From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH V7 1/3] OPP: Add new bindings to address shortcomings of existing bindings Date: Thu, 4 Jun 2015 11:37:52 -0700 Message-ID: <20150604183752.GI490@codeaurora.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Viresh Kumar Cc: Rafael Wysocki , rob.herring@linaro.org, linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, arnd.bergmann@linaro.org, nm@ti.com, broonie@kernel.org, mike.turquette@linaro.org, grant.likely@linaro.org, olof@lixom.net, Sudeep.Holla@arm.com, devicetree@vger.kernel.org, viswanath.puttagunta@linaro.org, l.stach@pengutronix.de, thomas.petazzoni@free-electrons.com, linux-arm-kernel@lists.infradead.org, ta.omasab@gmail.com, kesavan.abhilash@gmail.com, khilman@linaro.org, santosh.shilimkar@oracle.com List-Id: devicetree@vger.kernel.org On 06/04, Viresh Kumar wrote: > Current OPP (Operating performance point) device tree bindings have been > insufficient due to the inflexible nature of the original bindings. Over > time, we have realized that Operating Performance Point definitions and > usage is varied depending on the SoC and a "single size (just frequency, > voltage) fits all" model which the original bindings attempted and > failed. > > The proposed next generation of the bindings addresses by providing a > expandable binding for OPPs and introduces the following common > shortcomings seen with the original bindings: > > - Getting clock/voltage/current rails sharing information between CPUs. > Shared by all cores vs independent clock per core vs shared clock per > cluster. > > - Support for specifying current levels along with voltages. > > - Support for multiple regulators. > > - Support for turbo modes. > > - Other per OPP settings: transition latencies, disabled status, etc.? > > - Expandability of OPPs in future. > > This patch introduces new bindings "operating-points-v2" to get these problems > solved. Refer to the bindings for more details. > > We now have multiple versions of OPP binding and only one of them should > be used per device. > > Reviewed-by: Rob Herring > Signed-off-by: Viresh Kumar Ok. I'm still interested to see if this binding will have to change to support how multiple regulators will be matched up with the device using the OPP. But for now, Reviewed-by: Stephen Boyd -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Thu, 4 Jun 2015 11:37:52 -0700 Subject: [PATCH V7 1/3] OPP: Add new bindings to address shortcomings of existing bindings In-Reply-To: References: Message-ID: <20150604183752.GI490@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/04, Viresh Kumar wrote: > Current OPP (Operating performance point) device tree bindings have been > insufficient due to the inflexible nature of the original bindings. Over > time, we have realized that Operating Performance Point definitions and > usage is varied depending on the SoC and a "single size (just frequency, > voltage) fits all" model which the original bindings attempted and > failed. > > The proposed next generation of the bindings addresses by providing a > expandable binding for OPPs and introduces the following common > shortcomings seen with the original bindings: > > - Getting clock/voltage/current rails sharing information between CPUs. > Shared by all cores vs independent clock per core vs shared clock per > cluster. > > - Support for specifying current levels along with voltages. > > - Support for multiple regulators. > > - Support for turbo modes. > > - Other per OPP settings: transition latencies, disabled status, etc.? > > - Expandability of OPPs in future. > > This patch introduces new bindings "operating-points-v2" to get these problems > solved. Refer to the bindings for more details. > > We now have multiple versions of OPP binding and only one of them should > be used per device. > > Reviewed-by: Rob Herring > Signed-off-by: Viresh Kumar Ok. I'm still interested to see if this binding will have to change to support how multiple regulators will be matched up with the device using the OPP. But for now, Reviewed-by: Stephen Boyd -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project