Re: [PATCH 00/14] usb: typec: UCSI driver overhaul

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Hi,

On Thu, Oct 10, 2019 at 05:51:23PM +0000, Ajay Gupta wrote:
> Hi Heikki,
> 
> > > > > Hi Ajay,
> > > > >
> > > > > Here's the pretty much complete rewrite of the I/O handling that I
> > > > > was talking about. The first seven patches are not actually
> > > > > related to this stuff, but I'm including them here because the
> > > > > rest of the series is made on top of them. I'm including also that
> > > > > fix patch I send you earlier.
> > > > >
> > > > > After this it should be easier to handle quirks. My idea how to
> > > > > handle the multi-instance connector alt modes is that we "emulate"
> > > > > the PPM in ucsi_ccg.c in order to handle them, so ucsi.c is not
> > > > > touched at
> > > all.
> > > > >
> > > > > We can now get the connector alternate modes that the actual
> > > > > controller supplies during probe - before registering the ucsi
> > > > > interface
> > > > How can ucsi_ccg.c get the connector alternate modes before
> > > > registering ucsi interface? PPM reset, notification enable, etc.
> > > > is done during ucsi registration. UCSI spec says:
> > > > " The only commands the PPM is required to process in the "PPM Idle
> > > > (Notifications Disabled)" state are SET_NOTIFICATION_ENABLE and
> > > > PPM_RESE"
> > > >
> > > > Also, it doesn't look correct if ucsi_ccg.c has to replicate most of
> > > > the stuff done in ucsi_init() of ucsi.c.
> > >
> > > How about if we split ucsi_init() into a function that first simply
> > > constructs the struct ucsi and struct ucsi_connector instances without
> > > registering anything, and into separate functions that then register
> > > the ports, altmodes and what have you. I don't think that should be a
> > > huge problem. It will make ucsi.c even more like a library, which is probable
> > a good thing.
> > Do you mean the solution to follow steps (a->b->c->d1) or (a->b->c->d2) ?
> > a) ucsi_ccg.c calls first part of split ucsi_init()
> > b) ucsi_ccg.c uses ucsi_send_command() to collect actual alternate modes.
> > c) ucsi_ccg.c looks into actual alternate modes and squashes if duplicate
> > altmode found.
> > d1) ucsi_ccg.c calls new method to register connector alternate modes.
> > This method issues GET_ALTERNATE_MODES command again and ucsi_ccg.c is
> > expected to send squashed alternate mode.  This will require changes in
> > .read(), .sync_write() and
> > .async_write() to make it appear as if the squashed data coming from the ppm.
> > OR
> > d2) ucsi_ccg.c calls new method to register squashed connector alternate
> > modes.
> > This method doesn't issue GET_ALTERNATE_MODES commands to PPM but
> > simply registers the alternate mode values passed to this function.
> > 
> > If you mean the (a->b->c->d2) solution then it looks fine to me and would wait
> > for patches from you. This solution would mean that GET_ALTERNATE_MODES
> > for connector is done only by each ucsi_xxx.c and not by ucsi.c
> 
> I am waiting for your comments on this.

Sorry Ajay. I lost track of this thread.

The above is not exactly what I had in mind, but something like that.
But in any case, I'll start wringing the patches then.


thanks,

-- 
heikki



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