[PATCH 1/2] arm64: dts: updates serial aliases for ls1043a rdb and qds boards

Stuart Yoder
2016-08-29T18:30:59Z

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd at arndb.de]
> Sent: Monday, August 29, 2016 6:01 AM
> To: Stuart Yoder <stuart.yoder@nxp.com>
> Cc: devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org; shawnguo at kernel.org
> Subject: Re: [PATCH 1/2] arm64: dts: updates serial aliases for ls1043a rdb and qds boards
>
> On Friday, August 26, 2016 3:46:20 PM CEST Stuart Yoder wrote:
> > - serial0 = &lpuart0;
> > - serial1 = &lpuart1;
> > - serial2 = &lpuart2;
> > - serial3 = &lpuart3;
> > - serial4 = &lpuart4;
> > - serial5 = &lpuart5;
> > + serial0 = &duart0;
> > + serial1 = &duart1;
> > + serial2 = &duart2;
> > + serial3 = &duart3;
>
> It looks like your board has six uarts that are all driven with the
> lpuart driver, but after the change, you only list four. Should
> the serial4 and serial5 aliases keep pointing at lpuart devices
> so you can still drive all physical connectors?

The only existing reference I can find to the serial aliases is if the
OF_STDOUT_VIA_ALIAS is enabled in u-boot to specify the console. The
standard ls1043aqds_defconfig in u-boot specifies DUARTs for the console,
which is why I'm proposing making the 4 DUARTs the default serial aliases
in the device tree.

There is a separate defconfig in u-boot to enable/use LPUARTs instead
of the normal DUARTs. For that scenario, my take is that firmware should
update the DT aliases to reflect the actual use of the serial ports.

But, the default should be the DUARTs which is the normal case for this
board, which is why this patch is changing them.

Thanks,
Stuart