Messages in this thread | | | Date | Wed, 30 Oct 2013 00:11:37 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH v3 02/10] spmi: Linux driver framework for SPMI |
| |
On Mon, Oct 28, 2013 at 01:12:35PM -0500, Josh Cartwright wrote: > From: Kenneth Heitke <kheitke@codeaurora.org> > > System Power Management Interface (SPMI) is a specification > developed by the MIPI (Mobile Industry Process Interface) Alliance > optimized for the real time control of Power Management ICs (PMIC). > > SPMI is a two-wire serial interface that supports up to 4 master > devices and up to 16 logical slaves. > > The framework supports message APIs, multiple busses (1 controller > per bus) and multiple clients/slave devices per controller.
I haven't read this in depth, but... if you want to support runtime PM for your spmi devices, then I suggest that you also include the fragments to setup runtime PM in the bus-level probe handler and clean it up in the bus-level remove handler.
What that means is doing what PCI, AMBA and similar buses do:
pm_runtime_get_noresume(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev);
ret = driver->probe(dev); if (ret != 0) { pm_runtime_disable(dev); pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev); }
and:
pm_runtime_get_sync(dev); ret = driver->remove(dev); pm_runtime_put_noidle(dev);
pm_runtime_disable(dev); pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev);
What this means is that your devices get runtime enabled by default, but they have to do a pm_runtime_put() or similar in their probe function to benefit from it and a balancing pm_runtime_get() in their remove method.
The set_active() call above may need to be conditional upon whether the device really is in a powered up state at that point or not.
Others have made comments on various other issues so I won't repeat those points here.
| |