Messages in this thread | | | Date | Wed, 22 Feb 2012 14:21:02 +0800 | From | Dong Aisheng <> | Subject | Re: [PATCH 08/20] pinctrl: Assume map table entries can't have a NULL name field |
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On Tue, Feb 21, 2012 at 09:38:47AM -0800, Stephen Warren wrote: > Dong Aisheng wrote at Tuesday, February 21, 2012 6:08 AM: > > On Mon, Feb 20, 2012 at 2:45 PM, Stephen Warren <swarren@nvidia.com> wrote: > > > pinctrl_register_mappings() already requires that every mapping table > > > entry have a non-NULL name field. > > > > > > Logically, this makes sense too; drivers should always request a specific > > > named state so they know what they're getting. Relying on getting the > > > > Hmm? It makes me a little confused. > > IIRC we allow the driver to request NULL map name in the linaro > > connect discussion. > > For those devices they do not want to support multi states, they > > really don't want to care about the state name. > > The original way is convenient for such a case. > > With device tree, every state is always going to have /some/ name; the I remember the discussion is that pinctrl-name is optional and map name is always specified by pinctrl-name or automatically generated by the id of pinctrl property (e.g. for pinctrl-0, 0 is the name) However user may not want to care about it although there's a name.
BTW my above comment may not right since i still have not read all you patches in the series and do not know if any difference on your implementation with the original proposal i will continue to read your patches.
> binding we discussed didn't include any way to specify "no name" or > "default name" or "default state", so this will keeps things a little > more consistent. > > I possibly could be persuaded to allow NULL state names in the mapping > table. However, if so, I think they should work a little differently to > the code currently in pinctrl: Right now, a NULL parameter to pinmux_get() > allows matching against /any/ state name in the table. If we changed this Yes it's /any/ state but it's always the first state.
> to only allow matching against mapping table with a NULL name, that might > be OK, since it'd be very explicit what it matched. But, as I mentione If that how about many states with NULL name?
> above, migrating such a driver to device tree would require changing this I can see many changes, it looks just as the same as before (using first state as default state), did i understand right?
> so I'm not inclined to like that solution without strong requirements. > > In other words, what we have right now is something like: > > if name: > match = !strcmp(name, map->name) > else: > match = true > > If we continue to allow NULL names, I think we should change that to: > > if name: > match = map->name && !strcmp(name, map->name) > else: > match = !map->name As above many states name may be NULL. So here it becomes the first NULL name state.
Regards Dong Aisheng
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