From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753284AbeBSP6a (ORCPT ); Mon, 19 Feb 2018 10:58:30 -0500 Received: from mail-ot0-f195.google.com ([74.125.82.195]:35904 "EHLO mail-ot0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbeBSP60 (ORCPT ); Mon, 19 Feb 2018 10:58:26 -0500 X-Google-Smtp-Source: AH8x224zN7MWD8o/9Etp2a6qbFzmkEHQ6cN3nN/FAzzukDjnvFtdyHbMrKFNlQvl90EqHVr6BFK01g== Date: Mon, 19 Feb 2018 09:58:22 -0600 From: Rob Herring To: Lina Iyer Cc: andy.gross@linaro.org, david.brown@linaro.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, rnayak@codeaurora.org, bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2 02/10] dt-bindings: introduce RPMH RSC bindings for Qualcomm SoCs Message-ID: <20180219155822.4js35b53vu3wwt52@rob-hp-laptop> References: <20180215173507.10989-1-ilina@codeaurora.org> <20180215173507.10989-3-ilina@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180215173507.10989-3-ilina@codeaurora.org> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 15, 2018 at 10:34:59AM -0700, Lina Iyer wrote: > Add device binding documentation for Qualcomm Technology Inc's RPMH RSC > driver. The hardware block is used for communicating resource state > requests for shared resources. > > Cc: devicetree@vger.kernel.org > Signed-off-by: Lina Iyer > --- Changes in v2? > .../devicetree/bindings/arm/msm/rpmh-rsc.txt | 146 +++++++++++++++++++++ > 1 file changed, 146 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt > > diff --git a/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt b/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt > new file mode 100644 > index 000000000000..6cb36ae98bf9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt > @@ -0,0 +1,146 @@ > +RPMH RSC: > +------------ > + > +RPMH is the mechanism for communicating with the hardened resource > +accelerators. Requests to the resources can be written to the TCS mailbox > +registers and using a (addr, val) pair and triggered. Messages in the TCS are > +then sent in sequence over an internal bus. > + > +The hardware block (Direct Resource Voter or DRV) is a part of the h/w entity > +(Resource State Coordinator a.k.a RSC) that can handle a multiple sleep and > +active/wake resource requests. Multiple such DRVs can exist in a SoC and can > +be written to from Linux. The structure of each DRV follows the same template > +with a few variations that are captured by the properties here. > + > +Each DRV could have 'm' TCS instances. Each TCS could have 'n' slots. Each > +slot has a header (u32), address (u32), data (u32), status (u32) and a > +read-response (u32). A TCS when triggered will send all the enabled commands > +of the 'n' commands in that slot in sequence. > + > +A TCS may be triggered from Linux or triggered by the F/W after all the CPUs > +have powered off to facilitate idle power saving. TCS could be classified as - > + > + SLEEP, /* Triggered by F/W */ > + WAKE, /* Triggered by F/W */ > + ACTIVE, /* Triggered by Linux */ > + CONTROL /* Triggered by F/W */ > + > +The order in which they are described in the DT, should match the hardware > +configuration. > + > +Requests can be made for the state of a resource, when the subsystem is active > +or idle. When all subsystems like Modem, GPU, CPU are idle, the resource state > +will be an aggregate of the sleep votes from each of those subsystem. Drivers > +may request a sleep value for their shared resources in addition to the active > +mode requests. > + > +Control requests are instance specific requests that may or may not reach an > +accelerator. Only one platform device in Linux can request a control channel > +on a DRV. > + > +CONTROLLER: > +---------- > + > +PROPERTIES: > + > +- compatible: > + Usage: required > + Value type: > + Definition: Should be "qcom,rpmh-rsc". > + > +- reg: > + Usage: required > + Value type: > + Definition: The first register specifies the base address of the DRV. > + The second register specifies the start address of the > + TCS. > + > +- reg-names: > + Usage: required > + Value type: > + Definition: Maps the register specified in the reg property. Must be > + "drv" and "tcs". > + > +- interrupts: > + Usage: required > + Value type: > + Definition: The interrupt that trips when a message complete/response > + is received for this DRV from the accelerators. > + > +- qcom,drv-id: > + Usage: required > + Value type: > + Definition: the id of the DRV in the RSC block. > + > +- qcom,tcs-config: > + Usage: required > + Value type: > + Definition: the tuple defining the configuration of TCS. > + Must have 2 cells which describe each TCS type. > + . > + The order of the TCS must match the hardware > + configuration. > + - Cell #1 (TCS Type): TCS types to be specified - > + SLEEP_TCS > + WAKE_TCS > + ACTIVE_TCS > + CONTROL_TCS > + - Cell #2 (Number of TCS): > + > +- label: > + Usage: optional > + Value type: > + Definition: Name for the RSC. The name would be used in trace logs. > + > +Platform drivers that want to use the RSC to communicate with RPMH must Platform driver is a linux term. DT is not a platform driver instantiation language. > +specify their bindings as child of the corresponding RSC controllers. > + > +EXAMPLE 1: > + > +For a TCS whose RSC base address is is 0x179C0000 and is at a DRV id of 2, the > +register offsets for DRV2 start at 0D00, the register calculations are like > +this - > +First tuple: 0x179C0000 + 0x10000 * 2 = 0x179E0000 > +Second tuple: 0x179E0000 + 0xD00 = 0x179E0D00 > + > + apps_rsc: rsc@179e000 { > + label = "apps_rsc"; > + compatible = "qcom,rpmh-rsc"; > + reg = <0x179e0000 0x10000>, <0x179e0d00 0x3000>; > + reg-names = "drv", "tcs"; > + interrupts = > + qcom,drv-id = <2>; > + qcom,tcs-config = , > + , > + , > + ; > + > + foo-clk { > + compatible = "foo-clk"; What is this? Child nodes need to be documented too. > + }; > + }; > +