drm/mediatek: dpi: Add bus format negotiation

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 <jitao.shi@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -549,6 +549,80 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	return 0;
 }
 
+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)
+{
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
+	u32 *output_fmts;
+
+	*num_output_fmts = 0;
+
+	if (!dpi->conf->output_fmts) {
+		dev_err(dpi->dev, "output_fmts should not be null\n");
+		return NULL;
+	}
+
+	output_fmts = kcalloc(dpi->conf->num_output_fmts, sizeof(*output_fmts),
+			     GFP_KERNEL);
+	if (!output_fmts)
+		return NULL;
+
+	*num_output_fmts = dpi->conf->num_output_fmts;
+
+	memcpy(output_fmts, dpi->conf->output_fmts,
+	       sizeof(*output_fmts) * dpi->conf->num_output_fmts);
+
+	return output_fmts;
+}
+
+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(1, 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->output_fmt = out_bus_format;
+	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)
 {
@@ -601,6 +675,12 @@ static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
 	.mode_valid = mtk_dpi_bridge_mode_valid,
 	.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)
@@ -647,11 +727,6 @@ 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: