From patchwork Thu Apr 4 17:03:04 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 2394291 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id 589903FD1A for ; Thu, 4 Apr 2013 17:07:39 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UNndS-0003aD-Aq for patchwork-linux-arm@patchwork.kernel.org; Thu, 04 Apr 2013 17:07:38 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UNna6-0001r3-T2; Thu, 04 Apr 2013 17:04:10 +0000 Received: from smtp.infotech.no ([82.134.31.41]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UNna2-0001qL-SB for linux-arm-kernel@lists.infradead.org; Thu, 04 Apr 2013 17:04:08 +0000 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 7BE1E204169; Thu, 4 Apr 2013 19:04:04 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id B8Q+ciTBFzxu; Thu, 4 Apr 2013 19:03:51 +0200 (CEST) Received: from [192.168.48.66] (unknown [98.143.101.107]) by smtp.infotech.no (Postfix) with ESMTPA id 70E722041AC; Thu, 4 Apr 2013 19:03:49 +0200 (CEST) Message-ID: <515DB248.6070105@interlog.com> Date: Thu, 04 Apr 2013 13:03:04 -0400 From: Douglas Gilbert User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Nicolas Ferre Subject: Re: [PATCH v3] ARM: at91: add Acme Systems Aria G25 board References: <20130402184947.GA8015@quad.lixom.net> <1365090153-1807-1-git-send-email-nicolas.ferre@atmel.com> In-Reply-To: <1365090153-1807-1-git-send-email-nicolas.ferre@atmel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130404_130407_205314_AEFCD839 X-CRM114-Status: GOOD ( 14.76 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: robertcnelson@gmail.com, jhovold@gmail.com, linux-kernel@vger.kernel.org, Ludovic Desroches , Jean-Christophe PLAGNIOL-VILLARD , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: dgilbert@interlog.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On 13-04-04 11:42 AM, Nicolas Ferre wrote: > From: Douglas Gilbert > > Signed-off-by: Douglas Gilbert > Signed-off-by: Nicolas Ferre > --- > Hi all, > > Here is the third revision of this patch. I plan to include it in a > pull-request real-soon-now! > > v3: - move to "at91-" prefix for .dts[i] files > - remove the rtc activation code because of the ongoing discussions > about this IP and its DT binding. > Nicolas, It's a pity that the rtc activation code is removed. At worst: rtc@fffffeb0 { status = "okay"; }; does nothing. Also it is unlikely to be changed by any movement on the rtc-at91rm9200 front. The lack of use of uart1 is for my own, private reasons. I think it would be more generally useful to show uart1's definition and disable it as shown in the attached patch fragment. I also note that my date line was removed. I like dates, so when I add comments like "the i2c-at91 driver is broken for the SAM9G20 ** and use the i2c-gpio driver instead" then this is not taken as an eternal truth. It worked in the past and hopefully it will work again in the future. While on the subject of I2C, I'm getting tired of seeing this oft-copied line: i2c-gpio,delay-us = <2>; /* ~100 kHz */ It is the clock half period in microseconds and for the 100 kHz (standard) I2C clock speed, it should be 5. Due to rounding (up) that gives a measured clock speed of around 88 kHz on my equipment. Crappy I2C devices *** seem to cope better with 12% below the standard clock frequency than 80% above it. Doug Gilbert ** broken in my tests on the FoxG20 with lk 3.9.0-rc5 *** if my experience is anything to go by there are many dodgy I2C devices, probably using I2C bit banging code borrowed from Wikipedia. --- a/arch/arm/boot/dts/ariag25.dts_orig 2013-04-04 11:58:40.518122816 -0400 +++ b/arch/arm/boot/dts/at91-ariag25.dts 2013-04-03 15:23:09.240385849 -0400 @@ -1,5 +1,5 @@ /* - * ariag25.dts - Device Tree file for Acme Systems Aria G25 (AT91SAM9G25 based) + * at91-ariag25.dts - Device Tree file for Acme Systems Aria G25 (AT91SAM9G25 based) * * Copyright (C) 2013 Douglas Gilbert , * Robert Nelson @@ -21,6 +21,7 @@ serial3 = &usart2; serial4 = &usart3; serial5 = &uart0; + serial6 = &uart1; }; chosen { @@ -121,6 +122,16 @@ status = "okay"; }; + uart1: serial@f8044000 { + compatible = "atmel,at91sam9260-usart"; + reg = <0xf8044000 0x200>; + interrupts = <16 4 5>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart1>; + /* Remove following or change to "okay" if wanted */ + status = "disabled"; + }; + spi0: spi@f0000000 { status = "okay"; cs-gpios = <&pioA 14 0>, <0>, <0>, <0>;