From patchwork Sat Jan 7 07:07:35 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ding Tianhong X-Patchwork-Id: 9502875 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4E278606E1 for ; Sat, 7 Jan 2017 07:14:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B58E28487 for ; Sat, 7 Jan 2017 07:14:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2F238284CF; Sat, 7 Jan 2017 07:14:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C242828487 for ; Sat, 7 Jan 2017 07:14:50 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cPlDE-0003qx-NS; Sat, 07 Jan 2017 07:14:48 +0000 Received: from szxga03-in.huawei.com ([119.145.14.66]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cPlD6-0003CT-PF for linux-arm-kernel@lists.infradead.org; Sat, 07 Jan 2017 07:14:44 +0000 Received: from 172.24.1.60 (EHLO SZXEML423-HUB.china.huawei.com) ([172.24.1.60]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id CNR72012; Sat, 07 Jan 2017 15:07:52 +0800 (CST) Received: from localhost (10.177.23.32) by SZXEML423-HUB.china.huawei.com (10.82.67.154) with Microsoft SMTP Server id 14.3.235.1; Sat, 7 Jan 2017 15:07:43 +0800 From: Ding Tianhong To: , , , , , , , , , Subject: [PATCH v7 1/4] arm64: arch_timer: Add device tree binding for hisilicon-161601 erratum Date: Sat, 7 Jan 2017 15:07:35 +0800 Message-ID: <1483772858-10380-2-git-send-email-dingtianhong@huawei.com> X-Mailer: git-send-email 1.8.5.2.msysgit.0 In-Reply-To: <1483772858-10380-1-git-send-email-dingtianhong@huawei.com> References: <1483772858-10380-1-git-send-email-dingtianhong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.177.23.32] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170106_231442_439106_4A646643 X-CRM114-Status: UNSURE ( 8.53 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ding Tianhong Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This erratum describes a bug in logic outside the core, so MIDR can't be used to identify its presence, and reading an SoC-specific revision register from common arch timer code would be awkward. So, describe it in the device tree. Signed-off-by: Ding Tianhong Acked-by: Rob Herring --- Documentation/devicetree/bindings/arm/arch_timer.txt | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt index ad440a2..935f142 100644 --- a/Documentation/devicetree/bindings/arm/arch_timer.txt +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -31,6 +31,14 @@ to deliver its interrupts via SPIs. This also affects writes to the tval register, due to the implicit counter read. +- hisilicon,erratum-161601 : A boolean property. Indicates the presence of + erratum 161601, which says that reading the counter is unreliable unless + reading twice on the register and the value of the second read is larger + than the first by less than 32. If the verification is unsuccessful, then + discard the value of this read and repeat this procedure until the verification + is successful. This also affects writes to the tval register, due to the + implicit counter read. + ** Optional properties: - arm,cpu-registers-not-fw-configured : Firmware does not initialize