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 4397E275AFF; Thu, 4 Dec 2025 21:33:51 +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=1764884032; cv=none; b=mR5jjRw8NrJTf7k6y69QWdjZZJ/x62ygcH1FH9Sw86tMfFjcSBA+8stpy0DMm1zl39SbqJe+4WFGUCM6+lZnPeTatWKBV/Ae2JvYBWhA1qNPZ4eQ9LVt/3iXLllRw9uk8sC8Xa3kc/f1zljDxaTslnxlrTU/45kdB2R6/ItvcGk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764884032; c=relaxed/simple; bh=ZllcKEFsuf2MwVYL4v/IYtcLUBaudASfSmPEepm6+M8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=W1riAaAW/oXKSZ5ttr7mNl5f30s3RB7hbE3auP+zAMHkz0KJt/qT7oZ4nZr4E1Grb39SfPWT7iaht/G93PiSIAw+UkqKroQs/7BWbDWMIROfYVyen2st7+L6WNQZvZ1i5ZoHyvHMBSjycYMweYf/E41wRUK6qAKJSIc8pDxF+/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=s8xcR65A; 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="s8xcR65A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A6C3C113D0; Thu, 4 Dec 2025 21:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764884031; bh=ZllcKEFsuf2MwVYL4v/IYtcLUBaudASfSmPEepm6+M8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=s8xcR65Ar5f4w3cpSYVX11nTV4PRsyakkWc01N2st/Ok1ftQ3RngdwqMd6nC+Vw/4 ocRpGnGZNTr8KCxM5ES0LH6hgBM+sDvqeFVff9kqPHpyu1s1NCzG63nvMebjdJLKxF N85S7Tn02PyXvfWoFrsYUs3so/E1BDNiTfElOLoAoqtpVxedRQ4c+jpM5UWLCdLCEl 4su4nL+1B0glGbCRNjxwPWeLhr/XKNRoWBNKlK9b44UAhWMtVc6Bh2jer9yLla5wbZ +K7BldJ1VzSN85pgnNSC5JGaazTWcVfqX+MLm2dF84GPrWVYVUrcJXvrvSCBA6xnK4 2KdwYyonmfGrA== Date: Thu, 4 Dec 2025 15:33:48 -0600 From: Rob Herring To: David Lechner Cc: Mark Brown , Krzysztof Kozlowski , Conor Dooley , Marcelo Schmitt , Michael Hennerich , Nuno =?iso-8859-1?Q?S=E1?= , Jonathan Cameron , Andy Shevchenko , Sean Anderson , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: Re: [PATCH v3 7/7] dt-bindings: iio: adc: adi,ad4030: add data-lanes property Message-ID: <20251204213348.GA2198382-robh@kernel.org> References: <20251201-spi-add-multi-bus-support-v3-0-34e05791de83@baylibre.com> <20251201-spi-add-multi-bus-support-v3-7-34e05791de83@baylibre.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251201-spi-add-multi-bus-support-v3-7-34e05791de83@baylibre.com> On Mon, Dec 01, 2025 at 08:20:45PM -0600, David Lechner wrote: > Add data-lanes property to specify the number of data lanes used on the > ad463x chips that support reading two samples at the same time using > two data lanes with a capable SPI controller. > > Signed-off-by: David Lechner > --- > v3 changes: new patch > > I added this one to give a real-world use case where spi-rx-bus-width > was not sufficient to fully describe the hardware configuration. > > spi-rx-bus-width = <4>; alone could be be interpreted as either: > > +--------------+ +----------+ > | SPI | | AD4630 | > | Controller | | ADC | > | | | | > | SDIA0 |<---| SDOA0 | > | SDIA1 |<---| SDOA1 | > | SDIA2 |<---| SDOA2 | > | SDIA3 |<---| SDOA3 | > | | | | > | SDIB0 |x | SDOB0 | > | SDIB1 |x | SDOB1 | > | SDIB2 |x | SDOB2 | > | SDIB3 |x | SDOB3 | > | | | | > +--------------+ +---------+ > > or > > +--------------+ +----------+ > | SPI | | AD4630 | > | Controller | | ADC | > | | | | > | SDIA0 |<---| SDOA0 | > | SDIA1 |<---| SDOA1 | > | SDIA2 |x | SDOA2 | > | SDIA3 |x | SDOA3 | > | | | | > | SDIB0 |<---| SDOB0 | > | SDIB1 |<---| SDOB1 | > | SDIB2 |x | SDOB2 | > | SDIB3 |x | SDOB3 | > | | | | > +--------------+ +---------+ > > Now, with data-lanes having a default value of [0] (inherited from > spi-peripheral-props.yaml), specifying: > > spi-rx-bus-width = <4>; > > is unambiguously the first case and the example given in the binding > documentation is the second case: > > spi-rx-bus-width = <2>; > data-lanes = <0>, <1>; I just reviewed this and all, but what if you just did: spi-rx-bus-width = <2>, <2>; So *-bus-width becomes equal to the number of serializers/channels. Rob