[PATCH v10 07/13] drm/mipi-dsi: Add helper to find input format

Aradhya Bhatia
2025-02-26T15:53:30Z

Add a helper API that can be used by the DSI hosts to find the required
input bus format for the given output dsi pixel format.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
---
drivers/gpu/drm/drm_mipi_dsi.c | 37 ++++++++++++++++++++++++++++++++++
include/drm/drm_mipi_dsi.h | 1 +
2 files changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 2e148753ea97..58326ccc7c79 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -36,6 +36,8 @@
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_print.h>

+#include <linux/media-bus-format.h>
+
#include <video/mipi_display.h>

/**
@@ -870,6 +872,41 @@ ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
}
EXPORT_SYMBOL(mipi_dsi_generic_read);

+/**
+ * drm_mipi_dsi_get_input_bus_fmt() - Get the required MEDIA_BUS_FMT_* based
+ * input pixel format for a given DSI output
+ * pixel format
+ * @dsi_format: pixel format that a DSI host needs to output
+ *
+ * Various DSI hosts can use this function during their
+ * &drm_bridge_funcs.atomic_get_input_bus_fmts operation to ascertain
+ * the MEDIA_BUS_FMT_* pixel format required as input.
+ *
+ * RETURNS:
+ * a 32-bit MEDIA_BUS_FMT_* value on success or 0 in case of failure.
+ */
+u32 drm_mipi_dsi_get_input_bus_fmt(enum mipi_dsi_pixel_format dsi_format)
+{
+ switch (dsi_format) {
+ case MIPI_DSI_FMT_RGB888:
+ return MEDIA_BUS_FMT_RGB888_1X24;
+
+ case MIPI_DSI_FMT_RGB666:
+ return MEDIA_BUS_FMT_RGB666_1X24_CPADHI;
+
+ case MIPI_DSI_FMT_RGB666_PACKED:
+ return MEDIA_BUS_FMT_RGB666_1X18;
+
+ case MIPI_DSI_FMT_RGB565:
+ return MEDIA_BUS_FMT_RGB565_1X16;
+
+ default:
+ /* Unsupported DSI Format */
+ return 0;
+ }
+}
+EXPORT_SYMBOL(drm_mipi_dsi_get_input_bus_fmt);
+
/**
* mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
* @dsi: DSI peripheral device
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index bd40a443385c..d6796ce9f5ff 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -293,6 +293,7 @@ void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
const void *payload, size_t size);
ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
size_t num_params, void *data, size_t size);
+u32 drm_mipi_dsi_get_input_bus_fmt(enum mipi_dsi_pixel_format dsi_format);

#define mipi_dsi_msleep(ctx, delay) \
do { \
--
2.34.1