Re: [PATCH 5/6] ARM: add low level debug uart for rk1108

[Andy Yan]

Hi Heiko:


On 2016å11æ04æ 15:36, Heiko Stuebner wrote:
> Am Donnerstag, 3. November 2016, 20:42:21 CET schrieb Andy Yan:
> > RK1108 UARTs are Synopsis DesignWare 8250 compatible.
> > Only with different register addresses.
> >
> > Signed-off-by: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
> > ---
> >
> >   arch/arm/Kconfig.debug | 30 ++++++++++++++++++++++++++++++
> >   1 file changed, 30 insertions(+)
> >
> > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
> > index d83f7c3..408540f 100644
> > --- a/arch/arm/Kconfig.debug
> > +++ b/arch/arm/Kconfig.debug
> > @@ -776,6 +776,30 @@ choice
> >   		  their output to the standard serial port on the RealView
> >   		  PB1176 platform.
> >
> > +	config DEBUG_RK1108_UART0
> > +		bool "Kernel low-level debugging messages via Rockchip RK1108 UART0"
> > +		depends on ARCH_ROCKCHIP
> > +		select DEBUG_UART_8250
> > +		help
> > +		  Say Y here if you want kernel low-level debugging support
> > +                  on Rockchip RK1108 based platforms.
> > +
> > +	config DEBUG_RK1108_UART1
> > +		bool "Kernel low-level debugging messages via Rockchip RK1108 UART1"
> > +		depends on ARCH_ROCKCHIP
> > +		select DEBUG_UART_8250
> > +		help
> > +		  Say Y here if you want kernel low-level debugging support
> > +		  on Rockchip RK1108 based platforms.
> > +
> > +	config DEBUG_RK1108_UART2
> > +		bool "Kernel low-level debugging messages via Rockchip RK1108 UART2"
> > +		depends on ARCH_ROCKCHIP
> > +		select DEBUG_UART_8250
> > +		help
> > +		  Say Y here if you want kernel low-level debugging support
> > +		  on Rockchip RK1108 based platforms.
> > +
> are you sure, you need all 3 of them?
>
> I.e. most Rockchip SoCs so far had one uart somewhat designated as debug uart.
> Most likely due to it not having rts/cts and being used in reference
> schematics, but no one ever used another uart than uart2 on previous socs. So
> ideally we could check and only add uarts we actually need for now. More can
> be added later anyway once boards try to use them.
>
>
> Heiko

    Actually, I have two boards on my hand, one uses uart0 as debug 
port and the another uses uart2, so I add all of them here.

   I have a question here, I not very clear how to get the 
DEBUG_UART_VIRT value here,  I now set the value I got from uart driver 
and it works , is there some rule or  method to calculate this 
DEBUG_UART_VIRT value on different platform?
>