From: Nikhil Badola <nikhil.badola@freescale.com>
To: <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC: <gregkh@linuxfoundation.org>, <stern@rowland.harvard.edu>,
        Nikhil Badola <nikhil.badola@freescale.com>,
        Suresh Gupta <suresh.gupta@freescale.com>
Subject: [PATCH 2/3][v2] drivers: usb :fsl: Implement Workaround for USB Erratum A007792
Date: Mon, 15 Jun 2015 15:47:29 +0530
Message-ID: <1434363449-19508-1-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>
---
Changes for v2 : None

 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 5352e74..716aa8b 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -129,6 +129,15 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
 	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 2195956..17e1e6b 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 == FSL_USB_VER_NONE) {
 			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 0d4855cd..bdb40f6 100644
--- a/include/linux/fsl_devices.h
+++ b/include/linux/fsl_devices.h
@@ -97,6 +97,7 @@ 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;
-- 
1.7.11.7


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