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

[Wolfgang Grandegger]

Hello Marek,

Am 28.02.22 um 15:51 schrieb Marek Vasut:
> On 2/28/22 15:13, Wolfgang Grandegger wrote:
>> The command "ums 0 mmc 0" does not work because the USB port is still
>> in reset. Releasing it in board_usb_init() fixes the problem. This issue
>> has been observed and fixed on the Aries MCVEVP board.
>>
>> Signed-off-by: Wolfgang Grandegger <wg at aries-embedded.de>
>> ---
>>   arch/arm/dts/socfpga_cyclone5_mcvevk.dts                | 1 +
>>   arch/arm/mach-socfpga/board.c                           | 8 ++++++++
>>   arch/arm/mach-socfpga/include/mach/reset_manager_gen5.h | 2 ++
>>   3 files changed, 11 insertions(+)
>>
>> diff --git a/arch/arm/dts/socfpga_cyclone5_mcvevk.dts
>> b/arch/arm/dts/socfpga_cyclone5_mcvevk.dts
>> index ceaec29770..a673837f25 100644
>> --- a/arch/arm/dts/socfpga_cyclone5_mcvevk.dts
>> +++ b/arch/arm/dts/socfpga_cyclone5_mcvevk.dts
>> @@ -12,6 +12,7 @@
>>       aliases {
>>           ethernet0 = &gmac0;
>>           stmpe-i2c0 = &stmpe1;
>> +        udc0 = &usb1;
>>       };
>>         chosen {
>> 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.

> There is drivers/reset/reset-socfpga.c which should handle the reset of
> the DWC2 USB IP.

See above!

Wolfgang