总目录：高通821平台LCD调试
上一篇：LK部分流程（一）
一、GCDB初始化
./lk/dev/gcdb/display/gcdb_display.c
gcdb_display_init ()主要的初始化代码如下：在该函数中有一个重要的函数就是 oem_panel_select()，该函数就是根据你的hw_id 确定使用哪一款LCD，hw_id 这个是在高通的私有代码中传过来的。另外一个比较重要的函数是msm_display_init(&panel)，这个函数将oem_panel_select中获得到的信息进行初始化动作，因此有必要首先需要分析oem_panel_select这个函数体的功能。
pan_type = oem_panel_select(panel_name, &panelstruct, &(panel.panel_info),
&dsi_video_mode_phy_db);
dsi_panel_init(&(panel.panel_info), &panelstruct)
panel.panel_info.mipi.mdss_dsi_phy_db = &dsi_video_mode_phy_db;
panel.pll_clk_func = mdss_dsi_panel_clock;
panel.dfps_func = mdss_dsi_mipi_dfps_config;
panel.power_func = mdss_dsi_panel_power;
panel.pre_init_func = mdss_dsi_panel_pre_init;
panel.bl_func = mdss_dsi_bl_enable;
panel.dsi2HDMI_config = mdss_dsi2HDMI_config;
/*
* If dfps enabled, reserve fb memory to store pll
* codes and pass pll codes values to kernel. */
if (panel.panel_info.dfps.panel_dfps.enabled) {
panel.panel_info.dfps.dfps_fb_base = base;
base += DFPS_PLL_CODES_SIZE;
dprintf(SPEW, "dfps base=0x%p,d, fb_base=0x%p!\n",
panel.panel_info.dfps.dfps_fb_base, base);
}
panel.fb.base = base;
panel.fb.width = panel.panel_info.xres;
panel.fb.height = panel.panel_info.yres;
panel.fb.stride = panel.panel_info.xres;
panel.fb.bpp = panel.panel_info.bpp;
panel.fb.format = panel.panel_info.mipi.dst_format;
ret = msm_display_init(&panel);二、oem_panel_select
指定panel_id = TIANMA_2K_VIDEO_PANEL，这个是实际选择屏起作用的选项
switch (hw_id) {
case HW_PLATFORM_MTP:
case HW_PLATFORM_FLUID:
case HW_PLATFORM_SURF:
#if DISPLAY_AUO_SPLITDSI_VIDEO_PANEL
panel_id = JDI_FHD_VIDEO_PANEL;
#elif DISPLAY_SAMSUNG_FHD_VIDEO_PANEL
panel_id = SAMSUNG_FHD_VIDEO_PANEL;
#elif DISPLAY_TIANMA_FHD_VIDEO_PANEL
panel_id = TIANMA_FHD_VIDEO_PANEL;
#elif DISPLAY_TIANMA_2K_VIDEO_PANEL
panel_id = TIANMA_2K_VIDEO_PANEL;
#endif
break;然后会调用init_panel_data根据panel_id 来执行对应的初始化动作，初始化中获得的屏参数来源于
bootable/bootloader/lk/dev/gcdb/display/include/panel_tianma_2k_video.h，该头文件是按照panel.h为参考格式填充，具体参数由屏厂商提供。
case TIANMA_2K_VIDEO_PANEL:
pan_type = PANEL_TYPE_DSI;
pinfo->lcd_reg_en = 0;
panelstruct->paneldata = &tianma_2k_dualdsi_video_panel_data;
panelstruct->panelres = &tianma_2k_dualdsi_video_panel_res;
panelstruct->color = &tianma_2k_dualdsi_video_color;
panelstruct->videopanel = &tianma_2k_dualdsi_video_video_panel;
panelstruct->commandpanel = &tianma_2k_dualdsi_video_command_panel;
panelstruct->state = &tianma_2k_dualdsi_video_state;
panelstruct->laneconfig = &tianma_2k_dualdsi_video_lane_config;
panelstruct->paneltiminginfo
= &tianma_2k_dualdsi_video_timing_info;
panelstruct->panelresetseq
= &tianma_2k_dualdsi_video_reset_seq;
panelstruct->backlightinfo = &tianma_2k_dualdsi_video_backlight;
pinfo->labibb = &tianma_2k_dualdsi_video_labibb;
pinfo->mipi.panel_on_cmds
= tianma_2k_dualdsi_video_on_command;
pinfo->mipi.num_of_panel_on_cmds
= TIANMA_2K_DUALDSI_VIDEO_ON_COMMAND;
pinfo->mipi.panel_off_cmds
= tianma_2k_dualdsi_video_off_command;
pinfo->mipi.num_of_panel_off_cmds
= TIANMA_2K_DUALDSI_VIDEO_OFF_COMMAND;
memcpy(phy_db->timing,
tianma_2k_dualdsi_thulium_video_timings,
MAX_TIMING_CONFIG * sizeof(uint32_t));
pinfo->mipi.tx_eot_append = true;
/*
* remove DUAL_PIPE_FLAG because on this target for this panel,
* it will be added based on one of the selected configurations.
*/
panelstruct->paneldata->panel_operating_mode &= ~DUAL_PIPE_FLAG;
panelstruct->config = &tianma_2k_dualdsi_video_config0;
if (oem_data) {
switch (oem_data->cfg_num[0]) {
case -1: /* default */
case 0:
panelstruct->config =
&tianma_2k_dualdsi_video_config0;
break;
case 1:
panelstruct->config =
&tianma_2k_dualdsi_video_config1;
break;
default:
dprintf(CRITICAL, "topology config%d not supported. fallback to default config0\n",
oem_data->cfg_num[0]);
panelstruct->config = &tianma_2k_dualdsi_video_config0;
}
//oem_data->swap_dsi_ctrl = 1; // use swap
}
pinfo->lm_split[0] = panelstruct->config->lm_split[0];
pinfo->lm_split[1] = panelstruct->config->lm_split[1];
pinfo->num_dsc_enc = panelstruct->config->num_dsc_enc;
break;