From: Dirk Behme <dirk.behme@gmail.com>
To: linux-sh@vger.kernel.org
Subject: Re: [RFC 0/6] mmc: sdhi: add basic r8a7795 support
Date: Mon, 25 Jan 2016 16:25:02 +0000 [thread overview]
Message-ID: <56A64C5E.5040601@gmail.com> (raw)
In-Reply-To: <1453220461-2598-1-git-send-email-wsa@the-dreams.de>
On 25.01.2016 10:08, Dirk Behme wrote:
> On 25.01.2016 09:51, Yoshihiro Shimoda wrote:
>>> From: Dirk Behme
>>> Sent: Friday, January 22, 2016 8:31 PM
>>>
>>> On 22.01.2016 11:32, Yoshihiro Shimoda wrote:
>>>> Hi Dirk-san, Wolfram-san,
>>>>
>>>>>> And third, from reading the r8a7795 manual I think the manual
>>>>>> talks about
>>>>>>
>>>>>> https://github.com/dirkbehme/linux-renesas-rcar-gen3/commit/f2a727c859916d59dca85dbb72c1b61da3fd6da0
>>>>>>
>>>>>>
>>>>>> But testing this it doesn't work. So either the manual is wrong,
>>>>>> or I missed
>>>>>> anything else.
>>>>>
>>>>> I have seen this patch and my gut feeling is that it won't make a
>>>>> difference? SCLKDIVEN is like CBUSY plus some more cycles AFAIU.
>>>>> But I
>>>>> am not working on DMA issues now, this has to wait.
>>>>
>>>> I'm not sure we have to use CBSY bit instead of SCLKDIVEN on r8a7795.
>>>
>>>
>>> The r8a7795 manual I have has several
>>>
>>> "Do / Do not xxx when the CBSY bit in SD_INFO2 is set to x"
>>>
>>> It always talks about CBSY, not SCLKDIVEN.
>>
>> Thank you for the detail. I agree with you about r8a7795.
>> However, on previous SoC, it doesn't have CBSY bit.
>> So, I guess we have to keep compatible for previous SoC somehow.
>
>
> Yes, ack.
>
> I've been thinking about implementing a "delay callback", which waits
> for bit 13 on previous SoCs and for bit 14 for r8a7795.
Thinking about this, is there a runtime detection of r8a7795 vs.
previous SoCs? Anything like a function or macro e.g. is_system_gen3()
or similar?
Best regards
Dirk
next prev parent reply other threads:[~2016-01-25 16:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 16:20 [RFC 0/6] mmc: sdhi: add basic r8a7795 support Wolfram Sang
2016-01-19 16:56 ` Dirk Behme
2016-01-22 8:54 ` Wolfram Sang
2016-01-22 10:32 ` Yoshihiro Shimoda
2016-01-22 11:26 ` Dirk Behme
2016-01-22 11:30 ` Dirk Behme
2016-01-22 11:36 ` Dirk Behme
2016-01-22 21:30 ` Wolfram Sang
2016-01-25 8:51 ` Yoshihiro Shimoda
2016-01-25 9:08 ` Dirk Behme
2016-01-25 16:25 ` Dirk Behme [this message]
2016-01-25 19:24 ` Wolfram Sang
2016-01-25 20:47 ` Geert Uytterhoeven
2016-01-26 6:12 ` Dirk Behme
2016-01-26 8:34 ` Wolfram Sang
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