Finding the right input bus format throughout the pipeline is hard
so add atomic_get_input_bus_fmts callback and initialize with the
proper input format from list of supported output formats.
This format can be used in pipeline for negotiating bus format between
the DSI-end of this bridge and the other component closer to pipeline
components.
List of Pixel formats are taken from,
AN13573 i.MX 8/RT MIPI DSI/CSI-2, Rev. 0, 21 March 2022
3.7.4 Pixel formats
Table 14. DSI pixel packing formats
Reviewed-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
---
Changes for v12:
- update the logic suggested by Marek
Changes for v11:
- collect RB from Frieder
- drop extra line
Changes for v10:
- none
Changes for v9:
- added MEDIA_BUS_FMT_FIXED
- return MEDIA_BUS_FMT_RGB888_1X24 output_fmt if supported output_fmt
list is unsupported.
- added MEDIA_BUS_FMT_YUYV10_1X20, MEDIA_BUS_FMT_YUYV12_1X24
Changes for v8:
- added pixel formats supported by NXP AN13573 i.MX 8/RT MIPI DSI/CSI-2
Changes for v7 - v4:
- none
Changes for v3:
- include media-bus-format.h
Changes for v2:
- none
Changes for v1:
- new patch
drivers/gpu/drm/exynos/exynos_drm_dsi.c | 62 +++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 5518d92c8455..9459c138d0e0 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -12,6 +12,7 @@
#include <linux/component.h>
#include <linux/gpio/consumer.h>
#include <linux/irq.h>
+#include <linux/media-bus-format.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/phy/phy.h>
@@ -1466,6 +1467,66 @@ static void exynos_dsi_atomic_post_disable(struct drm_bridge *bridge,
pm_runtime_put_sync(dsi->dev);
}
+/*
+ * This pixel output formats list referenced from,
+ * AN13573 i.MX 8/RT MIPI DSI/CSI-2, Rev. 0, 21 March 2022
+ * 3.7.4 Pixel formats
+ * Table 14. DSI pixel packing formats
+ */
+static const u32 exynos_dsi_pixel_output_fmts[] = {
+ MEDIA_BUS_FMT_YUYV10_1X20,
+ MEDIA_BUS_FMT_YUYV12_1X24,
+ MEDIA_BUS_FMT_UYVY8_1X16,
+ MEDIA_BUS_FMT_RGB101010_1X30,
+ MEDIA_BUS_FMT_RGB121212_1X36,
+ MEDIA_BUS_FMT_RGB565_1X16,
+ MEDIA_BUS_FMT_RGB666_1X18,
+ MEDIA_BUS_FMT_RGB888_1X24,
+};
+
+static bool exynos_dsi_pixel_output_fmt_supported(u32 fmt)
+{
+ int i;
+
+ if (fmt == MEDIA_BUS_FMT_FIXED)
+ return false;
+
+ for (i = 0; i < ARRAY_SIZE(exynos_dsi_pixel_output_fmts); i++) {
+ if (exynos_dsi_pixel_output_fmts[i] == fmt)
+ return true;
+ }
+
+ return false;
+}
+
+static u32 *
+exynos_dsi_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts)
+{
+ u32 *input_fmts;
+
+ input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
+ if (!input_fmts)
+ return NULL;
+
+ if (!exynos_dsi_pixel_output_fmt_supported(output_fmt))
+ /*
+ * Some bridge/display drivers are still not able to pass the
+ * correct format, so handle those pipelines by falling back
+ * to the default format till the supported formats finalized.
+ */
+ output_fmt = MEDIA_BUS_FMT_RGB888_1X24;
+
+ input_fmts[0] = output_fmt;
+ *num_input_fmts = 1;
+
+ return input_fmts;
+}
+
static int exynos_dsi_atomic_check(struct drm_bridge *bridge,
struct drm_bridge_state *bridge_state,
struct drm_crtc_state *crtc_state,
@@ -1514,6 +1575,7 @@ static const struct drm_bridge_funcs exynos_dsi_bridge_funcs = {
.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
.atomic_reset = drm_atomic_helper_bridge_reset,
+ .atomic_get_input_bus_fmts = exynos_dsi_atomic_get_input_bus_fmts,
.atomic_check = exynos_dsi_atomic_check,
.atomic_pre_enable = exynos_dsi_atomic_pre_enable,
.atomic_enable = exynos_dsi_atomic_enable,
--
2.25.1
