From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753063AbbENHDC (ORCPT ); Thu, 14 May 2015 03:03:02 -0400 Received: from mail-ie0-f179.google.com ([209.85.223.179]:36492 "EHLO mail-ie0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751743AbbENHCz (ORCPT ); Thu, 14 May 2015 03:02:55 -0400 MIME-Version: 1.0 In-Reply-To: <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> <55538540.1010505@arm.com> Date: Thu, 14 May 2015 12:32:55 +0530 Message-ID: Subject: Re: [PATCH 1/4] mailbox: add support for System Control and Power Interface(SCPI) protocol From: Jassi Brar To: Sudeep Holla Cc: Linux Kernel Mailing List , Liviu Dudau , Lorenzo Pieralisi , "Jon Medhurst (Tixy)" , Rob Herring , Mark Rutland , Devicetree List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2015 at 10:39 PM, Sudeep Holla wrote: > On 13/05/15 17:52, Jassi Brar 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] > Thanks for the link. I wish I had access to the spec earlier. >>> .../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 :) > client/protocol drivers don't usually reside with controller drivers. drivers/firmware/ seems more appropriate. > 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. > drivers/firmware/ should do too. BTW is scpi_protocol.c meant/tested to work over arm_mhu.c? The spec says so but I don't see how because you pass 'struct scpi_xfer*' as the message whereas arm_mhu.c expects u32*