Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932319AbaGWPKa (ORCPT ); Wed, 23 Jul 2014 11:10:30 -0400 Received: from mail-oa0-f53.google.com ([209.85.219.53]:44765 "EHLO mail-oa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262AbaGWPK1 (ORCPT ); Wed, 23 Jul 2014 11:10:27 -0400 MIME-Version: 1.0 In-Reply-To: <1405507426-18992-1-git-send-email-grygorii.strashko@ti.com> References: <1405507426-18992-1-git-send-email-grygorii.strashko@ti.com> Date: Wed, 23 Jul 2014 17:10:26 +0200 Message-ID: Subject: Re: [PATCH v1] gpio: keystone: add dsp gpio controller driver From: Linus Walleij To: Grygorii Strashko , Suman Anna , Jaswinder Singh , Alexander Shiyan Cc: Santosh Shilimkar , Alexandre Courbot , "linux-gpio@vger.kernel.org" , ivan.khoronzhuk@ti.com, Muralidharan Karicheri , Rob Herring , Kumar Gala , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" 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, Jul 16, 2014 at 12:43 PM, Grygorii Strashko wrote: > From: Murali Karicheri > > On Keystone SOCs, ARM host can send interrupts to DSP cores using the > DSP GPIO controller IP. Each DSP GPIO controller provides 28 IRQ signals for > each DSP core. This is one of the component used by the IPC mechanism used > on Keystone SOCs. > > Keystone 2 DSP GPIO controller has specific features: > - each GPIO can be configured only as output pin; > - setting GPIO value to 1 causes IRQ generation on target DSP core; > - reading pin value returns 0 - if IRQ was handled or 1 - IRQ is still > pending. > > Signed-off-by: Murali Karicheri > Signed-off-by: Grygorii Strashko Pardon me. How is this GENERAL PURPOSE Input/Output? It seems very very much SPECIAL PURPOSE to me, it's like you're just shoehorning some IPC mechanism into the GPIO subsystem, and this may be because the datasheet calls it GPIO when it's not. What other stuff than DSP is connected to these lines, and is it really even external lines? Aren't these just polysilicon rails pretty much hammered to be used by the DSP and nothing else. What is the difference between this and a mailbox IRQ line and the kind of stuff handled by drivers/mailbox? I'd like Suman and Jassi to have a look at this to see if it's actually a mailbox before we proceed. And if you proceed with this, please integrate it with drivers/gpio/gpio-syscon.c, I don't need more special syscons GPIO handlers. > +#include Kconfig needs depends on MFD_SYSCON, right? Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/