From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C14972594BD; Sun, 12 Oct 2025 17:06:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760288812; cv=none; b=a8xD0XSqQQsVPI6WfZvTgzHgyFOIPzUotGqR+xqi7teok1MdQffOfDKXzKsKGUB5zs2XZPoE0Un4GPs9oZ7KJhxFLLKcWCCmmWQ2CfYQlogWiyKW3Sb+nBbsR8T/fDQuo0tEwXCC1nagAzqCP7kjJjRqTKnhStAgTh5vjxPgRsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760288812; c=relaxed/simple; bh=c4XBUmYW5+yztJ9CHlJGDquaE7OdDtySN6VncUWd2bg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XKBux32TjUznAACIU1aD88xagZl6ugjPzd3qaV98mPG0+Se8XtkVcLVC+LYk1C4xwc4zFVyL5Uhph2HLKG/Ogu1C3f1/KfehakhgJJjF1+G/DSTfP/aUwZhTo8N1ZUBtBhDaDzp6kSFwEqkkghvtdtQX+wr4lrYPyuhllOl/xT0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LsX/d7ie; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LsX/d7ie" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E6C8C4CEE7; Sun, 12 Oct 2025 17:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760288812; bh=c4XBUmYW5+yztJ9CHlJGDquaE7OdDtySN6VncUWd2bg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LsX/d7ie/IrQVm8XgaQ9Guws0w+MoB5TRp+V6zHrWSKBo7PY8e+HQFmk6ZMxKdyHJ nKr5i3P0h4aEnpu6ArNEuPt+VToiUU9BOgtPWPAc22iwcO1XyloRHBmjwZyC5W/4Y/ +75VWl1mwLSI8wLj26HnjcytuXaW+za2qMHpXOZgxiPPZkqfHcoZCXVKnPVhTcRMgV dCW7Jop8ZtmUV3FG+ylg0P1FKqJPaO8MpguiTLTgZ4M2BfOUfm5u+O0CIRBrDRBWtv HThu9WaT6qe4mcKTU9oDeMn1kOGSHqA6hzvD6gQtYssKmhSXJP3R/XWEj5H8wZKRVO bhk7ZvEfbpesQ== Date: Sun, 12 Oct 2025 18:06:44 +0100 From: Jonathan Cameron To: Shrikant Raskar Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, dlechner@baylibre.com, nuno.sa@analog.com, andy@kernel.org, matt@ranostay.sg, skhan@linuxfoundation.org, david.hunter.linux@gmail.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linux.dev Subject: Re: [PATCH v2 1/2] dt-bindings: iio: max30100: Add pulse-width property Message-ID: <20251012180644.019616c9@jic23-huawei> In-Reply-To: <20251008031737.7321-2-raskar.shree97@gmail.com> References: <20251008031737.7321-1-raskar.shree97@gmail.com> <20251008031737.7321-2-raskar.shree97@gmail.com> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 8 Oct 2025 08:47:36 +0530 Shrikant Raskar wrote: > The appropriate LED pulse width for the MAX30100 depends on > board-specific optical and mechanical design (lens, enclosure, > LED-to-sensor distance) and the trade-off between measurement > resolution and power consumption. Encoding it in Device Tree > documents these platform choices and ensures consistent behavior. > > Tested on: Raspberry Pi 3B + MAX30100 breakout board. > > Signed-off-by: Shrikant Raskar > > Changes since v1: > Add unit suffix. > Drop redundant description. > > Link to v1: > https://lore.kernel.org/all/20251004015623.7019-2-raskar.shree97@gmail.com/ > --- > .../devicetree/bindings/iio/health/maxim,max30100.yaml | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml b/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml > index 967778fb0ce8..5c651a0151cc 100644 > --- a/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml > +++ b/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml > @@ -27,6 +27,11 @@ properties: > LED current whilst the engine is running. First indexed value is > the configuration for the RED LED, and second value is for the IR LED. > > + maxim,pulse-width-us: > + maxItems: 1 > + description: Pulse width in microseconds I continued the discussion on v1 but just to make sure it is not missed, add a bit more here briefly touching on factors that govern what the right value is here. Thanks, Jonathan > + enum: [200, 400, 800, 1600] > + > additionalProperties: false > > required: > @@ -44,6 +49,7 @@ examples: > compatible = "maxim,max30100"; > reg = <0x57>; > maxim,led-current-microamp = <24000 50000>; > + maxim,pulse-width-us = <1600>; > interrupt-parent = <&gpio1>; > interrupts = <16 2>; > };