* Stephen Warren <swar...@wwwdotorg.org> [130621 12:18]: > On 06/21/2013 12:25 AM, Tony Lindgren wrote: > > * Stephen Warren <swar...@wwwdotorg.org> [130620 12:32]: > >> > >> I assume you mean there shouldn't be any issue *modifying* the pinctrl > >> API to allow multiple states to be active at once? And where you're > >> talking about having multiple sets active at once already, you're > >> talking about some other API? > > > > Nope, the standard pinctrl API. At least I have not seen issues with > > having multiple states active the same time in a single driver. > > Please take a look at the implementation of pinctrl_select_state(). It > very explicitly performs the following steps: > > 1) Find all pins(groups) that are used in the current state but not the > new state, and execute pinctrl_disable_setting() on them. (For mux > settings only, not pin config, since the core doesn't have any idea how > to reverse config settings). > > 2) For all settings in the new state, apply those settings. > > So, it very explicitly only allows a single state to be set at a time. > Equally, p->state (the field which stores the currently selected state) > is a single item, not a set/list/array.
OK thanks I get now what you're saying. I did not see the p->state issue as the disable function won't do anything for the SoCs that I mostly deal with. > So, this code needs rework if you want the core to support the concept > of having multiple states active at once, since it needs separate > pinctrl_activate_state() and pinctrl_deactivate_state() APIs, in order > to avoid step (1) above. And of course, p->state would need to be a > set/list/array. I'll think about it a bit and do a patch to fix this. It seems that that we need just two entries in the p->state array: static (default), and dynamic. Then the dynamic would be typically one of: active, idle, rx, tx. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
