RK3128开发板在android显示端做分辨率调整

Platform: Rockchip
OS: Android 7.1.2
Kernel: 3.10

最近使用480P小屏幕开发时，碰到某些第三方APP的屏幕适配有BUG，如果直接修改配置文件会导致屏幕显示异常，因些只能直接在android显示端做分辨率调整。

修改路径：kernel\drivers\video\rockchip\rk_fb.c

第一步：修改成需要的显示分辨率

int rk_fb_prase_timing_dt(struct device_node *np, struct rk_screen *screen)
{
struct display_timings *disp_timing;
struct display_timing *dt;

disp_timing = of_get_display_timings(np);
if (!disp_timing) {
	pr_err("parse display timing err\n");
	return -EINVAL;
}
dt = display_timings_get(disp_timing, disp_timing->native_mode);
/* 修改屏幕显示分辨率*/

• dt->hactive.typ = 1280;

• dt->vactive.typ = 720;
  rk_fb_video_mode_from_timing(dt, screen);

  return 0;
  }
  第二步：修改显示分辨率后，会导致显示区域也被相对缩放，因此需要修改显示窗口缩放规则

static void rk_fb_update_win(struct rk_lcdc_driver *dev_drv,
struct rk_lcdc_win *win,
struct rk_fb_reg_win_data reg_win_data)
{
...
} else {
/ 对小于720P的屏幕不做缩放处理 */

• if (reg_win_data->reg_area_data[i].xsize >= 1280 && reg_win_data->reg_area_data[i].ysize >= 720){
    				win->area[i].xpos =
    					reg_win_data->reg_area_data[i].xpos *
    					cur_screen->mode.xres /
    					primary_screen.mode.xres;
    				win->area[i].ypos =
    					reg_win_data->reg_area_data[i].ypos *
    					cur_screen->mode.yres /
    					primary_screen.mode.yres;
    				win->area[i].xsize =
    					reg_win_data->reg_area_data[i].xsize *
    					cur_screen->mode.xres /
    					primary_screen.mode.xres;
    				win->area[i].ysize =
    					reg_win_data->reg_area_data[i].ysize *
    					cur_screen->mode.yres /
    					primary_screen.mode.yres;
  

• }
  
    			/* recalc display size if set hdmi scaler when at ONE_DUAL mode */
    			if (inf->disp_mode == ONE_DUAL && hdmi_switch_state) {
    				if (cur_screen->xsize > 0 &&
    				    cur_screen->xsize <= cur_screen->mode.xres) {
    					win->area[i].xpos =
    						((cur_screen->mode.xres - cur_screen->xsize) >> 1) +
    						cur_screen->xsize * win->area[i].xpos / cur_screen->mode.xres;
    					win->area[i].xsize =
    						win->area[i].xsize * cur_screen->xsize / cur_screen->mode.xres;
    				}
    				if (cur_screen->ysize > 0 && cur_screen->ysize <= cur_screen->mode.yres) {
    					win->area[i].ypos =
    						((cur_screen->mode.yres - cur_screen->ysize) >> 1) +
    						cur_screen->ysize * win->area[i].ypos / cur_screen->mode.yres;
    					win->area[i].ysize =
    						win->area[i].ysize * cur_screen->ysize / cur_screen->mode.yres;
    				}
    			}
    		}
  

...
}

目前屏幕显示正常，无触摸屏，触摸屏触摸效果是否会有异常暂时未知。

原作者：wuxin131765