From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Date: Mon, 25 Jan 2016 16:25:02 +0000 Subject: Re: [RFC 0/6] mmc: sdhi: add basic r8a7795 support Message-Id: <56A64C5E.5040601@gmail.com> List-Id: References: <1453220461-2598-1-git-send-email-wsa@the-dreams.de> In-Reply-To: <1453220461-2598-1-git-send-email-wsa@the-dreams.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org 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