Re: [PATCH V2 03/10] Documentation: dt-bindings: firmware: tegra: add bindings of the BPMP

From: Stephen Warren
Date: Mon Jul 18 2016 - 12:18:17 EST


On 07/18/2016 01:44 AM, Joseph Lo wrote:
Hi Rob,

Thanks for your reviewing.

On 07/12/2016 12:05 AM, Stephen Warren wrote:
On 07/11/2016 08:22 AM, Rob Herring wrote:
On Tue, Jul 05, 2016 at 05:04:24PM +0800, Joseph Lo wrote:
The BPMP is a specific processor in Tegra chip, which is designed for
booting process handling and offloading the power management, clock
management, and reset control tasks from the CPU. The binding document
defines the resources that would be used by the BPMP firmware driver,
which can create the interprocessor communication (IPC) between the CPU
and BPMP.

diff --git
a/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
b/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt

+NVIDIA Tegra Boot and Power Management Processor (BPMP)
+
+The BPMP is a specific processor in Tegra chip, which is designed for
+booting process handling and offloading the power management, clock
+management, and reset control tasks from the CPU. The binding document
+defines the resources that would be used by the BPMP firmware driver,
+which can create the interprocessor communication (IPC) between the
CPU
+and BPMP.
+
+Required properties:
+- name : Should be bpmp
+- compatible
+ Array of strings
+ One of:
+ - "nvidia,tegra186-bpmp"
+- mboxes : The phandle of mailbox controller and the mailbox
specifier.
+- shmem : List of the phandle of the TX and RX shared memory area that
+ the IPC between CPU and BPMP is based on.

I think you can use memory-region here.

Isn't memory-region intended for references into the /reserved-memory
node. If so, that isn't appropriate in this case since this property
typically points at on-chip SRAM that isn't included in the OS's view of
"system RAM".
Agree with that.


Or, should /reserved-memory be used even for (e.g. non-DRAM) memory
regions that aren't represented by the /memory/reg property?


For shmem, I follow the same concept of the binding for arm,scpi
(.../arm/arm,scpi.txt) that is currently using in mainline. Do you think
that is more appropriate here?

Personally I think the shmem property name used by the current patch is fine. Still, if Rob feels strongly about changing it, that's fine too.