Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70C56C54EED for ; Mon, 30 Jan 2023 13:46:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236172AbjA3Nqg (ORCPT ); Mon, 30 Jan 2023 08:46:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235504AbjA3Nqd (ORCPT ); Mon, 30 Jan 2023 08:46:33 -0500 X-Greylist: delayed 61 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 30 Jan 2023 05:46:31 PST Received: from smtpcmd0987.aruba.it (smtpcmd0987.aruba.it [62.149.156.87]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95F5B15552 for ; Mon, 30 Jan 2023 05:46:31 -0800 (PST) Received: from [192.168.1.56] ([79.0.204.227]) by Aruba Outgoing Smtp with ESMTPSA id MUTPp35dC1uCfMUTPpl5ku; Mon, 30 Jan 2023 14:45:28 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1675086328; bh=SHJyHui5zOsg78nOi+x9KjRAzGa6YUx9oLlYvFANGP8=; h=Date:MIME-Version:Subject:To:From:Content-Type; b=bKF4yJmFxii4n7STENx9DdYHzJgqqgXSGJuoa33xpKJpLVnhNhsdA2XnfrQ7oyB5u Fb4BkyzElxJfQBQF1EEP6jAreNBnhbfSIfGvvnz19C7OKj5AlS6nRfHyrcvx7g9ybJ pXRZ5xm9sYzL+9aCmCTEFtxqaRVegT3vNedTE+ci0E+wdjut/BwAmh+7oe5uQOI6cV KVcorxQ8UDciHg3fUJ0jMUlOj7M8YaEXLFg9aKxFYxVJ4YCpzGADm4uUtNRbTsFBqG nMAyma9ct+/DmnOdUUWC/O51vPx4W541wlmNx3YYjehnz75p+ffoj1BosfKplzpwfO k3v+hpE6hhJFA== Message-ID: Date: Mon, 30 Jan 2023 14:45:27 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: PPS functionality for Intel Timed I/O Content-Language: en-US To: "N, Pandith" Cc: "linux-kernel@vger.kernel.org" , "Sangannavar, Mallikarjunappa" , "D, Lakshmi Sowjanya" , "T R, Thejesh Reddy" , "Hall, Christopher S" References: From: Rodolfo Giometti In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfJjfrVdnufnvClFqupD2x86OEVR0RGtgkrUbP4lM5KS7YliuU5ypE5oTdWVmm4VgJlGDrRK9uMbzP19MqIX+0rjHFdsrKIbT7Zs0WDm+kzQKTDWq2CZX pq5hlpYmHm70sshxoB04rz19fAETUjvMQ8lyoZ/8yJEItKEElLI77T0x4J3F76GSalOXoN23t6hVy3m8JdVRmcAxbIYbxAdRQ405JIW/i1RmH4w5vv6F8Sps j4ssxX4ifay8ZPHK8Li3+yrP78DhBtOPyeSUi88+o+s5mm5GsGp6i0cL8cg/FYfh8GdKl7ciTBn/05XClyv4wCAauzVdQkuUy+R/78gQl/7YScJmaJ7s/YY6 yl4AF90bNfX6remTcSV79FUHvf18U7lJP/TGZzD2IVApHx4r9nFuNJpAIKe+mD0BtsZjBzIR Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/01/23 13:55, N, Pandith wrote: > Hi Rodolfo Giometti, Hello. > This is regarding Intel Timed I/O device as PPS. > > Intel Timed I/O is a precise device (10s of nanoseconds), that can send out pulses. > This is needed in IoT and server applications to measure offset between system clocks on multiple devices Can you please provide some URLs where to get further info from about this device? I'd like to know how this device works and its interfaces towards the CPU. > We are planning to implement a driver, for PPS output functionality using Timed I/O device. Great! :) > 1. Is there any support from PPS framework to start/stop pulse generation. > If yes, can we get the Pin number, offset(start time) from user space ? Nope, PPS signals are supposed to be always on. However you can start/stop pulses generation within the main driver of your device. > 2. Further, this device has the capability to capture the input events (pulses, nanosecond precision). > The same PIN can work in either input or output mode. > Can there be an PPS client driver supporting both modes ? I'm not sure to well understand what you mean, however a PPS client is a piece of code that captures PPS pulses and add a timestamp to them, while a PPS generator is a piece of code that (precisely) generates a PPS source according to the system's main clock (and not according to a peripheral's clock). Hope I've answered to your questions, if not feel free to ask more. Ciao, Rodolfo -- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming skype: rodolfo.giometti