Analysis on the hardware detection flow of SD card under Linux Sdio interface __linux

Mmc_alloc_host () Application Platform SD unit corresponding to the MMC_HOST structure->
Init_delayed_work (&host->detect, Mmc_rescan) creates a corresponding SDIO device insert for this platform SD unit
Detection kernel work_queue task column function Mmc_rescan->mmc_rescan () This is a shared function, if there are 4 SD card controllers on your arm platform,
Then 4 SD controllers will correspond to 4 mmc_host structures respectively, corresponding to 4 sdio device Insert detection kernel work_queue Task Force column,
But the work queue will call the Mmc_rescan () 1 functions, so the object-oriented class-sharing mechanism of the Linux kernel is doing well->

Use the Mmc_alloc_host () function to request a platform mmc_host structure that does not assign a bus pointer to it, assigning only the parent to which it belongs, that is, this MMC does not belong to a bus,
So this mmc_host corresponding dev will not be assigned to any driver drivers from any bus buses, which is also true.

Mmc_attach_sdio ()->mmc_attach_bus (host, &mmc_sdio_ops);
Mmc_sdio_init_card ()->sdio_init_func ()->sdio_alloc_func ()-> so that after detect to the SDIO device,
will assign dev corresponding to the SDIO_FUNC structure problem,

Call the Sdio_read_func_cis () Cistpl_manfid () to populate the SD card's vendor so that when the WLAN drives probe,
Will attempt to match the vendor in the WLAN-driven ID table, if successful, then the WLAN driver will take over the detected SD card