From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: [PATCH v4 1/6] arm64: arch_timer: Add device tree binding for hisilicon-161601 erratum Date: Sat, 26 Nov 2016 16:00:43 +0800 Message-ID: <1480147248-12828-2-git-send-email-dingtianhong@huawei.com> References: <1480147248-12828-1-git-send-email-dingtianhong@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1480147248-12828-1-git-send-email-dingtianhong@huawei.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, mark.rutland@arm.com, oss@buserror.net, devicetree@vger.kernel.org, shawnguo@kernel.org, stuart.yoder@nxp.com, linux-arm-kernel@lists.infradead.org, linuxarm@huawei.com, hanjun.guo@linaro.org Cc: Ding Tianhong List-Id: devicetree@vger.kernel.org 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. v2: Use the new erratum name and update the description. 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 ef5fbe9..c27b2c4 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 -- 1.9.0