From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v11 1/1] Mailbox: Add support for Platform Communication Channel Date: Tue, 18 Nov 2014 14:39:06 +0100 Message-ID: <1946980.r78SuCoQbW@wuerfel> References: <1415840378-1973-1-git-send-email-ashwin.chaugule@linaro.org> <1415840378-1973-2-git-send-email-ashwin.chaugule@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.17.13]:58745 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753511AbaKRNjY (ORCPT ); Tue, 18 Nov 2014 08:39:24 -0500 In-Reply-To: <1415840378-1973-2-git-send-email-ashwin.chaugule@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Ashwin Chaugule Cc: jaswinder.singh@linaro.org, broonie@kernel.org, lv.zheng@intel.com, linaro-acpi@lists.linaro.org, patches@linaro.org, linux-acpi@vger.kernel.org, rjw@rjwysocki.net On Wednesday 12 November 2014 19:59:38 Ashwin Chaugule wrote: > ACPI 5.0+ spec defines a generic mode of communication > between the OS and a platform such as the BMC. This medium > (PCC) is typically used by CPPC (ACPI CPU Performance management), > RAS (ACPI reliability protocol) and MPST (ACPI Memory power > states). > > This patch adds PCC support as a Mailbox Controller. As of > ACPI v5.1 there is no provision for clients to lookup mailbox > controllers in a way that Linux expects. e.g. in DT the clients > can list the mailboxes they can associate with in the DT binding > and then provide a unique index to lookup a channel within a mailbox. > Since the ACPI spec doesn't have anything similar, we introduce a > mailbox controller specific API so that when the client calls it, > we know to lookup in the context of a specific controller. This > also helps in keeping a consistent interface across DT and ACPI > for such drivers. > > This patch implements basic PCC support using the ACPI v5.1 > structures. IRQ mode support will be provided as follow up patches. > > Reviewed-by: Mark Brown > Signed-off-by: Ashwin Chaugule > Reviewed-by: Arnd Bergmann