From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751893AbdASCL4 (ORCPT ); Wed, 18 Jan 2017 21:11:56 -0500 Received: from ozlabs.org ([103.22.144.67]:59405 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751627AbdASCLy (ORCPT ); Wed, 18 Jan 2017 21:11:54 -0500 Subject: Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based FSI master To: Rob Herring , christopher.lee.bostic@gmail.com References: <1484260543-80300-1-git-send-email-christopher.lee.bostic@gmail.com> <20170118215755.xoamoc2rrzhy4kyz@rob-hp-laptop> Cc: mark.rutland@arm.com, linux@armlinux.org.uk, gregkh@linuxfoundation.org, mturquette@baylibre.com, geert+renesas@glider.be, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, joel@jms.id.au, linux-kernel@vger.kernel.org, andrew@aj.id.au, alistair@popple.id.au, benh@kernel.crashing.org, Chris Bostic From: Jeremy Kerr Message-ID: Date: Thu, 19 Jan 2017 10:11:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170118215755.xoamoc2rrzhy4kyz@rob-hp-laptop> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Chris, >>From this: >> + >> +The standard FSI master node >> +---------------------------- >> +This node describes a FSI master implmemented fully in hardware >> +with dedicated input/output pins required for its function (i.e. >> +not using generic GPIO pins). >> +Required property: >> + compatible = "ibm,fsi-master" and this: >> +Example: >> + >> +fsi-master { >> + compatible = "ibm,fsi-master-gpio", "ibm,fsi-master"; > > From the description, these should be mutually exclusive. I agree with Rob here. The intention is for "ibm,fsi-master" to be an abstract master -- simply indicating that this node describes a master, with no specific implementation, and "ibm,fsi-master-gpio" to be a GPIO-based implementation. A hardware-based FSI master would have a different compatible value, based on the hardware. We should remove references to implementations in the "The standard FSI master node" section, because this is independent of implementation. >> + clk-gpios = <&gpio 0>, <&gpio 6>; >> + data-gpios = <&gpio 1>, <&gpio 7>; >> + enable-gpios = <&gpio 2>, <&gpio 8>; >> + trans-gpios = <&gpio 3>, <&gpio 9>; >> + mux-gpios = <&gpio 4>, <&gpio 10>; Do we support multiple-link masters? This example implies a 2-link master. Cheers, Jeremy