[PATCH 3.16.y-ckt 091/104] drivers: usb :fsl: Implement Workaround for USB Erratum A007792

[Luis Henriques]

3.16.7-ckt19 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nikhil Badola <nikhil.badola at freescale.com>

commit 523f1dec58408b36e7683a3d61a0286eed1fc1c8 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 at freescale.com>
Signed-off-by: Suresh Gupta <suresh.gupta at freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/host/ehci-fsl.c      | 9 +++++++++
 drivers/usb/host/fsl-mph-dr-of.c | 6 ++++++
 include/linux/fsl_devices.h      | 1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index cf2734b532a7..c412c4f35007 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/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);
diff --git a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
index 9162d1b6c0a3..4d03afb7cf4a 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/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");
diff --git a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h
index a82296af413f..0f17316ce420 100644
--- a/include/linux/fsl_devices.h
+++ b/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;