Re: [PATCH] hw/i2c: flatten pca954x mux device

[Philippe Mathieu-Daudé]

On 1/2/22 17:30, Patrick Venture wrote:
> Previously this device created N subdevices which each owned an i2c bus.
> Now this device simply owns the N i2c busses directly.
>
> Tested: Verified devices behind mux are still accessible via qmp and i2c
> from within an arm32 SoC.
>
> Reviewed-by: Hao Wu <wuhaotsh@google.com>
> Signed-off-by: Patrick Venture <venture@google.com>
> ---
>   hw/i2c/i2c_mux_pca954x.c | 75 ++++++----------------------------------
>   1 file changed, 11 insertions(+), 64 deletions(-)

>   static void pca954x_init(Object *obj)
>   {
>       Pca954xState *s = PCA954X(obj);
>       Pca954xClass *c = PCA954X_GET_CLASS(obj);
>       int i;
>   
> -    /* Only initialize the children we expect. */
> +    /* SMBus modules. Cannot fail. */
>       for (i = 0; i < c->nchans; i++) {
> -        object_initialize_child(obj, "channel[*]", &s->channel[i],
> -                                TYPE_PCA954X_CHANNEL);
> +        /* start all channels as disabled. */
> +        s->enabled[i] = false;
> +        s->bus[i] = i2c_init_bus(DEVICE(s), "channel[*]");

This is not a QOM property, so you need to initialize manually:

-- >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 <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>