ARM: socfpga: gen5: release reset before using USB as device with ums

[Marek Vasut]

On 3/14/22 11:57, Wolfgang Grandegger wrote:
> Hello,
> 
> Am 28.02.22 um 16:22 schrieb Marek Vasut:
>> On 2/28/22 16:18, Wolfgang Grandegger wrote:
>>
>> Hi,
>>
>> [...]
>>
>>>>> diff --git a/arch/arm/mach-socfpga/board.c
>>>>> b/arch/arm/mach-socfpga/board.c
>>>>> index 7267163222..a2eed73fe9 100644
>>>>> --- a/arch/arm/mach-socfpga/board.c
>>>>> +++ b/arch/arm/mach-socfpga/board.c
>>>>> @@ -83,6 +83,14 @@ int board_usb_init(int index, enum usb_init_type
>>>>> init)
>>>>>         /* Patch the address from OF into the controller pdata. */
>>>>>         socfpga_otg_data.regs_otg = addr;
>>>>>     +#ifdef CONFIG_TARGET_SOCFPGA_GEN5
>>>>> +    /* First release reset of the USB port */
>>>>> +    if (addr == SOCFPGA_USB0_ADDRESS)
>>>>> +        socfpga_per_reset(SOCFPGA_RESET(USB0), 0);
>>>>> +    else if (addr == SOCFPGA_USB1_ADDRESS)
>>>>> +        socfpga_per_reset(SOCFPGA_RESET(USB1), 0);
>>>>> +#endif
>>>>
>>>> Is this really needed at all ?
>>>
>>> Yes, it's needed, otherwise "ums 0 mmc 0" does not work. It was working
>>> some time ago but commit 430b42f76a4e50ffef7cc2b3c195ff645a438433 did
>>> remove the ad-hoc reset code. I realize the issue an on Aries MCVEVP
>>> board, but I'm quite sure that it's present on all Cyclone5 boards.
>>
>> Can you investigate why the reset-socfpga.c does not release the USB
>> from reset instead ? That would be the right approach.
> 
> The attached patch works. It enables CONFIG_DM_USB_GADGET and adds
> "dr_mode = otg" to the USB device tree node. "ums 0 mmc 0" deasserts the
> reset for USB1 and re-assert it when done. All ok with that!
> 
> But then "usb start" is broken:
> 
>    => usb start
>    starting USB...
>    USB: drv id 110 name usb
>    USB: drv id 90 name serial
>    USB: drv id 101 name sysreset
>    USB: drv id 85 name reset
>    USB: drv id 22 name blk
>    USB: drv id 59 name mmc
>    USB: drv id 99 name syscon
>    USB: drv id 25 name cache
>    USB: drv id 43 name i2c
>    USB: drv id 40 name gpio
>    USB: drv id 36 name ethernet
>    USB: drv id 91 name simple_bus
>    USB: drv id 0 name root
>    No working controllers found
> 
> 
> The function "uclass_find()" does no longer find the USB host device
> (UCLASS_USB). The debug ouput is with:
> 
> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
> index 2578803b7a..b59a5dcdad 100644
> --- a/drivers/core/uclass.c
> +++ b/drivers/core/uclass.c
> @@ -35,6 +35,9 @@ struct uclass *uclass_find(enum uclass_id key)
>           * id to node.
>           */
>          list_for_each_entry(uc, gd->uclass_root, sibling_node) {
> +               if (key == UCLASS_USB)
> +                       printf("USB: drv id %d name %s\n",
> +                              uc->uc_drv->id, uc->uc_drv->name);
>                  if (uc->uc_drv->id == key)
>                          return uc;
>          }
> 
> Id 110 is UCLASS_USB_GADGET_GENERIC, but UCLASS_USB is gone. There is
> some magic with usb device scanning. Any idea what could cause that
> problem?

+CC Simon