From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 707DF409635; Tue, 28 Jul 2026 21:17:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785273446; cv=none; b=ga5bfaycRuWokyza0mn/iPK68k/E6V9/UsjbH1YNbLvMn4SCbpKJh8iGWOOgRz5EjaqW3iNY/0zie06P1TA5t47ewZL5fhB3lr3dKa9viEqqVs6p1qmWrD2V+etZy5TNstTA6Ba/xb7JQNwGtKgQjecu2hJNhGrQJ4O8pHyxBG4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785273446; c=relaxed/simple; bh=72f8biyVUgH335xMxu6GsNjwxPf4qtOV1/vFiyhG41w=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HD+T1b56C9bxe82AlRIDyanHeXNyz6UCyizvqsynI4/8WM/PZ5aBbCl2uSGBK0Z6ZNN+1OKOdcknNycGbL0oOw7ynqp0JCSSdTx/XQodnPATFxKBGGJNpCn+zcVYx7d8baDudSwwDJ3AvZ2L3ZtfP0LZBHCkRxMG5dNTqff8xj4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ga2S1uTO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ga2S1uTO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 844401F000E9; Tue, 28 Jul 2026 21:17:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785273445; bh=RPYyzEACWXmL3B1yuWD9+3WsAbReeEdqc/tsPpB+Cz8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ga2S1uTOGLy3klZKkkmwDKmf82X4HWiqyRgsDOjF7WDZFcYZhh4ME6B+Ts/Yhb9J/ GObH1TwC9F/3c6RLD/nCeGyaH6m0Xh4J+T5A1TomNDkk+ZHBiP8+ReNXGkNblMKXpi yMNYfuIorUmEXBt/9b9ImwbwrIeqX0ybORU2LMs1fqXU6I4j1TJILZPtAhUZffBFET C5vcZrunFh4NvOk3ROBZ91KqVRzGdmAloUdKR0LIQ4tpnIyAM6PgrTbJm64CvpEVrd sGpbzpGAzmuGMircFkRwv7JZ+mKcjNskIjfEM5UBwGSQSLPQX1kPe+Rjvr3/18OV9C /GOZKbJhaCwIg== Date: Tue, 28 Jul 2026 22:17:19 +0100 From: Jonathan Cameron To: Conor Dooley Cc: David Lechner , Janani Sunil , Lars-Peter Clausen , Michael Hennerich , Nuno =?UTF-8?B?U8Oh?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Philipp Zabel , Jonathan Corbet , Shuah Khan , Mark Brown , Marius Cristea , Marcus Folkesson , Kent Gustavsson , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Janani Sunil , linux-spi@vger.kernel.org, Kent Gustavsson Subject: Re: [PATCH v7 2/7] dt-bindings: iio: adc: microchip,mcp3564: Add spi-device-addr Message-ID: <20260728221719.7f668a73@jic23-huawei> In-Reply-To: <20260728-patronize-thwarting-56fab2e11077@spud> References: <20260722-ad5529r-driver-v7-0-7781cd74ad75@analog.com> <20260722-ad5529r-driver-v7-2-7781cd74ad75@analog.com> <20260725230739.63ff7000@jic23-huawei> <20260728-patronize-thwarting-56fab2e11077@spud> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 28 Jul 2026 17:00:55 +0100 Conor Dooley wrote: > On Sat, Jul 25, 2026 at 11:07:39PM +0100, Jonathan Cameron wrote: > > On Sat, 25 Jul 2026 15:57:07 -0500 > > David Lechner wrote: > > > > > On 7/22/26 2:54 AM, Janani Sunil wrote: > > > > Add the generic spi-device-addr property to the binding and deprecate > > > > the existing vendor specific microchip,hw-device-address property. > > > > > > > > Signed-off-by: Janani Sunil > > > > --- > > > > .../devicetree/bindings/iio/adc/microchip,mcp3564.yaml | 10 ++++++++-- > > > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml > > > > index 675319276197..de1ea289e7f5 100644 > > > > --- a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml > > > > +++ b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml > > > > @@ -80,6 +80,7 @@ properties: > > > > $ref: /schemas/types.yaml#/definitions/uint32 > > > > minimum: 0 > > > > maximum: 3 > > > > + deprecated: true > > > > description: > > > > The address is set on a per-device basis by fuses in the factory, > > > > configured on request. If not requested, the fuses are set for 0x1. > > > > @@ -91,6 +92,12 @@ properties: > > > > clocking of the device address (BITS[7:6] - top two bits of COMMAND BYTE > > > > which is first one on the wire). > > > > > > > > + spi-device-addr: > > > > + maxItems: 1 > > > > > > Does it not make sense to all for more than once device connected > > > to the same CS here? I would expect maxItems to be 4 to match the > > > number of possible addresses. > > > > > > > I think for this part their isn't a reason to aggregate. > > No magic accesses that touch them all at once. So this hits > > exactly the point you raised about how we set the address for > > more than one of them. > > No David is actually right here, and maxitems should be 4. > Setting the address for multiple was already discussed I thought, with > the property being an array and each compatible being used to determine > the "stride" between entries based on the number of supported channels? I don't think that applies for this device or at least to do so is a major driver rewrite, not a simple binding change. Probably we'd just add a bus and hang the 4 instances off it. They are running on own timing etc so we can't grab data across all of them in any sort of synchronous way - the clocks will probably drift over time etc. They are independent devices (think of them using spi-device-address like an i2c address) - so why have one DT node for up to 4 of them? Note this is different from the AD5529R where the design is intended for them to operate as one single larger device. Jonathan > > > > > Jonathan > > > > > > + items: > > > > + enum: [0, 1, 2, 3] > > > > + default: [1] > > > > + > > > > "#io-channel-cells": > > > > const: 1 > > > > > > > > @@ -123,7 +130,6 @@ dependencies: > > > > required: > > > > - compatible > > > > - reg > > > > - - microchip,hw-device-address > > > > - spi-max-frequency > > > > > > > > allOf: > > > > @@ -159,7 +165,7 @@ examples: > > > > spi-cpha; > > > > spi-cpol; > > > > spi-max-frequency = <10000000>; > > > > - microchip,hw-device-address = <1>; > > > > + spi-device-addr = <1>; > > > > > > > > #address-cells = <1>; > > > > #size-cells = <0>; > > > > > > > > >