On Wed, Feb 2, 2022 at 9:31 AM Philippe Mathieu-Daudé <f4...@amsat.org>
wrote:
> On 2/2/22 17:40, Patrick Venture wrote:
>
> > Philippe,
> >
> > I0202 08:29:45.380384 6641 stream.go:31] qemu: child buses at
> > "pca9546": "channel[*]", "channel[*]", "channel[*]", "channel[*]"
> >
> > Ok, so that's interesting. In one system (using qom-list) it's
> > correct, but then when using it to do path assignment
> > (qdev-monitor), it fails...
> >
> > I'm not as fond of the name i2c-bus.%d, since they're referred to as
> > channels in the datasheet. If I do the manual name creation, can I
> > keep the name channel or should I pivot over?
> >
> > Thanks
> >
> >
> > -- >8 --
> > diff --git a/hw/i2c/i2c_mux_pca954x.c
> b/hw/i2c/i2c_mux_pca954x.c
> > index f9ce633b3a..a9517b612a 100644
> > --- a/hw/i2c/i2c_mux_pca954x.c
> > +++ b/hw/i2c/i2c_mux_pca954x.c
> > @@ -189,9 +189,11 @@ static void pca954x_init(Object *obj)
> >
> > /* SMBus modules. Cannot fail. */
> > for (i = 0; i < c->nchans; i++) {
> > + g_autofree gchar *bus_name =
> > g_strdup_printf("i2c.%d", i);
> > +
> > /* start all channels as disabled. */
> > s->enabled[i] = false;
> > - s->bus[i] = i2c_init_bus(DEVICE(s), "channel[*]");
> > + s->bus[i] = i2c_init_bus(DEVICE(s), bus_name);
> > }
> > }
> >
> > ---
> >
> > (look at HMP 'info qtree' output).
> >
> > > }
> > > }
> >
> > With the change:
> > Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org
> > <mailto:f4...@amsat.org>>
> > Tested-by: Philippe Mathieu-Daudé <f4...@amsat.org
> > <mailto:f4...@amsat.org>>
> >
> >
> > Just saw your reply, and found a bunch of other non-spam in my spam
> > folder. I sent the message to the anti-spam team, hopefully that'll
> > resolve this for myself and presumably others.
>
> Thanks. I suppose the problem is the amsat.org domain.
>
Yours aren't the only ones I've missed, but who knows.
>
> > I definitely see the same result with the qdev-monitor, but was really
> > surprised that the qom-list worked. I'll explicitly set the name, and
> > i2c.%d is fine. The detail that they're channels is not really
> > important to the end user presumably.
>
> I agree it is better to follow datasheets, thus I am fine if you
> change and use channel. How would it look like? "channel.0"?
> FYI qdev busses are described in docs/qdev-device-use.txt.
>
Thanks. I went with i2c.%d in v2, since I figured it wasn't super
important.
>
> We should be able to plug a device using some command line
> such "-device i2c_test_dev,bus=channel.0,addr=0x55".
> I wonder how to select the base PCA9548 ...
>
So I have been working on that, and I have been running into a different
issue, but related.
/smbus[1]/i2c-bus/pca9546/i2c.0 works to add a device via command line.
However, if there are two pca9546s on that main bus. So if i do:
/smbus[1]/i2c-bus/child[0]/i2c.0 it'll respond that there is no child[0],
but rather includes "pca9546, pca9546"
>
> Maybe we need to pass the PCA ID to pca954x_init(), so we can
> name "channel.2.0" for the 1st channel on the 2nd PCA?
>
It sounds like you're thinking about the same problem overall.
>
> Regards,
>
> Phil.
>
