Linux mmc drive frame (2) - important data structures

Outline

data structure	description
struct mmc_host	Mmc host controller is used to indicate a
struct mmc_card	Mmc used to indicate a device (card)
struct mmc_ios	IO bus settings
struct mmc_driver	Mmc card used to indicate drive
struct mmc_bus_ops	Bus operation function set, there mmc, sd, sdio three kinds
struct mmc_host_ops	Host controller operates the set of functions used to describe the function-operator interface card controller, for operating the register function from the host controller to the core layer layer, so that the core layer is isolated from the host controller and a particular
struct mmc_command	It represents a command mmc
struct mmc_data	Data indicate a mmc
struct mmc_request	It represents a request mmc
struct sdio_func	Sdio card can support a lot of Functions, Function corresponds to a struct sdio_func structure on the software, and finally reaction to the driver is a device model

mmc_host

struct mmc_host {
	int			index;
	const struct mmc_host_ops *ops;			/* host控制器操作函数集*/
	u32			ocr_avail;
	u32			ocr_avail_sdio;				/* SDIO-specific OCR */
	u32			ocr_avail_sd;				/* SD-specific OCR */
	u32			ocr_avail_mmc;				/* MMC-specific OCR */
	u32			caps;						/* Host能力标志位 */
	u32			caps2;						/* Host能力标志位2，32位不够再补一个32位 */
	struct mmc_ios		ios;				/* current io bus settings */
	int			rescan_disable;				/* disable card detection */
	int			rescan_entered;				/* used with nonremovable devices */
	struct mmc_card		*card;				/* 用来表示一个挂在当前host上的mmc设备（卡） */
	struct delayed_work	detect;				/* 卡检测函数 */
	int			detect_change;				/* 卡检测标志 */
	struct mmc_slot		slot;
	const struct mmc_bus_ops *bus_ops;		/* 当前总线操作函数集，mmc/sd/sdio */
	struct mmc_supply	supply;
	unsigned int		slotno;				/* used for sdio acpi binding */
	int			dsr_req;					/* DSR value is valid */
	u32			dsr;						/* optional driver stage (DSR) value */
	unsigned long		private[0] ____cacheline_aligned;
}

mmc_card

struct mmc_card {
    struct mmc_host     *host;        		/* 设备（卡）对应的host数据结构 */
    struct device       dev;          		/* the device */
    u32                 ocr;          		/* 当前 OCR 设定*/
    unsigned int        rca;          		/* relative card address of device */
    unsigned int        type;         		/* Card类型: MMC、SD、SDIO、COMBO */
    unsigned int        state;        		/* 当前卡的状态 */
    unsigned int        quirks;       		/* card quirks */
    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_ssr       ssr;          		/* yet more 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[7];     	/* SDIO functions (devices) */
    unsigned int        sd_bus_speed;      	/* Bus Speed Mode set for the card */
    unsigned int        mmc_avail_type;    	/* supported device type by both host and card */
    unsigned int        drive_strength;    	/* for UHS-I, HS200 or HS400 */
};

mmc_ios

struct mmc_ios {
	unsigned int	clock;					/* 时钟频率 */
	unsigned short	vdd;
	unsigned char	bus_mode;				/* 命令输出模式: 开漏模式、上拉模式 */
	unsigned char	chip_select;			/* SPI片选 */
	unsigned char	power_mode;				/* 电源供应模式：UNDEFINED、OFF、UP、ON */
	unsigned char	bus_width;				/* 数据总线宽度：1、4、8 */
	unsigned char	timing;					/* timing specification used */
	unsigned char	signal_voltage;			/* 信号电压值(1.8V or 3.3V) */
	unsigned char	drv_type;				/* 驱动了恶性type (A, B, C, D) */
	bool enhanced_strobe;					/* hs400es selection */
}

mmc_dirver

struct mmc_driver {
	struct device_driver drv;
	int (*probe)(struct mmc_card *card);
	void (*remove)(struct mmc_card *card);
	void (*shutdown)(struct mmc_card *card);
};

mmc_bus_ops

struct mmc_bus_ops {
	void (*remove)(struct mmc_host *);
	void (*detect)(struct mmc_host *);
	int (*pre_suspend)(struct mmc_host *);
	int (*suspend)(struct mmc_host *);
	int (*resume)(struct mmc_host *);
	int (*runtime_suspend)(struct mmc_host *);
	int (*runtime_resume)(struct mmc_host *);
	int (*power_save)(struct mmc_host *);
	int (*power_restore)(struct mmc_host *);
	int (*alive)(struct mmc_host *);
	int (*shutdown)(struct mmc_host *);
	int (*reset)(struct mmc_host *);
};

mmc_host_ops

struct mmc_host_ops {
    void    (*post_req)(struct mmc_host *, struct mmc_request *, int err);
    void    (*pre_req)(struct mmc_host *, struct mmc_request *, bool is_first_req);
    void    (*request)(struct mmc_host *host, struct mmc_request *req);
    void    (*set_ios)(struct mmc_host *, struct mmc_ios *);
    int     (*get_ro)(struct mmc_host *);
    int     (*get_cd)(struct mmc_host *);
    void    (*enable_sdio_irq)(struct mmc_host *, int enable);
    void    (*init_card)(struct mmc_host *, struct mmc_card *card);
    int     (*start_signal_voltage_switch)(struct mmc_host *, struct mmc_ios *);
    int     (*card_busy)(struct mmc_host *);
    int     (*execute_tuning)(struct mmc_host *, u32 opcode);
    int     (*prepare_hs400_tuning)(struct mmc_host *host, struct mmc_ios *ios);
    void    (*hs400_enhanced_strobe)(struct mmc_host *, struct mmc_ios *);
    int     (*select_drive_strength)(struct mmc_card *card,
                  unsigned int max_dtr, int host_drv, int card_drv, int *drv_type);
    void    (*hw_reset)(struct mmc_host *);
    void    (*card_event)(struct mmc_host *);
    int     (*multi_io_quirk)(struct mmc_card *, unsigned int direction, int blk_size);
};

mmc_command

struct mmc_command {
	u32			opcode;						/* command的操作码 */
	u32			arg;						/* command携带的参数 */
	u32			resp[4];					/* command发出后，如果需要应答，结果保存在resp数组中，最多可以保存128bits的应答 */
	unsigned int	flags;					/* 期望的应答类型 */
	unsigned int	retries;				/* 最大重发的次数 */
	int				error;					/* 如果最终还是出错，通过该字段返回错误的原因 */
	unsigned int	busy_timeout;			/* busy detect timeout in ms */
	bool			sanitize_busy;			/* Set this flag only for blocking sanitize request */
	struct mmc_data		*data;				/* data segment associated with cmd */
	struct mmc_request	*mrq;				/* associated request */
}

mmc_data

struct mmc_data {
	unsigned int		timeout_ns;			/* data timeout (in ns, max 80ms) */
	unsigned int		timeout_clks;		/* data timeout (in clocks) */
	unsigned int		blksz;				/* data block size */
	unsigned int		blocks;				/* number of blocks */
	unsigned int		blk_addr;			/* block address */
	int					error;				/* 如果数据出错，错误值保存在该字段 */
	unsigned int		flags;				/* 指明数据传输的方向，可采用下面的宏定义 */

#define MMC_DATA_WRITE		BIT(8)
#define MMC_DATA_READ		BIT(9)
/* Extra flags used by CQE */
#define MMC_DATA_QBR		BIT(10)			/* CQE queue barrier*/
#define MMC_DATA_PRIO		BIT(11)			/* CQE high priority */
#define MMC_DATA_REL_WR		BIT(12)			/* Reliable write */
#define MMC_DATA_DAT_TAG	BIT(13)			/* Tag request */
#define MMC_DATA_FORCED_PRG	BIT(14)			/* Forced programming */

	unsigned int		bytes_xfered;

	struct mmc_command	*stop;				/* stop command */
	struct mmc_request	*mrq;				/* associated request */

	unsigned int		sg_len;				/* sg数组的长度 */
	int					sg_count;			/* sg数组的个数 */
	struct scatterlist	*sg;				/* 保存需要传输的数据数组 */
	s32					host_cookie;		/* host private data */
}

mmc_request

struct mmc_request {
	struct mmc_command	*cmd;				/* start command，必须设置 */
	struct mmc_data		*data;				/* 传输的数据，非必须 */
	struct mmc_command	*stop;
 
	void *done_data;						/* completion data */
	void (*done)(struct mmc_request *);		/* 传输完成时的回调函数，用于通知传输请求的发起者 */
};

sdio_func

struct sdio_func {
	struct mmc_card		*card;		/* the card this device belongs to */
	struct device		dev;		/* the device */
	sdio_irq_handler_t	*irq_handler;	/* IRQ callback */
	unsigned int		num;		/* function number */
	unsigned char		class;		/* standard interface class */
	unsigned short		vendor;		/* vendor id */
	unsigned short		device;		/* device id */
	unsigned		max_blksize;	/* maximum block size */
	unsigned		cur_blksize;	/* current block size */
	unsigned		enable_timeout;	/* max enable timeout in msec */
	unsigned int		state;		/* function state */
#define SDIO_STATE_PRESENT	(1<<0)		/* present in sysfs */
	u8			*tmpbuf;	/* DMA:able scratch buffer */
	unsigned		num_info;	/* number of info strings */
	const char		**info;		/* info strings */
	struct sdio_func_tuple *tuples;
}