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authorJohannes Zink <j.zink@pengutronix.de>2023-09-29 15:33:33 +0300
committerNeil Armstrong <neil.armstrong@linaro.org>2023-10-09 12:10:05 +0300
commit1cd3ea3e4b124120dbdff3faf00a71c8fc6f6402 (patch)
treed7be077e5394269f7807e344ab7b90fdf1eb3009 /drivers/gpu/drm/panel
parent66b66c97f4074c38b1c53c49625ebdd9a33ba56d (diff)
downloadlinux-1cd3ea3e4b124120dbdff3faf00a71c8fc6f6402.tar.xz
drm/panel-simple: allow LVDS format override
Some panels support multiple LVDS data mapping formats, which can be used e.g. run displays on jeida-18 format when only 3 LVDS lanes are available. Add parsing of an optional data-mapping devicetree property, which also touches up the bits per color to match the bus format. Signed-off-by: Johannes Zink <j.zink@pengutronix.de> Link: https://lore.kernel.org/r/20230523-simplepanel_support_nondefault_datamapping-v5-3-0d7928edafab@pengutronix.de Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20230523-simplepanel_support_nondefault_datamapping-v5-3-0d7928edafab@pengutronix.de
Diffstat (limited to 'drivers/gpu/drm/panel')
-rw-r--r--drivers/gpu/drm/panel/panel-simple.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index bb89e6d047bc..de0b84599e53 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -40,6 +40,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>
+#include <drm/drm_of.h>
/**
* struct panel_desc - Describes a simple panel.
@@ -549,6 +550,51 @@ static void panel_simple_parse_panel_timing_node(struct device *dev,
dev_err(dev, "Reject override mode: No display_timing found\n");
}
+static int panel_simple_override_nondefault_lvds_datamapping(struct device *dev,
+ struct panel_simple *panel)
+{
+ int ret, bpc;
+
+ ret = drm_of_lvds_get_data_mapping(dev->of_node);
+ if (ret < 0) {
+ if (ret == -EINVAL)
+ dev_warn(dev, "Ignore invalid data-mapping property\n");
+
+ /*
+ * Ignore non-existing or malformatted property, fallback to
+ * default data-mapping, and return 0.
+ */
+ return 0;
+ }
+
+ switch (ret) {
+ default:
+ WARN_ON(1);
+ fallthrough;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+ fallthrough;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+ bpc = 8;
+ break;
+ case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+ bpc = 6;
+ }
+
+ if (panel->desc->bpc != bpc || panel->desc->bus_format != ret) {
+ struct panel_desc *override_desc;
+
+ override_desc = devm_kmemdup(dev, panel->desc, sizeof(*panel->desc), GFP_KERNEL);
+ if (!override_desc)
+ return -ENOMEM;
+
+ override_desc->bus_format = ret;
+ override_desc->bpc = bpc;
+ panel->desc = override_desc;
+ }
+
+ return 0;
+}
+
static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
{
struct panel_simple *panel;
@@ -601,6 +647,13 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
panel_simple_parse_panel_timing_node(dev, panel, &dt);
}
+ if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) {
+ /* Optional data-mapping property for overriding bus format */
+ err = panel_simple_override_nondefault_lvds_datamapping(dev, panel);
+ if (err)
+ goto free_ddc;
+ }
+
connector_type = desc->connector_type;
/* Catch common mistakes for panels. */
switch (connector_type) {