drivers: usb :fsl: Implement Workaround for USB Erratum A007792

commit 523f1dec upstream.

USB controller version-2.5 requires to enable internal UTMI
phy and program PTS field in PORTSC register before asserting
controller reset. This is must for successful resetting of the
controller and subsequent enumeration of usb devices
Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/usb/host/ehci-fsl.c

@@ -125,6 +125,15 @@ static int usb_hcd_fsl_probe(const struct hc_driver *driver,
 	if (pdata->have_sysif_regs && pdata->controller_ver < FSL_USB_VER_1_6)
 		setbits32(hcd->regs + FSL_SOC_USB_CTRL, 0x4);
 
+	/*
+	 * Enable UTMI phy and program PTS field in UTMI mode before asserting
+	 * controller reset for USB Controller version 2.5
+	 */
+	if (pdata->has_fsl_erratum_a007792) {
+		writel_be(CTRL_UTMI_PHY_EN, hcd->regs + FSL_SOC_USB_CTRL);
+		writel(PORT_PTS_UTMI, hcd->regs + FSL_SOC_USB_PORTSC1);
+	}
+
 	/* Don't need to set host mode here. It will be done by tdi_reset() */
 
 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);

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

@@ -206,6 +206,12 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
 	pdata->phy_mode = determine_usb_phy(prop);
 	pdata->controller_ver = usb_get_ver_info(np);
 
+	/* Activate Erratum by reading property in device tree */
+	if (of_get_property(np, "fsl,usb-erratum-a007792", NULL))
+		pdata->has_fsl_erratum_a007792 = 1;
+	else
+		pdata->has_fsl_erratum_a007792 = 0;
+
 	if (pdata->have_sysif_regs) {
 		if (pdata->controller_ver < 0) {
 			dev_warn(&ofdev->dev, "Could not get controller version\n");

include/linux/fsl_devices.h

@@ -92,6 +92,7 @@ struct fsl_usb2_platform_data {
 
 	unsigned	suspended:1;
 	unsigned	already_suspended:1;
+	unsigned        has_fsl_erratum_a007792:1;
 
 	/* register save area for suspend/resume */
 	u32		pm_command;