[coreboot] [PATCH] cs5536: Make NAND code optional and implement timing setting

Marc Jones marcj303 at gmail.com
Fri Feb 20 20:31:20 CET 2009


On Fri, Feb 20, 2009 at 11:47 AM, Mart Raudsepp
<mart.raudsepp at artecdesign.ee> wrote:
> On T, 2009-02-17 at 15:01 +0200, Mart Raudsepp wrote:
>> cs5536: Make NAND code optional and implement timing setting
>>
>> The reset value for NAND timings is the slowest possible for Flash interface.
>> Implement optionally setting it to a different value inside the NAND device.
>> Set it to appropriate values for Artec Group DBE61 and DBE62.
>> This results in a roughly two times quicker read time as measured by hdparm
>> for these boards.
>>
>> Because we can not cast to southbridge_amd_cs5536_nand_config if the board dts
>> does not have an entry for the NAND device, this change proposes a method for
>> reasonably clean way to only optionally compile in support for certain devices:
>> If a board wants to support an optional device, its Kconfig entry can select
>> that configuration. If it's optional even across the same board, it can expose
>> a subconfig option of the board, that describes it and if chosen selects the
>> device config. The source code for that device is conditionally compiled only
>> if the Kconfig option gets enabled by the configuration for the board.
>> A requirement is that if the board configuration can enable a device, it is
>> contained in the boards dts file as well.
>>
>> A perhaps better long-term alternative for this could be making dtc generate
>> preprocessor definitions for each device_configuration struct that it creates.
>> Then the source code file is always enabled, but that file can be wrapped
>> around a simple #ifdef check in its entirety.
>>
>> Conversion to the alternative approach from the short-term Kconfig approach
>> proposed here should be relatively easy, as to not block inclusion of the
>> Kconfig approach in the short term.
>>
>> Signed-off-by: Mart Raudsepp <mart.raudsepp at artecdesign.ee>
>
>
> Any comments, acks, rejections, anything? :)

I think it looks good but can you attach the patch instead of inline?
Pulling it from inline is hard to apply.

Marc




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