On mx31 the OTG host initialisation fails if you need to have
an ULPI transfert to initialize the PHY.
In order to be able to communicate with the PHY a complete reset
of the usb host is needed. After the PHY initialization the host
usb configuration registers need to be rewritten to avoid a host
controller lockup.
Signed-off-by: Philippe Rétornaz <philippe.retornaz@xxxxxxx>
---
drivers/usb/host/ehci-mxc.c | 98 ++++++++++++++++++++++++++++++++++++++-----
1 files changed, 87 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index 544ccfd..488a171 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/drivers/usb/host/ehci-mxc.c
@@ -29,6 +29,11 @@
#define PORTSC_OFFSET 0x184
#define USBMODE_OFFSET 0x1a8
#define USBMODE_CM_HOST 3
+#define USBCMD_OFFSET 0x140
+#define USBCMD_RS (1 << 0)
+#define USBCMD_RST (1 << 1)
+#define USBSTS_OFFSET 0x144
+#define USBSTS_HCH (1 << 12)
struct ehci_mxc_priv {
struct clk *usbclk, *ahbclk;
@@ -112,12 +117,73 @@ static const struct hc_driver ehci_mxc_hc_driver = {
.port_handed_over = ehci_port_handed_over,
};
+static int ehci_mxc_poll(void __iomem *ptr, u32 mask, u32 done, int usec)
+{
+ int i;
+
+ for (i = 0; i < usec; i++) {
+ if ((readl(ptr) & mask) == done)
+ return 0;
+ udelay(1);
+ }
+ return -ETIMEDOUT;
+}
+
+#define MXC_POLL_TIMEOUT 10000
+static int ehci_mxc_reset(struct usb_hcd *hcd)
+{
+ int ret;
+ int temp;
+
+ /* Wait for the controller to go idle */
+ ret = ehci_mxc_poll(hcd->regs + USBSTS_OFFSET,
+ USBSTS_HCH, USBSTS_HCH, MXC_POLL_TIMEOUT);
+ if (ret < 0)
+ return ret;
+
+ /* Stop the usb controller */
+ temp = readl(hcd->regs + USBCMD_OFFSET);
+ writel(temp & (~USBCMD_RS), hcd->regs + USBCMD_OFFSET);
+
+ ret = ehci_mxc_poll(hcd->regs + USBCMD_OFFSET, USBCMD_RS, 0,
+ MXC_POLL_TIMEOUT);
+ if (ret < 0)
+ return ret;
+
+ /* Reset the usb controller */
+ temp = readl(hcd->regs + USBCMD_OFFSET);
+ writel(temp | USBCMD_RST, hcd->regs + USBCMD_OFFSET);
+
+ ret = ehci_mxc_poll(hcd->regs + USBCMD_OFFSET, USBCMD_RST, 0,
+ MXC_POLL_TIMEOUT);
+
+ return ret;
+}
+
+static int ehci_mxc_setup_host_mode(struct platform_device *pdev,
+ struct usb_hcd *hcd)
+{
+ struct mxc_usbh_platform_data *pdata = pdev->dev.platform_data;
+ int temp;
+
+ /* set USBMODE to host mode */
+ temp = readl(hcd->regs + USBMODE_OFFSET);
+ writel(temp | USBMODE_CM_HOST, hcd->regs + USBMODE_OFFSET);
+
+ /* set up the PORTSCx register */
+ writel(pdata->portsc, hcd->regs + PORTSC_OFFSET);
+ mdelay(10);
+
+ /* setup specific usb hw */
+ return mxc_initialize_usb_hw(pdev->id, pdata->flags);
+}
+
static int ehci_mxc_drv_probe(struct platform_device *pdev)
{
struct mxc_usbh_platform_data *pdata = pdev->dev.platform_data;
struct usb_hcd *hcd;
struct resource *res;
- int irq, ret, temp;
+ int irq, ret;
struct ehci_mxc_priv *priv;
struct device *dev = &pdev->dev;
@@ -191,19 +257,20 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
clk_enable(priv->ahbclk);
}
- /* set USBMODE to host mode */
- temp = readl(hcd->regs + USBMODE_OFFSET);
- writel(temp | USBMODE_CM_HOST, hcd->regs + USBMODE_OFFSET);
-
- /* set up the PORTSCx register */
- writel(pdata->portsc, hcd->regs + PORTSC_OFFSET);
- mdelay(10);
-
- /* setup specific usb hw */
- ret = mxc_initialize_usb_hw(pdev->id, pdata->flags);
+ ret = ehci_mxc_setup_host_mode(pdev, hcd);
if (ret < 0)
goto err_init;
+ /* i.Mx31 OTG host has a bug, if you don't do a reset, then ULPI
+ * transfers timeout. */
+ if (cpu_is_mx31() && pdev->id == 0) {
+ ret = ehci_mxc_reset(hcd);
+ if (ret < 0) {
+ dev_err(dev, "Unable to reset USB controller");
+ goto err_init;
+ }
+ }
+
/* Initialize the transceiver */
if (pdata->otg) {
pdata->otg->io_priv = hcd->regs + ULPI_VIEWPORT_OFFSET;
@@ -213,6 +280,15 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
dev_err(dev, "unable to enable vbus on transceiver\n");
}
+ /* i.Mx31 OTG host has a bug, if you do an ULPI transfer then the host
+ * controller stays busy. Rewriting the register is enough to make it
+ * working */
+ if (cpu_is_mx31() && pdev->id == 0) {
+ ret = ehci_mxc_setup_host_mode(pdev, hcd);
+ if (ret < 0)
+ goto err_init;
+ }
+
priv->hcd = hcd;
platform_set_drvdata(pdev, priv);
--
1.6.3.3
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