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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 7145DC43461 for ; Wed, 31 Mar 2021 15:41:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4475661028 for ; Wed, 31 Mar 2021 15:41:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235702AbhCaPlJ (ORCPT ); Wed, 31 Mar 2021 11:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235615AbhCaPkk (ORCPT ); Wed, 31 Mar 2021 11:40:40 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE8BFC061574; Wed, 31 Mar 2021 08:40:39 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id v23so8103326ple.9; Wed, 31 Mar 2021 08:40:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=R6vLllu9NqucYXJnQP0Sflwu7dB317CsKp7w2fmXXOU=; b=iqNHS7tFCrbcBhgDkH9R3OIxnlD/q3+u1fbyGpF47PAhllzkR+CWKoMzHvzJd9AQEc NNItEbX4+t2n9J+oh/8FopoPdDgbWkzzZ3L8raSn0291kxGefxSG/RH3tyuerPO+9guV j2Dtn9mNYPWDEsPqWzmcwgrVcneKUIen5J7uyRTBGS0g+OTgI5HrDRdl/2rio+K9aZkz CeUYppQrihGYM2b19CgdJRQF3MwnBSwa9kyrRABFXdHR38tbWcpwYvi4XckYMiIK2xJF jhtXpF+Xd5ciq9x0HPohdqrNbXg9c+vIlR5DpjJRpRA1s9LVEkIMuZUhLp0IMJXsM6w2 1cWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=R6vLllu9NqucYXJnQP0Sflwu7dB317CsKp7w2fmXXOU=; b=m0YNxpym2FWcjPfbrb2wuyZtEFYXIPXHAwZ9+e/rrq9cVrMnQtbL4aOwim7iPTvgW4 4WO/QUMw1qBnv9ctqsducjZDHa697qM1NZ2WNfAGQnDs1fyCvaguKqCS7VRfO2kn4LAk 2max/rTQQ5uoGWzY5B6qhESj0SNYpMQr9yRAtnOL8HIn23CE8qSaOpUnGf6RKFcdH6Iy g2PZa1iN3bFC7AIamrlbyDb2TLVP4LDzn1fqb044FI38csMYFibsy5/NJCfkccg4rT7J ypPstE8v4pxqG5nt5ZKUs+ZVfmO3aRSI33A0Q+Qchee7vFhIHzzwOwT2+ewSwj2v5iAP c/uw== X-Gm-Message-State: AOAM532V2WGt0P0qW5JxPIDqhzp37ZuHxIJnBTukw2taYF1OCO4JBbo8 B4aB8pSF76GWsJAf9EETtnEnLkQLaCDR3Ra3hiQ= X-Google-Smtp-Source: ABdhPJwv2pyxhDNSlO7MQXhBGTADia4NSvtEr8A19JdTQLSff9QIY/yCzRKsle2Yiz/YnL7AN8zfL7P+bP08E/0vXqo= X-Received: by 2002:a17:902:ee02:b029:e6:5397:d79c with SMTP id z2-20020a170902ee02b02900e65397d79cmr3801793plb.21.1617205239423; Wed, 31 Mar 2021 08:40:39 -0700 (PDT) MIME-Version: 1.0 References: <20210329174928.18816-1-henning.schild@siemens.com> <20210329174928.18816-3-henning.schild@siemens.com> <20210330135808.373c3308@md1za8fc.ad001.siemens.net> <20210330143011.0e8ae4a0@md1za8fc.ad001.siemens.net> <20210330172305.67b6e050@md1za8fc.ad001.siemens.net> In-Reply-To: <20210330172305.67b6e050@md1za8fc.ad001.siemens.net> From: Andy Shevchenko Date: Wed, 31 Mar 2021 18:40:23 +0300 Message-ID: Subject: Re: [PATCH v3 2/4] leds: simatic-ipc-leds: add new driver for Siemens Industial PCs To: Henning Schild Cc: Linux Kernel Mailing List , Linux LED Subsystem , Platform Driver , linux-watchdog@vger.kernel.org, Srikanth Krishnakar , Jan Kiszka , Gerd Haeussler , Guenter Roeck , Wim Van Sebroeck , Mark Gross , Hans de Goede , Pavel Machek , Enrico Weigelt Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org On Tue, Mar 30, 2021 at 6:33 PM Henning Schild wrote: > Am Tue, 30 Mar 2021 15:41:53 +0300 > schrieb Andy Shevchenko : > > On Tue, Mar 30, 2021 at 3:35 PM Henning Schild > > wrote: > > > Am Tue, 30 Mar 2021 15:15:16 +0300 > > > schrieb Andy Shevchenko : > > > > On Tue, Mar 30, 2021 at 2:58 PM Henning Schild > > > > wrote: > > > > > Am Tue, 30 Mar 2021 14:04:35 +0300 > > > > > schrieb Andy Shevchenko : > > > > > > On Mon, Mar 29, 2021 at 8:59 PM Henning Schild > > > > > > wrote: > > > > > > > > > +static struct simatic_ipc_led simatic_ipc_leds_mem[] = { > > > > > > > + {0x500 + 0x1A0, "red:" LED_FUNCTION_STATUS "-1"}, > > > > > > > + {0x500 + 0x1A8, "green:" LED_FUNCTION_STATUS "-1"}, > > > > > > > + {0x500 + 0x1C8, "red:" LED_FUNCTION_STATUS "-2"}, > > > > > > > + {0x500 + 0x1D0, "green:" LED_FUNCTION_STATUS "-2"}, > > > > > > > + {0x500 + 0x1E0, "red:" LED_FUNCTION_STATUS "-3"}, > > > > > > > + {0x500 + 0x198, "green:" LED_FUNCTION_STATUS "-3"}, > > > > > > > + { } > > > > > > > +}; > > > > > > > > > > > > It seems to me like poking GPIO controller registers directly. > > > > > > This is not good. The question still remains: Can we simply > > > > > > register a GPIO (pin control) driver and use an LED GPIO > > > > > > driver with an additional board file that instantiates it? > > > > > > > > > > I wrote about that in reply to the cover letter. My view is > > > > > still that it would be an abstraction with only one user, just > > > > > causing work and likely not ending up as generic as it might > > > > > eventually have to be. > > > > > > > > > > The region is reserved, not sure what the problem with the > > > > > "poking" is. > > > > > > > > > > > > > Maybe i do not understand all the benefits of such a split at > > > > > this point in time. At the moment i only see work with hardly > > > > > any benefit, not just work for me but also for maintainers. I > > > > > sure do not mean to be ignorant. Maybe you go into details and > > > > > convince me or we wait for other peoples opinions on how to > > > > > proceed, maybe there is a second user that i am not aware of? > > > > > Until i am convinced otherwise i will try to argue that a > > > > > single-user-abstraction is needless work/code, and should be > > > > > done only when actually needed. > > > > > > > > I have just read your messages (there is a cover letter and > > > > additional email which was sent lately). > > > > > > > > I would like to know what the CPU model number on that board is. > > > > Than we can continue to see what possibilities we have here. > > > > > > I guess we are talking about the one that uses memory mapped, that > > > is called an "IPC127E" and seems to have either Intel Atom E3940 or > > > E3930 which seems to be Apollo Lake. > > > > Yep. And now the question, in my patch series you should have got the > > apollolake-pinctrl driver loaded (if not, we have to investigate why > > it's not being instantiated). This will give you a read GPIO driver. > > Ok, so there is the existing driver i asked about several times. Thanks > for pointing it out. If you remember, I asked you about the chip twice :-) I assumed that we were talking about Apollo Lake and that's why I insisted that the driver is in the kernel source tree. > > So, you may use regular LED GPIO on top of it > > (https://elixir.bootlin.com/linux/latest/source/drivers/leds/leds-gpio.c). > > I would like to understand why it can't be achieved. > > Will have a look. Unfortunately this one box is missing in my personal > collection, but let us assume that one can be converted to that > existing driver. OK! > I guess that will still mean the PIO-based part of the LED driver will > have to stay as is. Probably yes. I haven't looked into that part and I have no idea what's going on on that platform(s). -- With Best Regards, Andy Shevchenko