From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) (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 669CA4C9E09 for ; Sun, 18 Oct 2026 14:37:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792334275; cv=none; b=oV7FtzT9C2RwhDsqO3afXAWAGqjC25j+3PChs6udUDkKMqDjqqohIS2KSe7Tsm9TBQGKnLvbSImPiEE+SBwUvfWnlGCdDxCrLbMzXwEeuCCkq6g+TYlqkwl925eBcOst7afsstq1y/jS4xZw0deJ37KfdjaTqIS43VRFfZ0RC2E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792334275; c=relaxed/simple; bh=UYFoFX0tGdhtBbyo/PtF8ivZOPxks5UDgHk9noFc/r4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JwSPX1coNrDqU1ezoZMrjNqxQT70YMNv1HTBl8kPBcgnH1pS2KgWArNJZCLm9FEztXKgVQk5eKWjBjo6Z8qCP8CYie8kt5sfU1rwwt+92ElDYN8j2k5QXQulZG5uDWyUu/h9RtTY9LjoarCBxKraFNmYgV4FtJbZo4LeYeWP2yM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=SBnUNqhJ; arc=none smtp.client-ip=209.85.221.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SBnUNqhJ" Received: by mail-wr1-f44.google.com with SMTP id ffacd0b85a97d-48af4d4e61fso714243f8f.2 for ; Sun, 18 Oct 2026 07:37:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792334273; x=1792939073; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=iL6GDYV/Gzptn6Y+1zackEOFhZyQVLBTkqU0BFO4s1I=; b=SBnUNqhJlsNQ058UhjSIABvVOLMW8MMRmSn1dibFENROTSAch6CU6O3jfd7GI4h13/ rUFLXzxi2RTCzkXsjhqHUQ9wa9aCM7eDe/68Nw1OBit+0zQdUdhlJSW9fFCyBzlm2HbB UNGXjSPgeYduAPF/hTyfZFcR7LzpWCUIKsVsuSPcgdAjgzzuZuhBw5xnAlSgwuHbi3Me MWeguJ4dHVzkLWocX6/uiqR9IyXmp+S3zAHGro9ODJSC+tB3wExdovZWR6vCqBZt07u+ TAxJq4Cjindm4pWXxfmbA+fl2Iv0fjte9yypBO3RW1TWV/N7QW2mz/nB6kLLKG7rD3b6 0beQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792334273; x=1792939073; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=iL6GDYV/Gzptn6Y+1zackEOFhZyQVLBTkqU0BFO4s1I=; b=2irkjY1/BL6pyP03Au3SlExjR4o54UprGjS5Z/ZVkJDlym1pE1jef/nCFrUx5mJUpX U5VxUuFk7d78/JjqMwVvcMoY59p3OtGloXEAh1nYLKiEW3JaoBR4UoSNwRxMp0z0r2WZ OjW8zUWxrhNWFYZ8mOTr6Tpc6BTayf2aM+PYKjiFtI7EnKSucaLMCipwbBkp6co7NSZx HswPzkbeX88O5toBjKu/9Woj4BHG5nbvfuacmngx2sX3a+Qp3ByY6HPc8SLLlszoX8o1 pps7X95AFIb2StacX5KY+HTxEepx8iYOaTLwU4QzuQ8EYyC5lxXV4b8Bm1nBXx5L9chy JgHQ== X-Forwarded-Encrypted: i=1; AKwUvBw2Og5J4cZX90n0bkMWutPR0IBer2+7Vdegb1RLfEBqBjwPHlBelmt5rUY0N0zznIKZcxRGDW32JRCd@vger.kernel.org X-Gm-Message-State: AFq9FYLIXmjD9pufm5Xnqxn+MOk6ypTr/CwaOChbHULtd76s2v12QnJn 5FiJALFK3mZpHTLyWShLWlcv/W7tVHoWk6+HoYME0RuY3ep8BdGpJ8tF X-Gm-Gg: AYBFou1jfRJLPLuYEkMURJ80SvkrO6HNFextmcmrzIvJaU6WZmyWQa5ckZl7g7UPzSi Vcu5aaf040ldO86tTWtb1COgvhTcRDVfjN2JO1nAr2SR8mF8aRurm2jR9tsOFLQrg2Kaz/B/BDw VK2q165Lgc6e2cBuloTy55TMbnQtiD+/s7V2hzVVwe7u4xkLVQrpJDZSuAM1bFs35+BmRyIrSNQ DrxG/ooRw+n7TmXMpbXmk4b98Q1uy1Mo8XjI/m8YqzdmPA+duhXC2IjOOuRtXzSIv7ae6YYgKQz rQa1wsZBxWi4Kk63yJVXB3HQEhbp7SQ3AkK0yZGRdFBfEvLk7lg4JDOZfOejsCx0XDndfG8oS9w IHq3vS9o3/I6Ux5/1IQVBQM+mH/KFJBoZYHc4ABHhBBi52ylPhJkfahbOkSOM0WUcyQFeu4mk1w pheQ8vDAgDH6vUZf8dKp+fGWXe97DiRermSR6qHcNawPycCQI0T08MeNgcRSfTmuVFQLrdE2gJC OZx44PcSOg4J9Ve7PEJ4xzlUFG+n4mxjUi9jAqIidbMMg== X-Received: by 2002:a05:6000:605:b0:488:89c7:31aa with SMTP id ffacd0b85a97d-48e07fa5687mr11225648f8f.39.1792334272541; Sun, 18 Oct 2026 07:37:52 -0700 (PDT) Received: from zeus.localdomain (212.71.14.70.adsl.dyn.edpnet.net. [212.71.14.70]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48dfd510d60sm16559652f8f.58.2026.10.18.07.37.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 18 Oct 2026 07:37:52 -0700 (PDT) From: Sander Speetjens To: Alexandre Belloni Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , Jonathan Bell , Stefan Wahren , linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, sander.speetjens@gmail.com, pbrobinson@gmail.com, Conor Dooley , Krzysztof Kozlowski Subject: [PATCH v12 2/3] dt-bindings: rtc: Add property for Raspberry Pi 5 RTC Date: Sun, 18 Oct 2026 16:37:11 +0200 Message-ID: <20261018143712.1040152-3-sander.speetjens@gmail.com> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261018143712.1040152-1-sander.speetjens@gmail.com> References: <20261018143712.1040152-1-sander.speetjens@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The Raspberry Pi 5 has a built-in RTC that can be battery-backed via the VBAT pin. When a rechargeable coin cell is used, the hardware requires a trickle-charge voltage to keep the battery topped up. Expose the trickle-voltage-millivolt DT property so the driver can program the correct charge voltage for board specific configurations with the attached battery. The property is added to the existing raspberrypi,bcm2835-firmware binding (rather than creating a new RTC node) because the RTC is accessed exclusively through the firmware mailbox interface. We only $ref the individual property from rtc.yaml and do not reference the full schema, because the firmware node name does not match the $nodename pattern required by rtc.yaml. Acked-by: Conor Dooley Acked-by: Krzysztof Kozlowski Signed-off-by: Sander Speetjens --- V11 -> V12: No changes V11: https://lore.kernel.org/linux-rtc/20261014083016.332338-1-sander.speetjens@gmail.com .../bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml index 983ea80eaec9..dc71fd57834e 100644 --- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml +++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml @@ -133,6 +133,11 @@ properties: required: - compatible + trickle-voltage-millivolt: + $ref: /schemas/rtc/rtc.yaml#/properties/trickle-voltage-millivolt + minimum: 1300 + maximum: 5000 + required: - compatible - mboxes @@ -144,6 +149,7 @@ examples: firmware { compatible = "raspberrypi,bcm2835-firmware", "simple-mfd"; mboxes = <&mailbox>; + trickle-voltage-millivolt = <3300>; firmware_clocks: clocks { compatible = "raspberrypi,firmware-clocks"; -- 2.56.0