Messages in this thread | | | Date | Fri, 13 Jan 2012 11:55:08 +0800 | From | Shawn Guo <> | Subject | Re: [RFC PATCH v3 2/5] pinctrl: add dt binding support for pinmux mappings |
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On Thu, Jan 12, 2012 at 12:56:52PM -0800, Stephen Warren wrote: > Dong Aisheng wrote at Thursday, January 12, 2012 1:36 AM: > > Stephen Warren wrote at Thursday, January 12, 2012 4:18 AM: > > > Dong Aisheng wrote at Tuesday, January 10, 2012 1:21 AM: > > > > Stephen Warren wrote at Saturday, January 07, 2012 2:03 AM: > ... > > > Personally, I think I'd be OK with the sysfs pinctrl map file only containing > > > the map entries for devices that had used the pinctrl API, and hence only > > > parsing the pinmux properties in pinmux_get(). > > > > Actually I already did it like that in the patch I sent: > > https://lkml.org/lkml/2012/1/5/153 > > > > Originally I'd like to do like that but I found an inconsistent issue that > > the sysfs pinctrl map file will behave differently between dt and non-dt > > Platform. For non-dt, it means showing all exist map entries. For dt, it means > > Only used pinmux map entries. > > > > And in current design when device calls pinmux_get, it will search a predefined > > pinmux_maps array to find which function and group it is binded to. > > If switch to the new way, we only dynamically create pinmux map and dynamically > > register it when pinmux_get is called, first we need to change the code path in > > pinmux_get in a totally different way, second for support that we may also better > > to change pinmux_maps array to a list. > > But after changing the pinmux_maps to a list, what about using in non-dt? > > > > So without any strong reason i still think it would be better to keep consistency > > With the non-dt pinctrl subsystem. > > And the effort would be minimum since besides constructing the map by parsing > > Device tree, everyting is the same as before in pinmux map and we could re-use > > the current code. > > OK. I think this can work out pretty easily with a bus notifier as I > mentioned before. > > But, one thought on doing this in pinmux_get(). I'd simply implement a > Function that read a DT node's pinmux property/node, converted it to a > pinmux mapping table, and registered it with the pinctrl core. Then, > pinmux_get() could simply call this before doing anything else at all. > I don't think you'd need to modify how pinmux_get() worked at all. > This sounds like a pretty good idea to me.
-- Regards, Shawn
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