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 7E24733D4E9; Mon, 19 Oct 2026 11:24:21 +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=1792409063; cv=none; b=YjFC8mSXPfCMT4T47rpw9cET/8J5kyur+HnVA7Bbfi7BMUrfCZsc+p2bHMF28UNlr00gRGttFXQvYXuQVN5nV3wLINBQaGgABnfDdsTXgo7InnIPXkDe/Op+3Xz1jYWKL09kJhefRDQuFy0wPUV3eqAykycyZkHSLAAsm9LicbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792409063; c=relaxed/simple; bh=mK5//vkxGCMjGmgSS0WchDdkPqMImf50AUAtxpkkxxM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JTQC0BNdkfXV2mEi9YdjH+XVbvBlmjVlZ7koTb5OS+PdRH7wEcc3CMR2vxuXwPwBU4493tiil3THC5G9Ki6A5EQMRk8F8vUJzgdDfXb4Dobrb1iDedkBoEjiG5F3fMSCfx+aTZyIS21oPW+nxe1qqY9x8zcFVVGZ8Hwl5wHI3Eo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eUIhvj9k; 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="eUIhvj9k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEB7D1F000C4; Mon, 19 Oct 2026 11:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792409060; bh=PKWuic2G/HGRtF1u1BPrf6xxiud57cUAtpu/hY9Z7zk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=eUIhvj9kR4RHH88tNnYvfd3YtdegYy5pr8/ExGG5M+QAXa89Wu/VHIOMqDkGNH5H7 Su0qNxZAcoI4sPOCDTf/PxiY0LWkfd5KW+Cc3JbPG1rGUfm5zPuV4leWABc5ubUKLJ 91De2w4+/1D8uoMlBbI7QoAMER/bPzXrPY7+u3zvxD+mqHuR3wocWgpsxYSQej76vJ vuxn5SnlroL+QW3ysz/ffBbngUvWCwDvJAqN5E9rFl5Z13cDFOuhnFrprJK6vHHR+9 dTEul+HkEyG/A9RKrMkn1PUnkYMNR8uH6xXx1f5JXgB5uvKApIr1RBcedX4DhDUhhR cRJXNcZzXIRDQ== Message-ID: <324dcc61-6085-446c-8bf7-564486f319bd@kernel.org> Date: Mon, 19 Oct 2026 12:24:13 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/3] phy: core: add generic MIPI C-PHY configuration API To: Bryan O'Donoghue , Anusha Arun Nandi , david@ixit.cz, andersson@kernel.org, konradybcio@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, vladimir.zapolskiy@linaro.org, loic.poulain@oss.qualcomm.com, mchehab@kernel.org Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, gjorgji.rosikopulos@oss.qualcomm.com, jigarkumar.zala@oss.qualcomm.com, hariram.purushothaman@oss.qualcomm.com, akapatra@quicinc.com, linux-media@vger.kernel.org, krzysztof.kozlowski@oss.qualcomm.com, daniel@quora.org, konrad.dybcio@oss.qualcomm.com, christopher.obbard@linaro.org, alex.vinarskis@gmail.com References: <20261017041733.3946816-1-anusha.nandi@oss.qualcomm.com> <20261017041733.3946816-2-anusha.nandi@oss.qualcomm.com> From: Bryan O'Donoghue Content-Language: en-GB Autocrypt: addr=bod@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 19/10/2026 11:24, Bryan O'Donoghue wrote: > On 18/10/2026 00:00, Bryan O'Donoghue wrote: >>> +    unsigned int        lanes; >> >> This statement and how you go about using the data aren't consistent. > > Re-reading this. > > unsigned int trios; would be fine too => data_lanes and lane_polarities > is a multiple of trios - always three - does it imply that the first > three entries in data-lanes == the first trio ? > > Presumably. > > That would work too. > > data-lanes = <4 5 6 1 2 3>; > > => > > trios = 2 > > => > > data_lanes[4, 5, 6, 1, 2, 3]; > > trio[0]:lanes == [4, 5, 6]; > trio[1]:lanes == [1, 2, 3]; > > Probably "trios" instead of "lanes" makes more sense here and the driver > just always validates that count(data_lanes) % 3 is always false. > > --- > bod I'm going to argue with myself. data-lanes = <1> => lanes = 1; // not trios no need to introduce a new term => three pads on the Soc => The question is - is data_lanes required for the CPHY opts struct ? For the qcom CAMSS case the answer ~ always no - we will be attaching a sensor and will read-back the positions from that endpoint. It is conceivable that other systems may want to pass data-lanes down to the driver because they won't have a media-graph but, I'd say we should arbitrate that then - leave it up to someone who needs the fields to add them. => lanes // the CSID and PHY should agree symbol_rate // so both the CSID and phy agree on symbols per second Remove: - lane_positions - lane_polarities Since at least for this series, they won't be needed. The CSID still needs to know the number of lanes and how many symbols so that it can calculate bandwidth so .... lets just include the data we know we need. struct cphy_opts {lanes; rate/symbols}; dropping lane_positions and lane_polarities. I've no objection to the low-level timing variables myself but OTOH we don't require them at this point in time. Perhaps drop unless/until someone can show a need for them. Excellent bod, agree with you now. --- bod