drm/bridge: synopsys: dw-mipi-dsi: Add mode fixup support

Vendor drivers may need to fixup mode due to pixel clock tree limitation,
so introduce the ->mode_fixup() callcack to struct dw_mipi_dsi_plat_data
and call it at atomic check stage if available.

Signed-off-by: Liu Ying <[e-mail]>
Reviewed-by: Robert Foss <[e-mail]>
Signed-off-by: Robert Foss <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

···
 					   struct drm_crtc_state *crtc_state,
 					   struct drm_connector_state *conn_state)
 {
+	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
+	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
+	bool ret;
+
 	bridge_state->input_bus_cfg.flags =
 		DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+
+	if (pdata->mode_fixup) {
+		ret = pdata->mode_fixup(pdata->priv_data, &crtc_state->mode,
+					&crtc_state->adjusted_mode);
+		if (!ret) {
+			DRM_DEBUG_DRIVER("failed to fixup mode " DRM_MODE_FMT "\n",
+					 DRM_MODE_ARG(&crtc_state->mode));
+			return -EINVAL;
+		}
+	}
 
 	return 0;
 }

include/drm/bridge/dw_mipi_dsi.h

···
 					   unsigned long mode_flags,
 					   u32 lanes, u32 format);
 
+	bool (*mode_fixup)(void *priv_data, const struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+
 	u32 *(*get_input_bus_fmts)(void *priv_data,
 				   struct drm_bridge *bridge,
 				   struct drm_bridge_state *bridge_state,