On 12/22/21 21:08, Adam Ford wrote:
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.
Yes and this does not work, because you need to know whether the IP is in host and gadget mode before probe happens I think. Indeed, that's why OTG is unsupported thus far. But please do dig in and try to find a proper solution.
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.
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