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 BDA7144F546; Thu, 1 Oct 2026 06:28:34 +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=1790836116; cv=none; b=L0DgW5SyagxJpvyuJu2409+BWyLfhRPNVDUQi1hqeXs93mP1Z90YDt2O4KMf/HmPBVzi7G7mBiRMFSpvpsr93igLdhWRqlB0Yh/HFhVflkDR/jEfFlS8wjNMdXnJkaM5fR5Qcodnu8A+8hOtDc4o6lE8kAUnO3HQpnI5nyjxOL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790836116; c=relaxed/simple; bh=xxXb3SKpnFWn8+on/9SBePs9fDpfk4ahxd5ZkwYMgzo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HMplqy394vyJjn9bcstdYPfTFwvF3ULUt7rDEpkEC9TYChfGN7BGP2Q7YB7V6v9ghLN9QxCFF2pziMPEQcbYVRs0FjN9aYECQcctwsxm9zEFTI/VcnM5AhPriB1Kv6l0CHcmF94A9HPsJAxOK9Hjz/PaAuDrtfUJJLs+8FgR1X0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UXNChz04; 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="UXNChz04" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33C551F000FF; Thu, 1 Oct 2026 06:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790836114; bh=v4A8AWeG5UdU3l+v/s+Hlf/e4vUv52p2AFz1neNQlEI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UXNChz04yFGja/nd3GqEHe8ekEic4stbjx0l28h3p1fHwXm90tQViFBPRGj3vhrHW IZUnW4fQ/t1cozDnOxtCIuM5OwVo69TXLicUDtY95TZX2dwef4lLD4dzY84oLZGV0N D3i0mvKk+Stv47KaH43R/mZ0bWT7+LpjQKAz7iksd7JGgPUkPLg+i7mv7XaZ67BiuI GW4YYb+4T4rG7cW+2pYI20n0fWOIhVBvOvp9zoqpeMLlqKfP0W9Ble+qH2+Ie/PxEM Syp35LaLKP6P1/WhPWaAExx8Q0C7aJyyozN/kbQmueeRDVrYJ1nisN8F+2r+Z+Dvkd abOrBQhcJL44A== Date: Thu, 1 Oct 2026 08:28:30 +0200 From: Krzysztof Kozlowski To: Devarsh Thakkar Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Nishanth Menon , Vignesh Raghavendra , Tero Kristo , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 02/14] dt-bindings: display: Add Solomon SSD16xx e-paper controller binding Message-ID: <20261001-neon-dazzling-urchin-46b103@quoll> References: <20260927182329.4193961-1-devarsht@ti.com> <20260927182329.4193961-3-devarsht@ti.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260927182329.4193961-3-devarsht@ti.com> On Sun, Sep 27, 2026 at 11:53:17PM +0530, Devarsh Thakkar wrote: > Add device tree binding for the Solomon Systech SSD16xx family of e-Paper > display controllers (SSD1683 [1], SSD1673 [3], SSD1680 [4], SSD1681 [5]). > A nit, subject: drop second/last, redundant "binding". The "dt-bindings" prefix is already stating that these are bindings. See also: https://elixir.bootlin.com/linux/v7.1-rc7/source/Documentation/devicetree/bindings/submitting-patches.rst#L23 > The binding covers the 4-wire SPI interface with required GPIO pins for > reset (active-low), busy status (active-high), and data/command selection. > The spi-max-frequency is capped at 20 MHz per the SSD1683 datasheet [1] > which is also the maximum supported frequency amongst the family. > > An optional rotation property allows static display orientation to be > configured from device tree. > > The data/command selection GPIO pin is also kept as optional since various > SSD16XX controllers such as SSD1683 [1] support 3-wire mode too with > data/command selection bit transmitted as first bit before sending the data > sequence. > > The first supported compatible is for Gooddisplay GDEY042T81 which is 4.2", > 400x300 resolution black/white e-paper display using SSD1683 controller. > > Links: > [1] : https://www.crystalfontz.com/controllers/SolomonSystech/SSD1683 > [2] : https://files.seeedstudio.com/wiki/Other_Display/42-epaper/GDEY042T81.pdf > [3] : https://www.crystalfontz.com/controllers/SolomonSystech/SSD1673 > [4] : https://www.crystalfontz.com/controllers/SolomonSystech/SSD1680 > [5] : https://www.crystalfontz.com/controllers/SolomonSystech/SSD1681 > > Signed-off-by: Devarsh Thakkar > --- > Changes from v1: > - Added fallback compatible for the controller > - Wrap lines to 80 > > .../bindings/display/solomon,ssd16xx.yaml | 87 +++++++++++++++++++ > 1 file changed, 87 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/solomon,ssd16xx.yaml > > diff --git a/Documentation/devicetree/bindings/display/solomon,ssd16xx.yaml b/Documentation/devicetree/bindings/display/solomon,ssd16xx.yaml > new file mode 100644 > index 000000000000..b31fb862de04 > --- /dev/null > +++ b/Documentation/devicetree/bindings/display/solomon,ssd16xx.yaml Filename must match compatible. > @@ -0,0 +1,87 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/display/solomon,ssd16xx.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Solomon Systech SSD16xx controller based e-paper display panels > + > +maintainers: > + - Devarsh Thakkar > + > +description: > + The SSD16xx family includes e-paper display controllers (SSD1673, > + SSD1680, SSD1681, SSD1683, SSD1677) with integrated gate driver, > + source driver and timing controller. Different panels use these > + controllers in monochrome or 3-color (black/white/red) configurations. > + The controller uses a 4-wire SPI interface and requires GPIO pins for > + reset, busy status, and data/command control. A 3-wire mode is also > + available where the D/C bit is transmitted along the SPI data line > + before each byte. > + > +allOf: > + - $ref: /schemas/spi/spi-peripheral-props.yaml# > + > +properties: > + compatible: > + items: > + - enum: > + # Good Display 4.2" 400x300 monochrome e-ink panel > + - gooddisplay,gdey042t81 > + - enum: No, fallback cannot be enumeration. > + - solomon,ssd1683 > + > + reg: > + maxItems: 1 > + > + spi-max-frequency: > + maximum: 20000000 > + > + reset-gpios: > + maxItems: 1 > + description: > + GPIO connected to the RSTB (reset) pin. Active low. > + > + busy-gpios: > + maxItems: 1 > + description: > + GPIO connected to the BUSY pin. Active high when the controller > + is busy updating the display. > + > + dc-gpios: > + maxItems: 1 > + description: > + GPIO connected to the D/C (Data/Command) pin. Low for command, > + high for data. > + > + rotation: > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 90, 180, 270] > + description: > + Display rotation in degrees clockwise. > + Is this display controller or panel? If panel, then missing ref to panel-common. If display controller, then description is misleading. Best regards, Krzysztof