On Wed, Dec 22, 2021 at 1:31 PM Marek Vasut marex@denx.de wrote:

On 12/22/21 13:52, Adam Ford wrote:

...

The imx8mm and imx8mn appear compatible with imx7d-usb flags in the OTG driver. If the dr_mode is defined as host or peripheral, the device appears to operate correctly, however the auto host/peripheral detection results in an error.

Simply adding checks in ehci_usb_phy_mode for 8mm and 8mn in ehci_usb_phy_mode is not enough, because ehci_usb_of_to_plat is run before the clock is enabled which results in a hang.

Enable the USB clock in ehci_usb_of_to_plat and add checks in ehci_usb_phy_mode for 8mm and 8mn to enable auto detection of the OTG mode on i.MX8M Mini and Nano.

I was under the impression that of_to_plat() was meant to parse DT into driver local data, so frobbing with clock there could be a problem, right ? +CC Simon.

If that's true, we'll likely need to move the functions from ehci_usb_of_to_plat to the probe function to run after the clocks are enabled, because the call to usb_get_dr_mode hangs without the clocks running. usb_get_dr_mode tells the driver if it's a host or device mode.

We could make a temporary clock instead of passing the clock to the priv structure. I intentionally shut the clock off as soon as we're finished reading the register so it didn't collide with the existing functions.

adam

...

diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c index 1bd6147c76..fa0798171b 100644 --- a/drivers/usb/host/ehci-mx6.c +++ b/drivers/usb/host/ehci-mx6.c @@ -543,7 +543,7 @@ static int ehci_usb_phy_mode(struct udevice *dev) plat->init_type = USB_INIT_DEVICE; else plat->init_type = USB_INIT_HOST;

• } else if (is_mx7()) {
  

• } else if (is_mx7() || is_imx8mm() || is_imx8mn()) {
          phy_status = (void __iomem *)(addr +
                                        USBNC_PHY_STATUS_OFFSET);
          val = readl(phy_status);
  

@@ -561,11 +561,30 @@ static int ehci_usb_phy_mode(struct udevice *dev)

static int ehci_usb_of_to_plat(struct udevice *dev) { +#if CONFIG_IS_ENABLED(CLK)

• int ret = 0;
  

• struct ehci_mx6_priv_data *priv = dev_get_priv(dev);
  

• ret = clk_get_by_index(dev, 0, &priv->clk);
  

• if (ret < 0)
  

•         return ret;
  

• ret = clk_enable(&priv->clk);
  

• if (ret)
  

•         return ret;
  

+#endif

• struct usb_plat *plat = dev_get_plat(dev);
  enum usb_dr_mode dr_mode;
  
  dr_mode = usb_get_dr_mode(dev_ofnode(dev));
  
  

+#if CONFIG_IS_ENABLED(CLK)

• ret = clk_disable(&priv->clk);
  

• if (ret)
  

•         return ret;
  

+#endif

• switch (dr_mode) {
  case USB_DR_MODE_HOST:
          plat->init_type = USB_INIT_HOST;