From nobody Tue Feb 10 06:25:38 2026 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 1F2352DEA6B for ; Wed, 28 Jan 2026 15:38:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769614716; cv=none; b=jwjGEd/d4/ez/b3m9uQQ1V/pEGb+J+t2xPGpAjHCzT5khHPf6kd1lG8MJkOnTp3RG4uJ+1jzxsDNcZnmHCIF1/9At1vjVDrcSRd1oWTR6zBu2EtFBHLKrKGxpUU2hCMoJGjvJwPw51F2FWMBpf1zreH7IA8Wlr9GHYorhhwVGoc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769614716; c=relaxed/simple; bh=8OlP/76Ew+hhf0/5eOzjr5oQG0D+UPVg93zLkxqIWvE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=opTFhiH7LYYLqPr26ZIfb3zugfoQLnq1aR9pfhlKpi3rNa/vM79cG9za18/IVL5dZbw73Tv/L0WVzn5W0JChzc1PybsCRMGVZcveKWw0h+irC3qVpLihqZrjHbPJ7QTp8jZwuKPZx4pd97+sVLcr11yM9/2AI1fgDaEChzqErmI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vl7cg-0003ot-Nh; Wed, 28 Jan 2026 16:38:26 +0100 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac] helo=dude04) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vl7cg-002wSR-2p; Wed, 28 Jan 2026 16:38:26 +0100 Received: from ore by dude04 with local (Exim 4.98.2) (envelope-from ) id 1vl7cg-0000000FRAO-0SOw; Wed, 28 Jan 2026 16:38:26 +0100 From: Oleksij Rempel To: Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , David Jander Subject: [PATCH v3 5/8] dt-bindings: iio: dac: maxim,ds4424: add maxim,rfs-ohms property Date: Wed, 28 Jan 2026 16:38:21 +0100 Message-ID: <20260128153824.3679187-6-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260128153824.3679187-1-o.rempel@pengutronix.de> References: <20260128153824.3679187-1-o.rempel@pengutronix.de> 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-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The Maxim DS4422/DS4424 and DS4402/DS4404 current DACs determine their full-scale output current via external resistors (Rfs) connected to the FSx pins. Without knowing these values, the full-scale range of the hardware is undefined. Add the 'maxim,rfs-ohms' property to describe these physical components. This property is required to provide a complete description of the hardware configuration. Signed-off-by: Oleksij Rempel Acked-by: Conor Dooley --- changes v3: - Moved minItems and maxItems to the main property definition - Refined property description to state that values depend on chip variant and hardware requirements, deliberately avoiding specific "typical" ranges to prevent unnecessary hard-limit enforcement. - Corrected the rfs-ohms example to use a plausible value within datasheet typical range. - Removed redundant constraint definitions from the allOf logic. changes v2: - make maxim,rfs-ohms a required property as the hardware range is undefined without external resistors. - add allOf constraints to enforce 2 vs 4 items in maxim,rfs-ohms based on compatible string. - drop explicit $ref for maxim,rfs-ohms to fix dt_binding_check warning. - update example in binding to include the new required property. --- .../bindings/iio/dac/maxim,ds4424.yaml | 35 +++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml b/= Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml index efe63e6cb55d..4323df2036ac 100644 --- a/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml +++ b/Documentation/devicetree/bindings/iio/dac/maxim,ds4424.yaml @@ -27,9 +27,43 @@ properties: =20 vcc-supply: true =20 + maxim,rfs-ohms: + description: | + Array of resistance values in Ohms for the external Rfs resistors + connected to the FS pins. These values determine the full-scale + output current. The actual resistance depends on the chip variant + and specific hardware design requirements. + minItems: 2 + maxItems: 4 + required: - compatible - reg + - maxim,rfs-ohms + +allOf: + - if: + properties: + compatible: + contains: + enum: + - maxim,ds4402 + - maxim,ds4422 + then: + properties: + maxim,rfs-ohms: + maxItems: 2 + - if: + properties: + compatible: + contains: + enum: + - maxim,ds4404 + - maxim,ds4424 + then: + properties: + maxim,rfs-ohms: + minItems: 4 =20 additionalProperties: false =20 @@ -43,6 +77,7 @@ examples: compatible =3D "maxim,ds4424"; reg =3D <0x10>; /* When A0, A1 pins are ground */ vcc-supply =3D <&vcc_3v3>; + maxim,rfs-ohms =3D <40000>, <40000>, <40000>, <40000>; }; }; ... --=20 2.47.3