From patchwork Wed Aug 28 10:24:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ivan Mikhaylov X-Patchwork-Id: 11118469 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DD1B4112C for ; Wed, 28 Aug 2019 10:24:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD7CE217F5 for ; Wed, 28 Aug 2019 10:24:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yadro.com header.i=@yadro.com header.b="ftjErji2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726836AbfH1KYZ (ORCPT ); Wed, 28 Aug 2019 06:24:25 -0400 Received: from mta-02.yadro.com ([89.207.88.252]:60554 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726738AbfH1KYY (ORCPT ); Wed, 28 Aug 2019 06:24:24 -0400 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id 07E1F42ECE; Wed, 28 Aug 2019 10:24:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= content-type:content-type:content-transfer-encoding:mime-version :references:in-reply-to:x-mailer:message-id:date:date:subject :subject:from:from:received:received:received; s=mta-01; t= 1566987860; x=1568802261; bh=87VA5h5waSDTUF2CVQN/4Wwh9JYi5VNM4bl aFGLhSMY=; b=ftjErji2haH19AzZFUWJf73ObDZba5bpxrSSs758XIdfDgACCZk jPlBP+oacojsvpJcH/Aq0ofG5bq36R++M4CPVB+RcmRQYJxUXVx26Iyk/bGeYABI 10uOLFbik5rkwD2UUHG7HkcmPXm+H/zjYStNE9UUWOOxCX8ZpzlFMMas= X-Virus-Scanned: amavisd-new at yadro.com Received: from mta-01.yadro.com ([127.0.0.1]) by localhost (mta-01.yadro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id maoMV8-Mbqiy; Wed, 28 Aug 2019 13:24:20 +0300 (MSK) Received: from T-EXCH-02.corp.yadro.com (t-exch-02.corp.yadro.com [172.17.10.102]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mta-01.yadro.com (Postfix) with ESMTPS id D90F3404CB; Wed, 28 Aug 2019 13:24:20 +0300 (MSK) Received: from localhost.dev.yadro.com (172.17.15.69) by T-EXCH-02.corp.yadro.com (172.17.10.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.669.32; Wed, 28 Aug 2019 13:24:20 +0300 From: Ivan Mikhaylov To: Guenter Roeck , Wim Van Sebroeck CC: Joel Stanley , Andrew Jeffery , , , , , Alexander Amelkin , , Rob Herring , Mark Rutland , , Ivan Mikhaylov Subject: [PATCH v4 4/4] aspeed/watchdog: Add access_cs0 option for alt-boot Date: Wed, 28 Aug 2019 13:24:02 +0300 Message-ID: <20190828102402.13155-5-i.mikhaylov@yadro.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190828102402.13155-1-i.mikhaylov@yadro.com> References: <20190828102402.13155-1-i.mikhaylov@yadro.com> MIME-Version: 1.0 X-Originating-IP: [172.17.15.69] X-ClientProxiedBy: T-EXCH-01.corp.yadro.com (172.17.10.101) To T-EXCH-02.corp.yadro.com (172.17.10.102) Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org The option for the ast2400/2500 to get access to CS0 at runtime. Signed-off-by: Ivan Mikhaylov Reviewed-by: Guenter Roeck --- .../ABI/testing/sysfs-class-watchdog | 34 +++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-watchdog b/Documentation/ABI/testing/sysfs-class-watchdog index 6317ade5ad19..675f9b537661 100644 --- a/Documentation/ABI/testing/sysfs-class-watchdog +++ b/Documentation/ABI/testing/sysfs-class-watchdog @@ -72,3 +72,37 @@ Description: It is a read/write file. When read, the currently assigned pretimeout governor is returned. When written, it sets the pretimeout governor. + +What: /sys/class/watchdog/watchdog1/access_cs0 +Date: August 2019 +Contact: Ivan Mikhaylov , + Alexander Amelkin +Description: + It is a read/write file. This attribute exists only if the + system has booted from the alternate flash chip due to + expiration of a watchdog timer of AST2400/AST2500 when + alternate boot function was enabled with 'aspeed,alt-boot' + devicetree option for that watchdog or with an appropriate + h/w strapping (for WDT2 only). + + At alternate flash the 'access_cs0' sysfs node provides: + ast2400: a way to get access to the primary SPI flash + chip at CS0 after booting from the alternate + chip at CS1. + ast2500: a way to restore the normal address mapping + from (CS0->CS1, CS1->CS0) to (CS0->CS0, + CS1->CS1). + + Clearing the boot code selection and timeout counter also + resets to the initial state the chip select line mapping. When + the SoC is in normal mapping state (i.e. booted from CS0), + clearing those bits does nothing for both versions of the SoC. + For alternate boot mode (booted from CS1 due to wdt2 + expiration) the behavior differs as described above. + + This option can be used with wdt2 (watchdog1) only. + + When read, the current status of the boot code selection is + shown. When written with any non-zero value, it clears + the boot code selection and the timeout counter, which results + in chipselect reset for AST2400/AST2500.