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=-2.7 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, URIBL_BLOCKED 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 C350BC433E1 for ; Tue, 30 Mar 2021 12:43:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F9D860232 for ; Tue, 30 Mar 2021 12:43:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232011AbhC3Mmk (ORCPT ); Tue, 30 Mar 2021 08:42:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232005AbhC3MmK (ORCPT ); Tue, 30 Mar 2021 08:42:10 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 641DDC061574; Tue, 30 Mar 2021 05:42:10 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id k23-20020a17090a5917b02901043e35ad4aso9394615pji.3; Tue, 30 Mar 2021 05:42:10 -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=48tUu54cByxZHo/3axsPb6lFroueR0ATEX9TwKibhQM=; b=nmk4/47mAoZRN6qc0DYjBUtF2T2BdmmK5vP/PLO1Ql7xZDDttcocYTERJWcu5Awvgd rtRoIezc7VmNBUPm6kMJciEiOx8eAUPYv6B93nBCpCM1uAeq6HWHMZLZxGPdFqRd7KEj Nx4Z+lrWBqoz1alpTo5oYRuJx70lEHCc3eUPKfVUg12kpqKz7t9Uors+dPS6js7kq7+b jjvuxQy51Ys2EGYfLkY2T/uuN63OF8nGP7QkWH0IVfjKdTxA0ymqRjPLUhT969j4N4K5 vJP5IjCclkXr18egR8q0cHHe8zW/Op1ozYZ641uBpfpbBZfcmzTc1Ibi3JyOobXPZMfZ fW7A== 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=48tUu54cByxZHo/3axsPb6lFroueR0ATEX9TwKibhQM=; b=UycrMEYP77FdxjypR90/38vKMqFj7dpMyM2CL9y/scQd1/TCK2Q4G1V7NmFY3Ux2p9 EOHB6VTFJ/UGKfXKVk2jaNldr8OtRYuhbm5n0oMLPKzFDty2bRdxiSeXvEVhZzV88cnl 35/lJFHECOLJpii0RYspWiVCHpHT57zQ2CE8TOXsnhj0A/KFmNdTsHXIyYQGyQLdvV0G ss9rlAMCals68nLrctoMv8Ba2AT2bjK4JSOqcFcbfzPjRjM1BNJST0auK1NISkRF2QLB o6OvdBj9mcZMmost5dSlftSQe3l5jZZPnm+pDEisE7SldfGQfPv91nnWJZttGeSurDQ2 e8Og== X-Gm-Message-State: AOAM532W4DIGLv2BQPr4QYqSgiS3RIjoW0mLiloRf8EtoVSN8DKK4ryD CzmkQiCEsKtsUy1zh1O1Wsi0Y9ryxjMvqjEYRYZBBvXtXBBnKyQm X-Google-Smtp-Source: ABdhPJxqccrN/RIign4IMW4LMZUmK33dcsoq2xGOJlRGeopU16QDRQUYLMXXyJaZ2gLFgMTxBir84hi5ovZVnAP9Czw= X-Received: by 2002:a17:90a:e454:: with SMTP id jp20mr4306008pjb.129.1617108129895; Tue, 30 Mar 2021 05:42:09 -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> In-Reply-To: <20210330143011.0e8ae4a0@md1za8fc.ad001.siemens.net> From: Andy Shevchenko Date: Tue, 30 Mar 2021 15:41:53 +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 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. 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. -- With Best Regards, Andy Shevchenko