ENGR00162583-2 usb driver: avoid class driver access register after usb is off

- An well-behavior class driver should disable their endpoints
after being notified disconnect with host, we use all endpoints
are stopped (ep->stopped)  to indicates the class
driver will not visit device driver any more.
the ep-stopped will be initialized as 1 for non-control endpoint
it will be 0 after fsl_ep_enable, and be 1 after fsl_ep_disable.
Where is a non-sleep wait routine at disconnect event for waiting all
endpoints are stopped
- Some controller's (like i.mx6q) DP will change from J
to SE0 slowly after the cable disconnects with host, in that case there
will be a wakeup interrupt after driver enables the wakeup interrupt.
For i.mx6q, there is a discharge routine for DP after the disconnection.
- Should not wait vbus to low during first otg switch, as the wait will
be timeout when the usb cable is connecting to host.

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

2 files changed, 15 insertions, 5 deletions

diff --git a/drivers/usb/otg/fsl_otg.c b/drivers/usb/otg/fsl_otg.c
index a30815cba3f1..be8e0160a197 100755
--- a/drivers/usb/otg/fsl_otg.c
+++ b/drivers/usb/otg/fsl_otg.c
@@ -168,11 +168,11 @@ static void fsl_otg_wait_stable_vbus(bool on)
 	fsl_otg_clk_gate(true);
 	/* Wait for vbus change  to B_SESSION_VALID complete */
 	timeout = jiffies + FSL_VBUS_CHANGE_TIMEOUT;
-	while ((le32_to_cpu(usb_dr_regs->otgsc)&OTGSC_INTSTS_B_SESSION_VALID) == !on) {
+	while ((le32_to_cpu(usb_dr_regs->otgsc)&OTGSC_STS_B_SESSION_VALID) != (on << 11)) {
 		if (time_after(jiffies, timeout)) {
 			printk(KERN_ERR"wait otg vbus change timeout! \n");
 			fsl_otg_clk_gate(false);
-			break;
+			return;
 		}
 		msleep(10);
 	}
@@ -619,8 +619,11 @@ static int fsl_otg_set_host(struct otg_transceiver *otg_p, struct usb_bus *host)
 		 * so suspend the host after a short delay.
 		 */
 		otg_dev->host_working = 1;
-		if (otg_dev->fsm.id)
+
+		if (otg_dev->fsm.id) {
+			otg_dev->host_first_call = true;
 			schedule_otg_work(&otg_dev->otg_event, 100);
+		}
 		else {
 			/* if the device is already at the port */
 			otg_drv_vbus(&otg_dev->fsm, 1);
@@ -733,8 +736,12 @@ static void fsl_otg_event(struct work_struct *work)
 	if (fsm->id) {		/* switch to gadget */
 		fsl_otg_start_host(fsm, 0);
 		otg_drv_vbus(fsm, 0);
-		fsl_otg_wait_stable_vbus(false);
-		fsl_otg_wait_dischrg_vbus();
+		if (og->host_first_call == false) {
+			fsl_otg_wait_dischrg_vbus();
+			fsl_otg_wait_stable_vbus(false);
+		} else {
+			og->host_first_call = false;
+		}
 		b_session_irq_enable(false);
 		fsl_otg_start_gadget(fsm, 1);
 	} else {			/* switch to host */
@@ -943,6 +950,7 @@ static int fsl_otg_conf(struct platform_device *pdev)
 	fsl_otg_tc->otg.start_hnp = fsl_otg_start_hnp;
 	fsl_otg_tc->otg.start_srp = fsl_otg_start_srp;
 	fsl_otg_tc->otg.dev = &pdev->dev;
+	fsl_otg_tc->host_first_call = false;
 
 	fsl_otg_dev = fsl_otg_tc;
 
diff --git a/drivers/usb/otg/fsl_otg.h b/drivers/usb/otg/fsl_otg.h
index a8536815d0bf..d3d382bd8e32 100755
--- a/drivers/usb/otg/fsl_otg.h
+++ b/drivers/usb/otg/fsl_otg.h
@@ -385,6 +385,8 @@ struct fsl_otg {
 	/*used for usb host */
 	struct work_struct work_wq;
 	u8	host_working;
+	/*Used for host init call,we need to avoid  discharge Vbus when usb cable connect to PC*/
+	bool host_first_call;
 
 	int irq;
 };