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LCD模块加载启动分析_remote-endpoint

作者：Cpp五条 | 2024-03-25 11:04:02

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remote-endpoint

本文主要是基于rk3566/rk3568平台通过LCD uboot 和 设备树 的代码 对 vop - encoder/connector - panel 三者如何建立联系的进行分析。

一、设备树部分

设备树主要是借助remote-endpoint属性来达到选择相应的外设配置。

1、display-subsystem的设备树信息

1）以ports属性指定相应的vop端点

2）以route_dsi0 指定uboot 阶段的logo配置，其中的connect属性指定的vop需与ports的一致。

  1.         display_subsystem: display-subsystem {
  2.                 compatible = "rockchip,display-subsystem";
  3.                 memory-region = <&drm_logo>, <&drm_cubic_lut>;
  4.                 memory-region-names = "drm-logo", "drm-cubic-lut";
  5.                 ports = <&vop_out>;
  6.                 devfreq = <&dmc>;
  7.  
  8.                 route {
  9.                         route_dsi0: route-dsi0 {
  10.                                 status = "okay";
  11.                                 logo,uboot = "logo.bmp";
  12.                                 logo,kernel = "logo_kernel.bmp";
  13.                                 logo,mode = "center";
  14.                                 charge_logo,mode = "center";
  15.                                 connect = <&vp0_out_dsi0>;
  16.                         };
  17.                         route_dsi1: route-dsi1 {
  18.                                 status = "disabled";
  19.                                 logo,uboot = "logo.bmp";
  20.  
  21.                 route {
  22.                         route_dsi0: route-dsi0 {
  23.                                 status = "okay";
  24.                                 logo,uboot = "logo.bmp";
  25.                                 logo,kernel = "logo_kernel.bmp";
  26.                                 logo,mode = "center";
  27.                                 charge_logo,mode = "center";
  28.                                 connect = <&vp0_out_dsi0>;
  29.                         };
  30.               
  31.                 };
  32.         };

2、vop的设备树信息 

1）以ports -> port -> endpoint -> remote-endpoint 的顺序，通过remote-endpoint 属性来指定远端的设备端点

  1.  
  2.         vop: vop@fe040000 {
  3.                 compatible = "rockchip,rk3568-vop";
  4.                 reg = <0x0 0xfe040000 0x0 0x3000>, <0x0 0xfe044000 0x0 0x1000>;
  5.                 reg-names = "regs", "gamma_lut";
  6.                 rockchip,grf = <&grf>;
  7.                 interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
  8.                 clocks = <&cru ACLK_VOP>, <&cru HCLK_VOP>, <&cru DCLK_VOP0>, <&cru DCLK_VOP1>, <&cru DCLK_VOP2>;
  9.                 clock-names = "aclk_vop", "hclk_vop", "dclk_vp0", "dclk_vp1", "dclk_vp2";
  10.                 iommus = <&vop_mmu>;
  11.                 power-domains = <&power RK3568_PD_VO>;
  12.                 status = "okay";
  13.  
  14.                 vop_out: ports {
  15.                         #address-cells = <1>;
  16.                         #size-cells = <0>;
  17.  
  18.                         vp0: port@0 {
  19.                                 #address-cells = <1>;
  20.                                 #size-cells = <0>;
  21.                                 reg = <0>;
  22.  
  23.                                 vp0_out_dsi0: endpoint@0 {
  24.                                         reg = <0>;
  25.                                         remote-endpoint = <&dsi0_in_vp0>;
  26.                                 };
  27.  
  28.                                 vp0_out_dsi1: endpoint@1 {
  29.                                         reg = <1>;
  30.                                         remote-endpoint = <&dsi1_in_vp0>;
  31.                                 };
  32.  
  33.                                 vp0_out_edp: endpoint@2 {
  34.                                         reg = <2>;
  35.                                         remote-endpoint = <&edp_in_vp0>;
  36.                                 };
  37.  
  38.                                 vp0_out_hdmi: endpoint@3 {
  39.                                         reg = <3>;
  40.                                         remote-endpoint = <&hdmi_in_vp0>;
  41.                                 };
  42.                         };
  43.  
  44.                         vp1: port@1 {
  45.                                 #address-cells = <1>;
  46.                                 #size-cells = <0>;
  47.                                 reg = <1>;
  48.  
  49.                                 vp1_out_dsi0: endpoint@0 {
  50.                                         reg = <0>;
  51.                                         remote-endpoint = <&dsi0_in_vp1>;
  52.                                 };
  53.  
  54.                                 vp1_out_dsi1: endpoint@1 {
  55.                                         reg = <1>;
  56.                                         remote-endpoint = <&dsi1_in_vp1>;
  57.                                 };
  58.  
  59.                                 vp1_out_edp: endpoint@2 {
  60.                                         reg = <2>;
  61.  
  62.                         vp1: port@1 {
  63.                                 #address-cells = <1>;
  64.                                 #size-cells = <0>;
  65.                                 reg = <1>;
  66.  
  67.                                 vp1_out_dsi0: endpoint@0 {
  68.                                         reg = <0>;
  69.                                         remote-endpoint = <&dsi0_in_vp1>;
  70.                                 };
  71.  
  72.                                 vp1_out_dsi1: endpoint@1 {
  73.                                         reg = <1>;
  74.                                         remote-endpoint = <&dsi1_in_vp1>;
  75.                                 };
  76.  
  77.                                 vp1_out_edp: endpoint@2 {
  78.                                         reg = <2>;
  79.                                         remote-endpoint = <&edp_in_vp1>;
  80.                                 };
  81.  
  82.                                 vp1_out_hdmi: endpoint@3 {
  83.                                         reg = <3>;
  84.                                         remote-endpoint = <&hdmi_in_vp1>;
  85.                                 };
  86.  
  87.                                 vp1_out_lvds: endpoint@4 {
  88.                                         reg = <4>;
  89.                                         remote-endpoint = <&lvds_in_vp1>;
  90.                                 };
  91.                         };
  92.  
  93.                         vp2: port@2 {
  94.                                 #address-cells = <1>;
  95.                                 #size-cells = <0>;
  96.  
  97.                                 reg = <2>;
  98.  
  99.                                 vp2_out_lvds: endpoint@0 {
  100.                                         reg = <0>;
  101.                                         remote-endpoint = <&lvds_in_vp2>;
  102.                                 };
  103.  
  104.                                 vp2_out_rgb: endpoint@1 {
  105.                                         reg = <1>;
  106.                                         remote-endpoint = <&rgb_in_vp2>;
  107.                                 };
  108.                         };
  109.                 };
  110.         };

3、dsi的设备树信息

1）dsi -> ports -> port dsi0_in_vp0(endpoint) 下的remote-endpoint 为dsi与vop间建立关系的属性配置，其中dsi作为输入端，另一端接的是vop out端。

2）dsi -> ports -> port -> dsi_out_panel1/dsi_out_panel2/dsi_out_panel3(endpoint)下的remote-endpoint 为dsi 与 panel 间建立关系的属性配置。此处代表有三个panel。因此 若想多屏可以在此处增加节点达到和新panel建立联系。

3）dsi->panel 为panel的配置。正常是单独创建个屏dtsi文件后，在文件中引用（&dsi0) 来进行新增屏。此处只是为了更好的分析而集成在一起（本身设备树在编译的时候也是覆盖的操作）。

4）dsi -> panel -> ports -> port -> panel1_in_dsi(endpoint) 下的remote-endpoint 为panel与dsi间的关系，即此处是连到dsi_out_panel1上。

  1. dsi0: dsi@fe060000 {
  2.                 compatible = "rockchip,rk3568-mipi-dsi";
  3.                 reg = <0x0 0xfe060000 0x0 0x10000>;
  4.                 interrupts = <GIC_SPI 68 IRQ_TYPE_LEVEL_HIGH>;
  5.                 clocks = <&cru PCLK_DSITX_0>, <&cru HCLK_VO>, <&video_phy0>;
  6.                 clock-names = "pclk", "hclk", "hs_clk";
  7.                 resets = <&cru SRST_P_DSITX_0>;
  8.                 reset-names = "apb";
  9.                 phys = <&video_phy0>;
  10.                 phy-names = "mipi_dphy";
  11.                 power-domains = <&power RK3568_PD_VO>;
  12.                 rockchip,grf = <&grf>;
  13.                 #address-cells = <1>;
  14.                 #size-cells = <0>;
  15.                 status = "okay";
  16.  
  17.                 ports {
  18.                         #address-cells = <1>;
  19.                         #size-cells = <0>;
  20.  
  21.                         dsi0_in: port@0 {
  22.                                 reg = <0>;
  23.                                 #address-cells = <1>;
  24.                                 #size-cells = <0>;
  25.  
  26.                                 dsi0_in_vp0: endpoint@0 {
  27.                                         reg = <0>;
  28.                                         remote-endpoint = <&vp0_out_dsi0>;
  29.                                         status = "okay";
  30.                                 };
  31.  
  32.                         };
  33. 					   port@1 {
  34. 								reg = <1>;
  35. 								dsi_out_panel1: endpoint {
  36. 										remote-endpoint = <&panel1_in_dsi>;
  37. 								};
  38. 						};
  39.  
  40. 						port@2 {
  41. 								reg = <2>;
  42. 								dsi_out_panel2: endpoint {
  43. 										remote-endpoint = <&panel2_in_dsi>;
  44. 								};
  45. 						};
  46.  
  47. 						port@3 {
  48. 								reg = <3>;
  49. 								dsi_out_panel3: endpoint {
  50. 										remote-endpoint = <&panel3_in_dsi>;
  51. 								};
  52. 						};
  53.                 };
  54. 				panel@0 {
  55. 						status = "okay";
  56. 						compatible = "simple-panel-dsi";
  57. 						reg = <0>;
  58. 						num = <0>;
  59. 						id = [22];
  60. 						lcd-ic = "st7703";
  61. 						lcd-vendor = "hbs";
  62. 						id-reg = <0xDA>;
  63. 						power-supply = <&vcc3v3_lcd0_n>;
  64. 						reset-gpios = <&gpio3 RK_PD1 GPIO_ACTIVE_LOW>;
  65. 						enable-gpios = <&gpio0 RK_PD5 GPIO_ACTIVE_HIGH>;
  66. 						//backlight = <&backlight>;
  67. 						reset-delay-ms = <60>;
  68. 						enable-delay-ms = <60>;
  69. 						prepare-delay-ms = <60>;
  70. 						unprepare-delay-ms = <60>;
  71. 						disable-delay-ms = <60>;
  72. 						init-delay-ms = <60>;
  73. 						dsi,flags = <(MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
  74. 								MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET)>;
  75. 						dsi,format = <MIPI_DSI_FMT_RGB888>;
  76. 						dsi,lanes  = <4>;
  77. 						panel-init-sequence = [
  78. 								39 00 04 B9 F1 12 83
  79. 								39 00 04 B2 C8 12 30
  80. 							   ...//省略无关代码
  81. 								13 FA 02 11 00
  82. 								13 32 02 29 00
  83. 						];
  84.  
  85. 						panel-exit-sequence = [
  86. 								05 32 01 28
  87. 								05 FA 01 10
  88. 						];
  89.  
  90. 						display-timings {
  91. 								native-mode = <&dsi0_timing0>;
  92. 								dsi0_timing0: timing0 {
  93. 										clock-frequency = <66276000>;
  94. 										hactive = <720>;
  95. 										vactive = <1280>;
  96. 										hfront-porch = <50>;
  97. 										hsync-len = <20>;
  98. 										hback-porch = <50>;
  99. 										vfront-porch = <15>;
  100. 										vsync-len = <5>;
  101. 										vback-porch = <15>;
  102. 										hsync-active = <0>;
  103. 										vsync-active = <0>;
  104. 										de-active = <0>;
  105. 										pixelclk-active = <1>;
  106. 								};
  107. 						};
  108.  
  109. 						ports {
  110. 								#address-cells = <1>;
  111. 								#size-cells = <0>;
  112.  
  113. 								port@0 {
  114. 										reg = <0>;
  115. 										panel1_in_dsi: endpoint {
  116. 												remote-endpoint = <&dsi_out_panel1>;
  117. 										};
  118. 								};
  119. 						};
  120. 				};
  121. 				panel@1 {
  122. 						status = "okay";
  123. 						compatible = "simple-panel-dsi";
  124. 						reg = <0>;
  125. 						num = <1>;
  126. 						id = [15];
  127. 						id-reg = <0xDA>;
  128. 						power-supply = <&vcc3v3_lcd0_n>;
  129. 						reset-gpios = <&gpio3 RK_PD1 GPIO_ACTIVE_LOW>;
  130. 						enable-gpios = <&gpio0 RK_PD5 GPIO_ACTIVE_HIGH>;
  131. 						//backlight = <&backlight>;
  132. 						reset-delay-ms = <60>;
  133. 						enable-delay-ms = <60>;
  134. 						prepare-delay-ms = <60>;
  135. 						unprepare-delay-ms = <60>;
  136. 						disable-delay-ms = <60>;
  137. 						init-delay-ms = <60>;
  138. 						dsi,flags = <(MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
  139. 								MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET)>;
  140. 						dsi,format = <MIPI_DSI_FMT_RGB888>;
  141. 						dsi,lanes  = <4>;
  142. 						panel-init-sequence = [
  143. 								39 00 04 B9 F1 12 83
  144. 								...//省略无关代码
  145. 								39 00 03 C8 10 01
  146. 								13 78 02 11 00
  147. 								13 0A 02 29 00
  148. 						];
  149.  
  150. 						panel-exit-sequence = [
  151. 								05 0A 01 28
  152. 								05 78 01 10
  153. 						];
  154.  
  155. 						display-timings {
  156. 								native-mode = <&dsi0_timing1>;
  157. 								dsi0_timing1: timing0 {
  158. 										clock-frequency = <62640000>;
  159. 										hactive = <720>;
  160. 										vactive = <1280>;
  161. 										hfront-porch = <10>;
  162. 										hsync-len = <25>;
  163. 										hback-porch = <45>;
  164. 										vfront-porch = <10>;
  165. 										vsync-len = <4>;
  166. 										vback-porch = <11>;
  167. 										hsync-active = <0>;
  168. 										vsync-active = <0>;
  169. 										de-active = <0>;
  170. 										pixelclk-active = <1>;
  171. 								};
  172. 						};
  173.  
  174. 						ports {
  175. 								#address-cells = <1>;
  176. 								#size-cells = <0>;
  177.  
  178. 								port@0 {
  179. 										reg = <0>;
  180. 										panel2_in_dsi: endpoint {
  181. 												remote-endpoint = <&dsi_out_panel2>;
  182. 										};
  183. 								};
  184. 						};
  185. 				};
  186. };

 二、uboot部分

uboot部分主要是打算借助uboot上解析设备树部分的代码来进行分析。

1、通过ofnode_for_each_subnode遍历route节点下的子节点，即为route-dsi0。

2、通过route-dsi0 -> connect的属性值来定位到vop上的节点vp0_out_dsi0。

3、找到vop的节点后，通过uclass_get_device_by_ofnode启动vop设备，最终会执行到相应的rockchip_vop_probe函数（正常下，使用U_BOOT_DRIVER只会回调bind函数，而不会执行probe的）。

4、在执行到rockchip_of_find_connector函数时，实际传进的参数为vop节点下的vp0_out_dsi0。

  1. static int rockchip_display_probe(struct udevice *dev)
  2. {
  3. 	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
  4. 	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
  5. 	const void *blob = gd->fdt_blob;
  6. 	
  7. 	//省略无关代码
  8.  
  9. 	route_node = dev_read_subnode(dev, "route");
  10. 	if (!ofnode_valid(route_node))
  11. 		return -ENODEV;
  12.  
  13. 	ofnode_for_each_subnode(node, route_node) {
  14. 		if (!ofnode_is_available(node))
  15. 			continue;
  16. 		phandle = ofnode_read_u32_default(node, "connect", -1);
  17. 		if (phandle < 0) {
  18. 			printf("Warn: can't find connect node's handle\n");
  19. 			continue;
  20. 		}
  21. 		ep_node = of_find_node_by_phandle(phandle);
  22. 		if (!ofnode_valid(np_to_ofnode(ep_node))) {
  23. 			printf("Warn: can't find endpoint node from phandle\n");
  24. 			continue;
  25. 		}
  26. 		port_node = of_get_parent(ep_node);
  27. 		if (!ofnode_valid(np_to_ofnode(port_node))) {
  28. 			printf("Warn: can't find port node from phandle\n");
  29. 			continue;
  30. 		}
  31.  
  32. 		port_parent_node = of_get_parent(port_node);
  33. 		if (!ofnode_valid(np_to_ofnode(port_parent_node))) {
  34. 			printf("Warn: can't find port parent node from phandle\n");
  35. 			continue;
  36. 		}
  37.  
  38. 		is_ports_node = strstr(port_parent_node->full_name, "ports") ? 1 : 0;
  39. 		if (is_ports_node) {
  40. 			vop_node = of_get_parent(port_parent_node);
  41. 			if (!ofnode_valid(np_to_ofnode(vop_node))) {
  42. 				printf("Warn: can't find crtc node from phandle\n");
  43. 				continue;
  44. 			}
  45. 		} else {
  46. 			vop_node = port_parent_node;
  47. 		}
  48.  
  49. 		ret = uclass_get_device_by_ofnode(UCLASS_VIDEO_CRTC,
  50. 						  np_to_ofnode(vop_node),
  51. 						  &crtc_dev);
  52. 		if (ret) {
  53. 			printf("Warn: can't find crtc driver %d\n", ret);
  54. 			continue;
  55. 		}
  56. 		crtc = (struct rockchip_crtc *)dev_get_driver_data(crtc_dev);
  57.  
  58. 		conn_dev = rockchip_of_find_connector(np_to_ofnode(ep_node));
  59. 		if (!conn_dev) {
  60. 			printf("Warn: can't find connect driver\n");
  61. 			continue;
  62. 		}
  63.  
  64. 		conn = (const struct rockchip_connector *)dev_get_driver_data(conn_dev);
  65.  
  66. 		phy = rockchip_of_find_phy(conn_dev);
  67.  
  68. 		bridge = rockchip_of_find_bridge(conn_dev);
  69. 		if (bridge)
  70. 			panel = rockchip_of_find_panel(bridge->dev);
  71. 		else
  72. 			panel = rockchip_of_find_panel(conn_dev);
  73.  
  74. 		s = malloc(sizeof(*s));
  75. 		if (!s)
  76. 			continue;
  77.  
  78. 	return 0;
  79. }

5、 通过子节点获取父节点的操作来定位，因此rockchip_of_find_connector函数下的conn即为dsi0节点，因此再次通过uclass_get_device_by_ofnode来加载dsi设备，即会调用dw_mipi_dsi_probe函数。

  1. static struct udevice *rockchip_of_find_connector(ofnode endpoint)
  2. {
  3. 	ofnode ep, port, ports, conn;
  4. 	uint phandle;
  5. 	struct udevice *dev;
  6. 	int ret;
  7.  
  8. 	if (ofnode_read_u32(endpoint, "remote-endpoint", &phandle))
  9. 		return NULL;
  10.  
  11. 	ep = ofnode_get_by_phandle(phandle);
  12. 	if (!ofnode_valid(ep) || !ofnode_is_available(ep))
  13. 		return NULL;
  14.  
  15. 	port = ofnode_get_parent(ep);
  16. 	if (!ofnode_valid(port))
  17. 		return NULL;
  18.  
  19. 	ports = ofnode_get_parent(port);
  20. 	if (!ofnode_valid(ports))
  21. 		return NULL;
  22.  
  23. 	conn = ofnode_get_parent(ports);
  24. 	if (!ofnode_valid(conn) || !ofnode_is_available(conn))
  25. 		return NULL;
  26.  
  27. 	ret = uclass_get_device_by_ofnode(UCLASS_DISPLAY, conn, &dev);
  28. 	if (ret)
  29. 		return NULL;
  30.  
  31. 	return dev;
  32. }

 6、rockchip_of_find_bridge查找是否存在bridge设备

  1. static struct rockchip_bridge *rockchip_of_find_bridge(struct udevice *conn_dev)
  2. {
  3. 	ofnode node, ports, port, ep;
  4. 	struct udevice *dev;
  5. 	int ret;
  6.  
  7. 	ports = dev_read_subnode(conn_dev, "ports");
  8. 	if (!ofnode_valid(ports))
  9. 		return NULL;
  10.  
  11. 	ofnode_for_each_subnode(port, ports) {
  12. 		u32 reg;
  13.  
  14. 		if (ofnode_read_u32(port, "reg", &reg))
  15. 			continue;
  16.  
  17. 		if (reg != PORT_DIR_OUT)
  18. 			continue;
  19.  
  20. 		ofnode_for_each_subnode(ep, port) {
  21. 			ofnode _ep, _port, _ports;
  22. 			uint phandle;
  23.  
  24. 			if (ofnode_read_u32(ep, "remote-endpoint", &phandle))
  25. 				continue;
  26.  
  27. 			_ep = ofnode_get_by_phandle(phandle);
  28. 			if (!ofnode_valid(_ep))
  29. 				continue;
  30.  
  31. 			_port = ofnode_get_parent(_ep);
  32. 			if (!ofnode_valid(_port))
  33. 				continue;
  34.  
  35. 			_ports = ofnode_get_parent(_port);
  36. 			if (!ofnode_valid(_ports))
  37. 				continue;
  38.  
  39. 			node = ofnode_get_parent(_ports);
  40. 			if (!ofnode_valid(node))
  41. 				continue;
  42.  
  43. 			ret = uclass_get_device_by_ofnode(UCLASS_VIDEO_BRIDGE,
  44. 							  node, &dev);
  45. 			if (!ret)
  46. 				goto found;
  47. 		}
  48. 	}
  49.  
  50. 	return NULL;
  51.  
  52. found:
  53. 	return (struct rockchip_bridge *)dev_get_driver_data(dev);
  54. }

7、在dsi0的节点下，通过ports -> port -> remote-endpoint来找到panel@1/2/3节点下的port 的endpoint节点，再依次通过获取父节点的方式获取到panel的节点，最后通过uclass_get_device_by_ofnode函数启动panel，即执行rockchip_panel_probe回调 

  1. static struct rockchip_panel *rockchip_of_find_panel(struct udevice *dev)
  2. {
  3. 	ofnode panel_node, ports, port, ep, port_parent_node;
  4. 	struct udevice *panel_dev;
  5. 	int ret;
  6.  
  7. 	panel_node = dev_read_subnode(dev, "panel");
  8. 	if (ofnode_valid(panel_node) && ofnode_is_available(panel_node)) {
  9. 		ret = uclass_get_device_by_ofnode(UCLASS_PANEL, panel_node,
  10. 						  &panel_dev);
  11. 		if (!ret)
  12. 			goto found;
  13. 	}
  14.  
  15. 	ports = dev_read_subnode(dev, "ports");
  16. 	if (!ofnode_valid(ports))
  17. 		return NULL;
  18.  
  19. 	ofnode_for_each_subnode(port, ports) {
  20. 		u32 reg;
  21.  
  22. 		if (ofnode_read_u32(port, "reg", &reg))
  23. 			continue;
  24.  
  25. 		if (reg != PORT_DIR_OUT)
  26. 			continue;
  27.  
  28. 		ofnode_for_each_subnode(ep, port) {
  29. 			ofnode _ep, _port;
  30. 			uint phandle;
  31. 			bool is_ports_node = false;
  32.  
  33. 			if (ofnode_read_u32(ep, "remote-endpoint", &phandle))
  34. 				continue;
  35.  
  36. 			_ep = ofnode_get_by_phandle(phandle);
  37. 			if (!ofnode_valid(_ep))
  38. 				continue;
  39.  
  40. 			_port = ofnode_get_parent(_ep);
  41. 			if (!ofnode_valid(_port))
  42. 				continue;
  43.  
  44. 			port_parent_node = ofnode_get_parent(_port);
  45. 			is_ports_node = strstr(port_parent_node.np->full_name, "ports") ? 1 : 0;
  46. 			if (is_ports_node)
  47. 				panel_node = ofnode_get_parent(port_parent_node);
  48. 			else
  49. 				panel_node = ofnode_get_parent(_port);
  50. 			if (!ofnode_valid(panel_node))
  51. 				continue;
  52.  
  53. 			ret = uclass_get_device_by_ofnode(UCLASS_PANEL,
  54. 							  panel_node,
  55. 							  &panel_dev);
  56. 			if (!ret)
  57. 				goto found;
  58. 		}
  59. 	}
  60.  
  61. 	return NULL;
  62.  
  63. found:
  64. 	return (struct rockchip_panel *)dev_get_driver_data(panel_dev);
  65. }

三、总结

1、由设备树分析可知：在display-subsystem 下通过ports -> port ->endpoint -> remote-endpoint的方式来实现建立vop - dsi - panel 的联系

2、由uboot分析可知：在rockchip_display_probe中先解析对应设备树节点，通过dev_read_subnode、of_find_node_by_phandle、of_get_parent、uclass_get_device_by_xxx（uclass_get_device_by_ofnode）等系列函数去启动vop 、connector(dsi）、panel等设备。

如下：整体的框架

2f2b18c25ede42ea8fa41cf48283be19.png

 注：

1）vop *（video out processor）代表有多个处理器时的情况。

2）panel* 是代表存在多屏情况下的因素。

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