SD卡驱动-源代码树分析

来源：互联网发布：java reference 编辑：程序博客网时间：2024/06/15 10:40

\mmc_blk_init(void)\register_blkdev(MMC_BLOCK_MAJOR,"mmc")\mmc_register_driver(&mmc_driver);\(&mmc_driver)->drv.bus=&mmc_bus_type;\driver_register(&(&mmc_driver)->drv);module_init(mmc_blk_init)struct bus_type mmc_bus_type={.match = mmc_bus_match;.probe = mmc_bus_probe;};\mmc_bus_probe(struct device *dev)\drv->probe();struct mmc_driver mmc_driver={.probe = mmc_blk_probe;}\mmc_blk_probe(card)\struct mmc_blk_data *md;\md = mmc_blk_alloc(card);\mmc_blk_readonly(card)\alloc_disk(1<<MMC_SHIFT)\mmc_init_queue\blk_init_queue(mmc_request,lock)//mmc_request里面有wake_up_process\blk_queue_prep_rq\blk_queue_ordered\kthread_run(mmc_queue_thread,mq,"mmcqd")\md->queue.issue_fn = mmc_blk_issue_rq\常规的gendisk赋值工作\mmc_blk_set_blksize\mmc_claim_host//一个控制器可以服务多个对象所以需申请\mmc_wait_for_cmd\mmc_releaes_host//释放控制器\mmc_set_drvdata //\add_disk//使用add_disk向内核注册块设备驱动struct mmc_blk_data{struct gendisk * disk;struct mmc_queue queue;}struct mmc_queue{struct request *req;struct request_queue *queue;}\mmc_request(q)\wake_up_process(q->queuedata->thread)\try_to_wake_up(mq->thread,TASK_ALL,0)\...\mmc_queue_thread(void *d)\down(&d->thread_sem)//获得线程的信号量\set_current_state(TASK_INTERRUPTIBLE)//设置当前线程运行状态为可中断\up(&d->thread_sem)//释放线程的信号量\schedule();//内核发起调度\mq->issue_fn(d,req)\mmc_blk_issue_rq\mmc_claim_host\brq.mrq.cmd = &brq.cmd//因为struct mmc_request中的内容为指针，所以需要指代 \brq.mrq.data = &brq.data\mmc_queue_map_sg\mmc_wait_for_req(card->host,*brq.mrq)struct mmc_blk_request{struct mmc_request mrq;//传递给core和host层的一个mmc封装请求struct mmc_command cmd;struct mmc_command stop;struct mmc_data data;}部分card层与core层的接口函数：mmc_claim_host();mmc_release_host();mmc_wait_for_req();mmc_wait_for_cmd();

几个代码树结构：

\blk_init_queue(rfn,lock)
   \blk_init_queue_node(rfn,lock,-1)
       \q->request_fn = rfn;
       \blk_queue_make_request(q,__make_request)
           \q->make_request_fn=__make_request;

blk_init_queue是和blk_cleanup_queue搭配使用的

\mmc_wait_for_cmd(host,cmd,retries)\mmc_wait_for_req(host,mrq)\mmc_start_request(host,mrq)\host->ops->request(host,mrq)\mrq->done_data = &complete\mrq->done = mmc_wait_done\wait_for_completion(&complete)

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