[RESEND PATCH v2] ARM: debug: add support for Palmchip BK-310x UART

[Måns Rullgård]

Marc Gonzalez <marc_gonzalez at sigmadesigns.com> writes:

> On 27/01/2016 01:44, Måns Rullgård wrote:
>
>> Kevin Hilman <khilman at baylibre.com> writes:
>> 
>>> Marc Gonzalez <marc_gonzalez at sigmadesigns.com> writes:
>>>
>>>> From: Mans Rullgard <mans at mansr.com>
>>>>
>>>> Some SoCs use a Palmchip BK-310x UART which is mostly 16550 compatible
>>>> but with a different register layout.
>>>
>>> ... because UART register layout is where we really need innovation. ;)
>>>
>>>> While this UART has previously
>>>> only been supported in MIPS based chips (Alchemy, Ralink), the ARM based
>>>> SMP87xx series from Sigma Designs also uses it.
>>>>
>>>> This patch allows the debug console to work with this type of UART.
>>>>
>>>> Signed-off-by: Mans Rullgard <mans at mansr.com>
>>>> Signed-off-by: Marc Gonzalez <marc_gonzalez at sigmadesigns.com>
>>>
>>> It appears this was previously acked by Arnd also?
>>> https://lkml.org/lkml/2015/11/9/116
>>>
>>>> ---
>>>> Peter, this is the patch I've been using on Tango for earlyprintk support.
>>>> arm-soc, this is just the Nov 8 patch with my Signed-off-by tag.
>>>> ---
>>>>  arch/arm/Kconfig.debug            |  9 +++++++++
>>>>  arch/arm/include/debug/palmchip.S | 11 +++++++++++
>>>>  2 files changed, 20 insertions(+)
>>>>  create mode 100644 arch/arm/include/debug/palmchip.S
>>>>
>>>> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
>>>> index 259c0ca9c99a..708aa9150c00 100644
>>>> --- a/arch/arm/Kconfig.debug
>>>> +++ b/arch/arm/Kconfig.debug
>>>> @@ -1304,6 +1304,7 @@ config DEBUG_SIRFSOC_UART
>>>>  config DEBUG_LL_INCLUDE
>>>>  	string
>>>>  	default "debug/sa1100.S" if DEBUG_SA1100
>>>> +	default "debug/palmchip.S" if DEBUG_UART_8250_PALMCHIP
>>>
>>> minor nit: We're trying (not always with great success) to keep various
>>> parts of this file sorted alphanumerically.  Can you please insert the
>>> new entries accordingly?
>> 
>> It has to precede the regular 8250 entry so as to take precedence over
>> that.
>
> <confused> Are you all talking about these 2 lines:
>
> 	default "debug/palmchip.S" if DEBUG_UART_8250_PALMCHIP
> 	default "debug/8250.S" if DEBUG_LL_UART_8250 || DEBUG_UART_8250
>
> default "debug/palmchip.S" is supposed to come before default "debug/8250.S" ?
>
> Because, in my config, there is no DEBUG_LL_UART_8250 to be seen, and
> # CONFIG_DEBUG_UART_8250 is not set

CONFIG_DEBUG_LL_UART_8250=y here.  In fact DEBUG_UART_8250_PALMCHIP
depends on "DEBUG_LL_UART_8250 || DEBUG_UART_8250" so one of those
*must* be set for any of this to matter.

-- 
Måns Rullgård