Re: [edk2-devel] [PATCH v1 1/1] Platform/RaspberryPi/ConfigDxe: Fix JTAG Pinout for Pi3/4

["Pete Batard" <pete@akeo.ie>]

With Andrei's reply, that's an RB for me:

On 2020.09.29 15:01, Samer El-Haj-Mahmoud wrote:
> Thanks Pete and Andrei. Should we count these as RB or AB for the patch?
> 
> Reviewed-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
> 
> *From:* devel@edk2.groups.io <devel@edk2.groups.io> *On Behalf Of 
> *Andrei Warkentin via groups.io
> *Sent:* Monday, September 21, 2020 4:01 PM
> *To:* Pete Batard <pete@akeo.ie>; Jeff Booher-Kaeding 
> <Jeff.Booher-Kaeding@arm.com>; devel@edk2.groups.io
> *Cc:* Ard Biesheuvel <Ard.Biesheuvel@arm.com>; Leif Lindholm 
> <leif@nuviainc.com>
> *Subject:* Re: [edk2-devel] [PATCH v1 1/1] 
> Platform/RaspberryPi/ConfigDxe: Fix JTAG Pinout for Pi3/4
> 
> Hi folks,
> 
> No objection at all. IIRC the original pin selection was driven by an 
> article I read about using OpenOCD with Pi 3.
> 
> A
> 
> ------------------------------------------------------------------------
> 
> *From:*Pete Batard <pete@akeo.ie <mailto:pete@akeo.ie>>
> *Sent:* Tuesday, September 15, 2020 7:26 AM
> *To:* Jeff Booher-Kaeding <jeff.booher-kaeding@arm.com 
> <mailto:jeff.booher-kaeding@arm.com>>; devel@edk2.groups.io 
> <mailto:devel@edk2.groups.io> <devel@edk2.groups.io 
> <mailto:devel@edk2.groups.io>>
> *Cc:* Ard Biesheuvel <ard.biesheuvel@arm.com 
> <mailto:ard.biesheuvel@arm.com>>; Leif Lindholm <leif@nuviainc.com 
> <mailto:leif@nuviainc.com>>; Andrei Warkentin <awarkentin@vmware.com 
> <mailto:awarkentin@vmware.com>>
> *Subject:* Re: [PATCH v1 1/1] Platform/RaspberryPi/ConfigDxe: Fix JTAG 
> Pinout for Pi3/4
> 
> Copying Andrei on this, as the existing JTAG pinout is not technically
> incorrect, since GPIO pin 4 can be used for TDI in ALT5 mode, and we are
> using the relevant ALT mode in the existing code. See
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsysprogs.com%2FVisualKernel%2Ftutorials%2Fraspberry%2Fjtagsetup%2F&amp;data=02%7C01%7Cawarkentin%40vmware.com%7C1c1badf5e6f1433b44b508d859728a32%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637357695767996220&amp;sdata=rGIzM4Io36gFJrAK%2F4xZs0fm0DpXVvamhOYYXfc09ek%3D&amp;reserved=0
> 
> As far as I'm concerned, I think it makes sense to use the same ALT mode
> and have all the JTAG pins grouped, but I'd like to confirm whether we
> deliberately chose not to use GPIO 26 in order to leave it available for
> some other purpose, before I approve this patch.
> 
> If Andrei says he's okay with it, then I see no objection to this change.
> 
> Regards,
> 
> /Pete
> 
> On 2020.09.14 22:32, Jeff Booher-Kaeding wrote:
>  > Updated the pinout to match the Pi4 datasheet, tested with the RPi4, 
> Pi3 Datasheet has same pinout.
>  >
>  > Signed-off-by: Jeff Booher-Kaeding <Jeff.booher-kaeding@arm.com 
> <mailto:Jeff.booher-kaeding@arm.com>>
>  >
>  > Cc: Ard Biesheuvel <ard.biesheuvel@arm.com 
> <mailto:ard.biesheuvel@arm.com>>
>  > Cc: Leif Lindholm <leif@nuviainc.com <mailto:leif@nuviainc.com>>
>  > Cc: Pete Batard <pete@akeo.ie <mailto:pete@akeo.ie>>
>  > ---
>  >   Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c | 6 +++---
>  >   1 file changed, 3 insertions(+), 3 deletions(-)
>  >
>  > diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c 
> b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
>  > index ac1004fe1836..6e793efb8227 100644
>  > --- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
>  > +++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
>  > @@ -502,7 +502,7 @@ ApplyVariables (
>  >      * 1           VREF        N/A               1
>  >
>  >      * 3           nTRST       GPIO22    ALT4    15
>  >
>  >      * 4           GND         N/A               9
>  >
>  > -   * 5           TDI         GPIO4     ALT5    7
>  >
>  > +   * 5           TDI         GPIO26    ALT4    37
>  >
>  >      * 7           TMS         GPIO27    ALT4    13
>  >
>  >      * 9           TCK         GPIO25    ALT4    22
>  >
>  >      * 11          RTCK        GPIO23    ALT4    16
>  >
>  > @@ -510,14 +510,14 @@ ApplyVariables (
>  >      */
>  >
>  >     if (PcdGet32 (PcdDebugEnableJTAG)) {
>  >
>  >       GpioPinFuncSet (22, GPIO_FSEL_ALT4);
>  >
>  > -    GpioPinFuncSet (4, GPIO_FSEL_ALT5);
>  >
>  > +    GpioPinFuncSet (26, GPIO_FSEL_ALT4);
>  >
>  >       GpioPinFuncSet (27, GPIO_FSEL_ALT4);
>  >
>  >       GpioPinFuncSet (25, GPIO_FSEL_ALT4);
>  >
>  >       GpioPinFuncSet (23, GPIO_FSEL_ALT4);
>  >
>  >       GpioPinFuncSet (24, GPIO_FSEL_ALT4);
>  >
>  >     } else {
>  >
>  >       GpioPinFuncSet (22, GPIO_FSEL_INPUT);
>  >
>  > -    GpioPinFuncSet (4, GPIO_FSEL_INPUT);
>  >
>  > +    GpioPinFuncSet (26, GPIO_FSEL_INPUT);
>  >
>  >       GpioPinFuncSet (27, GPIO_FSEL_INPUT);
>  >
>  >       GpioPinFuncSet (25, GPIO_FSEL_INPUT);
>  >
>  >       GpioPinFuncSet (23, GPIO_FSEL_INPUT);
>  >

Reviewed-by: Pete Batard <pete@akeo.ie>