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=-18.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,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 7C57CC4320E for ; Tue, 3 Aug 2021 22:42:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5ED4E60F58 for ; Tue, 3 Aug 2021 22:42:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230024AbhHCWmg (ORCPT ); Tue, 3 Aug 2021 18:42:36 -0400 Received: from mail-co1nam11on2056.outbound.protection.outlook.com ([40.107.220.56]:3137 "EHLO NAM11-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S229789AbhHCWmf (ORCPT ); Tue, 3 Aug 2021 18:42:35 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=PtOSyZH9tqHfyc1JrfCiga1mAMQHhDBozAN+9N8WeMUn9ZxKg83OgwqtQ100OukEkAgzH9mUFcJhEjwP4LuaDpkK/8HP5ud7Djc/HtiAAGQTwn4b8xtXSdHFXlpCFU84pfN5E2EhA2sBMeLgiCrdIyOEU+agT6SNkVP7GFlQKGH8IkcN0uHhcbnwkO9DvoUvnwtiC7V+ADh2d5J6pX7k9DfjbdU0aHH68z7RcP3gJrOgy32FnKrzfpOkblnc0rxWFQ8BbPvVbLdG1hulihO3aaQ8Hve6iojmjB9W77FXmculnyahkzVAAN8CaIOds0UfgXaCfGcqjjwsJVbN13zEfQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=4yNIcm2dWrbyLDF9EtqdjwAylc4XLdnFTGwg1SCLuAs=; b=VOgsiaMAAxpC0gBOh5eSSih4fQ0XbnhCvcIzYfppMPmSl2dCha+LgEnZJbMdmiblssY+vVKjAPv7GVe/qb84Srndvx/dFyuy45tZ7+ukn9X/9B3kN9sKZtJGP6bJmMpT8B4jPIpAjbij+x/1p9675t6wfVxKRNIWNJktZJn/VAdhhQtwNq0cagopZ0c2dFYuYZW3zxOR4uSiuus5JqtAm7zyldPAIt3iftKZkwt2NuQE4vF+gLfBkTZqhQbtX6wHn06ApRDKNyMgGEDzKeR0Mn2xmoLPCacvp7FSNydiUWeP4CeMA9z6eW1Ju2ZLB4sEWIs6P08m/6NYF/IihMlyLw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.112.34) smtp.rcpttodomain=kernel.org smtp.mailfrom=nvidia.com; dmarc=pass (p=quarantine sp=none pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=4yNIcm2dWrbyLDF9EtqdjwAylc4XLdnFTGwg1SCLuAs=; b=mAo/dEUD+Lz1olQpfYTQX5yqLS+TevqkE7WJ3ILSk/AGOYQ29ENX2CgMBwLIiUo7Kl99+8VTUx8ZnTsMOZqXxxBjvnkmJ0/sNSpO9GvczUyK1etE8Uq3WNdYhw1H6fUWRzDC7odlWpTvqHO9D3Pvsp8TRki1sdb61jjbAPq5AaYoDiSwKOxZnrz9odnrtcCObZH764JICfdNswHeNIr+JnKP9kSGe9i2zZiKwwMm0rlrr+p2vV2weeYr7+C/TcsIykCIz1Ulz5dE2kBGTJbPZ/iwTL8GwnCvVgDMURx/TaJdv8PHwJ53TuYCgoHcNApl/20s/W2n3VhYR/E24F2mfw== Received: from DM6PR08CA0002.namprd08.prod.outlook.com (2603:10b6:5:80::15) by BN8PR12MB3108.namprd12.prod.outlook.com (2603:10b6:408:40::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4373.25; Tue, 3 Aug 2021 22:42:22 +0000 Received: from DM6NAM11FT028.eop-nam11.prod.protection.outlook.com (2603:10b6:5:80:cafe::bc) by DM6PR08CA0002.outlook.office365.com (2603:10b6:5:80::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4373.18 via Frontend Transport; Tue, 3 Aug 2021 22:42:22 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.112.34) smtp.mailfrom=nvidia.com; kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.112.34 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.112.34; helo=mail.nvidia.com; Received: from mail.nvidia.com (216.228.112.34) by DM6NAM11FT028.mail.protection.outlook.com (10.13.173.140) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.4373.18 via Frontend Transport; Tue, 3 Aug 2021 22:42:21 +0000 Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 3 Aug 2021 22:42:22 +0000 Received: from [172.17.173.69] (172.20.187.6) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 3 Aug 2021 22:42:21 +0000 Subject: Re: [RFC 08/11] gpiolib: cdev: Add hardware timestamp clock type To: Jon Hunter , , , , , , , , , , References: <20210625235532.19575-1-dipenp@nvidia.com> <20210625235532.19575-9-dipenp@nvidia.com> <7e49e6a9-bd7c-1b97-50e6-bc803addc27f@nvidia.com> <65bf01e1-66e1-7eec-0052-4d707f4a3f6b@nvidia.com> <8d3257f3-54b1-e658-245d-3a070aba44c4@nvidia.com> X-Nvconfidentiality: public From: Dipen Patel Message-ID: Date: Tue, 3 Aug 2021 15:51:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <8d3257f3-54b1-e658-245d-3a070aba44c4@nvidia.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [172.20.187.6] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To DRHQMAIL107.nvidia.com (10.27.9.16) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 7a96896a-f35a-4c04-b994-08d956cff518 X-MS-TrafficTypeDiagnostic: BN8PR12MB3108: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:4714; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.112.34;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:schybrid03.nvidia.com;CAT:NONE;SFS:(4636009)(346002)(136003)(396003)(376002)(39860400002)(46966006)(36840700001)(7636003)(16526019)(7416002)(53546011)(2906002)(921005)(110136005)(2616005)(36906005)(26005)(8936002)(16576012)(316002)(186003)(426003)(356005)(31696002)(86362001)(336012)(70206006)(70586007)(478600001)(36756003)(5660300002)(31686004)(36860700001)(82740400003)(8676002)(83380400001)(47076005)(6666004)(82310400003)(83996005)(43740500002)(2101003);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Aug 2021 22:42:21.8903 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 7a96896a-f35a-4c04-b994-08d956cff518 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.34];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT028.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR12MB3108 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/3/21 9:42 AM, Jon Hunter wrote: > > On 30/07/2021 03:33, Dipen Patel wrote: >> >> On 7/9/21 1:30 AM, Jon Hunter wrote: >>> On 26/06/2021 00:55, Dipen Patel wrote: >>>> This patch adds new clock type for the GPIO controller which can >>>> timestamp gpio lines using hardware means. To expose such >>>> functionalities to the userspace, code has been added in this patch >>>> where during line create call, it checks for new clock type and if >>>> requested, calls hardware timestamp related API from gpiolib.c. >>>> During line change event, it retrieves timestamp in nano seconds by >>>> calling gpiod_get_hw_timestamp API from gpiolib.c. At the line release, >>>> it disables this functionality by calling gpiod_hw_timestamp_control. >>>> >>>> Signed-off-by: Dipen Patel >>>> --- >>>>   drivers/gpio/gpiolib-cdev.c | 65 +++++++++++++++++++++++++++++++++++-- >>>>   include/uapi/linux/gpio.h   |  1 + >>>>   2 files changed, 64 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c >>>> index 1631727bf0da..9f98c727e937 100644 >>>> --- a/drivers/gpio/gpiolib-cdev.c >>>> +++ b/drivers/gpio/gpiolib-cdev.c >>>> @@ -518,6 +518,7 @@ struct linereq { >>>>        GPIO_V2_LINE_DRIVE_FLAGS | \ >>>>        GPIO_V2_LINE_EDGE_FLAGS | \ >>>>        GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ >>>> +     GPIO_V2_LINE_FLAG_EVENT_CLOCK_HARDWARE | \ >>>>        GPIO_V2_LINE_BIAS_FLAGS) >>>>     static void linereq_put_event(struct linereq *lr, >>>> @@ -540,9 +541,20 @@ static void linereq_put_event(struct linereq *lr, >>>>     static u64 line_event_timestamp(struct line *line) >>>>   { >>>> +    bool block; >>>> + >>>>       if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) >>>>           return ktime_get_real_ns(); >>>>   +    if (test_bit(FLAG_EVENT_CLOCK_HARDWARE, &line->desc->flags)) { >>>> +        if (irq_count()) >>>> +            block = false; >>>> +        else >>>> +            block = true; >>>> + >>>> +        return gpiod_get_hw_timestamp(line->desc, block); >>>> +    } >>>> + >>>>       return ktime_get_ns(); >>>>   } >>> >>> Looking at line_event_timestamp() and the callers of this function, it >>> appears that this should always return nanoseconds. Does >>> gpiod_get_hw_timestamp() return nanoseconds? >> Yes, it returns in ns to align with line_event_timestamp. > > > It might be worth updating the function name to gpiod_get_hw_timestamp_ns() so that this is clear. Wouldn't be sufficient to right into its description rather embed in API name? > > Jon > > -- > nvpublic