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

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>

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 5352e74..716aa8b 100644 (file)
--- 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 (file)
--- 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 0d4855c..bdb40f6 100644 (file)
--- 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;