From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCHv3 7/8] mailbox/omap: add code to support the wkupm3 operations Date: Mon, 26 Aug 2013 20:50:43 -0700 Message-ID: <87li3n6bcc.fsf@linaro.org> References: <1375825238-18299-1-git-send-email-s-anna@ti.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1375825238-18299-1-git-send-email-s-anna@ti.com> (Suman Anna's message of "Tue, 6 Aug 2013 16:40:38 -0500") Sender: linux-omap-owner@vger.kernel.org To: Suman Anna Cc: Tony Lindgren , Benoit Cousson , Paul Walmsley , Ohad Ben-Cohen , Jassi Brar , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Suman Anna writes: > The WkupM3 mailbox used for triggering PM operations such as suspend > and resume on AM33x/AM43x is special in that the M3 processor cannot > access the mailbox registers. However, an interrupt is needed to be > sent to request the M3 to perform a desired PM operation. This patch > adds the support for this special mailbox through separate ops for > this mailbox. These ops are designed to have the WkupM3's Rx interrupt > programmed within the driver, during transmission of a message. The > message is immediately read back and the internal mailbox interrupt > acknowledged as well to avoid triggering any spurious interrupts to > the M3. > > Signed-off-by: Suman Anna Dumb Q: why does all this extra logic belong in the mailbox driver and not in the wkup_m3 driver? To me, this seems like part of the IPC protocol between the MPU and M3 firmware, and not an inherent part of the AM33xx mbox. Kevin