From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9FD262FE071; Thu, 23 Apr 2026 12:14:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776946450; cv=none; b=nVzWzS0N+Mz+u8ZY8ioaX/d+Fbr7ZL6Tiwxv1yPFc0BsmkxoQh0whSZ7yLIsskooDzecoeci/sKGcXwMw/XbGQKbF673dVjcQB1mRilpimkpM5hrSYgjVkqlrn1oRN3pmX6LcBQcOozExPAp4pCmeMbkBVoJhZit62dPC6Pqg/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776946450; c=relaxed/simple; bh=fwfsOCUr0TcQkp7tEbYBpDWspQA1NJ42HA1HzS41bhE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gyoVXcPJJNp418oFZq+savQbqCjSZwf+1i1RYDShlySr+IvaXiYQ7lbkHoEAPZDs09o3pRu7ltW3B9hJ0msYGkRxI6GhSrywUFPzp48kUdX3EtdtCEkx7ZpqHcOBaKNtZADiNMqxC2eKR+7JaMolm9o1dxUrbI7yRJ5AtWVu4HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Uci2kGEe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Uci2kGEe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCC0DC2BCB4; Thu, 23 Apr 2026 12:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776946450; bh=fwfsOCUr0TcQkp7tEbYBpDWspQA1NJ42HA1HzS41bhE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Uci2kGEeHACqNZt9VivFf/9FMudT22tazrokBtrF/957ZIkHz37JHkiBDbprO/n6o g6fleyuvbpUR1arqjsSJ8rVUu72Q3dWhE1e6MIbiFkjR/Rj/AfwUiD4YW+gwzzg+Pv Z2Y52o3iyfgZZbm54k3br+du44sTX3BKsSQR30vYbUHZjjLy8M1fMJnZrX39IwUw+j bEYnMi/jO2q4GAqosJEJWg9uKg7q4OQxIa2gd5aMulaX2dsZ9iBlQFmzDO+5uxsQhW n+No12ayuMBF8eBZERNyDvmal9mjaA6jE5B2HvpyeWoifJ5tKMXh7RHz3x0w9DdeSJ 5JqA8hwgXWj0Q== Date: Thu, 23 Apr 2026 14:14:07 +0200 From: Maxime Ripard To: Tomi Valkeinen Cc: Dmitry Baryshkov , Dave Stevenson , Neil Armstrong , Jessica Zhang , David Airlie , Simona Vetter , Maarten Lankhorst , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Thierry Reding , Sam Ravnborg , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] drm/panel: simple: Add timings for Raspberry Pi 7" panel Message-ID: <20260423-kickass-fat-boa-209f68@houat> References: <20260420-rpi-7inch-v1-0-e68d5c9c44bc@ideasonboard.com> <20260420-rpi-7inch-v1-2-e68d5c9c44bc@ideasonboard.com> <3z3u5mbngmbzsch3mzs3twlh3aec6r7jokstzv3ghxyusrzt6b@jqvdnuiapx6e> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha384; protocol="application/pgp-signature"; boundary="l42rpwgug4qvdd4g" Content-Disposition: inline In-Reply-To: --l42rpwgug4qvdd4g Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH 2/2] drm/panel: simple: Add timings for Raspberry Pi 7" panel MIME-Version: 1.0 Hi, On Thu, Apr 23, 2026 at 03:01:51PM +0300, Tomi Valkeinen wrote: > On 22/04/2026 22:22, Dmitry Baryshkov wrote: > > On Mon, Apr 20, 2026 at 04:13:36PM +0300, Tomi Valkeinen wrote: > > > Add timings for the panel used in Raspberry Pi 7" DSI Display module: > > > https://www.raspberrypi.com/products/raspberry-pi-touch-display/ > > >=20 > > > This has been tested with version v1.1 of the display module. > > >=20 > > > The panel is very strict about the back-porch values, they must be > > > exactly 46 for hbp and 23 for vbp. Other timings can be defined quite > > > freely. > > >=20 > > > The panel is exclusive to Raspberry Pi, and different versions of the > > > display module can have panels from different vendors which are fully > > > compatible. Also, as the panel vendors are not public, the compatible > > > string used is "raspberrypi,7inch-dsi". > > >=20 > > > Note that while the display module has a DSI connector, and the > > > compatible has "dsi" in it, we use DRM_MODE_CONNECTOR_DPI as the panel > > > itself is a parallel video panel. The display module (as of v1.1) uses > > > TC358762 DSI-to-DPI bridge to do the conversion. > > >=20 > > > We could use DRM_MODE_CONNECTOR_DSI here, which would have the benefit > > > of showing a "DSI-1" connector to the userspace. However, the panel I= S a > > > DPI panel, and gets its input from a DSI-to-DPI bridge, and the > > > panel-simple.c behaves differently depending on the connector type us= ed, > > > so, DRM_MODE_CONNECTOR_DPI it is. > > >=20 > > > Signed-off-by: Tomi Valkeinen > > > --- > > > drivers/gpu/drm/panel/panel-simple.c | 32 +++++++++++++++++++++++++= +++++++ > > > 1 file changed, 32 insertions(+) > > >=20 > > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/p= anel/panel-simple.c > > > index 91ab280869ba..e75eb20301f2 100644 > > > --- a/drivers/gpu/drm/panel/panel-simple.c > > > +++ b/drivers/gpu/drm/panel/panel-simple.c > > > @@ -4208,6 +4208,35 @@ static const struct panel_desc rocktech_rk043f= n48h =3D { > > > .connector_type =3D DRM_MODE_CONNECTOR_DPI, > > > }; > > > +static const struct display_timing raspberrypi_7inch_timing =3D { > > > + .pixelclock =3D { 10000000, 30000000, 50000000 }, > > > + .hactive =3D { 800, 800, 800 }, > > > + .hfront_porch =3D { 16, 72, 354 }, > > > + .hsync_len =3D { 1, 32, 40 }, > > > + .hback_porch =3D { 46, 46, 46 }, > > > + .vactive =3D { 480, 480, 480 }, > > > + .vfront_porch =3D { 7, 21, 147 }, > > > + .vsync_len =3D { 1, 2, 20 }, > > > + .vback_porch =3D { 23, 23, 23 }, > > > + .flags =3D DISPLAY_FLAGS_VSYNC_HIGH | DISPLAY_FLAGS_HSYNC_HIGH, > > > + /* Note: the rest of the flags are defined below in bus_flags */ > > > +}; > >=20 > > This looks pretty close to powertip panels that have been used before > > hand in those modules. Are you sure that powertip,ph800480t013-idf02 > > or powertip,ph800480t032-zhc19 don't work for you? >=20 > I haven't tested those, but the hbp and vbp do not seem to be the same. F= or > me, they had to be exactly as they are here. This was also confirmed from > Raspberry Pi, the panel datasheet had min/typ/max values (i.e. not ranges) > of 46 and 23 for back porches. >=20 > Where did the information come from that powertip,ph800480t013-idf02 or > powertip,ph800480t032-zhc19 are used in the display modules? Or did you m= ean > that while those models are not used in the Raspberry display module, peo= ple > have used them successfully? It also looks like we have panel-raspberrypi-touchscreen.c and raspberrypi,= dsi-7inch in panel-ilitek-ili9881c.c. There's clearly more than one "7-inch rpi panel" so clarifying how it compares to the other two drivers would help. Maxime --l42rpwgug4qvdd4g Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJUEABMJAB0WIQTkHFbLp4ejekA/qfgnX84Zoj2+dgUCaeoNCgAKCRAnX84Zoj2+ dhsWAX9AHrU2W2fFm/uveFasTWet7GE1drDNeX7LmFmoHRFj3yuOcmq0yX3kwvt3 AMZFopwBgIzJ95+EcE5i5ONE+nfqbyrDhIBSmdkZLMzc0si4yQtmVS/s4235D7SS dYCczWlFyQ== =03EF -----END PGP SIGNATURE----- --l42rpwgug4qvdd4g--