Re: [PATCH v9 07/12] dt-bindings: mfd: Add a document for PECI client MFD

From: Jae Hyun Yoo
Date: Wed Jan 02 2019 - 13:29:30 EST

Hi Lee,

On 12/21/2018 6:47 AM, Lee Jones wrote:
On Tue, 18 Dec 2018, Jae Hyun Yoo wrote:

This commit adds a dt-bindings document for PECI client MFD.

+* Intel PECI client bindings


+PECI (Platform Environment Control Interface) is a one-wire bus interface that
+provides a communication channel from PECI clients in Intel processors and
+chipset components to external monitoring or control devices. PECI is designed
+to support the following sideband functions:
+- Processor and DRAM thermal management
+- Platform Manageability
+- Processor Interface Tuning and Diagnostics
+- Failure Analysis
+Required properties:
+- compatible : Should be "intel,peci-client".
+- reg : Should contain address of a client CPU. According to the PECI
+ specification, client addresses start from 0x30.
+ peci-bus@0 {
+ compatible = "vendor,soc-peci";
+ reg = <0x0 0x1000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ peci-client@30 {
+ compatible = "intel,peci-client";
+ reg = <0x30>;
+ };
+ peci-client@31 {
+ compatible = "intel,peci-client";
+ reg = <0x31>;
+ };

The PECI Client driver (masquerading as an MFD driver in this set)
doesn't actually do anything special. Instead of detailing it here,
register the child devices directly instead.

Main purpose of the PECI client driver is providing 'reg' value to its
child devices. If I add the child nodes directly, compiler will make
warnings while building dtb because the child nodes are using the same
unit address.