一、注冊平臺設備

platform_device_register(&usr_mci_device);

二、填寫平臺設備結構體

static struct platform_device usr_mci_device= {

.name????????? = "xxx",

.id???????????? = 0,

.dev = {

.release???? = usr_mci_platdev_release,

.dma_mask? = &usr_mmc_dmamask,

.coherent_dma_mask = DMA_BIT_MASK(32),

},

.num_resources? ? = ARRAY_SIZE(usr_mci_resources),

.resource???? ???? = usr_mci_resources,

};

三、填寫資源結構體(物理地址查芯片手冊)

static struct resource usr_mci_resources[] = {

[0] = {

.start????????? = CONFIG_USR_IOBASE,

.end??????????? = CONFIG_USR_IOBASE + USR_MCI_IO_SIZE - 1,

.flags????????? = IORESOURCE_MEM,

},

[1] = {

.start????????? = CONFIG_USR_INTR,

.end??????????? = CONFIG_USR_INTR,

.flags????????? = IORESOURCE_IRQ,

},

};

四、注冊平臺驅動

platform_driver_register(&usr_mci_driver);

五、填寫平臺驅動結構體

static struct platform_driver usr_mci_driver= {
.probe = usr_mci_probe,
.remove = usr_mci_remove,
.suspend = usr_mci_suspend,
.resume = usr_mci_resume,
.driver = {
.name = DRIVER_NAME,
},
};

六、重寫probe函數

static int __devinit usr_mci_probe(struct platform_device *pdev)

七、創建一個自己的設備結構體

struct usr_host {
struct mmc_host *mmc;
spinlock_t lock;
struct mmc_request *mrq;
struct mmc_command *cmd;
struct mmc_data *data;
void __iomem *base;
unsigned int card_status;
struct scatterlist *dma_sg;
unsigned int dma_sg_num;
unsigned int dma_alloc_size;
unsigned int dma_dir;
dma_addr_t dma_paddr;
unsigned int *dma_vaddr;
struct timer_list timer;
unsigned int irq;
unsigned int irq_status;
unsigned int is_tuning;
wait_queue_head_t intr_wait;
unsigned long pending_events;
unsigned int id;

};

struct usr_host?*host;

八、分配一個包含了mmc_host的自定義結構體（core需要）

struct?mmc_host *mmc;

mmc = mmc_alloc_host(sizeof(struct usr_host), &pdev->dev);

九、初始化mmc_host結構體

mmc->ops

mmc->f_min

mmc->f_max

mmc->caps

mmc->max_blk_count

mmc->max_segs

mmc->max_seg_size

mmc->max_req_size

mmc->ocr_avail

mmc->ocr

十、初始化usr_host

host=mmc->private;

host->dma_vaddr =?dma_alloc_coherent(&pdev->dev, PAGE_SIZE,&host->dma_paddr, GFP_KERNEL);

host->mmc = mmc;

host->id

host->base

十一、初始化SDIO的時鐘、驅動能力

十二、SDIO復位

十三、SDIO重上電

十四、設置時鐘相位

十五、設置閾值

十六、設置中斷狀態

十七、設置中斷屏蔽

十八、設置DMA搬移數據

十九、設置全局中斷使能

二十、設置FIFO突發長度與FIFO大小

二十一、卡檢測

二十二、初始化定時器，定時處理函數為卡檢測

二十三、獲取資源結構體的軟中斷號

二十四、初始化等待隊列

init_waitqueue_head(&host->intr_wait);

二十五、request_irq注冊中斷

二十六、寫中斷函數（喚醒等待隊列）

static irqreturn_t usr_irq(int irq, void *dev_id)

{

wake_up(&host->intr_wait);

}

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