mmc子系统学习笔记四 mmc子系统的结构组织

从这一节起，我们正式进入mmc子系统学习笔记内容，这边walfred就根据自己的观点，整理了一份Linux下mmc子系统的结构组织框架，相信带着这个框架来理解学习mmc子系统应该会起到不错的效果。下面是mmc子系统的结构组织：

         在Linux中，系统中mmc子系统本身没有任何README文档,所以此算一个"帮助文档"。其将涉及到3条总线，2块设备，2个驱动。

三条总线

总线名

platform

mmc

sdio

类型

struct bus_type

变量名

platform_bus

mmc_bus_type

sdio_bus_type

         这个我们可以在/sys/bus中查看。

两块设备

设备名

msm_sdcc

mmc_card

类型

struct  platform_device

struct mmc_card

备注

msm_sdcc(soc)

由前者sdcc的驱动，对mmc/sd/sdio的统一抽象

       msm_sdcc（全称应该是sdcardcontroller集成到soc，所以属platform_device,优点具有较好的移植性和安全性），mmc_card（由前者sdcc的驱动，对mmc/sd/sdio的统一抽象）;

 两组驱动

驱动名

msmsdcc_driver

mmc_driver

类型

struct platform_driver

struct mmc_driver

备注

 

 

         对应与上面的2块设备，分别是msmsdcc_driver,mmc_driver;

它们之间的关系

         关于platform总线，下文研究的主线一

         驱动msmsdcc_driver，以及设备msm_sdcc是通过platform_bus关联。

         关于mmc总线，下文研究的主线二

         驱动mmc_driver，以及设备mmc_card是通过该总线关联

         关于sdio总线

         尚未过多研究，此处暂时并考虑。以后会陆续补充。

相关结构体

这是描述一个platform设备的

struct platform_device {

     const char    * name;

     int      id;

     struct device dev;

     u32      num_resources;

     struct resource    * resource;

 

     const struct platform_device_id  *id_entry;

 

     /* arch specific additions */

     struct pdev_archdata   archdata;

};

这是msm_device_sdc设备

struct platform_device msm_device_sdc1 = {

     .name         = "msm_sdcc",//platform_device名

     .id      = 1,

     .num_resources     = ARRAY_SIZE(resources_sdc1),//资源个数

     .resource = resources_sdc1,//指向资源的指针

     .dev     = {

         .coherent_dma_mask = 0xffffffff,

     },

};

platform driver这是描述一个msmsdcc_driver设备驱动的

static struct platform_driver msmsdcc_driver = {

     .probe        = msmsdcc_probe,

     .suspend = msmsdcc_suspend,

     .resume       = msmsdcc_resume,

     .driver       = {

         .name    = "msm_sdcc",

     },

};

描述mmc card的结构体

/*

 * MMC device

 */

struct mmc_card {

     struct mmc_host        *host;        /* the host this device belongs to */

     struct device      dev;     /* the device */

     unsigned int       rca;     /* relative card address of device */

     unsigned int       type;         /* card type */

#define MMC_TYPE_MMC        0        /* MMC card */

#define MMC_TYPE_SD         1        /* SD card */

#define MMC_TYPE_SDIO       2        /* SDIO card */

     unsigned int       state;        /* (our) card state */

#define MMC_STATE_PRESENT   (1<<0)        /* present in sysfs */

#define MMC_STATE_READONLY  (1<<1)        /* card is read-only */

#define MMC_STATE_HIGHSPEED (1<<2)        /* card is in high speed mode */

#define MMC_STATE_BLOCKADDR (1<<3)        /* card uses block-addressing */

     unsigned int       quirks; /* card quirks */

#define MMC_QUIRK_LENIENT_FN0    (1<<0)        /* allow SDIO FN0 writes outside of the VS CCCR range */

#define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1)   /* use func->cur_blksize */

                            /* for byte mode */

 

     u32           raw_cid[4];   /* raw card CID */

     u32           raw_csd[4];   /* raw card CSD */

     u32           raw_scr[2];   /* raw card SCR */

     struct mmc_cid         cid;     /* card identification */

     struct mmc_csd         csd;     /* card specific */

     struct mmc_ext_csd ext_csd; /* mmc v4 extended card specific */

     struct sd_scr      scr;     /* extra SD information */

     struct sd_switch_caps  sw_caps; /* switch (CMD6) caps */

 

     unsigned int       sdio_funcs;   /* number of SDIO functions */

     struct sdio_cccr   cccr;         /* common card info */

     struct sdio_cis        cis;     /* common tuple info */

     struct sdio_func   *sdio_func[SDIO_MAX_FUNCS]; /* SDIO functions (devices) */

     unsigned      num_info; /* number of info strings */

     const char         **info;       /* info strings */

     struct sdio_func_tuple *tuples; /* unknown common tuples */

 

     struct dentry      *debugfs_root;

};

描述mmc card驱动的结构体

static struct mmc_driver mmc_driver = {

     .drv     = {

         .name    = "mmcblk",

     },

     .probe        = mmc_blk_probe,

     .remove       = mmc_blk_remove,

     .suspend = mmc_blk_suspend,

     .resume       = mmc_blk_resume,

};

控制的结构体

struct msmsdcc_host {

     struct resource        *cmd_irqres;

     struct resource        *pio_irqres;

     struct resource        *memres;

     struct resource        *dmares;

     void __iomem       *base;

     int           pdev_id;

     unsigned int       stat_irq;

 

     struct msmsdcc_curr_req curr;

 

     struct mmc_host        *mmc;

     struct clk         *clk;         /* main MMC bus clock */

     struct clk         *pclk;        /* SDCC peripheral bus clock */

     unsigned int       clks_on; /* set if clocks are enabled */

     struct timer_list  busclk_timer;

 

     unsigned int       eject;        /* eject state */

 

     spinlock_t         lock;

 

     unsigned int       clk_rate; /* Current clock rate */

     unsigned int       pclk_rate;

 

     u32           pwr;

     u32           saved_irq0mask;    /* MMCIMASK0 reg value */

     struct mmc_platform_data *plat;

 

     struct timer_list  timer;

     unsigned int       oldstat;

 

     struct msmsdcc_dma_data dma;

     struct msmsdcc_pio_data pio;

     int           cmdpoll;

     struct msmsdcc_stats   stats;

 

#ifdef CONFIG_MMC_MSM7X00A_RESUME_IN_WQ

     struct work_struct resume_task;

#endif

 

     /* Command parameters */

     unsigned int       cmd_timeout;

     unsigned int       cmd_pio_irqmask;

     unsigned int       cmd_datactrl;

     struct mmc_command *cmd_cmd;

     u32           cmd_c;

 

};