Hans de Goede <hdegoede@xxxxxxxxxx> writes: > Hi, > > On 10-06-18 16:01, Hans de Goede wrote: >> Bay Trail / BYT SoCs do not have a builtin device-mode phy, instead >> they require an external ULPI phy for device-mode. >> >> Only some BYT devices have an external phy, but even on those devices >> device-mode is not working because the dwc3 does not see the phy. >> >> The problem is that the ACPI fwnode for the dwc3 does not contain the >> expected GPIO resources for the GPIOs connected to the chip-select and >> reset pins of the phy. >> >> I've found the workaround which some Android x86 kernels use for this: >> https://github.com/BORETS24/Kernel-for-Asus-Zenfone-2/blob/master/arch/x86/platform/intel-mid/device_libs/pci/platform_usb_otg.c >> Which boils down to hardcoding the GPIOs for these devices. >> >> The good news it that all boards (*) use the same GPIOs. >> >> This commit fixes the ULPI phy not woring by adding a gpiod_lookup_table >> call which adds a hardcoded mapping for BYT devices. Note that the mapping >> added by gpiod_add_lookup_table is a fallback mapping, so boards which >> properly provide GPIO resources in the ACPI firmware-node resources >> will not use this. >> >> *) Except for the first revision of the evalulation-kit, which normal users >> don't have >> >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> --- >> Changes in v3: >> -Add the mapping with gpiod_add_lookup_table() unconditionally on BYT >> devices, as they are only used after checking for GPIO resources in ACPI > > Ping? AFAIK this series is ready for merging now and it is necessary to > make gadget mode work on all Bay Trail devices which support gadget > mode. now queued for v4.19 -- balbi
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