From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (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 ADE5B2E6CBC; Fri, 7 Nov 2025 15:11:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762528299; cv=none; b=cjjWZlr8SV2rG2KzdO96grxPgm/5lFrsx/mBQ4j1W9reqrOeyUWC0mk/N9rjn+vIoXVO0RRLLmh+oLgyf9qQh26QFiXbbm3JHO+JojUzqZgOXtHViXPAXJkN+0hJKhgLw3LtQNJRSMGXvryHvmljEOcpboWVatX9Njn6vRc7mtI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762528299; c=relaxed/simple; bh=yJlWwZ3a12j7omKvOIsqDNOsBjKnkPkdtmc70OuHjRQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rhuUxhGlELHUK90jbXRzE7bvDJdkcjXJL7Rhcerxj0XcL3PPb+aoulSk5na+c81aI52v3foBEXD4Pey2Ixh+gPTQ0v/vpmXC1o0PLPX/XncDMKkzeNKS0LiPDWixO4q5LCxtjfmoGgWOgo2fU2GM7JkomAb9SwxTPV5l7leEl44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=cJZE8GZg; arc=none smtp.client-ip=80.241.56.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="cJZE8GZg" Received: from smtp2.mailbox.org (smtp2.mailbox.org [10.196.197.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4d32Zg6GRGz9tNR; Fri, 7 Nov 2025 16:11:23 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1762528284; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Vy+NNLP394OwYxNRijQPvvDO7IMwiwg8RBHcds0M8FQ=; b=cJZE8GZg+N198UtZfYrAVmdKAtJBrrVVkioaD4ZOc9/TDy1z63PTOeAv6j+SNs8/bPzYC9 JOs9bWu2tpIO6uuFgG6AKrXOPYr5cteqWw+aGCwS2s2/qWM3CU7j1k1wkKJXuRv2yIGHhU DK4p0zb8zrtlKhxpafKd6RV9/K4EEpYV/ahYx5idiMrpFIddLaL+V5Q3V+Cc1RhUz4jGl/ E/AaRx5C1kIUJU1pS9Nn8HcZujIGvbsObt1nkRrcFHviOZLerSOkKniqitprQbzSq/oEDb uS0DAVnEXSiH0xp/lumQsu6fIDy2GC3b8MMUDf+FwXsA4/0CnqCC1cLaUd6dbg== Message-ID: Date: Fri, 7 Nov 2025 16:11:15 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2 2/2] drm/bridge: add support for lontium lt9211c bridge To: Nilesh Laad Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Marek Vasut , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, venkata.valluru@oss.qualcomm.com, jessica.zhang@oss.qualcomm.com, Yi Zhang , Gopi Botlagunta References: <20251107-add-lt9211c-bridge-v2-0-b0616e23407c@oss.qualcomm.com> <20251107-add-lt9211c-bridge-v2-2-b0616e23407c@oss.qualcomm.com> <30b5f19b-1ce9-4239-bf0a-d83d647608ce@mailbox.org> Content-Language: en-US From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-MBO-RS-ID: f902cdf5302f7a21187 X-MBO-RS-META: ii1978emft34czfyu9hytrgg97y7df3e On 11/7/25 2:52 PM, Nilesh Laad wrote: > On Fri, Nov 07, 2025 at 02:20:58PM +0100, Marek Vasut wrote: >> On 11/7/25 2:02 PM, Nilesh Laad wrote: >>> From: Yi Zhang >>> >>> LT9211c is a Single/Dual-Link DSI/LVDS or Single DPI input to >>> Single-link/Dual-Link DSI/LVDS or Single DPI output bridge chip. >>> Add support for DSI to LVDS bridge configuration. >> How does this differ from existing drivers/gpu/drm/bridge/lontium-lt9211.c ? >> Can existing lt9211 driver be extended instead ? If not, why ? Details >> please ... > LT9211 and LT9211C differ completely in register programming sequences. > Even lontium mentioned that register configuration are different for lt9211 and lt9211c. Lontium seems to often suggest, that users should use their provided register patches without thinking about the content at all. Do you have access to the register documentation, and can you compare LT9211 and LT9211C register layout? Are they identical or do they differ? > Nearly every function would require duplicated logic with if (chip_type) branching, > as register sequence are completely different. > Having both sequences in single file is not looking good, hence want to merge as separate driver. Can we somehow use regmap_register_patch() and register patches in driver data to avoid duplication ? -- Best regards, Marek Vasut