Messages in this thread | | | From | Ricardo Ribalda Delgado <> | Date | Thu, 17 Sep 2020 13:38:53 +0200 | Subject | Re: [PATCH] regmap: Add support for 12/20 register formatting |
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HI Mark
On Thu, Sep 17, 2020 at 1:22 PM Mark Brown <broonie@kernel.org> wrote: > > On Thu, Sep 17, 2020 at 08:31:54AM +0200, Ricardo Ribalda Delgado wrote: > > On Wed, Sep 16, 2020 at 6:29 PM Mark Brown <broonie@kernel.org> wrote: > > > > What exactly is the format you're trying to describe here? It sounds > > > like there's two blocks of padding in here (I'm assuing that's what > > > dummy means) but what's the exact arrangement here and what are the > > > commands? It sounds like this might not work ideally with things like > > > the cache code (if it makes things seems sparser than they are) and > > > might not be obvious to someone looking at the datsheet. > > > The format is > > > XXXXCCCCAAAADDDDDDDDDDDDDDDDXXXX > > > Where X is dont care, C is command, A is address and D is data bits. I > > > Shall I add this to the commit message? I want to send a V2 anyway, > > because I screwed up the identity (ribalda.com instead of kernel.org) > > Yes, please. I was fairly sure it worked, it was just a question of if > it was ideal for the format described. The only issue I can see with > the above is that the users will need to left shift their data - on the > face of it it would seem better to add a facility for padding the LSBs > of the data field to the core so that users can just use the data field > as documented.
I was thinking also about that, the problem is that there are many devices on that family that are "software" compatible and it only changes the width of the data. Eg:
DDDDDDDDDDDDDDDDXXXX DDDDDDDDDDDDXXXXXXXX DDDDDDDDXXXXXXXXXXXX
So if we need to make a driver, we could use the same driver for all the chips on that family, saying to the user that the data size is always 20 bits....
I will send v2 ASAP with the updated doc.
Thanks
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