From: Suresh Gupta <B42813@xxxxxxxxxxxxx>
PHY_CLK_VALID bit for UTMI PHY in USBDR does not set even
if PHY is providing valid clock. Workaround for this
involves resetting of PHY and check PHY_CLK_VALID bit
multiple times. If PHY_CLK_VALID bit is still not set even
after 5 retries, it would be safe to deaclare that PHY
clock is not available.
This erratum is applicable for USBDR less then ver 2.4.
Signed-off-by: Suresh Gupta <B42813@xxxxxxxxxxxxx>
Signed-off-by: Yinbo Zhu <yinbo.zhu@xxxxxxx>
---
Change in v4:
Incorrect indentation of the continuation line.
replace pr_err with dev_err.
drivers/usb/host/ehci-fsl.c | 38 +++++++++++++++++++++++++++-----------
drivers/usb/host/ehci-fsl.h | 3 +++
2 files changed, 30 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 38674b7..373a816 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -183,6 +183,17 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
return retval;
}
+static bool usb_phy_clk_valid(struct usb_hcd *hcd)
+{
+ void __iomem *non_ehci = hcd->regs;
+ bool ret = true;
+
+ if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) & PHY_CLK_VALID))
+ ret = false;
+
+ return ret;
+}
+
static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
enum fsl_usb2_phy_modes phy_mode,
unsigned int port_offset)
@@ -226,6 +237,17 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
/* fall through */
case FSL_USB2_PHY_UTMI:
case FSL_USB2_PHY_UTMI_DUAL:
+ /* PHY_CLK_VALID bit is de-featured from all controller
+ * versions below 2.4 and is to be checked only for
+ * internal UTMI phy
+ */
+ if (pdata->controller_ver > FSL_USB_VER_2_4 &&
+ pdata->have_sysif_regs && !usb_phy_clk_valid(hcd)) {
+ dev_err(dev,
+ "%s: USB PHY clock invalid\n", dev_name(dev));
+ return -EINVAL;
+ }
+
if (pdata->have_sysif_regs && pdata->controller_ver) {
/* controller version 1.6 or above */
tmp = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
@@ -249,17 +271,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
break;
}
- /*
- * check PHY_CLK_VALID to determine phy clock presence before writing
- * to portsc
- */
- if (pdata->check_phy_clk_valid) {
- if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) &
- PHY_CLK_VALID)) {
- dev_warn(hcd->self.controller,
- "USB PHY clock invalid\n");
- return -EINVAL;
- }
+ if (pdata->have_sysif_regs &&
+ pdata->controller_ver > FSL_USB_VER_1_6 &&
+ !usb_phy_clk_valid(hcd)) {
+ dev_warn(hcd->self.controller, "USB PHY clock invalid\n");
+ return -EINVAL;
}
ehci_writel(ehci, portsc, &ehci->regs->port_status[port_offset]);
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index cbc4220..9d18c6e 100644
--- a/drivers/usb/host/ehci-fsl.h
+++ b/drivers/usb/host/ehci-fsl.h
@@ -50,4 +50,7 @@
#define UTMI_PHY_EN (1<<9)
#define ULPI_PHY_CLK_SEL (1<<10)
#define PHY_CLK_VALID (1<<17)
+
+/* Retry count for checking UTMI PHY CLK validity */
+#define UTMI_PHY_CLK_VALID_CHK_RETRY 5
#endif /* _EHCI_FSL_H */
--
1.7.1
