From nobody Mon Feb 9 22:19:08 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 AB7B740FDB2 for ; Wed, 4 Feb 2026 14:17:02 +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=1770214622; cv=none; b=FJQAllj354LWpUnwzgx94Jn57Q53LWBR/EpD2+Z9byh0xcZ+UD2g7Vs7dCK5nclzt32dRYaKaWuW+wedKmgqhjNiHAfDJEKoClI4hhKs8Y4v3dJna9+xGO6/TpmZn0h8T6uP2vc84F8BK4+A70B9ZYiMG8Owt/IDA4Jr0LsuKaM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770214622; c=relaxed/simple; bh=nhAV7my+EoRqgRVfBJsqee3GVieKUTY8YxKwg5lBrs0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C/b1sDyNDqvIRaXocioxIXH7D4bKEl/4YrI116SNDKL4wowBKhXtdMGMR/TG6T9f0A1ZTdZqdwVTT5mc2TM4FqhSnql/FQaHyqKfwtqHcOgLcIigh+KYS3O3opcU0zDPwNW1Ix/qcCNraVpeBfu8Nr1q0TKaC2E+XYa/a9oDPuw= 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 1vndR1-0001Qp-HP; Wed, 04 Feb 2026 15:00:47 +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 1vndR1-0045FX-24; Wed, 04 Feb 2026 15:00:46 +0100 Received: from ore by dude04 with local (Exim 4.98.2) (envelope-from ) id 1vndR0-00000001dhK-3WeU; Wed, 04 Feb 2026 15:00:46 +0100 From: Oleksij Rempel To: Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Oleksij Rempel , Conor Dooley , 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 v5 12/13] dt-bindings: iio: dac: maxim,ds4424: add maxim,rfs-ohms property Date: Wed, 4 Feb 2026 15:00:44 +0100 Message-ID: <20260204140045.390677-13-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260204140045.390677-1-o.rempel@pengutronix.de> References: <20260204140045.390677-1-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 v5: - no changes changes v4: - no changes 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