自定义修改RK系列嵌入式板子uboot命令行界面分辨率

迷南。 2023-06-19 11:22 43阅读 0赞

kernel/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c 作如下修改：
    static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
    {
    	struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
    					     connector);
    	struct edid *edid;
    	struct drm_display_mode *mode;
    	//const u8 def_modes[6] = {4, 16, 31, 19, 17, 2};
        //此处修改为自己要固定的分辨率vic。分辨率的结构体数组定义为在kernel/drivers/gpu/drm/drm_edid.c中定义的edid_cea_modes[]数组。
    	const u8 def_modes[1] = {1};
    	struct drm_display_info *info = &connector->display_info;
    	struct hdr_static_metadata *metedata =
    			&connector->display_info.hdmi.hdr_panel_metadata;
    	int i, ret = 0;
    
    	if (!hdmi->ddc)
    		return 0;
    
    	edid = drm_get_edid(connector, hdmi->ddc);
    	//if (edid) {
        //直接将该处的edid注释，改成if(0)。执行else中的固定分辨率程序。
    	if(0){
    		dev_dbg(hdmi->dev, "got edid: width[%d] x height[%d]\n",
    			edid->width_cm, edid->height_cm);
    
    		hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid);
    		hdmi->sink_has_audio = drm_detect_monitor_audio(edid);
    		drm_mode_connector_update_edid_property(connector, edid);
    		cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier, edid);
    		ret = drm_add_edid_modes(connector, edid);
    		/* Store the ELD */
    		drm_edid_to_eld(connector, edid);
    		drm_mode_connector_update_hdr_property(connector, metedata);
    		kfree(edid);
    	} else {
    		hdmi->sink_is_hdmi = true;
    		hdmi->sink_has_audio = true;
    		for (i = 0; i < sizeof(def_modes); i++) {
    			mode = drm_display_mode_from_vic_index(connector,
    							       def_modes,
    							       31, i);
    			if (mode) {
    				if (!i)
    					mode->type = DRM_MODE_TYPE_PREFERRED;
    				drm_mode_probed_add(connector, mode);
    				ret++;
    			}
    		}
    		info->edid_hdmi_dc_modes = 0;
    		info->hdmi.y420_dc_modes = 0;
    		info->color_formats = 0;
    
    		dev_info(hdmi->dev, "failed to get edid\n");
    	}
    
    	return ret;
    }

kernel/drivers/gpu/drm/drm_edid.c 文件定义如下：
    /*
     * Probably taken from CEA-861 spec.
     * This table is converted from xorg's hw/xfree86/modes/xf86EdidModes.c.
     *
     * Index using the VIC.
     */
    static const struct drm_display_mode edid_cea_modes[] = {
    	/* 0 - dummy, VICs start at 1 */
    	{ },
    	/* 1 - 640x480@60Hz */
    	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 25175, 640, 656,
    		   752, 800, 0, 480, 490, 492, 525, 0,
    		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
    	  .vrefresh = 60, .picture_aspect_ratio = HDMI_PICTURE_ASPECT_4_3, },
    	/* 2 - 720x480@60Hz */
    	{ DRM_MODE("720x480", DRM_MODE_TYPE_DRIVER, 27000, 720, 736,
    		   798, 858, 0, 480, 489, 495, 525, 0,
    		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
    	  .vrefresh = 60, .picture_aspect_ratio = HDMI_PICTURE_ASPECT_4_3, },

即可改为640X480分辨率