From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f177.google.com (mail-yw1-f177.google.com [209.85.128.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A34EC76035; Mon, 2 Sep 2024 09:55:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725270947; cv=none; b=gfZoYOXFz8ml1FIQcbOs9Zs1hkmaNoHTZXh1Xjw9ouLrnAY1PypP4XZvXvi6tAWGwf6U+YxXU9XbklO2VPFVEAIb8spxvc6DCCI2xGfp3vqgud+LUlb8GDiigjD0Kk1+NtHIxVg9RC0IAvm7HpcALvtNqQlEBlEWO6ekZFOhemw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725270947; c=relaxed/simple; bh=N1G+YOdCXmW6ZM5XS6QgL8CFfLIUCedjbdwaaDSoylU=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=s+QJ2Lpu8qNHIOqI6FtiCqnbKUjfAATw0LDF1d8JcctV56mDdhMzv9mCjRix87onZPxDh1w44AbznpNOxnvPCERRlJg4V+EIXrGawRwNeJOAspHg5RRcwMZrM9Bz3RVK/cgK5VFSvbdX6MgxhaVMbOknsYP0k4lP2wsUxzcNUVg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.128.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-yw1-f177.google.com with SMTP id 00721157ae682-6d5893cd721so15636517b3.0; Mon, 02 Sep 2024 02:55:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725270944; x=1725875744; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+MAn5qVpDY22aHv+DFM/MBUkQ/9x+sYh3IxT5133w4g=; b=bK5B73Tpd6I9+GDHybEefl/xaREHvldjWWRw7ajEQZa4xbqdGmDWkoyYrSxYcJM1iz guWww2HSGX1wH/b7X0TQSeAZ7mHTIEqalvvoH0rcZA9xSWu+qqfgbmWhEmwlHcI5o5HC KHLMUvhGNdkC5juDHfKjNn4irM8cJZe9uDvU39Bbdb+AC5fltuDdQXQ1ofp8kV8GjOoS mZ/tBMH/DLWMnyAshwttpu2qQuLm11rzDV1Wi+yEHsdceMcPbIh5iR5NA/tH/D/UdB9d 3fkMn2+VeOQqOqD4KcweBvODHzh0mwO0gH76HoZ0e8Ypf+YvuRNQX0Rrf8zAz+M9lBuw 5UPQ== X-Forwarded-Encrypted: i=1; AJvYcCXTWtkwNloUMkuOnUWjRUffK/U1k0mjceQgayGItGJtqMP4PsD5zjMrcjQPSQhyMfYfUBSeSCvyTaQ3@vger.kernel.org, AJvYcCXZsJfADVvUPAzePPsF0oI4kI9pqc1w2B4xCqr2YH1QazRWph2sjgQCHPofzGyK5r+hIkjbR2il2iml@vger.kernel.org X-Gm-Message-State: AOJu0YyP+1JRDvAjlhRkJmGmnVZw2NPB5QwDWVmBHD3c5xrVyna4JsZG csIwKxXLYEC3vespyHXlWw5cFL9lNEvVzjrR7wCXGB5fLPDhlW4nROf3yncO X-Google-Smtp-Source: AGHT+IEJ+ptSMdMs26WdNp0s8JHpnHf+1nwtv1QlQhRD1U9a+bp1XcduxpH0bJSM/9wkGKfF4t4VjA== X-Received: by 2002:a05:690c:6309:b0:6be:2044:9367 with SMTP id 00721157ae682-6d40e17ff2amr112413307b3.15.1725270944361; Mon, 02 Sep 2024 02:55:44 -0700 (PDT) Received: from mail-yw1-f182.google.com (mail-yw1-f182.google.com. [209.85.128.182]) by smtp.gmail.com with ESMTPSA id 00721157ae682-6d2d438e15dsm15247087b3.66.2024.09.02.02.55.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Sep 2024 02:55:44 -0700 (PDT) Received: by mail-yw1-f182.google.com with SMTP id 00721157ae682-6d5893cd721so15636357b3.0; Mon, 02 Sep 2024 02:55:44 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCVWCOH/kIGAaw+t0W2WsGzDqna50Je9b7LJGOBMwoQVSwzI24ROo0oYqKW1mhYWYjNhwpzK27ARZTzG@vger.kernel.org, AJvYcCXlDuO63eonStLW66r8CsBLHHjuU71fndhbVCsHsVdpWy0+qiZcPKG+CAKIa63uxYWgfDwCBFVqVwRz@vger.kernel.org X-Received: by 2002:a05:690c:62c6:b0:6d7:4dea:5f16 with SMTP id 00721157ae682-6d74dea5f7bmr31804377b3.26.1725270943798; Mon, 02 Sep 2024 02:55:43 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240826150840.25497-4-wsa+renesas@sang-engineering.com> <20240826150840.25497-5-wsa+renesas@sang-engineering.com> In-Reply-To: From: Geert Uytterhoeven Date: Mon, 2 Sep 2024 11:55:31 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 1/2] dt-bindings: i2c: renesas,rcar-i2c: document SMBusAlert usage To: Wolfram Sang Cc: linux-renesas-soc@vger.kernel.org, Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Magnus Damm , linux-i2c@vger.kernel.org, devicetree@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Wolfram, On Sat, Aug 31, 2024 at 5:31=E2=80=AFPM Wolfram Sang wrote: > > IIUIC, this is not a property of the hardware, but a side-channel > > independent from the actual I2C controller hardware? Then a generic > > "smbus-alert-gpios" property sounds more appropriate to me. > > It is not generic. While it is true that most I2C controllers do need > GPIOs as a side channel, there are controllers having... > > > BTW, are you aware of any I2C controller having a dedicated input pin > > for this? > > ... this. Check 'i2c-stm32f7.c' or 'i2c-xlp9xx.c'. OK... Still, this interrupt is not a property of the R-Car i2C hardware block, so it should not be modelled as such. To me, this looks similar to hardware flow control on serial ports: some ports support this in hardware, other ports need to use GPIOs, or board designers may still decide to use a GPIO anyway. See Documentation/devicetree/bindings/serial/serial.yaml and drivers/tty/serial/serial_mctrl_gpio.c, which uses GPIO interrupts. Gr{oetje,eeting}s, Geert --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds