On 12/09/18 11:59, Lee Jones wrote:
On 12/09/18 09:58, Lee Jones wrote:
+static const struct mfd_cell wcd9335_devices[] = {
+ { .name = "wcd9335-codec", },
+};
Are there more devices to come?
Yes, that is the plan, we are kind of limited in hardware setup to test few
things like soundwire controller. We are exploring other ways to test these.
I normally don't accept MFDs with just one device enabled. Since it's
not really an MFD (M == Multi) until it has more than one function.
WCD9335 Codec hw itself has multiple hw blocks.
If the issue is about adding more entries to mfd cells then we should be
able to add below entry:
{ .name = "wcd9335-soundwire-controller", },
Actual driver for soundwire controller is not something We can test with
regular dragon boards, it needs special hw for smart speakers. Once we have
that we can test and post the drivers for that.
Otherwise
Are you suggesting that I move everything to sound/soc/codecs and then back
to mfd once soundwire controller driver is added?
My preference would be for you to add at least one other (tested)
device. However, in your case I know where you live, so I can throw
tomatoes at your house if you don't upstream more device support
promptly!;)
When will you be enabling more devices? If the answer is 'never',
then creating an MFD is a waste of time.
Vinod Koul is exploring this and ATM we are trying to sort out the hw
setup. Hopefully we should be sorted with Qcom help!
[...]
+ struct device_node *ifc_dev_np;
ifc isn't very forthcoming. Any way you can improve the name?
ifc was suggested in dt bindings by Rob, I can proably rename to
interface_node.
ifc is a horrible variable name - just sayin'.
[...]
+ ret = wcd9335_bring_up(wcd);
So the device_status call-back brings up the hardware?
device status reports the device status at runtime. We can not communicate
with the device until it is up, enumerated by slimbus and a logical address
is assigned to it. So the best place to initialize it is in status callback
where all the above are expected to be done.
Right, I understand what's happening. I just think the semantics are
wrong. The Subsystem (I'm assuming it's a Subsystem) requests for
status and it ends up initiating a start-up sequence. Just from a
purist's point of view (I understand that it "works"), it's not good
practice.
Probe is expected to setup the external configurations like regulators/pins
and so on which gets the device out of reset and ready to be enumerated by
the slimbus controller.
I suggest fully starting the device in probe() is a better approach.
Its catch-22 situation, without device being powered up and reset correctly
there is no way to enumerate it.
Isn't power-up and reset also done in probe()?
What am I missing?
There are two parts for device to be ready to talk at bus level:
1> power up and reset,
2> enumerate and assign a logical address by the slimbus controller.
First part as you said is already done in probe.
When second part happens when status callback is invoked, that is when
the slimdevice is ready for any kind of communication at bus level.
--srini
