From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH 1/4] mailbox: add support for System Control and Power Interface(SCPI) protocol Date: Wed, 13 May 2015 18:09:20 +0100 Message-ID: <55538540.1010505@arm.com> References: <1430134846-24320-1-git-send-email-sudeep.holla@arm.com> <1430134846-24320-2-git-send-email-sudeep.holla@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jassi Brar Cc: Sudeep Holla , Linux Kernel Mailing List , Liviu Dudau , Lorenzo Pieralisi , "Jon Medhurst (Tixy)" , Rob Herring , Mark Rutland , Devicetree List List-Id: devicetree@vger.kernel.org On 13/05/15 17:52, Jassi Brar wrote: > On Mon, Apr 27, 2015 at 5:10 PM, Sudeep Holla wrote: >> This patch adds support for System Control and Power Interface (SCPI) >> Message Protocol used between the Application Cores(AP) and the System >> Control Processor(SCP). The MHU peripheral provides a mechanism for >> inter-processor communication between SCP's M3 processor and AP. >> >> SCP offers control and management of the core/cluster power states, >> various power domain DVFS including the core/cluster, certain system >> clocks configuration, thermal sensors and many others. >> >> This protocol driver provides interface for all the client drivers using >> SCPI to make use of the features offered by the SCP. >> > Is the SCPI specification available somewhere to look into? > Yes sorry posted the link separately(as reply to Tixy in the cover letter) since it was not available when I posted the patches. You can grab the protocol @[1] or [2] >> Signed-off-by: Sudeep Holla >> Cc: Rob Herring >> Cc: Mark Rutland >> CC: Jassi Brar >> Cc: Liviu Dudau >> Cc: Lorenzo Pieralisi >> Cc: Jon Medhurst (Tixy) >> Cc: devicetree@vger.kernel.org >> --- >> .../devicetree/bindings/mailbox/arm,scpi.txt | 121 ++++ >> drivers/mailbox/Kconfig | 19 + >> drivers/mailbox/Makefile | 2 + >> drivers/mailbox/scpi_protocol.c | 694 +++++++++++++++++++++ >> > Why in drivers/mailbox/ ? This is a 'consumer' driver and seems > Juno(ARM) specific. > Not just JUNO alone though it's first one to use, it will used in next few platforms(foreseeable future) from ARM Ltd. I have put that in drivers/mailbox for 2 reasons: 1. It's mailbox protocol :) 2. ARM64 doesn't have platform code like ARM32 and moreover it's strictly not specific to JUNO or any single platform. It may get reused on other platforms. Regards, Sudeep [1] http://community.arm.com/servlet/JiveServlet/download/8401-40-18262/DUI0922A_scp_message_interface.pdf [2] https://wiki.linaro.org/ARM/Juno?action=AttachFile&do=get&target=DUI0922A_scp_message_interface.pdf