Qcom_lcd_driver 之二 -- IOCTL

最新推荐文章于 2023-03-20 18:03:05 发布

原创最新推荐文章于 2023-03-20 18:03:05 发布 · 139 阅读

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本文深入分析了MSM FB ioctl命令的用途和MDP blit流程实现细节，包括overlay操作、blit命令处理、内存一致性确保等关键步骤。


static int msm_fb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
+-- ...
+-- switch (cmd) {
        case MSMFB_OVERLAY_GET:
        case MSMFB_OVERLAY_SET:
        case MSMFB_OVERLAY_UNSET:
        case MSMFB_OVERLAY_PLAY:
        case MSMFB_OVERLAY_PLAY_ENABLE:
        case MSMFB_BLIT:
        case MSMFB_SET_CCS_MATRIX:
        case MSMFB_GET_CCS_MATRIX:
        case MSMFB_GRP_DISP:
        case MSMFB_SUSPEND_SW_REFRESHER:
        case MSMFB_RESUME_SW_REFRESHER:
        case MSMFB_CURSOR:
        case MSMFB_SET_LUT:
        case MSMFB_HISTOGRAM:
        case MSMFB_GET_PAGE_PROTECTION:
        case MSMFB_SET_PAGE_PROTECTION:
    }
+-- ...

//处理用户空间传入的request list
msm_fb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)   //for MSMFB_BLIT ...
+-- msmfb_blit(info, argp);
    +-- copy_from_user(&req_list_header, p, sizeof(req_list_header))
    +-- p += sizeof(req_list_header);
    +-- count = req_list_header.count;
    +-- while (count > 0) {
            req_list_count = count;
            if (req_list_count > MAX_LIST_WINDOW)
                req_list_count = MAX_LIST_WINDOW;
            if (copy_from_user(&req_list, p, sizeof(struct mdp_blit_req)*req_list_count))
                return -EFAULT;
            msm_fb_ensure_memory_coherency_before_dma(info, req_list, req_list_count);
            for (i = 0; i < req_list_count; i++) {
                if (!(req_list[i].flags & MDP_NO_BLIT)) {
                    int ret = mdp_blit(info, &(req_list[i]));  //Do the actual blit ...           
                    if (ret)
                        return ret;
                }
            }
            msm_fb_ensure_memory_coherency_after_dma(info, req_list, req_list_count);
            count -= req_list_count;
            p += sizeof(struct mdp_blit_req)*req_list_count;
        }


int 
mdp_blit(struct fb_info *info, struct mdp_blit_req *req)
+-- mdp_ppp_blit(info, req);