[PATCH] ARM: debug: add support for alternate 8250 register layout

[Måns Rullgård]

Sergei Shtylyov <sergei.shtylyov at cogentembedded.com> writes:

> On 10/2/2015 5:26 PM, Måns Rullgård wrote:
>
>>>> Some SoCs have a UART with a non-standard register layout. This
>>>> allows the debug console to work with these.
>>>
>>>> Signed-off-by: Mans Rullgard <mans at mansr.com>
>>>> ---
>>>> I would have preferred a more accurate description of the UART, but I've
>>>> not managed to figure out who the vendor is.
>>>
>>>     You haven't seem the Alchemy datasheets? I can send you some if so.
>>
>> I have.  They don't say where Alchemy bought the UART block.
>
>    In fact, seeing at least Au1550 databook googling for "alchemy databook".
> The UART registers are described there. Perhaps, it's not accurate
> enought for your needs, though...

I have all the information I need about how it works.

>>>> ---
>>>>    arch/arm/Kconfig.debug        |  4 ++++
>>>>    arch/arm/include/debug/8250.S | 12 ++++++++++++
>>>>    2 files changed, 16 insertions(+)
>>>>
>>>> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
>>>> index 0cfd7f9..8d5c837 100644
>>>> --- a/arch/arm/Kconfig.debug
>>>> +++ b/arch/arm/Kconfig.debug
>>>> @@ -1597,6 +1597,10 @@ config DEBUG_UART_8250_WORD
>>>>    		DEBUG_BCM_KONA_UART || DEBUG_RK32_UART2 || \
>>>>    		DEBUG_BRCMSTB_UART
>>>>
>>>> +config DEBUG_UART_8250_AU
>>>> +       bool "8250 UART has Alchemy register layout"
>>>> +       depends on DEBUG_LL_UART_8250 || DEBUG_UART_8250
>>>> +
>>>
>>>     So Alchemy UART got reused on ARM?
>>
>> The UART is actually a Palmchip IP core used by several SoC companies.
>
>    Hm, how have you figured out that;s Palmchip if the Alchemy
> databooks are silent about that? :-)

Someone with access to hardware design files told me.

-- 
Måns Rullgård
mans at mansr.com