高通LCD bring up流程

前言kernel添加LCD的dtsi将屏的dtsi放到平台的dtsi中电压配置lk添加屏的.h文件Panel configurationPanel resolutionPanel color informationPanel on/off command informationPanel timingoem_panel.c

前言

高通平台LCD的bring up可分为两部分：kernel、lk。在点屏之前要仔细看LCD电路原理图和IC spec，搞清楚LCD亮屏需要满足的上电条件和时序要求。同时找FAE拿到初始化代码。

kernel

添加LCD的dtsi

参考FAE提供的初始化信息，填写分辨率、hfp\hbp\hpw、vfp\vbp\vpw，一般来讲FAE会提供初始化代码、hfp\hbp\hpw、vfp\vbp\vpw、spec等信息

arch/arm64/boot/dts/qcom/dsi-panel-XXX-xxxp-video.dtsi

&mdss_mdp {dsi_hx8394f_720p_video: qcom,mdss_dsi_hx8394f_720p_video {//保持一致就好qcom,mdss-dsi-panel-name = "hx8394f 720p video mode dsi panel";//panel nameqcom,mdss-dsi-panel-controller = <&mdss_dsi0>;//保持不变；指定此panel将映射到的DSI控制器的模型qcom,mdss-dsi-panel-type = "dsi_video_mode";//指定面板操作模式。//“dsi_video_mode” = 启用视频模式//“dsi_cmd_mode” = 启用命令模式qcom,mdss-dsi-panel-destination = "display_1";//指定面板的目标显示，保持不变qcom,mdss-dsi-panel-framerate = <60>;//指每秒显示60帧，一帧就是一个完整的图像（一般都是60）qcom,mdss-dsi-virtual-channel-id = <0>; //指定虚拟频道标识符，默认为0；保持不变qcom,mdss-dsi-stream = <0>;//指定要使用的数据包流：0 = 流 0（默认值）;1 = 流 1。保持不变qcom,mdss-dsi-panel-width = <720>;//分辨率-wqcom,mdss-dsi-panel-height = <1440>;//分辨率-hqcom,mdss-dsi-h-front-porch = <60>;//hfp-表示一行的有效数据结束到下一个水平同步信号开始之间的VCLK的个数，对应驱动中的right_margin；qcom,mdss-dsi-h-back-porch = <60>;//hbp-表示从水平同步信号开始到一行的有效数据开始之间的VCLK的个数，对应驱动中的left_margin；qcom,mdss-dsi-h-pulse-width = <18>;//hpw-表示水平同步信号的宽度，用VCLK计算，对应驱动中的hsync_len；（设置一行有几个像素）qcom,mdss-dsi-h-sync-skew = <0>;//水平同步倾斜值：0 = 默认值。保持不变qcom,mdss-dsi-v-back-porch = <12>;//vbp-表示在一帧图像开始时，垂直同步信号以后的无效的行数，对应驱动中的upper_margin；qcom,mdss-dsi-v-front-porch = <15>;//vfp-表示在一帧图像结束后，垂直同步信号以前的无效的行数，对应驱动中的lower_margin；qcom,mdss-dsi-v-pulse-width = <2>;//vpw-表示垂直同步脉冲的宽度，用行数计算，对应驱动中vsync_len；（有多少显示的行）qcom,mdss-dsi-h-left-border = <0>;//水平左边框（单位：像素）:0 = 默认值。保持不变qcom,mdss-dsi-h-right-border = <0>;//水平右边框（单位：像素）:0 = 默认值。保持不变qcom,mdss-dsi-v-top-border = <0>;//垂直上边框（单位：像素）:0 = 默认值。保持不变qcom,mdss-dsi-v-bottom-border = <0>;//垂直下边框（单位：像素）:0 = 默认值。保持不变qcom,mdss-dsi-bpp = <24>; // 指定面板的每像素位数。// 3 = 适用于 rgb111// 8 = 适用于 rgb332// 12 = 适用于 rgb444// 16 = 适用于 rgb565// 18 = 适用于 rgb666// 24 = 适用于 rgb888qcom,mdss-dsi-color-order = "rgb_swap_rgb"; // 指定 R、G 和 B 通道排序"rgb_swap_rgb" =DSI_RGB_SWAP_RGB默认值）qcom,mdss-dsi-underflow-color = <0xff>;// 指定面板下溢颜色的控制器设置：0xff = 默认值。保持不变qcom,mdss-dsi-border-color = <0>;//如有边框，定义边框颜色值。0 = 默认值。qcom,mdss-dsi-on-command = [39 01 00 00 00 00 04 B9 FF 83 94//根据FAE提供的初始化代码填写39 01 00 00 00 00 03 C0 1F 31...05 01 00 00 78 00 02 11 0005 01 00 00 14 00 02 29 00];qcom,mdss-dsi-off-command = [//根据FAE提供的初始化代码填写05 01 00 00 14 00 02 28 0005 01 00 00 78 00 02 10 00];qcom,mdss-dsi-on-command-state = "dsi_lp_mode";//指定用于发送 ON /OFF命令的控制状态的字符串。//"dsi_lp_mode" = DSI 低功率模式（默认值）//"dsi_hs_mode" = DSI 高速模式qcom,mdss-dsi-off-command-state = "dsi_lp_mode";qcom,mdss-dsi-h-sync-pulse = <0>; //指定面板的脉冲模式选项。//0 = 不在 vs/ve 数据包之后发送hsa/he（默认值）//1 = 在 vs/ve 数据包之后发送 hsa/heqcom,mdss-dsi-traffic-mode = "non_burst_sync_event";//指定面板流量模式//"non_burst_sync_pulse" = 使用同步脉冲的非突发流量（默认值）//"non_burst_sync_event" = 使用同步 启动事件的非突发流量//"burst_mode" = 突发模式qcom,mdss-dsi-lane-map = "lane_map_0123";// 指定数据通道交换配置; 保持不变//"lane_map_0123" = <0 1 2 3>（默认值）qcom,mdss-dsi-bllp-eof-power-mode;//用于确定低功率空白期（BLLP）EOF 模式期间的 DSI 通道状态qcom,mdss-dsi-bllp-power-mode;//用于确定低功率空白期（BLLP）模式 期间的 DSI 通道状态qcom,mdss-dsi-tx-eot-append;qcom,mdss-dsi-lane-0-state;//指定是否启用数据通道 0qcom,mdss-dsi-lane-1-state;qcom,mdss-dsi-lane-2-state;qcom,mdss-dsi-lane-3-state;qcom,mdss-dsi-panel-timings// 高通表格计算出来的= [87 1C 12 00 42 42 18 21 17 03 04 00];qcom,mdss-dsi-t-clk-post = <0x04>;//指定模式切换后的字节时钟周期qcom,mdss-dsi-t-clk-pre = <0x1B>;// 指定模式切换前的字节时钟周期qcom,mdss-dsi-dma-trigger = "trigger_sw";//指定用于 DMA 路径的触发机制//"none" = 无触发//"trigger_te" = 断开用于触发的检查信 号线//"trigger_sw" = 由软件触发（默认设置） "trigger_sw_seof" = 软件触发和帧触 发的开始/结束。//"trigger_sw_te" = 软件触发和 TEqcom,mdss-dsi-mdp-trigger = "none";//指定用于 MDP 路径的触发机制;"none" = 无触发qcom,mdss-dsi-lp11-init;//确保在reset前，保证DSI clock和data都要及时被拉高qcom,mdss-dsi-reset-sequence = <1 10>, <0 10>, <1 10>; //列出重置 GPIO 值和睡眠序列的数组//每个命令具有下面定义的格式：//--> 重置 GPIO 值：高电平低电平//--> 睡眠值：多少毫秒};};

将屏的dtsi放到平台的dtsi中

指定要用哪个屏幕

#include "dsi-panel-hx8394f-720p-video.dtsi"&mdss_dsi0 {//对应 .dtsi中“panel-controller”qcom,dsi-pref-prim-pan = <&dsi_hx8394f_720p_video>;//与屏的dtsi中保持一致pinctrl-names = "mdss_default", "mdss_sleep";pinctrl-0 = <&mdss_dsi_active &mdss_te_active>;pinctrl-1 = <&mdss_dsi_suspend &mdss_te_suspend>;qcom,regulator-ldo-mode;//低压差线性稳压器（一种电压转换芯片）qcom,platform-te-gpio = <&tlmm 24 0>;qcom,platform-reset-gpio = <&tlmm 60 0>;//qcom,platform-bklight-en-gpio = <&tlmm 93 0>;//qcom,platform-enable-gpio = <&tlmm 94 0>;};&dsi_hx8394f_720p_video {qcom,panel-supply-entries = <&dsi_panel_pwr_supply>;//一个节点，列出用于为DSI面板供电的电源元件qcom,mdss-dsi-bl-pmic-control-type = "bl_ctrl_pwm";//用于指定此面板的背光控制的实现qcom,mdss-dsi-bl-pmic-pwm-frequency = <100>;//PWM周期（以微秒为单位）qcom,mdss-dsi-bl-pmic-bank-select = <0>; //PG背光通道qcom,mdss-dsi-pwm-gpio = <&pm8916_mpps 4 0>;// PMIC gpio绑定到背光// esd检查qcom,esd-check-enabled;//启用ESD恢复功能qcom,mdss-dsi-panel-status-check-mode = "reg_read"; //指定用于ESD恢复的面板状态检查方法；“ reg_read” =读取面板状态寄存器以检查面板状态qcom,mdss-dsi-panel-status-command = [06 01 00 01 00 00 01 09];//基于qcom dsi控制器协议的多个dcs数据包形成的字节流，以读取面板状态qcom,mdss-dsi-panel-status-command-state = "dsi_hs_mode";qcom,mdss-dsi-panel-status-value = <0x80 0x73 0x06>;//多个整数数组，每个整数数组指定用于检查面板状态的面板状态寄存器的值。 每个数组的大小是qcom，mdss-dsi-panel-status-read-length中指定的长度总和，并且必须相等。qcom,mdss-dsi-panel-on-check-value = <0x80 0x73 0x06>;qcom,mdss-dsi-panel-status-read-length = <3>;//数组长度};

电压配置

除lab、ibb外，还有vdd、vddio自己在平台代码找一下

drivers/video/fbdev/msm/mdss_dsi.c

&mdss_dsi0 {lab-supply = <&lab_regulator>;ibb-supply = <&ibb_regulator>;};&labibb {status = "ok";qpnp,qpnp-labibb-mode = "lcd";};&ibb_regulator {qcom,qpnp-ibb-discharge-resistor = <32>;};&dsi_panel_pwr_supply {qcom,panel-supply-entry@2 {reg = <2>;qcom,supply-name = "lab";qcom,supply-min-voltage = <4600000>;qcom,supply-max-voltage = <6000000>;qcom,supply-enable-load = <100000>;qcom,supply-disable-load = <100>;};qcom,panel-supply-entry@3 {reg = <3>;qcom,supply-name = "ibb";qcom,supply-min-voltage = <4600000>;qcom,supply-max-voltage = <6000000>;qcom,supply-enable-load = <100000>;qcom,supply-disable-load = <100>;qcom,supply-post-on-sleep = <20>;};};

修改设备树显示电压"regulator-l17"，“regulator-l6”

lk

/android/bootable/bootloader/lk

添加屏的.h文件

.h中很多参数都是根据dtsi填写的

/dev/gcdb/display/include/panel_xxxx_xxxp_video.h

.h中用到的结构体定义在

/android/bootable/bootloader/lk/dev/gcdb/display/include/panel.h

Panel configuration

static struct panel_config hx8394f_720p_video_panel_data = {"qcom,mdss_dsi_hx8394f_720p_video", "dsi:0:", "qcom,mdss-dsi-panel",10, 0, "DISPLAY_1", 0, 0, 60, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, NULL};

对应结构体定义与解析

struct panel_config{char *panel_node_id;//"qcom,mdss_dsi_st7703p_720p_video" 与dtsi保持一致char *panel_controller; //"dsi:0:"对应dtsi中“panel-controller”char *panel_compatible;// "qcom,mdss-dsi-panel" 保持不变uint16_t panel_interface;//看电路图上有几个mipi接口就填几uint16_t panel_type; //video是MIPI_VIDEO_PANEL(0)， cmd是MIPI_CMD_PANEL(1)char *panel_destination;// "DISPLAY_1" 对应dtsi中panel-destinationuint32_t panel_orientation;//屏幕旋转方向，默认为0/* panel_clockrate is deprecated in favor of panel_bitclock_freq */uint32_t panel_clockrate;//默认为0，不建议修改uint16_t panel_framerate;// 刷新率，一般为60uint16_t panel_channelid;//保持不变uint16_t dsi_virtualchannel_id;//对应DTS中虚拟频道ID（保持不变）uint16_t panel_broadcast_mode;//保持不变uint16_t panel_lp11_init;//确保在reset前，保证DSI clock和data都要及时被拉高uint16_t panel_init_delay;// 初始化延迟uint16_t dsi_stream;//保持不变uint8_t interleave_mode;//交错模式（保持不变）uint32_t panel_bitclock_freq;//保持不变uint32_t panel_operating_mode;//操作模式，默认为0uint32_t panel_with_enable_gpio;//保持不变uint8_t mode_gpio_state;//保持不变char *slave_panel_node_id;//NULL};

Panel resolution

根据dtsi写，从左到右依次为分辨率(width*high)、hfp、hbp、hpw、hss、vfp、vbp、vpw…

static struct panel_resolution hx8394f_720p_video_panel_res = {720, 1440, 58, 58, 16, 0, 15, 12, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0// w, h, hfp, hbp, hpw, hss, vfp, vpw ...};

以下参数在上面dtsi中有详细介绍，这里就不再重复了

struct panel_resolution{uint16_t panel_width;uint16_t panel_height;uint16_t hfront_porch;//hfpuint16_t hback_porch;//hbpuint16_t hpulse_width;//hpwuint16_t hsync_skew;//hss - 水平同步倾斜值uint16_t vfront_porch;//vfpuint16_t vback_porch;//vbpuint16_t vpulse_width;//vpwuint16_t hleft_border;//水平左边框uint16_t hright_border;//水平右边框uint16_t vtop_border;//垂直上边框uint16_t vbottom_border;//垂直下边框uint16_t hactive_res;//0uint16_t vactive_res;//0uint16_t invert_data_polarity;//0uint16_t invert_vsync_polarity;//垂直脉冲模式uint16_t invert_hsync_polarity;//水平脉冲模式};

Panel color information

static struct color_info hx8394f_720p_video_color = {24, 0, 0xff, 0, 0, 0};

struct color_info{uint8_t color_format;uint8_t color_order;uint8_t underflow_color;uint8_t border_color;uint8_t pixel_packing;uint8_t pixel_alignment;};

对应dtsi中

"rgb_swap_rgb"对应0

在安卓R上，pixel_alignment在代码中并没有去解析

Panel on/off command information

初始化代码

eg：

static char st7703p_720p_video_on_cmd1[] = {0x06, 0x00, 0x39, 0xC0,0xB1, 0x85, 0x00, 0x24,0xDA, 0x01, 0xFF, 0xFF,};

dtsi 的qcom,mdss-dsi-on-command中，每一行为一个cmd，cmd=0开始

第一行第一个数和第二个数之和是数值的个数（第2个一般是0x00），后面两个是datatype；(23,15,05对应80,29和39对应c0).

第二行开始写数值，结尾一行不足4个的填写0xff.

注意：始化代码最后两行只写一行

static char st7703p_720p_video_on_cmd22[] = {0x11, 0x00, 0x05, 0x80,};static char st7703p_720p_video_on_cmd23[] = {0x29, 0x00, 0x05, 0x80};

mipi_dsi_cmd结构体中，第一个参数是相应数组的总数，包括第一行和0xff在内

static struct mipi_dsi_cmd st7703p_720p_video_on_command[] = {{0x08, st7703p_720p_video_on_cmd0, 0x00},{0x0C, st7703p_720p_video_on_cmd1, 0x00},{0x08, st7703p_720p_video_on_cmd2, 0x00},{0x10, st7703p_720p_video_on_cmd3, 0x00},...

ST7703P_720P_VIDEO_ON_COMMAND 是初始化命令的个数，也就是刚刚填的cmd的个数

#define ST7703P_720P_VIDEO_ON_COMMAND 24

Panel timing

根据dtsi的timings来算

oem_panel.c

android/bootable/bootloader/lk/target/msmxxxx/oem_panel.c

#include "include/panel_xxxxxx_xxxp_video.h"

将panel加入枚举

/*---------------------------------------------------------------------------*//* static panel selection variable *//*---------------------------------------------------------------------------*/enum {TRULY_1080P_VIDEO_PANEL,TRULY_1080P_CMD_PANEL,...ST7703P_720P_VIDEO_PANEL,ILI9881C_720P_VIDEO_PANEL,UNKNOWN_PANEL};

加入panel_list

/** The list of panels that are supported on this target.* Any panel in this list can be selected using fastboot oem command.*/static struct panel_list supp_panels[] = {{"truly_1080p_video", TRULY_1080P_VIDEO_PANEL},{"truly_1080p_cmd", TRULY_1080P_CMD_PANEL},...{"st7703p_720p_video", ST7703P_720P_VIDEO_PANEL},{"ili9881c_720p_video", ILI9881C_720P_VIDEO_PANEL},};

将 panel_st7703p_720p_video.h中的数据依次赋值

case ST7703P_720P_VIDEO_PANEL:panelstruct->paneldata = &st7703p_720p_video_panel_data;panelstruct->panelres= &st7703p_720p_video_panel_res;panelstruct->color= &st7703p_720p_video_color;panelstruct->videopanel = &st7703p_720p_video_video_panel;panelstruct->commandpanel = &st7703p_720p_video_command_panel;panelstruct->state= &st7703p_720p_video_state;panelstruct->laneconfig = &st7703p_720p_video_lane_config;panelstruct->paneltiminginfo= &st7703p_720p_video_timing_info;panelstruct->panelresetseq= &st7703p_720p_video_panel_reset_seq;panelstruct->backlightinfo = &st7703p_720p_video_backlight;pinfo->mipi.panel_on_cmds= st7703p_720p_video_on_command;pinfo->mipi.num_of_panel_on_cmds= ST7703P_720P_VIDEO_ON_COMMAND;pinfo->mipi.panel_off_cmds= st7703p_720p_video_off_command;pinfo->mipi.num_of_panel_off_cmds= ST7703P_720P_VIDEO_OFF_COMMAND;memcpy(phy_db->timing,st7703p_720p_video_timings, TIMING_SIZE);pinfo->mipi.signature = ST7703P_720P_VIDEO_SIGNATURE;phy_db->regulator_mode = DSI_PHY_REGULATOR_LDO_MODE;break;

注意：不要忘记配置供电模式