[PATCH 6/7] drm/vc4: dpi: Change the default DPI format to being 18bpp, not 24.

From: Maxime Ripard <maxime@cerno.tech>
To: Maxime Ripard <mripard@kernel.org>, Eric Anholt <eric@anholt.net>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	Rob Herring <robh@kernel.org>, Emma Anholt <emma@anholt.net>
Cc: dri-devel@lists.freedesktop.org,
	Joerg Quinten <aBUGSworstnightmare@gmail.com>,
	Chris Morgan <macromorgan@hotmail.com>,
	Maxime Ripard <maxime@cerno.tech>,
	Dave Stevenson <dave.stevenson@raspberrypi.com>,
	linux-kernel@vger.kernel.org,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: [PATCH 6/7] drm/vc4: dpi: Change the default DPI format to being 18bpp, not 24.
Date: Thu, 13 Oct 2022 11:56:50 +0200	[thread overview]
Message-ID: <20221013-rpi-dpi-improvements-v1-6-8a7a96949cb0@cerno.tech> (raw)
In-Reply-To: <20221013-rpi-dpi-improvements-v1-0-8a7a96949cb0@cerno.tech>

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

DPI hasn't really been used up until now, so the default has
been meaningless.
In theory we should be able to pass the desired format for the
adjacent bridge chip through, but framework seems to be missing
for that.

As the main device to use DPI is the VGA666 or Adafruit Kippah,
both of which use RGB666, change the default to being RGB666 instead
of RGB888.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_dpi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c
index ecbe4cd87036..fdae02760b6d 100644
--- a/drivers/gpu/drm/vc4/vc4_dpi.c
+++ b/drivers/gpu/drm/vc4/vc4_dpi.c
@@ -150,8 +150,8 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 	}
 	drm_connector_list_iter_end(&conn_iter);
 
-	/* Default to 24bit if no connector or format found. */
-	dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
+	/* Default to 18bit if no connector or format found. */
+	dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, DPI_FORMAT);
 
 	if (connector) {
 		if (connector->display_info.num_bus_formats) {

-- 
b4 0.11.0-dev-7da52
