全志8916平台MIPI_LCD调试方法

LCD的MIPI命令格式

在litter kernel中和kernel中的MIPI命令格式稍有不同。
1、LK短包格式

寄存器地址	寄存器值	参数个数	结束标志（固定）
0x11	0x00	0x05	0x80

2、LK长包格式

数据个数（2个）	补位	表示可以多个参数	标志（固定）
0x02	0x00	0x39	0xC0
寄存器地址	寄存器值	补齐	补齐
0x36	0x08	0xFF	0xFF

长包和短包的数据个数都为4的倍数。

3、kernel短包

表示0个参数	固定	固定	固定	延时（ms）	延时（ms）	数据长度	地址	无参数补零
0x05	0x01	0x00	0x00	0x11	0x00	0x02	0x11	0x00

4、kernel长包

可多个参数	固定	固定	固定	延时（ms）	延时（ms）	数据长度	地址	参数值
0x39	0x01	0x00	0x00	0x11	0x00	0x02	0x36	0x08

代码修改

全志平台的LK和kernel会读取同一份LCD初始化代码，只需要在
/loong/chips/msm8916/devices/c10/config.dtsi b/loong/chips/msm8916/devices/c10/config.dtsi
/loong/chips/msm8916/devices/c10/panel-video.dtsi b/loong/chips/msm8916/devices/c10/panel-video.dtsi中
添加对应的LCD配置参数即可。
LK运行时会有一个选屏过程在文件
/bootable/bootloader/lk/target/msm8916/oem_panel.c b/bootable/bootloader/lk/target/msm8916/oem_panel.c

void oem_panel_adaptive(void *fdt)
{ 
...
		switch(auto_pan_loop)
			{
			case 0:
		//NH2
		gpio_val3=0;       //4个gpio用于选择屏幕
		gpio_val2=0;
		gpio_val1=1;
		gpio_val0=1;
		break;
		    case 1:
			//帝晶
		gpio_val3=0;
		gpio_val2=0;
		gpio_val1=1;
		gpio_val0=0;
		break;
		    case 2:
			//普耐 
		gpio_val3=1;
		gpio_val2=0;
		gpio_val1=1;
		gpio_val0=0;
		break;
		default:
			break;
			}
		sprintf(pars_name, "qcom,dsi-pref-prim-str-%d%d%d%d", gpio_val3, gpio_val2, gpio_val1, gpio_val0);
		sprintf(lcd_selet_gpios, "%d%d%d%d\0", gpio_val3, gpio_val2, gpio_val1, gpio_val0);
		dprintf(CRITICAL, "jiyh lcd_selet_gpios = %s ==============================\n", lcd_selet_gpios);
		auto_pan_loop++;
	}
		sprintf(PANEL_DEVICE_PATH, "/soc/qcom,mdss_mdp@1a00000/");

	/*find the node name*/
	ret = parse_panel_node_name(fdt, pars_name, node_name);
	if(!ret)
		strcat(PANEL_DEVICE_PATH, node_name);
	else
		strcat(PANEL_DEVICE_PATH, "mdss_dsi_video");
	
	dprintf(INFO,"pars_name = %s, node_name = %s, PANEL_DEVICE_PATH=%s\n", 
		pars_name, node_name, PANEL_DEVICE_PATH);
}

此段代码会遍历每种屏幕，并根据gpio值设置屏幕ID值pinfo->mipi.signature

int oem_panel_parse_dt(void *fdt,  struct panel_struct *panelstruct,
			struct msm_panel_info *pinfo,
			struct mdss_dsi_phy_ctrl *phy_db)
{
     ...
    	if(strcmp(lcd_selet_gpios,"1110")==0)
	pinfo->mipi.signature = 0x9367; //国显
	else if(strcmp(lcd_selet_gpios,"0010")==0)
		pinfo->mipi.signature = 0x018000;//帝晶
	else if(strcmp(lcd_selet_gpios,"1010")==0)
		pinfo->mipi.signature = 0x6820;//普耐
	else if(strcmp(lcd_selet_gpios,"0011")==0)
		pinfo->mipi.signature = 0x0011;//NH2
	else 
		pinfo->mipi.signature = 0x0;
	...
}

pinfo->mipi.signature会与mipi_dsi.c中通过mipi命令读取的实际屏幕ID比较，匹配则停止遍历进入下一步
/bootable/bootloader/lk/platform/msm_shared/mipi_dsi.c b/bootable/bootloader/lk/platform/msm_shared/mipi_dsi.c

uint32_t mdss_dsi_read_panel_signature(uint32_t panel_signature)
{
	int ret = 0;
dprintf(CRITICAL, "%s:jiyh panel_signature %x -----------------------a\n", __func__,panel_signature);
#if (DISPLAY_TYPE_MDSS == 1)

   switch(panel_signature)
   	{
	   	case 0x9367 :
			ret = mipi_jd9367_manufacture_ida();//国显
			break;
		case 0x018000 :
			ret = mipi_dj_manufacture_ida();//帝晶
			break;
		case 0x6820 :
			ret = mipi_rm68200_manufacture_ida();//普耐
			break;
		case 0x0011 :
			ret = mipi_nh2_manufacture_ida();//NH2根据实际情况自行添加读取ID函数
			break;
	  default:
			break;
   	}
	if (ret != panel_signature)
		ret = panel_signature;
	else 
		ret=0;
	dprintf(CRITICAL, "%s:jiyh  ret = %x-------------------b\n", __func__, ret);

exit_read_signature:
	/* Keep the non detectable panel at the end and set panel signature 0xFFFF */
	if (panel_signature == 0xFFFF)
		ret = 0;
#endif
	return ret;
}

屏幕ID匹配成功后，会根据oem_panel.c中选择的gpio组合匹配loong/chips/msm8916/devices/c10/config.dtsi文件中的设置

...
&dsi_video_tv080wxm_nh2 {                                              //显示屏背光设置
	qcom,mdss-dsi-bl-pmic-control-type = "bl_ctrl_pwm";
	qcom,mdss-dsi-bl-pmic-pwm-frequency = <100>;
	qcom,mdss-dsi-bl-pmic-bank-select = <0>;
	qcom,mdss-dsi-pwm-gpio = <&pm8916_mpps 4 0>;
	qcom,cont-splash-enabled;
};

//注意：这个节点为了兼容多屏适配，必须按照下面的规则配置 否则出错
//0:  多屏的时候一定要加上这一项标示 qcom,dsi-multi-pan-support; 
//1： 必须保留 qcom,dsi-pref-prim-pan = <&dsi_video_boe>; 这一项为作为默认项。
//2:  qcom,platform-selectlcd-gpio-0 / 1 / 2 /3 这几个io作为选屏io, 他的值对应 qcom,dsi-pref-prim-pan-0000 和 qcom,dsi-pref-prim-str-0000
//         gpio-0 对应 -xxxx的 最后一位 , gpio-1 对应倒数第二位 ,其他类推
//3： pan-xxxx 和 str-xxxx 必须是对应的关系的节点名和别名{panel-video.dtsi中定义}，整个字符串最长128字符。 	
//4： qcom,dsi-pref-prim-pan-xxxx 对应的节点 在这个文件中 还有定义,修改的时候 必须一起修改
//GPIO50、GPIO51不做选屏电阻
&mdss_dsi0 {
	qcom,dsi-pref-prim-pan = <&dsi_video_nt35521_c8>;
	pinctrl-names = "mdss_default", "mdss_sleep";
	pinctrl-0 = <&mdss_dsi_active>;
	pinctrl-1 = <&mdss_dsi_suspend>;
	qcom,regulator-ldo-mode;
	qcom,platform-regulator-settings = [00 01 01 00 20 07 00];
	qcom,platform-enable-gpio = <&msm_gpio 97 0>;
	qcom,platform-reset-gpio = <&msm_gpio 25 0>;
	//qcom,platform-bklight-en-gpio = <&msm_gpio 24 0>;
	qcom,platform-vmipi-en-gpio = <&msm_gpio 24 0>;
	qcom,dsi-multi-pan-support;

    //NH2
	qcom,dsi-pref-prim-pan-0011 = <&dsi_video_tv080wxm_nh2>;          //pan_0011对应oem_panel.c中gpio值，dsi_video_tv080wxm_nh2
	                                                                                                            //对应panel-video.dtsi添加的LCD配置设备树节点
	qcom,dsi-pref-prim-str-0011 = "qcom,mdss_dsi_tv080wxm_nh2_800p_video";
}；

有关屏配置位于/loong/chips/msm8916/devices/c10/panel-video.dtsi，添加针对该屏的设备树节点

    dsi_video_tv080wxm_nh2: qcom,mdss_dsi_tv080wxm_nh2_800p_video{          //dsi_video_tv080wxm_nh2节点名称，在dts中可通过&节点名引用和修改
		qcom,mdss-dsi-panel-name = "qcom,mdss_dsi_tv080wxm_nh2_800p_video";     //节点字段名称，驱动中通过该名获取所需节点
		qcom,mdss-dsi-panel-controller = <&mdss_dsi0>;
		qcom,mdss-dsi-panel-type = "dsi_video_mode";
		qcom,mdss-dsi-panel-destination = "display_1";		
		qcom,mdss-dsi-panel-with-enable-gpio = <1>;
		qcom,mdss-dsi-panel-framerate = <60>;                      //帧率
		qcom,mdss-dsi-virtual-channel-id = <0>;
		qcom,mdss-dsi-stream = <0>;
		qcom,mdss-dsi-panel-width = <800>;                         //分辨率
		qcom,mdss-dsi-panel-height = <1280>;                       //分辨率
		qcom,mdss-dsi-h-front-porch = <16>;
		qcom,mdss-dsi-h-back-porch = <48>;
		qcom,mdss-dsi-h-pulse-width = <16>;
		qcom,mdss-dsi-h-sync-skew = <0>;
		qcom,mdss-dsi-v-front-porch = <8>;
		qcom,mdss-dsi-v-back-porch = <4>;
		qcom,mdss-dsi-v-pulse-width = <4>;
		qcom,mdss-dsi-h-left-border = <0>;
		qcom,mdss-dsi-h-right-border = <0>;
		qcom,mdss-dsi-v-top-border = <0>;
		qcom,mdss-dsi-v-bottom-border = <0>;
		qcom,mdss-dsi-bpp = <24>;
		qcom,mdss-dsi-underflow-color = <0xff>;
		qcom,mdss-dsi-border-color = <0>;
		qcom,mdss-dsi-pixel-packing = "tight";
	
	    qcom,mdss-dsi-on-command = [                   //初始化屏幕的mipi指令
			15 01 00 00 64 00 02 E0 00 
			15 01 00 00 00 00 02 E1 93 
			15 01 00 00 00 00 02 E2 65 
		...
		];
	
		qcom,mdss-dsi-off-command = [
			05 01 00 00 32 00 02 28 00
			05 01 00 00 78 00 02 10 00];
		qcom,mdss-dsi-on-command-state = "dsi_lp_mode";              //启动屏幕时mipi工作模式low power，参考规格书
		qcom,mdss-dsi-off-command-state = "dsi_lp_mode";
		qcom,mdss-dsi-h-sync-pulse = <1>;
		qcom,mdss-dsi-traffic-mode = "burst_mode";
		qcom,mdss-dsi-lane-map = "lane_map_0123";
		qcom,mdss-dsi-bllp-eof-power-mode;
		qcom,mdss-dsi-bllp-power-mode;
		qcom,mdss-dsi-lane-0-state;
		qcom,mdss-dsi-lane-1-state;
		qcom,mdss-dsi-lane-2-state;
		qcom,mdss-dsi-lane-3-state;                                 //4数据通道的mipi
		
		qcom,mdss-dsi-panel-timings = [D5 32 22 00 60 64 26 34 29 03 04 00];          //设置时钟频率
		qcom,mdss-dsi-t-clk-post = <0x04>;
		qcom,mdss-dsi-t-clk-pre = <0x1A>;
		
		qcom,mdss-dsi-bl-min-level = <1>;
		qcom,mdss-dsi-bl-max-level = <255>;
		qcom,mdss-dsi-dma-trigger = "trigger_sw";
		qcom,mdss-dsi-mdp-trigger = "none";
		
		qcom,mdss-dsi-reset-sequence = <1 10>, <0 20>, <1 30>;                     //上电复位时序（ms）
		qcom,mdss-pan-physical-width-dimension = <136>;
		qcom,mdss-pan-physical-height-dimension = <217>;
	};

修改平台的lcd_vdd电压

画板的时候lcd_vdd是由电源管理的ldo17供电，所以需要修改ldo17供电电压，全志平台的dts文件在loogn目录下
/loong/chips/msm8916/devices/default/dts/msm/msm8916-mdss.dtsi

mdss_dsi0: qcom,mdss_dsi@1a98000 {
...
    qcom,panel-supply-entries {
			#address-cells = <1>;
			#size-cells = <0>;

			qcom,panel-supply-entry@0 {
				reg = <0>;
				qcom,supply-name = "vdd";                               //修改vdd对应的电压为3.3V
				qcom,supply-min-voltage = <3300000>;
				qcom,supply-max-voltage = <3300000>;
				qcom,supply-enable-load = <100000>;
				qcom,supply-disable-load = <100>;
			};

			qcom,panel-supply-entry@1 {
				reg = <1>;
				qcom,supply-name = "vddio";
				qcom,supply-min-voltage = <1800000>;
				qcom,supply-max-voltage = <1800000>;
				qcom,supply-enable-load = <100000>;
				qcom,supply-disable-load = <100>;
			};
	};
};

由于vdd的电压是由ldo17引出的，所以还需要修改/loong/chips/msm8916/devices/default/dts/msm/msm8916-regulator.dtsi

/* RPM controlled regulators */
&rpm_bus {
...
    rpm-regulator-ldoa17 {
	     status = "okay";
		 pm8916_l17: regulator-l17 {
		     regulator-min-microvolt = <3300000>;
			 regulator-max-microvolt = <3300000>;
			 qcom,init-voltage = <3300000>;
			 status = "okay";
		 };
	};
};