From nobody Mon Dec 15 21:42:41 2025 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) (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 D31D622A7F7; Wed, 5 Feb 2025 09:55:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738749354; cv=none; b=uu83HJyuuqcKjUYCoQ7ybDBKmQwRwlPfbVsZELFI/Vu+Ndz6KqEXEZdHFUjjr+ovg4Xy8xHdiyyRI2EecvoMX3nn2ddsq7Sv28rIZl9ztVxDtq69eI0I0mGezBvFeqk9BV2Uc1PcBRaYox6HBmqFRMD2ffLcRdDsmXFVRWfeEgY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738749354; c=relaxed/simple; bh=lf2J/Jvva6CeFbVTIi/pV8rBqbhOFBSkkoEq6HHZWD8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ATNOQnSX2wWA/qVCFyYgD2BSVOYUhlQDXtSml4hqNEcgWgcGKiSWA24xe+K7z2X6oLiRS6MZE9+O0VIJC9/CFFVYEu6JQolE3Kjyc6pebjWVV/Km/+Zy8kCZNN0lU0ZKEZqmQH5Qn48v9RcuHzrZvE9PR2hCCSVaxqgrxn9Aj6A= 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=AzNPYTPV; arc=none smtp.client-ip=217.70.183.201 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="AzNPYTPV" Received: by mail.gandi.net (Postfix) with ESMTPA id DAC3B43404; Wed, 5 Feb 2025 09:55:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1738749350; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eOBdVJSBqhcVuEH+zRzYmH2H4Qw9RQMcHASYrX6Us4o=; b=AzNPYTPV2wQZEFo1sN9qEWj525uZz7pFpbtKEw6mG7WfQ+OME7EmZeyYqdArFT/wyGOR2H zAUQVCC6KppsD0X1iYHpaKtK7RAyyTftYSndzAmd5yHfBmdnbOfQV8Ecx3Vv13KdtRh8nF Pb0zvyDbhyi9h0dBzTz0as3LSIYZuLi2ftc2DjT8npVebYSXiTCVacOnkMY1+g4Hhwc+yk pcFbpoievDoA+pspCajOBF94ltTPlRYlYFnLi1duF9ePyM10/zZ02ky692udblJAsMeb2Z n9fET93nxnhQT052xu/n/WiYD5lb7WKp3tOfPPoWzdhlXJk+wtly/NC6CISjug== From: Herve Codina To: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Herve Codina Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli , Thomas Petazzoni Subject: [PATCH v3 1/2] dt-bindings: pwm: Add support for PWM nexus node Date: Wed, 5 Feb 2025 10:55:42 +0100 Message-ID: <20250205095547.536083-2-herve.codina@bootlin.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250205095547.536083-1-herve.codina@bootlin.com> References: <20250205095547.536083-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvfedufecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepjfgvrhhvvgcuvehoughinhgruceohhgvrhhvvgdrtghoughinhgrsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpefffffgfffgveekfefhhffgjeelueetieeffedttdegvdegjefghfevffegjeejveenucffohhmrghinhepghhithhhuhgsrdgtohhmpdguvghvihgtvghtrhgvvgdrohhrghenucfkphepvdgrtddumegvtdgrmedvgeeimeejjeeltdemvdeitgegmegvvddvmeeitdefugemheekrgenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvrgdtudemvgdtrgemvdegieemjeejledtmedviegtgeemvgdvvdemiedtfegumeehkegrpdhhvghloheplhhotggrlhhhohhsthdrlhhotggrlhguohhmrghinhdpmhgrihhlfhhrohhmpehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepuddtpdhrtghpthhtohepuhhklhgvihhnvghksehkvghrnhgvlhdrohhrghdprhgtphhtthhopehrohgshheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepkhhriihkodgut heskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheptghonhhorhdoughtsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomhdprhgtphhtthhopehlihhnuhigqdhpfihmsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepuggvvhhitggvthhrvggvsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhg X-GND-Sasl: herve.codina@bootlin.com Content-Type: text/plain; charset="utf-8" Platforms can have a standardized connector/expansion slot that exposes PWMs signals to expansion boards. A nexus node [1] allows to remap a phandle list in a consumer node through a connector node in a generic way. With this remapping, the consumer node needs to know only about the nexus node. Resources behind the nexus node are decoupled by the nexus node itself. This is particularly useful when this consumer is described in a device-tree overlay. Indeed, to have the exact same overlay reused with several base systems the overlay needs to known only about the connector is going to be applied to without any knowledge of the SoC (or the component providing the resource) available in the system. As an example, suppose 3 PWMs connected to a connector. The connector PWM 0 and 2 comes from the PWM 1 and 3 of the pwm-controller1. The connector PWM 1 comes from the PWM 4 of the pwm-controller2. An expansion device is connected to the connector and uses the connector PMW 1. Nexus node support in PWM allows the following description: soc { soc_pwm1: pwm-controller1 { #pwm-cells =3D <3>; }; soc_pwm2: pwm-controller2 { #pwm-cells =3D <3>; }; }; connector: connector { #pwm-cells =3D <3>; pwm-map =3D <0 0 0 &soc_pwm1 1 0 0>, <1 0 0 &soc_pwm2 4 0 0>, <2 0 0 &soc_pwm1 3 0 0>; pwm-map-mask =3D <0xffffffff 0x0 0x0>; pwm-map-pass-thru =3D <0x0 0xffffffff 0xffffffff>; }; expansion_device { pwms =3D <&connector 1 57000 0>; }; From the expansion device point of view, the PWM requested is the PWM 1 available at the connector regardless of the exact PWM wired to this connector PWM 1. Thanks to nexus node remapping described at connector node, this PWM is the PWM 4 of the pwm-controller2. [1] https://github.com/devicetree-org/devicetree-specification/blob/v0.4/so= urce/chapter2-devicetree-basics.rst#nexus-nodes-and-specifier-mapping Signed-off-by: Herve Codina Reviewed-by: Rob Herring (Arm) --- .../bindings/pwm/pwm-nexus-node.yaml | 65 +++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/pwm-nexus-node.ya= ml diff --git a/Documentation/devicetree/bindings/pwm/pwm-nexus-node.yaml b/Do= cumentation/devicetree/bindings/pwm/pwm-nexus-node.yaml new file mode 100644 index 000000000000..55412fe50d01 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm-nexus-node.yaml @@ -0,0 +1,65 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/pwm/pwm-nexus-node.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: PWM Nexus node properties + +description: + Platforms can have a standardized connector/expansion slot that exposes = PWMs + signals to expansion boards. + + A nexus node allows to remap a phandle list in a consumer node through a + connector node in a generic way. With this remapping, the consumer node = needs + to know only about the nexus node. Resources behind the nexus node are + decoupled by the nexus node itself. + +maintainers: + - Herve Codina + +select: true + +properties: + '#pwm-cells': true + + pwm-map: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + + pwm-map-mask: + $ref: /schemas/types.yaml#/definitions/uint32-array + + pwm-map-pass-thru: + $ref: /schemas/types.yaml#/definitions/uint32-array + +dependentRequired: + pwm-map: ['#pwm-cells'] + pwm-map-mask: [ pwm-map ] + pwm-map-pass-thru: [ pwm-map ] + +additionalProperties: true + +examples: + - | + pwm1: pwm@100 { + reg =3D <0x100 0x10>; + #pwm-cells =3D <3>; + }; + + pwm2: pwm@200 { + reg =3D <0x200 0x10>; + #pwm-cells =3D <3>; + }; + + connector: connector { + #pwm-cells =3D <3>; + pwm-map =3D <0 0 0 &pwm1 1 0 0>, + <1 0 0 &pwm2 4 0 0>, + <2 0 0 &pwm1 3 0 0>; + pwm-map-mask =3D <0xffffffff 0x0 0x0>; + pwm-map-pass-thru =3D <0x0 0xffffffff 0xffffffff>; + }; + + device { + pwms =3D <&connector 1 57000 0>; + }; --=20 2.47.1