Re: [PATCH 1/2] mmc: sdhci-iproc: Apply caps from bcm2835-mmc driver

[Eric Anholt <eric@anholt.net>]

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Stefan Wahren <stefan.wahren@i2se.com> writes:

> Hi Eric,
>
>> Eric Anholt <eric@anholt.net> hat am 3. Januar 2017 um 19:27 geschrieben:
>> 
>> 
>> Stefan Wahren <stefan.wahren@i2se.com> writes:
>> 
>> > Since the mmc module on bcm2835 neither provide a capabilities register nor 
>> > free documentation we must rely on the downstream implementation [1].
>> 
>> Yeah, caps reg is wired to 0, but it can do high speed.
>> 
>> Since we're VDD_330 only, I'm not sure the driver type flags do
>> anything, but I'm still good with having consistency.
>
> yes, the driver type flags currently have no benefit.
>
>> 
>> Reviewed-by: Eric Anholt <eric@anholt.net>
>> 
>> Interested in porting over the DMA support? :)
>
> AFAIK the sdhci doesn't support external DMA (required for bcm2835).
> So DMA support would result in a new driver, which i'm currently not interested.
>
> But i've prepared a fixup patch series for the sdhost driver i want to send to Gerd.
>
>> 
>> I also noticed that the emmc wrapper module claims it can run with a
>> clock from 50-100mhz, and the arasan says it can run at up to 50, 52, or
>> 208mhz depending on SD/MMC mode.  Could we get a boost from running the
>> module at a higher clock rate?
>
> Sorry, i can't follow. Do you mean DDR mode?

Apparently I what I was reading about was SDR104 mode, which also
requires 1.8V.

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