fsl/usb: Workarourd for USB erratum-A005697

The EHCI specification states the following in the SUSP bit description:
In the Suspend state, the port is sensitive to resume detection.
Note that the bit status does not change until the port is suspended and
that there may be a delay in suspending a port if there is a transaction
currently in progress on the USB.

However, in NXP USBDR controller, the PORTSCx[SUSP] bit changes immediately
when the application sets it and not when the port is actually suspended.

So the application must wait for at least 10 milliseconds after a port
indicates that it is suspended, to make sure this port has entered
suspended state before initiating this port resume using the Force Port
Resume bit. This bit is for NXP controller, not EHCI compatible.

Signed-off-by: Changming Huang <[e-mail]>
Signed-off-by: Ramneek Mehresh <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/ehci-fsl.c

···
 	if (pdata->has_fsl_erratum_a005275 == 1)
 		ehci->has_fsl_hs_errata = 1;
 
+	if (pdata->has_fsl_erratum_a005697 == 1)
+		ehci->has_fsl_susp_errata = 1;
+
 	if ((pdata->operating_mode == FSL_USB2_DR_HOST) ||
 			(pdata->operating_mode == FSL_USB2_DR_OTG))
 		if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0))

drivers/usb/host/ehci-hub.c

···
 	}
 	spin_unlock_irq(&ehci->lock);
 
+	if (changed && ehci_has_fsl_susp_errata(ehci))
+		/*
+		 * Wait for at least 10 millisecondes to ensure the controller
+		 * enter the suspend status before initiating a port resume
+		 * using the Force Port Resume bit (Not-EHCI compatible).
+		 */
+		usleep_range(10000, 20000);
+
 	if ((changed && ehci->has_tdi_phy_lpm) || fs_idle_delay) {
 		/*
 		 * Wait for HCD to enter low-power mode or for the bus
···
 				ehci_dbg(ehci, "Port%d phy low pwr mode %s\n",
 					wIndex, (temp1 & HOSTPC_PHCD) ?
 					"succeeded" : "failed");
+			}
+			if (ehci_has_fsl_susp_errata(ehci)) {
+				/* 10ms for HCD enter suspend */
+				spin_unlock_irqrestore(&ehci->lock, flags);
+				usleep_range(10000, 20000);
+				spin_lock_irqsave(&ehci->lock, flags);
 			}
 			set_bit(wIndex, &ehci->suspended_ports);
 			break;

drivers/usb/host/ehci.h

···
 	unsigned		no_selective_suspend:1;
 	unsigned		has_fsl_port_bug:1; /* FreeScale */
 	unsigned		has_fsl_hs_errata:1;	/* Freescale HS quirk */
+	unsigned		has_fsl_susp_errata:1;	/* NXP SUSP quirk */
 	unsigned		big_endian_mmio:1;
 	unsigned		big_endian_desc:1;
 	unsigned		big_endian_capbase:1;
···
 #else
 #define ehci_has_fsl_hs_errata(e)	(0)
 #endif
+
+/*
+ * Some Freescale/NXP processors have an erratum (USB A-005697)
+ * in which we need to wait for 10ms for bus to enter suspend mode
+ * after setting SUSP bit.
+ */
+#define ehci_has_fsl_susp_errata(e)	((e)->has_fsl_susp_errata)
 
 /*
  * While most USB host controllers implement their registers in

drivers/usb/host/fsl-mph-dr-of.c

···
 		of_property_read_bool(np, "fsl,usb-erratum-a007792");
 	pdata->has_fsl_erratum_a005275 =
 		of_property_read_bool(np, "fsl,usb-erratum-a005275");
+	pdata->has_fsl_erratum_a005697 =
+		of_property_read_bool(np, "fsl,usb_erratum-a005697");
 
 	/*
 	 * Determine whether phy_clk_valid needs to be checked

include/linux/fsl_devices.h

···
 	unsigned	already_suspended:1;
 	unsigned        has_fsl_erratum_a007792:1;
 	unsigned        has_fsl_erratum_a005275:1;
+	unsigned	has_fsl_erratum_a005697:1;
 	unsigned        check_phy_clk_valid:1;
 
 	/* register save area for suspend/resume */