From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DDD6CA9ECB for ; Thu, 31 Oct 2019 12:40:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C45320873 for ; Thu, 31 Oct 2019 12:40:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726982AbfJaMkd (ORCPT ); Thu, 31 Oct 2019 08:40:33 -0400 Received: from mail-sz.amlogic.com ([211.162.65.117]:14675 "EHLO mail-sz.amlogic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726506AbfJaMkd (ORCPT ); Thu, 31 Oct 2019 08:40:33 -0400 Received: from [10.28.19.135] (10.28.19.135) by mail-sz.amlogic.com (10.28.11.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1591.10; Thu, 31 Oct 2019 20:40:44 +0800 Subject: Re: [PATCH v3 2/4] dt-bindings: watchdog: add new binding for meson secure watchdog To: Rob Herring CC: Wim Van Sebroeck , Guenter Roeck , Kevin Hilman , Neil Armstrong , Jerome Brunet , Qianggui Song , Jianxin Pan , Jian Hu , LINUX-WATCHDOG , "open list:ARM/Amlogic Meson..." , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , "linux-kernel@vger.kernel.org" , References: <1571983984-11771-1-git-send-email-xingyu.chen@amlogic.com> <1571983984-11771-3-git-send-email-xingyu.chen@amlogic.com> <20191025203030.GA28391@bogus> <1914e315-3cb7-9251-f871-0024e0e4f68b@amlogic.com> <2808a8c9-a835-2706-f300-0deb924d3686@amlogic.com> From: Xingyu Chen Message-ID: <8a663e01-9d6e-cced-cb97-8e793006f0c6@amlogic.com> Date: Thu, 31 Oct 2019 20:40:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-Originating-IP: [10.28.19.135] X-ClientProxiedBy: mail-sz.amlogic.com (10.28.11.5) To mail-sz.amlogic.com (10.28.11.5) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Rob On 2019/10/30 21:41, Rob Herring wrote: > On Wed, Oct 30, 2019 at 7:59 AM Xingyu Chen wrote: >> >> Hi,Rob >> >> On 2019/10/30 4:51, Rob Herring wrote: >>> On Mon, Oct 28, 2019 at 3:35 AM Xingyu Chen wrote: >>>> >>>> Hi, Rob >>>> >>>> On 2019/10/26 4:30, Rob Herring wrote: >>>>> On Fri, Oct 25, 2019 at 02:13:02PM +0800, Xingyu Chen wrote: >>>>>> The binding targets the Meson-A/C series compatible SoCs, in which the >>>>>> watchdog registers are in secure world. >>>>>> >>>>>> Signed-off-by: Xingyu Chen >>>>>> --- >>>>>> .../bindings/watchdog/amlogic,meson-sec-wdt.yaml | 34 ++++++++++++++++++++++ >>>>>> 1 file changed, 34 insertions(+) >>>>>> create mode 100644 Documentation/devicetree/bindings/watchdog/amlogic,meson-sec-wdt.yaml >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/watchdog/amlogic,meson-sec-wdt.yaml b/Documentation/devicetree/bindings/watchdog/amlogic,meson-sec-wdt.yaml >>>>>> new file mode 100644 >>>>>> index 00000000..0bbc807 >>>>>> --- /dev/null >>>>>> +++ b/Documentation/devicetree/bindings/watchdog/amlogic,meson-sec-wdt.yaml >>>>>> @@ -0,0 +1,34 @@ >>>>>> +# SPDX-License-Identifier: (GPL-2.0+ OR MIT) >>>>>> +# Copyright (c) 2019 Amlogic, Inc >>>>>> +%YAML 1.2 >>>>>> +--- >>>>>> +$id: "http://devicetree.org/schemas/power/amlogic,meson-sec-wdt.yaml#" >>>>>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#" >>>>>> + >>>>>> +title: Amlogic Meson Secure Watchdog Timer >>>>>> + >>>>>> +maintainers: >>>>>> + - Xingyu Chen >>>>>> + >>>>>> +description: |+ >>>>>> + Secure Watchdog Timer used in Meson-A/C series Compatible SoCs >>>>>> + >>>>>> +properties: >>>>>> + compatible: >>>>>> + enum: >>>>>> + - amlogic,meson-sec-wdt >>>>> >>>>> If there are no other properties, then you don't need this. Just have >>>>> the secure firmware driver instantiate the watchdog. >>>> I'am very sorry i don't understand how to initialize the watchdog driver >>>> if the compatible property is removed, Could you give me more >>>> suggestions or examples ？ Thank you very much. >>> >>> platform_device_register_simple() from the secure firmware driver. >> Thanks for your help. The device node of wdt looks useless if I use this >> function to register device. if so, how should I get the pointer to >> secure-monitor in wdt driver ? or should I use directly arm_smccc to >> access the secfw ? > > You can use of_find_compatible_node(). There should only be one firmware node. Thanks for your answer. I seem to miss something about registration of watchdog device. The secure watchdog driver is used only to A1/C1 compatible SoCs, but is not support for previous SoCs (Eg: gxl axg). I have to think about platform difference If I use the platform_device_register_simple() to register the wdt device in secure fw driver, because fw driver is compatible with all known SoCs, but the secure wdt driver is only compatible with some SoCs. In other words, the registered wdt device is useless for gxl or axg. There is no such problem If I use the DT to describe the wdt device. > > Rob > > . >