Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753029AbcD1Osm (ORCPT ); Thu, 28 Apr 2016 10:48:42 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:35902 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752315AbcD1Osj (ORCPT ); Thu, 28 Apr 2016 10:48:39 -0400 Date: Thu, 28 Apr 2016 07:48:30 -0700 From: Eduardo Valentin To: Wei Ni Cc: thierry.reding@gmail.com, robh+dt@kernel.org, rui.zhang@intel.com, MLongnecker@nvidia.com, swarren@wwwdotorg.org, mikko.perttunen@kapsi.fi, linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 4/9] of: Add bindings of hw throttle for soctherm Message-ID: <20160428144828.GB19279@localhost.localdomain> References: <1461727554-15065-1-git-send-email-wni@nvidia.com> <1461727554-15065-5-git-send-email-wni@nvidia.com> <20160427233054.GA26451@localhost.localdomain> <5721B249.3010101@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5721B249.3010101@nvidia.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8272 Lines: 183 On Thu, Apr 28, 2016 at 02:48:41PM +0800, Wei Ni wrote: > > > On 2016年04月28日 07:30, Eduardo Valentin wrote: > > From: Eduardo Valentin > > To: Wei Ni > > Cc: thierry.reding@gmail.com, robh+dt@kernel.org, rui.zhang@intel.com, > > MLongnecker@nvidia.com, swarren@wwwdotorg.org, > > mikko.perttunen@kapsi.fi, linux-tegra@vger.kernel.org, > > linux-pm@vger.kernel.org, devicetree@vger.kernel.org, > > linux-kernel@vger.kernel.org > > Bcc: > > Subject: Re: [PATCH v2 4/9] of: Add bindings of hw throttle for soctherm > > Reply-To: > > In-Reply-To: <1461727554-15065-5-git-send-email-wni@nvidia.com> > > > > The patch title must say something about the fact that this is specific > > to nvidia thermal driver. > > Yes, it's my mistake, will fix it in next series. > > > > > On Wed, Apr 27, 2016 at 11:25:49AM +0800, Wei Ni wrote: > >> Add HW throttle configuration sub-node for soctherm, which > >> is used to describe the throttle event, and worked as a > >> cooling device. The "hot" type trip in thermal zone can > >> be bound to this cooling device, and trigger the throttle > >> function. > >> > >> Signed-off-by: Wei Ni > >> --- > >> .../bindings/thermal/nvidia,tegra124-soctherm.txt | 89 +++++++++++++++++++++- > >> 1 file changed, 87 insertions(+), 2 deletions(-) > >> > >> diff --git a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt > >> index edebfa0a985e..dc337d139f49 100644 > >> --- a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt > >> +++ b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt > >> @@ -10,8 +10,14 @@ Required properties : > >> - compatible : For Tegra124, must contain "nvidia,tegra124-soctherm". > >> For Tegra132, must contain "nvidia,tegra132-soctherm". > >> For Tegra210, must contain "nvidia,tegra210-soctherm". > >> -- reg : Should contain 1 entry: > >> +- reg : Should contain at least 2 entries for each entry in reg-names: > >> - SOCTHERM register set > >> + - Tegra CAR register set: Required for Tegra124 and Tegra210. > >> + - CCROC register set: Required for Tegra132. > >> +- reg-names : Should contain at least 2 entries: > >> + - soctherm-reg > >> + - car-reg > >> + - ccroc-reg > >> - interrupts : Defines the interrupt used by SOCTHERM > >> - clocks : Must contain an entry for each entry in clock-names. > >> See ../clocks/clock-bindings.txt for details. > >> @@ -25,17 +31,44 @@ Required properties : > >> - #thermal-sensor-cells : Should be 1. See ./thermal.txt for a description > >> of this property. See for a > >> list of valid values when referring to thermal sensors. > >> +- throttle-cfgs: A sub-node which is a container of configuration for each > >> + hardware throttle events. These events can be set as cooling devices. > >> + * throttle events: Sub-nodes must be named as "light" or "heavy". > >> + Properties: > >> + - priority: Each throttles has its own throttle settings, so the SW need > >> + to set priorities for various throttle, the HW arbiter can select the > >> + final throttle settings. > >> + Bigger value indicates higher priority, In general, higher priority > >> + translates to lower target frequency. SW needs to ensure that critical > >> + thermal alarms are given higher priority, and ensure that there is > >> + no race if priority of two vectors is set to the same value. > >> + - cpu-throt-depth: This property is for Tegra124 and Tegra210. It is > >> + the throttling depth of pulse skippers, it's the percentage > >> + throttling. > >> + - cpu-throt-level: This property is only for Tegra132, it is the level > >> + of pulse skippers, which used to throttle clock frequencies. It > >> + indicates cpu clock throttling depth, and the depth can be programmed. > >> + Must set as following values: > >> + TEGRA_SOCTHERM_THROT_LEVEL_LOW, TEGRA_SOCTHERM_THROT_LEVEL_MED > >> + TEGRA_SOCTHERM_THROT_LEVEL_HIGH, TEGRA_SOCTHERM_THROT_LEVEL_NONE > > > > These properties are not generic properties. My understanding is that > > you must have vendor prefix in such case. Same applies to the new nodes. > > Ok, will do it. > > > > >> + - #cooling-cells: Should be 1. This cooling device only support on/off state. > >> + See ./thermal.txt for a description of this property. > >> > >> Note: > >> - the "critical" type trip points will be set to SOC_THERM hardware as the > >> shut down temperature. Once the temperature of this thermal zone is higher > >> than it, the system will be shutdown or reset by hardware. > >> +- the "hot" type trip points will be set to SOC_THERM hardware as the throttle > >> +temperature. Once the the temperature of this thermal zone is higher > >> +than it, it will trigger the HW throttle event. > >> > >> Example : > >> > >> soctherm@700e2000 { > >> compatible = "nvidia,tegra124-soctherm"; > >> - reg = <0x0 0x700e2000 0x0 0x1000>; > >> + reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */ > >> + 0x0 0x60006000 0x0 0x400 /* CAR reg_base */ > >> + reg-names = "soctherm-reg", "car-reg"; > >> interrupts = ; > >> clocks = <&tegra_car TEGRA124_CLK_TSENSOR>, > >> <&tegra_car TEGRA124_CLK_SOC_THERM>; > >> @@ -44,6 +77,45 @@ Example : > >> reset-names = "soctherm"; > >> > >> #thermal-sensor-cells = <1>; > >> + > >> + throttle-cfgs { > >> + throttle_heavy: heavy { > >> + priority = <100>; > >> + cpu-throt-depth = <85>; > >> + > >> + #cooling-cells = <1>; > >> + }; > >> + throttle_light: light { > >> + priority = <80>; > >> + cpu-throt-depth = <50>; > >> + > >> + #cooling-cells = <1>; > >> + }; > >> + }; > > > > This is a sensor, which at the same time, has sub nodes that can be > > cooling devices. Is my understanding correct of what you are trying to > > do? > > Yes, we set this sub nodes as cooling devices. > Let me explain it. > The Tegra's soctherm has the HW throttle function, it will be triggered when the > temperatures reach to the "hot" type trip. These throttle events can be > configured to different levels "heavy" and "light" on different sensors. So it > something like cooling devices which can be bound with thermal zones, and in > this way, we can use the linux of-thermal framework to handle it. If not, we > have to add more codes to parse these configuration and set them for those > sensors. I had used this method to handle the shutdown function in Tegra's > soctherm driver in my previous series, however Rob didn't like it, he preferred > to use linux framework to handle it. > So I think it's better to set these throttle-cfgs as cooling devices, so they > can be bound to the cpu/gpu thermal zones easily. > > > > > > >> + }; > >> + > >> +Example: referring to Tegra132's "reg", "reg-names" and "throttle-cfgs" : > >> + > >> + soctherm@0,700e2000 { > >> + compatible = "nvidia,tegra132-soctherm"; > >> + reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */ > >> + 0x0 0x70040000 0x0 0x200>; /* CCROC reg_base */; > >> + reg-names = "soctherm-reg", "ccroc-reg"; > >> + > >> + throttle-cfgs { > >> + throttle_heavy: heavy { > >> + priority = <100>; > >> + cpu-throt-level = ; > >> + > >> + #cooling-cells = <1>; > >> + }; > >> + throttle_light: light { > >> + priority = <80>; > >> + cpu-throt-level = ; > >> + > >> + #cooling-cells = <1>; > > > > Could you please describe a little here what to expect of the above > > setup? > > Ok, let me describe it. > When the "heavy" cooling device triggered, the hardware will skip cpu clock's > pulse in HIGH level, and if the "light" triggered, the hardware will skip cpu > clock's pulse in MED level. > If these two devices are triggered in same time, the HW throttle arbiter will > select the highest priority as the final throttle settings to skip cpu pulse. I would prefer if you add these descriptions into your examples in your next version.