulator, 0, 0);
+			if (udc->vbus_active) {
+				cable_disconnected = true;
 			}
-			/* printk("USB cable dis-connected\n"); */
 		}
 	}
-}
 
+	if (cable_connected) {
+		/* set vbus active  and enable the usb clocks */
+		udc->vbus_active = 1;
+		platform_udc_clk_resume();
+		if (udc->transceiver)
+			fsl_udc_restart(udc);
+		/* Schedule work to wait for 1000 msec and check for
+		 * charger if setup packet is not received */
+		schedule_delayed_work(&udc->work, USB_CHARGER_DETECTION_WAIT_TIME_MS);
+		udc->current_limit_ma = USB_DEFAULT_CURRENT_LIMIT_MA;
+	}
+
+	if (cable_disconnected) {
+		/* If cable disconnected, cancel any delayed work */
+		cancel_delayed_work(&udc->work);
+		/* Reset all internal Queues and inform client driver */
+		spin_lock(&udc->lock);
+		reset_queues(udc);
+		spin_unlock(&udc->lock);
+		/* stop the controller and turn off the clocks */
+		dr_controller_stop(udc);
+		platform_udc_clk_suspend();
+		udc->vbus_active = 0;
+		udc->usb_state = USB_STATE_DEFAULT;
+		udc->current_limit_ma = 0;
+		if (udc->transceiver)
+			udc->transceiver->state = OTG_STATE_UNDEFINED;
+	}
+
+	if (udc->vbus_regulator) {
+		/* set the regulator current limit in uA */
+		regulator_set_current_limit(udc->vbus_regulator, 0,
+		udc->current_limit_ma * 1000);
+	}
+}
 /*
  * USB device controller interrupt handler
  */
@@ -2847,6 +2880,9 @@ static int __init fsl_udc_probe(struct platform_device *pdev)
 	/* create a work for controlling the clocks to the Phy */
 	INIT_WORK(&udc_controller->irq_work, fsl_udc_irq_work);
 
+	/* create a work for controlling the clocks to the Phy and pullup the D+ */
+	INIT_WORK(&udc_controller->vbus_work, fsl_udc_vbus_work);
+
 #if defined(CONFIG_ARCH_TEGRA)
 #ifdef CONFIG_USB_OTG_UTILS
 	/* Get the OTG transceiver. If OTG is enabled then transceiver
diff --git a/drivers/usb/gadget/fsl_usb2_udc.h b/drivers/usb/gadget/fsl_usb2_udc.h
index ad80b0d381b0..2a3827b12a69 100644..100755
--- a/drivers/usb/gadget/fsl_usb2_udc.h
+++ b/drivers/usb/gadget/fsl_usb2_udc.h
@@ -517,6 +517,8 @@ struct fsl_udc {
 	struct regulator *vbus_regulator;	/* regulator for drawing VBUS */
 	struct delayed_work work; /* delayed work for charger detection */
 	struct work_struct irq_work; /* irq work for controling the usb power*/
+	struct work_struct vbus_work; /* vbus work for enabling clocks and D+ lines*/
+	u32 current_limit_ma; /* stores current limit in mA */
 };
 
 /*-------------------------------------------------------------------------*/