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

From: Stephen Warren
Date: Mon Jun 27 2016 - 12:08:46 EST


On 06/27/2016 03:02 AM, Joseph Lo wrote:
The BPMP is a specific processor in Tegra chip, which is designed for
booting process handling and offloading the power management 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

+The BPMP is a specific processor in Tegra chip, which is designed for
+booting process handling and offloading the power management 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.

s/power management/power management, clock management, and reset control/?

+Required properties:
+- name : Should be bpmp
+- compatible : Should be "nvidia,tegra<chip>-bpmp"

Again, I'd suggest wording this as:

- compatible
Array of strings.
One of:
- "nvidia,tegra186-bpmp"

+- mboxes : The phandle of mailbox controller and the channel ID

s/channel ID/mailbox specifier/.

+ See "Documentation/devicetree/bindings/mailbox/
+ nvidia,tegra186-hsp.txt" and "Documentation/devicetree/
+ bindings/mailbox/mailbox.txt" for more details about the generic
+ mailbox controller and mailbox client driver bindings.

I'd rather not split the filenames across lines, since that makes grep fail to match. Perhaps add the following text to the introductory section at the start of the file to avoid having to mention some of the filenames in an indented block of text:

==========
This node is a mailbox consumer. See the following file for details of the mailbox subsystem, and the specifiers implemented by the relevant provider(s):

- Documentation/devicetree/bindings/mailbox/mailbox.txt
- Documentation/devicetree/bindings/mailbox/nvidia,tegra186-hsp.txt

This node is a clock and reset provider. See the following files for general documentation of those features, and the specifiers implemented by this node:

- Documentation/devicetree/bindings/clock/clock-bindings.txt
- include/dt-bindings/clock/tegra186-clock.h
- Documentation/devicetree/bindings/reset/reset.txt
- include/dt-bindings/reset/tegra186-reset.h
==========

Related, I would expect those two header files (tegra186-clock.h and tegra186-reset.h) to be part of this patch, since they form part of the definition of this binding.

+The shared memory bindings for BPMP
+-----------------------------------
+
+The shared memory area for the IPC TX and RX between CPU and BPMP are
+predefined and work on top of sysram, which is a sram inside the chip.

s/a sram/an SRAM/.

+Example:
...
+bpmp@d0000000 {

There should be no unit address ("@d0000000") in the node name, since there's no reg property.