From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF76910F7 for ; Mon, 24 Jun 2024 00:36:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.62.61 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719189372; cv=none; b=NbLat6EQB+SMUNv7njcvDYHvJhyyOsL+FWGVQByuhLpk6tbkrhhx991rCwTVt6skVG2hJjZSeqQjoSYt3VULMnWIcB1OYt84Ooo68ePAxCr4b1YsmX5hv6mTP1VxNYott22MzdX8Dp6ZTzuV/vqpu7y5qiLmQap6kSTd9Xhyrzg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719189372; c=relaxed/simple; bh=+9uKrirgTDm14xoslSEdOfQPQN7hq/gesvdzIaFtUq8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KSystZYFtxXbG6AjGGzbDSypG0Jl3MPOjv2v2YJjXjhk388Q1xs3GxyP3VStfft99u0GUusVVbVj8tdIceoJxZNU3FDFd3+XL37HBkpxKdLYVNTRFn3VZXXv+BxA6kaYogEjNrGcs6y9xIortxCkeYZ8qzo8kDe5JnaAYBEWdg4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=h0ZrV/P8; arc=none smtp.client-ip=85.214.62.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="h0ZrV/P8" Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 7576487D10; Mon, 24 Jun 2024 02:36:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1719189368; bh=1yAYvfxQRBFoY9EW6nYWKAvppWHHG5VJGdGF0apBJiw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=h0ZrV/P83vG5sVpgJLbIiGbs+wari06NiXoePhYZMkN6lPe0u7wra2z5qd18Ks0L2 xnvNxCWmy6ZWxwEJfMkckOmMcF0ohbxqWeBgdP8xlh+m1aPhZvq6+jzP52qilPd5vu 5hTWHEhIXAadvKfsjvgT4XIDfgFawMt5xGLLZic3Rp1Bp6N2tb0x1yxrwnkdwM/QW4 XqamWW5dMEpGv5/8ZVPar8ZMAKfl0ANx7ukzTFQufmsIOaen4Ggm9q4uFltRffN3TR kgBhhTF+vnuRuYC5dul0YRMYPlTWSnOzEqN4wdUpcfOUpaydJs+wso1gKIVUJJkXJv 6967jgHgmXqYw== Message-ID: <5190285f-0804-4577-ba6e-580f5d861459@denx.de> Date: Mon, 24 Jun 2024 02:05:27 +0200 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 v2 1/2] dt-bindings: display: bridge: tc358867: Document default DP preemphasis To: Conor Dooley Cc: dri-devel@lists.freedesktop.org, Andrzej Hajda , Conor Dooley , Daniel Vetter , David Airlie , Jernej Skrabec , Jonas Karlman , Krzysztof Kozlowski , Laurent Pinchart , Lucas Stach , Maarten Lankhorst , Maxime Ripard , Neil Armstrong , Rob Herring , Robert Foss , Thomas Zimmermann , devicetree@vger.kernel.org, kernel@dh-electronics.com References: <20240621155430.92894-1-marex@denx.de> <20240622-ruse-stock-2c2b8d0b1cfb@spud> <8d6bc5d3-6a21-4b90-a5f2-74b5597ba3b2@denx.de> <20240623-unadorned-human-deedc8fd4819@spud> Content-Language: en-US From: Marek Vasut In-Reply-To: <20240623-unadorned-human-deedc8fd4819@spud> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean On 6/23/24 7:20 PM, Conor Dooley wrote: > On Sun, Jun 23, 2024 at 04:48:47PM +0200, Marek Vasut wrote: >> On 6/22/24 1:56 PM, Conor Dooley wrote: >>> On Fri, Jun 21, 2024 at 05:53:53PM +0200, Marek Vasut wrote: >>>> Document default DP port preemphasis configurable via new DT property >>>> "toshiba,pre-emphasis". This is useful in case the DP link properties >>>> are known and starting link training from preemphasis setting of 0 dB >>>> is not useful. The preemphasis can be set separately for both DP lanes >>>> in range 0=0dB, 1=3.5dB, 2=6dB . >>>> >>>> Signed-off-by: Marek Vasut >>>> --- >>>> V2: - Fix the type to u8 array >>>> - Fix the enum items to match what they represent >>>> --- >>>> .../display/bridge/toshiba,tc358767.yaml | 18 ++++++++++++++++++ >>>> 1 file changed, 18 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml >>>> index 2ad0cd6dd49e0..6287eb2b40908 100644 >>>> --- a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml >>>> +++ b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml >>>> @@ -98,6 +98,24 @@ properties: >>>> reference to a valid eDP panel input endpoint node. This port is >>>> optional, treated as DP panel if not defined >>>> + properties: >>>> + endpoint: >>>> + $ref: /schemas/media/video-interfaces.yaml# >>>> + unevaluatedProperties: false >>>> + >>>> + properties: >>>> + toshiba,pre-emphasis: >>>> + description: >>>> + Display port output Pre-Emphasis settings for both ports. >>> >>> Why here and not in the port nodes? >> >> There was a short discussion about that in V1: >> >> https://lore.kernel.org/all/00e9ef90-3bbe-4556-8da9-462f65928781@denx.de/ >> >> " >> Let's keep it in the endpoint node. >> >> There is some mention in the TC9595 datasheet that the DP might operate >> in some split mode, where each DP lane is used to feed one display (?), >> so I assume in that case there might be two endpoints (?), but that is >> not supported right now. >> >> If that is ever needed, I guess this array would have minItems 1 and >> maxItems 2 and another endpoint would be added to the schema for this >> port 2. >> " > > Can this be put in the commit message please? Will do. >>>> + $ref: /schemas/types.yaml#/definitions/uint8-array >>>> + minItems: 2 >>>> + maxItems: 2 >>>> + items: >>>> + enum: >>>> + - 0 # No pre-emphasis >>>> + - 1 # 3.5dB pre-emphasis >>>> + - 2 # 6dB pre-emphasis >>> >>> I'd love to say please make this -bB and put this in units, but that'd >>> require it being a string.. >> >> I can do that. Do you think that's worth it ? > > I dunno, I'd advocate for it for any other unit cos I would ask for the > unit to be changed into something that didn't require fractions. But for > decibels, that just going to be confusing given how it works. I think > for dB it's just not worth it. All right then.