Re: [PATCH 2/6] mailbox/omap: add support for parsing dt devices

* Pavel Machek [off-list ref] [140704 01:07]:

Hi!

quoted

quoted

quoted

quoted

quoted

quoted

quoted

The non-DT support has to be maintained for now to not break
OMAP3 legacy boot, and the legacy-style code will be cleaned
up once OMAP3 is also converted to DT-boot only.

quoted

@@ -587,24 +606,157 @@ static int omap_mbox_unregister(struct omap_mbox_device *mdev)
 	return 0;
 }
 
+static const struct omap_mbox_device_data omap2_data = {
+	.num_users	= 4,
+	.num_fifos	= 6,
+	.intr_type	= MBOX_INTR_CFG_TYPE1,
+};
+
+static const struct omap_mbox_device_data omap3_data = {
+	.num_users	= 2,
+	.num_fifos	= 2,
+	.intr_type	= MBOX_INTR_CFG_TYPE1,
+};
+
+static const struct omap_mbox_device_data am335x_data = {
+	.num_users	= 4,
+	.num_fifos	= 8,
+	.intr_type	= MBOX_INTR_CFG_TYPE2,
+};

quoted

quoted

Aha, ok, then the intr_type should be derived from
compatible-string. Or rather... you should have three
compatible-strings for the three possibilities? (And then subtype,
currently unused, in case there are more hw differences).

The compatible string can and should be separate for each revision
unless they are the same exacat hardware revision.

ACK.

quoted

quoted

quoted

two are HW IP design parameters, so in general putting them in DT isn't
completely a bad idea, but I will wait to see if there are any further
comments on this from Tony or DT maintainers before I make changes.

Ok, right... I'd vote for putting them into DT.

I would avoid adding custom DT properties where possible and let the
driver just initialize the right data based on the compatible flag.

If these are HW IP design parameters, we can expect to see many
different combinations. Yet we know ahead of time how to handle
different parameters HW people select.

Thus IMO we should do it in the device tree.

Oh you mean from supporting new hardware with just .dts changes?

From that point of view it makes sense to have them as DT properties,

so I'm fine with that.

Let's just try to use something that's generic like fifosize. No idea
how the property for num_fifos should be handled though as that
implies some knowledge in the driver which num_users have fifos?

So unless that can be described clearly in a DT property as well,
the binding might be still unusable for new hardware :)

Regards,

Tony
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html