From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [Linaro-acpi] [PATCH v3 1/3] Mailbox: Add support for PCC mailbox and channels Date: Wed, 03 Sep 2014 16:50:27 +0200 Message-ID: <3269758.LiiZS9ag7d@wuerfel> References: <1409081738-5602-1-git-send-email-ashwin.chaugule@linaro.org> <5594980.1z2dWMD9C4@wuerfel> <20140903144921.GT29327@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.17.10]:53676 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932616AbaICOup (ORCPT ); Wed, 3 Sep 2014 10:50:45 -0400 In-Reply-To: <20140903144921.GT29327@sirena.org.uk> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linaro-acpi@lists.linaro.org Cc: Mark Brown , linux acpi , "Rafael J. Wysocki" On Wednesday 03 September 2014 15:49:21 Mark Brown wrote: > On Wed, Sep 03, 2014 at 01:23:21PM +0200, Arnd Bergmann wrote: > > On Tuesday 02 September 2014 16:15:05 Ashwin Chaugule wrote: > > > > Right. At least not in a way DT does. PCC clients know if something > > > needs to be written/read via PCC mailbox and can identify a PCC > > > subspace. (i.e. Mailbox channel). The PCC mailbox is uniquely > > > identified/defined in the spec. > > > > #define ACPI_ADR_SPACE_PLATFORM_COMM (acpi_adr_space_type) 10 > > > > So we could use this ID instead of a string and use that to look up > > > the PCC controller for a PCC client. > > > I didn't realize this was the case. Does that mean we can treat > > pcc as a linearly accessible address space the way we do for > > system memory, pci-config etc? > > > If that works, we should probably just have a regmap for it rather > > than expose the mailbox API to client drivers. > > A regmap doesn't seem to map very well here - as far as I can tell the > addresses referred to are mailboxes rather than registers or memory > addresses. I could be misunderstanding though. No, I think you are right. Nevermind then. Arnd