From: Nikhil Badola <nikhil.badola@freescale.com>
To: <linux-kernel@vger.kernel.org>
CC: <stern@rowland.harvard.edu>, <gregkh@linuxfoundation.org>,
        <linux-usb@vger.kernel.org>,
        Nikhil Badola <nikhil.badola@freescale.com>,
        Suresh Gupta <suresh.gupta@freescale.com>
Subject: [PATCH 4/5] drivers:usb:fsl: Implement Workaround for USB Erratum A007792
Date: Tue, 26 May 2015 17:16:07 +0530
Message-ID: <1432640767-18700-1-git-send-email-nikhil.badola@freescale.com>
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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>
---
 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 ab4eee3..e77a379 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -119,6 +119,15 @@ 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 5e0d600..5e21947 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -214,6 +214,12 @@ 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 6447b7b..63f266d 100644
--- a/include/linux/fsl_devices.h
+++ b/include/linux/fsl_devices.h
@@ -96,6 +96,7 @@ 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;
-- 
2.1.0

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