From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 B558223F420; Thu, 13 Feb 2025 13:20:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739452857; cv=none; b=BqkkLbjin4v1fJc56nJ7Qg3KRGfxf4FM9bJNJhKucX+rTe5qo9BaTODfSfVdETIqg9g0r2rNsnTEYDUTb48Xh3uYnr6nXvCr0TJIZGs18Q26/9MR9eAMwWx1aDgXMFpvJacP8oLe6MJslXMdOiJuYSqJUJ8qRYaQP6gM/kCcCgE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739452857; c=relaxed/simple; bh=OpqpLt6cXz6bNc4+IHQhnP78DOqIMnCQS+vmvfHWmLQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pdhz1D2/msiNxGpX/vjgnU440duf2cnlIieWRx5NSceCcJa5lStqiZnfB4bV5JwP/ucZBtZ42Qac0DKxNnbPxrJ3ynJaFq/MHqZ3W3tD1GqcmRg5SA6QlODsmGwMbhXDnwiQx3ahs9lypH2MqWtqry+Jl7/mlD69ZiCsJdXoSAc= ARC-Authentication-Results:i=1; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi, On 13/02/2025 14:33, Aradhya Bhatia wrote: >>> +  ti,companion-oldi: >>> +    $ref: /schemas/types.yaml#/definitions/phandle >>> +    description: >>> +      phandle to companion OLDI transmitter. This property is >>> mandatory for the >>> +      primarty OLDI TX if the OLDI TXes are expected to work either >>> in dual-lvds >>> +      mode or in clone mode. This property should point to the >>> secondary OLDI >>> +      TX. >>> + >>> +  ti,secondary-oldi: >>> +    type: boolean >>> +    description: >>> +      Boolean property to mark the OLDI transmitter as the secondary >>> one, when the >>> +      OLDI hardware is expected to run as a companion HW, in cases of >>> dual-lvds >>> +      mode or clone mode. The primary OLDI hardware is responsible >>> for all the >>> +      hardware configuration. >> >> I think these work, but I'm wondering if we would ever need to check >> something from the main oldi from the secondary oldi. In that case >> "crossed phandles" would be better, i.e. something like: >> >> (in the first oldi:) >> ti,slave-oldi = >> >> (in the second oldi:) >> ti,master-oldi = > > When I had first designed the code and the devicetree for OLDI, it was > done so with the belief that we wouldn't reqiure a bridge instance for > the secondary OLDI, at all. > > While that idea holds true for dual-lvds configuration, it doesn't so > for the clone mode configuration. For clone mode, as you pointed out, we > will require a 2nd bridge instance to configure any of the bridges and > panels that come after the 2nd OLDI. > > >> >> Then again, if we ever need that, even with these bindings the driver >> could find the first oldi, but needs to go via the dss's node. > > While it is possible to do it this way, it might not be the cleanest > one. And _if_ there is a ever a DSS in future with more than 2 OLDI > TXes, say 4, then the decipher logic may get too complicated. > > While I cannot think of any case where the secondary OLDI bridge DT > might need to access the primary OLDI bridge at the moment, I wonder if > we should play it safer and have this option anyway. > > Maybe something like this? > > (primary OLDI) > ti,primary-oldi; > ti,companion-oldi = ; > > (secondary OLDI) > ti,secondary-oldi; > ti,companion-oldi = ; How is this different than my proposal, except a bit more verbose? If you're thinking about a 4-OLDI hardware, how would this work there? (but I want to say that even if it's good to plan for the future, we shouldn't plan too much based on imaginary hardware =). Tomi