On 1 March 2018 at 10:57, Ludovic BARRE <ludovic.barre@xxxxxx> wrote: > Hi Ulf > > On 03/01/2018 10:06 AM, Ulf Hansson wrote: >> >> Hi Ludovic, >> >> On 28 February 2018 at 16:47, Ludovic Barre <ludovic.Barre@xxxxxx> wrote: >>> >>> From: Ludovic Barre <ludovic.barre@xxxxxx> >>> >>> This patch serie adds support of stm32 SDMMC controller. >>> stm32h7 is the first SoC to use stm32 SDMMC controller >>> (previous SoC had pl180 controller). >> >> >> I am a not convinced this isn't a new improved variant of the pl180. >> According to register layout and the code you submitted in patch2, >> there are great similarities to pl180 and the mmci driver. > > > In fact, ST designers which created stm32-sdmmc hardware block from scratch > are the same which have done the modifications on pl180 variant (stm32 > legacy f4, f7). > So some registers or bits name seem identical (or strongly inspirited) but > the engine and features are different. Well, in that case, I assume the driver would also need work differently, but when looking at the code in patch2 this doesn't seem to be the case. > > You could find the datasheet of STM32H7x3 on: > http://www.st.com/content/ccc/resource/technical/document/reference_manual/group0/c9/a3/76/fa/55/46/45/fa/DM00314099/files/DM00314099.pdf/jcr:content/translations/en.DM00314099.pdf > > Chapters: 55 Secure digital input/output MultiMediaCard interface > (SDMMC) Thanks for sharing this. However this confirms my view, it looks exactly as a new improved mmci variant. :-) > > This hardware block has own roadmap and some features are already in the > pipe for next SoC. That's fine. I don't have a problem extending the mmci driver, even several times, as to cope with new revisions. > > For code design: like I also worked on pl180 in the past :-) > my code is inspirited of this driver. Right, that may explain things a bit. However, besides a re-name of the registers, I really think that the code execution, dealing with IRQs etc, is very similar to the mmci driver. Isn't it? So, I think it's at least worth to give it a go with the mmci driver first, to see if we can get it to work. I guess you understand why I am pushing!? This is about maintenance - and I really want to avoid having a yet another driver to maintain, unless we can extend an existing one. [...] Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
