From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B6B432B989; Fri, 13 Feb 2026 08:29:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770971364; cv=none; b=KdVD67gSbqwR/lcslgVJSM2b1JG33+ginB/VXh+G/cXKswxgaFkU6H2IUq8sVWtRllZ0XbIRk8eellPtCDI6KbB5MSIPNv3C3KQxWcStnmcxQzuTUwsxLVXr3pANWOf/aRyBUjn17hVPMN9oZ7AfnXRG6lznIAe0mohfgsqJy20= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770971364; c=relaxed/simple; bh=RTo8u2Sedn1CnU8sFrvE0WSM41I0dJtuSDAEhq8+kRw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bTdqa81DCqSk3eLMRmE3OWfLmdwX0RzkwUMU8tQuYVxBVftSxjbLip6/i3DTH/PE9nNXopuFelPI4ZwWbCDNus/CYr74mZDCGEyNHCx4M82gp1HG/FftG3bZ77CL3Ns2GOUssSkUWMIc9QBPqWo0kjZ93uGm4V9r5cl+OEwav18= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=kX2tOZB6; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="kX2tOZB6" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 5A72EC237FD; Fri, 13 Feb 2026 08:29:30 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id B953F606CC; Fri, 13 Feb 2026 08:29:20 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 815FD10368E05; Fri, 13 Feb 2026 09:29:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1770971360; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=HTw/HXY0Gs/LRcdanaDRSbVGf28t6RLADO9IJc09aSQ=; b=kX2tOZB6aHe0Ba7nQ8QVjJLwvpMCkA1F71AAYE8sXzdBhBSC85zwePyXhYgkNVEqqyRDdw SGZgiCCGPDKvyNZxe8JZJd8d6YaWF5PpGcmmvM2PJfBG1pbl+0ztWbTJRD47amwkkwx2du sXwkDfsNMciFmP0SiewlO5qNEg5B2Qul6bRCVzJNYFzg4UWXdseoWscyV7YCHFqOq4J1mm BxJaHzr9H6aC5T7pGfXP/fOJDvfmpG6N3VJmP7BNkz2lhRqKpize45wGqZPguFyMa2W+z7 wobewpFhqkLTrNMfN2122VT/VECv6KfG3447Ve4ecdzzo/0s4jOaFQE/wb10PA== Date: Fri, 13 Feb 2026 09:29:14 +0100 From: Herve Codina To: Krzysztof Kozlowski Cc: James Hilliard , Geert Uytterhoeven , Bartosz Golaszewski , Rob Herring , linux-gpio@vger.kernel.org, Linus Walleij , Krzysztof Kozlowski , Conor Dooley , Alexander Stein , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] gpio: aggregator: add gpio-aggregator DT compatible Message-ID: <20260213092914.79790cb9@bootlin.com> In-Reply-To: <89c0dd51-fdd5-4368-b5f5-615143ffd166@kernel.org> References: <20260211081355.3028947-1-james.hilliard1@gmail.com> <20260211081355.3028947-2-james.hilliard1@gmail.com> <34a9b531-4f53-47ee-861e-1b18ff1a5752@kernel.org> <20260211214708.GA3947691-robh@kernel.org> <9afa52c1-b7de-4ccb-9114-a142567d21af@kernel.org> <89c0dd51-fdd5-4368-b5f5-615143ffd166@kernel.org> Organization: Bootlin X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Hi all, On Fri, 13 Feb 2026 08:31:21 +0100 Krzysztof Kozlowski wrote: > > > > Or is the issue just with the name of the compatible I used being > > called "gpio-aggregator"? > > No, the issue is that there is no hardware you are trying represent in DTS. Except if you have a piece of hardware that invert the gpio line. In that case you need to set GPIO_ACTIVE_LOW somewhere. The aggregator allows to describe this line inverter. Of course, if the gpio is connected to a hardware component handled by the kernel, the DT node describing this hardware can set the flag. The issue is for GPIOs that are just GPIOs and should by a user-space application as GPIOs. Some bindings exist for GPIO and do not describe the hardware but the feature. For instance: https://elixir.bootlin.com/linux/v6.18/source/Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml https://elixir.bootlin.com/linux/v6.18/source/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml https://elixir.bootlin.com/linux/v6.18/source/Documentation/devicetree/bindings/power/reset/gpio-restart.yaml Can we consider the gpio-aggregator describing the wires that should be grouped together. Industrial board can have some GPIOs grouped together and used as inputs or ouputs of this industrial board. As output they command an external system. As input, they get feedback from this system. gpio-aggregator describes those lines. In that sense, it describes hardware. Maybe the "gpio-aggregator" name doesn't reflect that and a compatible such as "gpio-equipment" could make sense. Best regards, Hervé