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 8BC1337E5D9; Fri, 16 Oct 2026 14:01:16 +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=1792159277; cv=none; b=Vk8RvUonzi0HkMQAdBzfVz4VPWGseeRzFetcYAFYpYL7PcYmDcEpx4TZs+NqsD1gDkkVXcAs1inYLPHnatW7Gco1kyalOD0+3SwsER6/Rjd8aHLDnWhS0p/X/su49SC34t9JWoMX4yRkpqt5E3daESq7WG3OPgIju55KBKLAhyM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792159277; c=relaxed/simple; bh=viXaTih9Z0Pr9/NCQaLyjxzbebUIIqMsvwdk1stm+Kg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F02ro3n5/S1cRYb/GLN7bEYjvRDVqdE8bZNzGYsHfeWrQ8bFljpFAapvlUF/I3YuB8fOGqphhxYJZeHafEfaKxR2zBbGM7ilvaCCy+DQZieniX6ZwgZS9lThhL2t0lqGZD7oSD542+DOYSUgVX991oT8lsD1VrcQTqx33BGs3iI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HZkt9gnO; 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="HZkt9gnO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12F121F000C4; Fri, 16 Oct 2026 14:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792159276; bh=MXys7ckdfZsaSqIv9WG3c/zyDXcn3l1gqjz0lpcesqU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HZkt9gnOetdK3cwJqZfyf/TaDWY69f6OurRre/WUGRspavzKJHxiM/DA5SgOexPGZ QRM4nwBBkDe3HPz4PednxZVmccKXPcMmcWatazO0SKDJDa37pAdak66NbQF9qef0Gp yAYJXMbhivsxdxsLds6zAp+mpjn3GRmPgcnNO5gac331CmQc+6oawJiflBx2SB0HE+ 1plY9j94/R430Bpu1i86kczeeRrqHuWJ2xQgnmN9rq8jxFkZn/kV/q4FI4QhnA2E0j HpTDYraqKa0RFdHemRUoFCYHwKgOrMevxLyB4fhP03tZTli8/Hpvv6p27NSZwNkyZv Pj6kQhag62uWg== Date: Fri, 16 Oct 2026 09:01:15 -0500 From: Rob Herring To: Jason Yang Cc: Vinod Koul , Neil Armstrong , Manivannan Sadhasivam , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Guochun Huang , Philipp Zabel , Michael Riesch , Sebastian Reichel , Bryan O'Donoghue , linux-phy@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 2/8] dt-bindings: phy: rockchip,rk3588-mipi-dcphy: Add a cell to select TX or RX Message-ID: <20261016140115.GA1798470-robh@kernel.org> References: <20261016-dcphy-rx-v1-v5-0-e63b49eabe2d@gmail.com> <20261016-dcphy-rx-v1-v5-2-e63b49eabe2d@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20261016-dcphy-rx-v1-v5-2-e63b49eabe2d@gmail.com> On Fri, Oct 16, 2026 at 04:56:36PM +0800, Jason Yang wrote: > The Samsung MIPI D-/C-PHY block on RK3588 and RK3576 has a transmitter > for DSI and a receiver for CSI-2, and two consumers can use them at the > same time. The single cell of this binding selects the mode and refers > to the transmitter, so the receiver cannot be described. > > Allow a second cell that selects the transmitter or the receiver. With > D-PHY: > > /* the MIPI DSI host, driving the transmitter */ > phys = <&mipidcphy0 PHY_TYPE_DPHY PHY_DIRECTION_TX>; > > /* the MIPI CSI-2 host, driving the receiver */ > phys = <&mipidcphy0 PHY_TYPE_DPHY PHY_DIRECTION_RX>; > > and with C-PHY: > > phys = <&mipidcphy0 PHY_TYPE_CPHY PHY_DIRECTION_TX>; > phys = <&mipidcphy0 PHY_TYPE_CPHY PHY_DIRECTION_RX>; > > The transmitter and the receiver cannot operate in different modes [1], > so the first cell must match in both consumers. > > Two cells describe the receiver as well. A single cell keeps referring > to the transmitter, so existing device trees are unaffected. > > [1] RK3588 TRM: section 22.1 (overview): "The TX and RX only support > operate in the same PHY mode." The problem here is this is an ABI break. An existing OS will not know what to do with 2 cells. Perhaps adding flags to the upper bits of the existing cell would work. Rob