Hi Kevin, On Tue, Jun 12, 2012 at 10:37 PM, Kevin Hilman <khilman@xxxxxx> wrote: > "ABRAHAM, KISHON VIJAY" <kishon@xxxxxx> writes: > >> Hi Kevin, Benoit, Paul, >> >> On Fri, Jun 1, 2012 at 2:16 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >>> On Thursday 31 May 2012, ABRAHAM, KISHON VIJAY wrote: >>>> > I would mark the multiplexed device compatible with "simple-bus", which >>>> > results in the child devices automatically getting added. >>>> >>>> hmm.. ocp2scp has a sysconfig register and it also has a module mode >>>> by which it can be enabled/disabled. I was making use of pm_runtime >>>> API's to control these registers (Apart from creating child devices, >>>> the driver also has a call to pm_runtime_enable). >>> >>> I see. >>> >>>> I'm not sure if with >>>> "simple-bus" we'll be able to do those. I have to check on that. >>> >>> How about making it compatible with both "simple-bus" and something >>> that handles the pm_runtime requirements? >>> >>> I don't understand enough of what needs to be done for pm_runtime >>> across a lot of devices, but I'd hope that it should be possible >>> to do that in a generic way based on the device definition. >> >> Is there already exists a generic way for handling pm_runtime >> requirements (as simple as doing a pm_runtime_enable on a device). > > As you've discovered, the runtime PM core handles the parent/child > relationships already. > >> So the actual problem is we have ocp2scp as parent and usb2phy and >> usb3phy as the child device. ocp2scp has the sysconfig register and it >> can be controlled using module mode bit (both of this can be >> controlled by pm_runtime). Whenever usb controller(dwc3/musb) wants to >> enable a phy, it calls an exported API in usb2/usb3 phy to enable it. >> These API's have pm_runtime_get_sync on usb2/usb3 device which in-turn >> calls pm_runtime_get_sync of ocp2scp because of parent->child >> relationship (For this both usb2/usb3 phy and ocp2scp devices should >> have called pm_runtime_enable). All I'm trying is to find a place to >> have pm_runtime_enable for ocp2scp. > > Maybe I'm not following, but why can't it be in the driver? Arnd feels it is pointless to have a driver that only does creation of child (and pm_runtime_enable of the device). He feels it would be better to have a generic way to do a runtime_enable of a device with dt. (Just like how there is a generic way to create child devices by giving .compatible as "simple-bus"). Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
