On Tue, Jun 20, 2017 at 3:48 PM, Scott BrandenI don't understand what you mean by fallback compatible then.
Hi Rob,Use of of_machine_is_compatible in drivers will result in the same
On 17-06-18 07:04 AM, Rob Herring wrote:
On Mon, Jun 12, 2017 at 01:26:00PM -0700, Arun Parameswaran wrote:
Add device tree binding documentation for the Broadcom DTEBindings describe h/w, not drivers.
PTP clock driver.
Signed-off-by: Arun Parameswaran <arun.parameswaran@xxxxxxxxxxxx>
Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt | 13
1 file changed, 13 insertions(+)
create mode 100644
diff --git a/Documentation/devicetree/bindings/ptp/brcm,ptp-dte.txt
new file mode 100644
@@ -0,0 +1,13 @@
+* Broadcom Digital Timing Engine(DTE) based PTP clock driver
+Looks too generic. You need SoC specific compatible strings.
+- compatible: should be "brcm,ptp-dte"
Rob, could you please help me understand the use of adding SoC specific
I still don't get it.
It's my understanding that the SoC compatibility string is to future proof
between different versions of the hardware block due to integration issues
or any other reason.
You can then compare in your driver because the strings were already used in
That would make sense if you can't already differentiate what SoC you are
But the SoC is already specified in the root of the device tree in the
Why can't you just use of_machine_is_compatible inside your driver when
mess we had with machine_is_X defines pre-DT. It practically
guarantees that you must update the driver for a new SoC (with
fallback compatibles you don't). Plus the matching logic for
of_machine_is_compatible is open coded logic in every driver which is
worse IMO than having a standard match table.
Please explain what I'm missing. I see other drivers already following theIf the IP blocks are all the same, you don't have to add them to any
approach and it makes more sense to me than adding SoC specific compatible
strings into every
drivers, just add fallback compatibles.