Add the atomic_get_output_bus_fmts, atomic_get_input_bus_fmts to negotiate
the possible output and input formats for the current mode and monitor,
and use the negotiated formats in a basic atomic_check callback.

Signed-off-by: Jitao Shi <redacted>
Signed-off-by: Rex-BC Chen <redacted>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 92 ++++++++++++++++++++++++++++--
 1 file changed, 87 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index c548780dd3a5..8822d9448ae8 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -536,6 +536,87 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
        return 0;
 }

+#define MAX_OUTPUT_SEL_FORMATS 2
+
+static u32 *mtk_dpi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
+                                       struct drm_bridge_state *bridge_state,
+                                       struct drm_crtc_state *crtc_state,
+                                       struct drm_connector_state *conn_state,
+                                       unsigned int *num_output_fmts)
+{
+       u32 *output_fmts;
+       struct mtk_dpi *dpi = bridge_to_dpi(bridge);
+
+       *num_output_fmts = 0;
+
+       output_fmts = kcalloc(MAX_OUTPUT_SEL_FORMATS, sizeof(*output_fmts),
+                             GFP_KERNEL);
+       if (!output_fmts)
+               return NULL;
+
+       /* Default 8bit RGB fallback */
+       if (dpi->conf->dual_edge) {
+               output_fmts[0] =  MEDIA_BUS_FMT_RGB888_2X12_LE;
+               output_fmts[1] =  MEDIA_BUS_FMT_RGB888_2X12_BE;
+               *num_output_fmts = 2;

+       } else {
+               output_fmts[0] =  MEDIA_BUS_FMT_RGB888_1X24;
+               *num_output_fmts = 1;
+       }
+
+       return output_fmts;
+}
+
+#define MAX_INPUT_SEL_FORMATS  1
+
+static u32 *mtk_dpi_bridge_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;
+
+       *num_input_fmts = 0;
+
+       input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+                            GFP_KERNEL);
+       if (!input_fmts)
+               return NULL;
+
+       *num_input_fmts = 1;
+       input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+
+       return input_fmts;
+}
+
+static int mtk_dpi_bridge_atomic_check(struct drm_bridge *bridge,
+                                      struct drm_bridge_state *bridge_state,
+                                      struct drm_crtc_state *crtc_state,
+                                      struct drm_connector_state *conn_state)
+{
+       struct mtk_dpi *dpi = bridge->driver_private;
+       unsigned int out_bus_format;
+
+       out_bus_format = bridge_state->output_bus_cfg.format;
+
+       dev_dbg(dpi->dev, "input format 0x%04x, output format 0x%04x\n",
+               bridge_state->input_bus_cfg.format,
+               bridge_state->output_bus_cfg.format);
+
+       dpi->ddr_edge_sel = (out_bus_format == MEDIA_BUS_FMT_RGB888_2X12_LE) ?
+                               true : false;
+
+       dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
+       dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
+       dpi->yc_map = MTK_DPI_OUT_YC_MAP_RGB;
+       dpi->color_format = MTK_DPI_COLOR_FORMAT_RGB;
+
+       return 0;
+}
+
 static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
                                 enum drm_bridge_attach_flags flags)
 {

@@ -574,6 +655,12 @@ static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
        .mode_set = mtk_dpi_bridge_mode_set,
        .disable = mtk_dpi_bridge_disable,
        .enable = mtk_dpi_bridge_enable,
+       .atomic_check = mtk_dpi_bridge_atomic_check,
+       .atomic_get_output_bus_fmts = mtk_dpi_bridge_atomic_get_output_bus_fmts,
+       .atomic_get_input_bus_fmts = mtk_dpi_bridge_atomic_get_input_bus_fmts,
+       .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,
 };

 void mtk_dpi_start(struct device *dev)

@@ -620,11 +707,6 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
        }
        drm_connector_attach_encoder(dpi->connector, &dpi->encoder);

-       dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
-       dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
-       dpi->yc_map = MTK_DPI_OUT_YC_MAP_RGB;
-       dpi->color_format = MTK_DPI_COLOR_FORMAT_RGB;
-
        return 0;

 err_cleanup:
--

2.18.0