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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF336C433FE for ; Thu, 13 Oct 2022 06:55:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbiJMGzl (ORCPT ); Thu, 13 Oct 2022 02:55:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229627AbiJMGzk (ORCPT ); Thu, 13 Oct 2022 02:55:40 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 249FCD0CFB for ; Wed, 12 Oct 2022 23:55:38 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id u21so1284521edi.9 for ; Wed, 12 Oct 2022 23:55:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=9bgNN7X2bMAPvjWH29NOgtDY27vanw717rBtzJJwDbg=; b=Ktc61kE9Kv6nh7yMDKWn1BqjT2xoztkpay/J/uSQP50IGWNBGXKmPQ9ciUP9Z2T26k 0icBep1Uz5i0A+DYVEK4d+kQWpnBgN/rAQFy41npkCbGeXh9FdL1Eq4hurFqr6dlWLaC 5lott/W5CHuL3CsfLnbVY8Tt9ELskSwun+f9raN68k4VE1BOe3gwrFyJ/XAjH+cUGx5D V8Cn9n1QatYvFKGct6knXI3P6mlY38GeNQxg/mhgTBGu4N839FzSm2WJ1mgdEjnY5W/2 s230v3eQq/cfmIeyI3J4G4dtdJbi1E7qcjJkEPUz98t127EDk3nZbUT3U3by/och4EEp q1Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=9bgNN7X2bMAPvjWH29NOgtDY27vanw717rBtzJJwDbg=; b=iB63JvBVzMh9JtexzaZ2QJ6jG6ON//LY2CWeTCzLtBBmL1UIS6Y02Yl9uNKoJILnzl Yf9tgbzAw9l3owWVC/OukdhPcR5mFKV3rcanayEIw/lWp0iAJrApTkxAfL2WHEWr3sjr fWYj12POM1lebAhI3Oo3sAy0VXtKsm+MdwvFl2N5fwO5iDN8unGV3jLD5Oe61q6WlvIH GgoDQ769lT+vkSZ4UWtL0eoZ4DTbde3I67auznEqD3yxL6k+vNFxstckUrlYMmH8bh/r DQpzV0wL4zvuPJ4eTJiS3GI54wWThHomCXdHTMJ/KTiQcrghqxUQ5ygQFojiQRr4Enyo exKw== X-Gm-Message-State: ACrzQf1rQ/LBjyGK7Itcf6ZwT+jl/AfvCx/58SLsewf5fVfRtfCGykcl JSvgUr5gX6YXB2HV1BToHQ85Bg== X-Google-Smtp-Source: AMsMyM6JUAOH69tO0WMYoFMsBQaKPo/jHOKhwzMRRQ4YgwYSCeBg0GqdzQRG/qtNzqnA3SjB+QnABA== X-Received: by 2002:a50:fd8b:0:b0:459:31f9:d3b with SMTP id o11-20020a50fd8b000000b0045931f90d3bmr30883080edt.304.1665644136573; Wed, 12 Oct 2022 23:55:36 -0700 (PDT) Received: from localhost ([86.61.181.4]) by smtp.gmail.com with ESMTPSA id q2-20020a1709063d4200b0078b1ff41f05sm2460243ejf.43.2022.10.12.23.55.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Oct 2022 23:55:35 -0700 (PDT) Date: Thu, 13 Oct 2022 08:55:34 +0200 From: Jiri Pirko To: Vadim Fedorenko Cc: Jakub Kicinski , Arkadiusz Kubalewski , netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, Vadim Fedorenko Subject: Re: [RFC PATCH v3 1/6] dpll: Add DPLL framework base functions Message-ID: References: <20221010011804.23716-1-vfedorenko@novek.ru> <20221010011804.23716-2-vfedorenko@novek.ru> <24d1d750-7fd0-44e2-318c-62f6a4a23ea5@novek.ru> <9a3608cf-21bb-18b1-796a-7325a613b641@novek.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9a3608cf-21bb-18b1-796a-7325a613b641@novek.ru> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Wed, Oct 12, 2022 at 10:12:43PM CEST, vfedorenko@novek.ru wrote: >On 12.10.2022 07:44, Jiri Pirko wrote: >> Tue, Oct 11, 2022 at 11:31:25PM CEST, vfedorenko@novek.ru wrote: >> > On 11.10.2022 09:47, Jiri Pirko wrote: >> > > Tue, Oct 11, 2022 at 10:32:22AM CEST, jiri@resnulli.us wrote: >> > > > Mon, Oct 10, 2022 at 09:54:26PM CEST, vfedorenko@novek.ru wrote: >> > > > > On 10.10.2022 10:18, Jiri Pirko wrote: >> > > > > > Mon, Oct 10, 2022 at 03:17:59AM CEST, vfedorenko@novek.ru wrote: >> > > > > > > From: Vadim Fedorenko >> > > >> > > [...] >> > > >> > > >> > > > > I see your point. We do have hardware which allows changing type of SMA >> > > > > connector, and even the direction, each SMA could be used as input/source or >> > > > > output of different signals. But there are limitation, like not all SMAs can >> > > > > produce IRIG-B signal or only some of them can be used to get GNSS 1PPS. The >> > > > >> > > > Okay, so that is not the *type* of source, but rather attribute of it. >> > > > Example: >> > > > >> > > > $ dpll X show >> > > > index 0 >> > > > type EXT >> > > > signal 1PPS >> > > > supported_signals >> > > > 1PPS 10MHz >> > > > >> > > > $ dpll X set source index 1 signal_type 10MHz >> > > > $ dpll X show >> > > > index 0 >> > > > type EXT >> > > > signal 10MHz >> > > > supported_signals >> > > > 1PPS 10MHz >> > > > >> > > > So one source with index 0 of type "EXT" (could be "SMA", does not >> > > > matter) supports 1 signal types. >> > > > >> > > > >> > > > Thinking about this more and to cover the case when one SMA could be >> > > > potencially used for input and output. It already occured to me that >> > > > source/output are quite similar, have similar/same attributes. What if >> > > > they are merged together to say a "pin" object only with extra >> > > > PERSONALITY attribute? >> > > > >> > > > Example: >> > > > >> > > > -> DPLL_CMD_PIN_GET - dump >> > > > ATTR_DEVICE_ID X >> > > > >> > > > <- DPLL_CMD_PIN_GET >> > > > >> > > > ATTR_DEVICE_ID X >> > > > ATTR_PIN_INDEX 0 >> > > > ATTR_PIN_TYPE EXT >> > > > ATTR_PIN_SIGNAL 1PPS (selected signal) >> > > > ATTR_PIN_SUPPORTED_SIGNALS (nest) >> > > > ATTR_PIN_SIGNAL 1PPS >> > > > ATTR_PIN_SIGNAL 10MHZ >> > > > ATTR_PIN_PERSONALITY OUTPUT (selected personality) >> > > > ATTR_PIN_SUPPORTED_PERSONALITIES (nest) >> > > > ATTR_PIN_PERSONALITY DISCONNECTED >> > > > ATTR_PIN_PERSONALITY INPUT >> > > > ATTR_PIN_PERSONALITY OUTPUT (note this supports both input and >> > > > output) >> > > > >> > > > ATTR_DEVICE_ID X >> > > > ATTR_PIN_INDEX 1 >> > > > ATTR_PIN_TYPE EXT >> > > > ATTR_PIN_SIGNAL 10MHz (selected signal) >> > > > ATTR_PIN_SUPPORTED_SIGNALS (nest) >> > > > ATTR_PIN_SIGNAL 1PPS >> > > > ATTR_PIN_SIGNAL 10MHZ >> > > > ATTR_PIN_PERSONALITY DISCONNECTED (selected personality - not >> > > > connected currently) >> > > > ATTR_PIN_SUPPORTED_PERSONALITIES (nest) >> > > > ATTR_PIN_PERSONALITY DISCONNECTED >> > > > ATTR_PIN_PERSONALITY INPUT (note this supports only input) >> > > > >> > > > ATTR_DEVICE_ID X >> > > > ATTR_PIN_INDEX 2 >> > > > ATTR_PIN_TYPE GNSS >> > > > ATTR_PIN_SIGNAL 1PPS (selected signal) >> > > > ATTR_PIN_SUPPORTED_SIGNALS (nest) >> > > > ATTR_PIN_SIGNAL 1PPS >> > > > ATTR_PIN_PERSONALITY INPUT (selected personality - note this is >> > > > now he selected source, being only >> > > > pin with INPUT personality) >> > > > ATTR_PIN_SUPPORTED_PERSONALITIES (nest) >> > > > ATTR_PIN_PERSONALITY DISCONNECTED >> > > > ATTR_PIN_PERSONALITY INPUT (note this supports only input) >> > > > >> > > > ATTR_DEVICE_ID X >> > > > ATTR_PIN_INDEX 3 >> > > > ATTR_PIN_TYPE SYNCE_ETH_PORT >> > > > ATTR_PIN_NETDEV_IFINDEX 20 >> > > > ATTR_PIN_PERSONALITY OUTPUT (selected personality) >> > > > ATTR_PIN_SUPPORTED_PERSONALITIES (nest) >> > > > ATTR_PIN_PERSONALITY DISCONNECTED >> > > > ATTR_PIN_PERSONALITY INPUT >> > > > ATTR_PIN_PERSONALITY OUTPUT (note this supports both input and >> > > > output) >> > > > >> > > > ATTR_DEVICE_ID X >> > > > ATTR_PIN_INDEX 4 >> > > > ATTR_PIN_TYPE SYNCE_ETH_PORT >> > > > ATTR_PIN_NETDEV_IFINDEX 30 >> > > > ATTR_PIN_PERSONALITY OUTPUT (selected personality) >> > > > ATTR_PIN_SUPPORTED_PERSONALITIES (nest) >> > > > ATTR_PIN_PERSONALITY DISCONNECTED >> > > > ATTR_PIN_PERSONALITY INPUT >> > > > ATTR_PIN_PERSONALITY OUTPUT (note this supports both input and >> > > > output) >> > > > >> > > > >> > > > This allows the user to actually see the full picture: >> > > > 1) all input/output pins in a single list, no duplicates >> > > > 2) each pin if of certain type (ATTR_PIN_TYPE) EXT/GNSS/SYNCE_ETH_PORT >> > > > 3) the pins that can change signal type contain the selected and list of >> > > > supported signal types (ATTR_PIN_SIGNAL, ATTR_PIN_SUPPORTED_SIGNALS) >> > > > 4) direction/connection of the pin to the DPLL is exposed over >> > > > ATTR_PIN_PERSONALITY. For each pin, the driver would expose it can >> > > > act as INPUT/OUTPUT and even more, it can indicate the pin can >> > > > disconnect from DPLL entirely (if possible). >> > > > 5) user can select the source by setting ATTR_PIN_PERSONALITY of certain >> > > > pin to INPUT. Only one pin could be set to INPUT and that is the >> > > > souce of DPLL. >> > > > In case no pin have personality set to INPUT, the DPLL is >> > > > free-running. >> > > >> > > Okay, thinking about it some more, I would leave the source select >> > > indepentent from the ATTR_PIN_PERSONALITY and selectable using device >> > > set cmd and separate attribute. It works better even more when consider >> > > autoselect mode. >> > > >> > > Well of course only pins with ATTR_PIN_PERSONALITY INPUT could be >> > > selected as source. >> > > >> > >> > Overall, I agree with this proposal, and as I've already said, the work is >> > going exactly the same way - to introduce pin object with separate set of >> > attributes. >> > I don't really like 'PERSONALITY' naming, I think we have to find a better >> > name. It looks like DIRECTION is slightly better. And the >> > CONNECTED/DISCONNECTED should be different attribute. And we also need >> >> Yeah, it is a matter of implementation. I just thought that this is >> possible to be done in a single attribute, because when the pin is >> disconnected, the direction has no meaning. >> >> >> > attribute PRIORITY to be able to configure (or hint) auto-select mode. There >> >> Sure, I didn't put the PRIORITY attribute to the example, but I believe >> it is very straightforward extension to add it. >> >> >> > are also special objects called muxes, which consist of several inputs and >> > one output, but they cannot synthonise signal, only pass one of the inputs to >> > output. We are still in kind of discussion whether to have them as separate >> > objects, or extend the amount of pins of DPLL device in this case. The >> > problem again in the auto-select mode and priorities. It would be great to >> > hear your thoughts about such objects. >> >> Does the mux have any attribute/configuration valuable for the user. >> If yes, it might make sense to have it as a separate object. Then we >> can have it as a tree of object of type MUX with leaves of PIN. > >Yes, that was the first thought, but implementation details are not great for now. > >> The question really is, if the user needs to know about muxes and work >> with them, or they can be abstracted out by the driver. > >Both ways will work I believe. It's more like our will to give users full >picture or hide it somehow with the implementation. >> >> Could you elaborate a bit more why auto-select mode and priorities are >> problematic with muxes in picture? > >AFAIU, some mux devices are not smart enough to make a decision suitable for >autoselect for the pins they have. In this case the autoselect process is >done in the DPLL device, which selects mux and not the pin directly. At the >same time there could be muxes that are smart enough to make a decision, and >it will be autoselect on top of autoselect (and several more layers) and it >doesn't sound great to me. I believe Arkadiusz will explain the mux a bit >better. >From what you write in this reply, I have a feeling that these details are not really interesting for user to see. So I tend to lean forward to abstract this out and leave the details to HW/FW/driver. > >> >> >> > >> > > > >> > > > This would introduce quite nice flexibility, exposes source/output >> > > > capabilities and provides good visilibity of current configuration. >> > > > >> > > > >> > > > > interface was created to cover such case. I believe we have to improve it to >> > > > > cover SyncE configuration better, but I personally don't have SyncE hardware >> > > > > ready to test and that's why I have to rely on suggestions from yours or >> > > > > Arkadiusz's experience. From what I can see now there is need for special >> > > > > attribute to link source to net device, and I'm happy to add it. In case of >> > > > > fixed configuration of sources, the device should provide only one type as >> > > > > supported and that's it. >> > > > > >> > > >> > > [...] >> > >