include/linux/mmc/host.h - kernel/msm-4.19 - Gitiles

 /*
  *  linux/include/linux/mmc/host.h
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  *  Host driver specific definitions.
  */
 #ifndef LINUX_MMC_HOST_H
 #define LINUX_MMC_HOST_H

 #include <linux/leds.h>
 #include <linux/sched.h>
 #include <linux/fault-inject.h>

 #include <linux/mmc/core.h>
 #include <linux/mmc/pm.h>

 struct mmc_ios {
 	unsigned int	clock;			/* clock rate */
 	unsigned short	vdd;

 /* vdd stores the bit number of the selected voltage range from below. */

 	unsigned char	bus_mode;		/* command output mode */

 #define MMC_BUSMODE_OPENDRAIN	1
 #define MMC_BUSMODE_PUSHPULL	2

 	unsigned char	chip_select;		/* SPI chip select */

 #define MMC_CS_DONTCARE		0
 #define MMC_CS_HIGH		1
 #define MMC_CS_LOW		2

 	unsigned char	power_mode;		/* power supply mode */

 #define MMC_POWER_OFF		0
 #define MMC_POWER_UP		1
 #define MMC_POWER_ON		2

 	unsigned char	bus_width;		/* data bus width */

 #define MMC_BUS_WIDTH_1		0
 #define MMC_BUS_WIDTH_4		2
 #define MMC_BUS_WIDTH_8		3

 	unsigned char	timing;			/* timing specification used */

 #define MMC_TIMING_LEGACY	0
 #define MMC_TIMING_MMC_HS	1
 #define MMC_TIMING_SD_HS	2
 #define MMC_TIMING_UHS_SDR12	MMC_TIMING_LEGACY
 #define MMC_TIMING_UHS_SDR25	MMC_TIMING_SD_HS
 #define MMC_TIMING_UHS_SDR50	3
 #define MMC_TIMING_UHS_SDR104	4
 #define MMC_TIMING_UHS_DDR50	5
 #define MMC_TIMING_MMC_HS200	6

 #define MMC_SDR_MODE		0
 #define MMC_1_2V_DDR_MODE	1
 #define MMC_1_8V_DDR_MODE	2
 #define MMC_1_2V_SDR_MODE	3
 #define MMC_1_8V_SDR_MODE	4

 	unsigned char	signal_voltage;		/* signalling voltage (1.8V or 3.3V) */

 #define MMC_SIGNAL_VOLTAGE_330	0
 #define MMC_SIGNAL_VOLTAGE_180	1
 #define MMC_SIGNAL_VOLTAGE_120	2

 	unsigned char	drv_type;		/* driver type (A, B, C, D) */

 #define MMC_SET_DRIVER_TYPE_B	0
 #define MMC_SET_DRIVER_TYPE_A	1
 #define MMC_SET_DRIVER_TYPE_C	2
 #define MMC_SET_DRIVER_TYPE_D	3
 };

 struct mmc_host_ops {
 	/*
 	 * Hosts that support power saving can use the 'enable' and 'disable'
 	 * methods to exit and enter power saving states. 'enable' is called
 	 * when the host is claimed and 'disable' is called (or scheduled with
 	 * a delay) when the host is released. The 'disable' is scheduled if
 	 * the disable delay set by 'mmc_set_disable_delay()' is non-zero,
 	 * otherwise 'disable' is called immediately. 'disable' may be
 	 * scheduled repeatedly, to permit ever greater power saving at the
 	 * expense of ever greater latency to re-enable. Rescheduling is
 	 * determined by the return value of the 'disable' method. A positive
 	 * value gives the delay in milliseconds.
 	 *
 	 * In the case where a host function (like set_ios) may be called
 	 * with or without the host claimed, enabling and disabling can be
 	 * done directly and will nest correctly. Call 'mmc_host_enable()' and
 	 * 'mmc_host_lazy_disable()' for this purpose, but note that these
 	 * functions must be paired.
 	 *
 	 * Alternatively, 'mmc_host_enable()' may be paired with
 	 * 'mmc_host_disable()' which calls 'disable' immediately.  In this
 	 * case the 'disable' method will be called with 'lazy' set to 0.
 	 * This is mainly useful for error paths.
 	 *
 	 * Because lazy disable may be called from a work queue, the 'disable'
 	 * method must claim the host when 'lazy' != 0, which will work
 	 * correctly because recursion is detected and handled.
 	 */
 	int (*enable)(struct mmc_host *host);
 	int (*disable)(struct mmc_host *host, int lazy);
 	/*
 	 * It is optional for the host to implement pre_req and post_req in
 	 * order to support double buffering of requests (prepare one
 	 * request while another request is active).
 	 * pre_req() must always be followed by a post_req().
 	 * To undo a call made to pre_req(), call post_req() with
 	 * a nonzero err condition.
 	 */
 	void	(*post_req)(struct mmc_host *host, struct mmc_request *req,
 			    int err);
 	void	(*pre_req)(struct mmc_host *host, struct mmc_request *req,
 			   bool is_first_req);
 	void	(*request)(struct mmc_host *host, struct mmc_request *req);
 	/*
 	 * Avoid calling these three functions too often or in a "fast path",
 	 * since underlaying controller might implement them in an expensive
 	 * and/or slow way.
 	 *
 	 * Also note that these functions might sleep, so don't call them
 	 * in the atomic contexts!
 	 *
 	 * Return values for the get_ro callback should be:
 	 *   0 for a read/write card
 	 *   1 for a read-only card
 	 *   -ENOSYS when not supported (equal to NULL callback)
 	 *   or a negative errno value when something bad happened
 	 *
 	 * Return values for the get_cd callback should be:
 	 *   0 for a absent card
 	 *   1 for a present card
 	 *   -ENOSYS when not supported (equal to NULL callback)
 	 *   or a negative errno value when something bad happened
 	 */
 	void	(*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
 	int	(*get_ro)(struct mmc_host *host);
 	int	(*get_cd)(struct mmc_host *host);

 	void	(*enable_sdio_irq)(struct mmc_host *host, int enable);

 	/* optional callback for HC quirks */
 	void	(*init_card)(struct mmc_host *host, struct mmc_card *card);

 	int	(*start_signal_voltage_switch)(struct mmc_host *host, struct mmc_ios *ios);

 	/* The tuning command opcode value is different for SD and eMMC cards */
 	int	(*execute_tuning)(struct mmc_host *host, u32 opcode);
 	void	(*enable_preset_value)(struct mmc_host *host, bool enable);
 	int	(*select_drive_strength)(unsigned int max_dtr, int host_drv, int card_drv);
 	void	(*hw_reset)(struct mmc_host *host);
 };

 struct mmc_card;
 struct device;

 struct mmc_async_req {
 	/* active mmc request */
 	struct mmc_request	*mrq;
 	/*
 	 * Check error status of completed mmc request.
 	 * Returns 0 if success otherwise non zero.
 	 */
 	int (*err_check) (struct mmc_card *, struct mmc_async_req *);
 };

 struct mmc_hotplug {
 	unsigned int irq;
 	void *handler_priv;
 };

 struct mmc_host {
 	struct device		*parent;
 	struct device		class_dev;
 	int			index;
 	const struct mmc_host_ops *ops;
 	unsigned int		f_min;
 	unsigned int		f_max;
 	unsigned int		f_init;
 	u32			ocr_avail;
 	u32			ocr_avail_sdio;	/* SDIO-specific OCR */
 	u32			ocr_avail_sd;	/* SD-specific OCR */
 	u32			ocr_avail_mmc;	/* MMC-specific OCR */
 	struct notifier_block	pm_notify;

 #define MMC_VDD_165_195		0x00000080	/* VDD voltage 1.65 - 1.95 */
 #define MMC_VDD_20_21		0x00000100	/* VDD voltage 2.0 ~ 2.1 */
 #define MMC_VDD_21_22		0x00000200	/* VDD voltage 2.1 ~ 2.2 */
 #define MMC_VDD_22_23		0x00000400	/* VDD voltage 2.2 ~ 2.3 */
 #define MMC_VDD_23_24		0x00000800	/* VDD voltage 2.3 ~ 2.4 */
 #define MMC_VDD_24_25		0x00001000	/* VDD voltage 2.4 ~ 2.5 */
 #define MMC_VDD_25_26		0x00002000	/* VDD voltage 2.5 ~ 2.6 */
 #define MMC_VDD_26_27		0x00004000	/* VDD voltage 2.6 ~ 2.7 */
 #define MMC_VDD_27_28		0x00008000	/* VDD voltage 2.7 ~ 2.8 */
 #define MMC_VDD_28_29		0x00010000	/* VDD voltage 2.8 ~ 2.9 */
 #define MMC_VDD_29_30		0x00020000	/* VDD voltage 2.9 ~ 3.0 */
 #define MMC_VDD_30_31		0x00040000	/* VDD voltage 3.0 ~ 3.1 */
 #define MMC_VDD_31_32		0x00080000	/* VDD voltage 3.1 ~ 3.2 */
 #define MMC_VDD_32_33		0x00100000	/* VDD voltage 3.2 ~ 3.3 */
 #define MMC_VDD_33_34		0x00200000	/* VDD voltage 3.3 ~ 3.4 */
 #define MMC_VDD_34_35		0x00400000	/* VDD voltage 3.4 ~ 3.5 */
 #define MMC_VDD_35_36		0x00800000	/* VDD voltage 3.5 ~ 3.6 */

 	unsigned long		caps;		/* Host capabilities */

 #define MMC_CAP_4_BIT_DATA	(1 << 0)	/* Can the host do 4 bit transfers */
 #define MMC_CAP_MMC_HIGHSPEED	(1 << 1)	/* Can do MMC high-speed timing */
 #define MMC_CAP_SD_HIGHSPEED	(1 << 2)	/* Can do SD high-speed timing */
 #define MMC_CAP_SDIO_IRQ	(1 << 3)	/* Can signal pending SDIO IRQs */
 #define MMC_CAP_SPI		(1 << 4)	/* Talks only SPI protocols */
 #define MMC_CAP_NEEDS_POLL	(1 << 5)	/* Needs polling for card-detection */
 #define MMC_CAP_8_BIT_DATA	(1 << 6)	/* Can the host do 8 bit transfers */
 #define MMC_CAP_DISABLE		(1 << 7)	/* Can the host be disabled */
 #define MMC_CAP_NONREMOVABLE	(1 << 8)	/* Nonremovable e.g. eMMC */
 #define MMC_CAP_WAIT_WHILE_BUSY	(1 << 9)	/* Waits while card is busy */
 #define MMC_CAP_ERASE		(1 << 10)	/* Allow erase/trim commands */
 #define MMC_CAP_1_8V_DDR	(1 << 11)	/* can support */
 						/* DDR mode at 1.8V */
 #define MMC_CAP_1_2V_DDR	(1 << 12)	/* can support */
 						/* DDR mode at 1.2V */
 #define MMC_CAP_POWER_OFF_CARD	(1 << 13)	/* Can power off after boot */
 #define MMC_CAP_BUS_WIDTH_TEST	(1 << 14)	/* CMD14/CMD19 bus width ok */
 #define MMC_CAP_UHS_SDR12	(1 << 15)	/* Host supports UHS SDR12 mode */
 #define MMC_CAP_UHS_SDR25	(1 << 16)	/* Host supports UHS SDR25 mode */
 #define MMC_CAP_UHS_SDR50	(1 << 17)	/* Host supports UHS SDR50 mode */
 #define MMC_CAP_UHS_SDR104	(1 << 18)	/* Host supports UHS SDR104 mode */
 #define MMC_CAP_UHS_DDR50	(1 << 19)	/* Host supports UHS DDR50 mode */
 #define MMC_CAP_SET_XPC_330	(1 << 20)	/* Host supports >150mA current at 3.3V */
 #define MMC_CAP_SET_XPC_300	(1 << 21)	/* Host supports >150mA current at 3.0V */
 #define MMC_CAP_SET_XPC_180	(1 << 22)	/* Host supports >150mA current at 1.8V */
 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
 #define MMC_CAP_MAX_CURRENT_200	(1 << 26)	/* Host max current limit is 200mA */
 #define MMC_CAP_MAX_CURRENT_400	(1 << 27)	/* Host max current limit is 400mA */
 #define MMC_CAP_MAX_CURRENT_600	(1 << 28)	/* Host max current limit is 600mA */
 #define MMC_CAP_MAX_CURRENT_800	(1 << 29)	/* Host max current limit is 800mA */
 #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
 #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */

 	unsigned int		caps2;		/* More host capabilities */

 #define MMC_CAP2_BOOTPART_NOACC	(1 << 0)	/* Boot partition no access */
 #define MMC_CAP2_CACHE_CTRL	(1 << 1)	/* Allow cache control */
 #define MMC_CAP2_POWEROFF_NOTIFY (1 << 2)	/* Notify poweroff supported */
 #define MMC_CAP2_NO_MULTI_READ	(1 << 3)	/* Multiblock reads don't work */
 #define MMC_CAP2_NO_SLEEP_CMD	(1 << 4)	/* Don't allow sleep command */
 #define MMC_CAP2_HS200_1_8V_SDR	(1 << 5)        /* can support */
 #define MMC_CAP2_HS200_1_2V_SDR	(1 << 6)        /* can support */
 #define MMC_CAP2_HS200		(MMC_CAP2_HS200_1_8V_SDR | \
 				 MMC_CAP2_HS200_1_2V_SDR)

 	mmc_pm_flag_t		pm_caps;	/* supported pm features */
 	unsigned int        power_notify_type;
 #define MMC_HOST_PW_NOTIFY_NONE		0
 #define MMC_HOST_PW_NOTIFY_SHORT	1
 #define MMC_HOST_PW_NOTIFY_LONG		2

 #ifdef CONFIG_MMC_CLKGATE
 	int			clk_requests;	/* internal reference counter */
 	unsigned int		clk_delay;	/* number of MCI clk hold cycles */
 	bool			clk_gated;	/* clock gated */
 	struct delayed_work	clk_gate_work; /* delayed clock gate */
 	unsigned int		clk_old;	/* old clock value cache */
 	spinlock_t		clk_lock;	/* lock for clk fields */
 	struct mutex		clk_gate_mutex;	/* mutex for clock gating */
 	struct device_attribute clkgate_delay_attr;
 	unsigned long           clkgate_delay;
 #endif

 	/* host specific block data */
 	unsigned int		max_seg_size;	/* see blk_queue_max_segment_size */
 	unsigned short		max_segs;	/* see blk_queue_max_segments */
 	unsigned short		unused;
 	unsigned int		max_req_size;	/* maximum number of bytes in one req */
 	unsigned int		max_blk_size;	/* maximum size of one mmc block */
 	unsigned int		max_blk_count;	/* maximum number of blocks in one req */
 	unsigned int		max_discard_to;	/* max. discard timeout in ms */

 	/* private data */
 	spinlock_t		lock;		/* lock for claim and bus ops */

 	struct mmc_ios		ios;		/* current io bus settings */
 	u32			ocr;		/* the current OCR setting */

 	/* group bitfields together to minimize padding */
 	unsigned int		use_spi_crc:1;
 	unsigned int		claimed:1;	/* host exclusively claimed */
 	unsigned int		bus_dead:1;	/* bus has been released */
 #ifdef CONFIG_MMC_DEBUG
 	unsigned int		removed:1;	/* host is being removed */
 #endif

 	/* Only used with MMC_CAP_DISABLE */
 	int			enabled;	/* host is enabled */
 	int			rescan_disable;	/* disable card detection */
 	int			nesting_cnt;	/* "enable" nesting count */
 	int			en_dis_recurs;	/* detect recursion */
 	unsigned int		disable_delay;	/* disable delay in msecs */
 	struct delayed_work	disable;	/* disabling work */

 	struct mmc_card		*card;		/* device attached to this host */

 	wait_queue_head_t	wq;
 	struct task_struct	*claimer;	/* task that has host claimed */
 	int			claim_cnt;	/* "claim" nesting count */

 	struct delayed_work	detect;
 	int			detect_change;	/* card detect flag */
 	struct mmc_hotplug	hotplug;

 	const struct mmc_bus_ops *bus_ops;	/* current bus driver */
 	unsigned int		bus_refs;	/* reference counter */

 	unsigned int		sdio_irqs;
 	struct task_struct	*sdio_irq_thread;
 	atomic_t		sdio_irq_thread_abort;

 	mmc_pm_flag_t		pm_flags;	/* requested pm features */

 #ifdef CONFIG_LEDS_TRIGGERS
 	struct led_trigger	*led;		/* activity led */
 #endif

 #ifdef CONFIG_REGULATOR
 	bool			regulator_enabled; /* regulator state */
 #endif

 	struct dentry		*debugfs_root;

 	struct mmc_async_req	*areq;		/* active async req */

 #ifdef CONFIG_FAIL_MMC_REQUEST
 	struct fault_attr	fail_mmc_request;
 #endif

 	unsigned int		actual_clock;	/* Actual HC clock rate */

 	unsigned long		private[0] ____cacheline_aligned;
 };

 extern struct mmc_host *mmc_alloc_host(int extra, struct device *);
 extern int mmc_add_host(struct mmc_host *);
 extern void mmc_remove_host(struct mmc_host *);
 extern void mmc_free_host(struct mmc_host *);

 static inline void *mmc_priv(struct mmc_host *host)
 {
 	return (void *)host->private;
 }

 #define mmc_host_is_spi(host)	((host)->caps & MMC_CAP_SPI)

 #define mmc_dev(x)	((x)->parent)
 #define mmc_classdev(x)	(&(x)->class_dev)
 #define mmc_hostname(x)	(dev_name(&(x)->class_dev))

 extern int mmc_suspend_host(struct mmc_host *);
 extern int mmc_resume_host(struct mmc_host *);

 extern int mmc_power_save_host(struct mmc_host *host);
 extern int mmc_power_restore_host(struct mmc_host *host);

 extern void mmc_detect_change(struct mmc_host *, unsigned long delay);
 extern void mmc_request_done(struct mmc_host *, struct mmc_request *);

 extern int mmc_cache_ctrl(struct mmc_host *, u8);

 static inline void mmc_signal_sdio_irq(struct mmc_host *host)
 {
 	host->ops->enable_sdio_irq(host, 0);
 	wake_up_process(host->sdio_irq_thread);
 }

 struct regulator;

 #ifdef CONFIG_REGULATOR
 int mmc_regulator_get_ocrmask(struct regulator *supply);
 int mmc_regulator_set_ocr(struct mmc_host *mmc,
 			struct regulator *supply,
 			unsigned short vdd_bit);
 #else
 static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
 {
 	return 0;
 }

 static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
 				 struct regulator *supply,
 				 unsigned short vdd_bit)
 {
 	return 0;
 }
 #endif

 int mmc_card_awake(struct mmc_host *host);
 int mmc_card_sleep(struct mmc_host *host);
 int mmc_card_can_sleep(struct mmc_host *host);

 int mmc_host_enable(struct mmc_host *host);
 int mmc_host_disable(struct mmc_host *host);
 int mmc_host_lazy_disable(struct mmc_host *host);
 int mmc_pm_notify(struct notifier_block *notify_block, unsigned long, void *);

 static inline void mmc_set_disable_delay(struct mmc_host *host,
 					 unsigned int disable_delay)
 {
 	host->disable_delay = disable_delay;
 }

 /* Module parameter */
 extern int mmc_assume_removable;

 static inline int mmc_card_is_removable(struct mmc_host *host)
 {
 	return !(host->caps & MMC_CAP_NONREMOVABLE) && mmc_assume_removable;
 }

 static inline int mmc_card_keep_power(struct mmc_host *host)
 {
 	return host->pm_flags & MMC_PM_KEEP_POWER;
 }

 static inline int mmc_card_wake_sdio_irq(struct mmc_host *host)
 {
 	return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
 }

 static inline int mmc_host_cmd23(struct mmc_host *host)
 {
 	return host->caps & MMC_CAP_CMD23;
 }

 static inline int mmc_boot_partition_access(struct mmc_host *host)
 {
 	return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
 }

 #endif /* LINUX_MMC_HOST_H */
	/*
	* linux/include/linux/mmc/host.h
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* Host driver specific definitions.
	*/
	#ifndef LINUX_MMC_HOST_H
	#define LINUX_MMC_HOST_H

	#include <linux/leds.h>
	#include <linux/sched.h>
	#include <linux/fault-inject.h>

	#include <linux/mmc/core.h>
	#include <linux/mmc/pm.h>

	struct mmc_ios {
	unsigned int clock; /* clock rate */
	unsigned short vdd;

	/* vdd stores the bit number of the selected voltage range from below. */

	unsigned char bus_mode; /* command output mode */

	#define MMC_BUSMODE_OPENDRAIN 1
	#define MMC_BUSMODE_PUSHPULL 2

	unsigned char chip_select; /* SPI chip select */

	#define MMC_CS_DONTCARE 0
	#define MMC_CS_HIGH 1
	#define MMC_CS_LOW 2

	unsigned char power_mode; /* power supply mode */

	#define MMC_POWER_OFF 0
	#define MMC_POWER_UP 1
	#define MMC_POWER_ON 2

	unsigned char bus_width; /* data bus width */

	#define MMC_BUS_WIDTH_1 0
	#define MMC_BUS_WIDTH_4 2
	#define MMC_BUS_WIDTH_8 3

	unsigned char timing; /* timing specification used */

	#define MMC_TIMING_LEGACY 0
	#define MMC_TIMING_MMC_HS 1
	#define MMC_TIMING_SD_HS 2
	#define MMC_TIMING_UHS_SDR12 MMC_TIMING_LEGACY
	#define MMC_TIMING_UHS_SDR25 MMC_TIMING_SD_HS
	#define MMC_TIMING_UHS_SDR50 3
	#define MMC_TIMING_UHS_SDR104 4
	#define MMC_TIMING_UHS_DDR50 5
	#define MMC_TIMING_MMC_HS200 6

	#define MMC_SDR_MODE 0
	#define MMC_1_2V_DDR_MODE 1
	#define MMC_1_8V_DDR_MODE 2
	#define MMC_1_2V_SDR_MODE 3
	#define MMC_1_8V_SDR_MODE 4

	unsigned char signal_voltage; /* signalling voltage (1.8V or 3.3V) */

	#define MMC_SIGNAL_VOLTAGE_330 0
	#define MMC_SIGNAL_VOLTAGE_180 1
	#define MMC_SIGNAL_VOLTAGE_120 2

	unsigned char drv_type; /* driver type (A, B, C, D) */

	#define MMC_SET_DRIVER_TYPE_B 0
	#define MMC_SET_DRIVER_TYPE_A 1
	#define MMC_SET_DRIVER_TYPE_C 2
	#define MMC_SET_DRIVER_TYPE_D 3
	};

	struct mmc_host_ops {
	/*
	* Hosts that support power saving can use the 'enable' and 'disable'
	* methods to exit and enter power saving states. 'enable' is called
	* when the host is claimed and 'disable' is called (or scheduled with
	* a delay) when the host is released. The 'disable' is scheduled if
	* the disable delay set by 'mmc_set_disable_delay()' is non-zero,
	* otherwise 'disable' is called immediately. 'disable' may be
	* scheduled repeatedly, to permit ever greater power saving at the
	* expense of ever greater latency to re-enable. Rescheduling is
	* determined by the return value of the 'disable' method. A positive
	* value gives the delay in milliseconds.
	*
	* In the case where a host function (like set_ios) may be called
	* with or without the host claimed, enabling and disabling can be
	* done directly and will nest correctly. Call 'mmc_host_enable()' and
	* 'mmc_host_lazy_disable()' for this purpose, but note that these
	* functions must be paired.
	*
	* Alternatively, 'mmc_host_enable()' may be paired with
	* 'mmc_host_disable()' which calls 'disable' immediately. In this
	* case the 'disable' method will be called with 'lazy' set to 0.
	* This is mainly useful for error paths.
	*
	* Because lazy disable may be called from a work queue, the 'disable'
	* method must claim the host when 'lazy' != 0, which will work
	* correctly because recursion is detected and handled.
	*/
	int (enable)(struct mmc_host host);
	int (disable)(struct mmc_host host, int lazy);
	/*
	* It is optional for the host to implement pre_req and post_req in
	* order to support double buffering of requests (prepare one
	* request while another request is active).
	* pre_req() must always be followed by a post_req().
	* To undo a call made to pre_req(), call post_req() with
	* a nonzero err condition.
	*/
	void (post_req)(struct mmc_host host, struct mmc_request *req,
	int err);
	void (pre_req)(struct mmc_host host, struct mmc_request *req,
	bool is_first_req);
	void (request)(struct mmc_host host, struct mmc_request *req);
	/*
	* Avoid calling these three functions too often or in a "fast path",
	* since underlaying controller might implement them in an expensive
	* and/or slow way.
	*
	* Also note that these functions might sleep, so don't call them
	* in the atomic contexts!
	*
	* Return values for the get_ro callback should be:
	* 0 for a read/write card
	* 1 for a read-only card
	* -ENOSYS when not supported (equal to NULL callback)
	* or a negative errno value when something bad happened
	*
	* Return values for the get_cd callback should be:
	* 0 for a absent card
	* 1 for a present card
	* -ENOSYS when not supported (equal to NULL callback)
	* or a negative errno value when something bad happened
	*/
	void (set_ios)(struct mmc_host host, struct mmc_ios *ios);
	int (get_ro)(struct mmc_host host);
	int (get_cd)(struct mmc_host host);

	void (enable_sdio_irq)(struct mmc_host host, int enable);

	/* optional callback for HC quirks */
	void (init_card)(struct mmc_host host, struct mmc_card *card);

	int (start_signal_voltage_switch)(struct mmc_host host, struct mmc_ios *ios);

	/* The tuning command opcode value is different for SD and eMMC cards */
	int (execute_tuning)(struct mmc_host host, u32 opcode);
	void (enable_preset_value)(struct mmc_host host, bool enable);
	int (*select_drive_strength)(unsigned int max_dtr, int host_drv, int card_drv);
	void (hw_reset)(struct mmc_host host);
	};

	struct mmc_card;
	struct device;

	struct mmc_async_req {
	/* active mmc request */
	struct mmc_request *mrq;
	/*
	* Check error status of completed mmc request.
	* Returns 0 if success otherwise non zero.
	*/
	int (err_check) (struct mmc_card , struct mmc_async_req *);
	};

	struct mmc_hotplug {
	unsigned int irq;
	void *handler_priv;
	};

	struct mmc_host {
	struct device *parent;
	struct device class_dev;
	int index;
	const struct mmc_host_ops *ops;
	unsigned int f_min;
	unsigned int f_max;
	unsigned int f_init;
	u32 ocr_avail;
	u32 ocr_avail_sdio; /* SDIO-specific OCR */
	u32 ocr_avail_sd; /* SD-specific OCR */
	u32 ocr_avail_mmc; /* MMC-specific OCR */
	struct notifier_block pm_notify;

	#define MMC_VDD_165_195 0x00000080 /* VDD voltage 1.65 - 1.95 */
	#define MMC_VDD_20_21 0x00000100 /* VDD voltage 2.0 ~ 2.1 */
	#define MMC_VDD_21_22 0x00000200 /* VDD voltage 2.1 ~ 2.2 */
	#define MMC_VDD_22_23 0x00000400 /* VDD voltage 2.2 ~ 2.3 */
	#define MMC_VDD_23_24 0x00000800 /* VDD voltage 2.3 ~ 2.4 */
	#define MMC_VDD_24_25 0x00001000 /* VDD voltage 2.4 ~ 2.5 */
	#define MMC_VDD_25_26 0x00002000 /* VDD voltage 2.5 ~ 2.6 */
	#define MMC_VDD_26_27 0x00004000 /* VDD voltage 2.6 ~ 2.7 */
	#define MMC_VDD_27_28 0x00008000 /* VDD voltage 2.7 ~ 2.8 */
	#define MMC_VDD_28_29 0x00010000 /* VDD voltage 2.8 ~ 2.9 */
	#define MMC_VDD_29_30 0x00020000 /* VDD voltage 2.9 ~ 3.0 */
	#define MMC_VDD_30_31 0x00040000 /* VDD voltage 3.0 ~ 3.1 */
	#define MMC_VDD_31_32 0x00080000 /* VDD voltage 3.1 ~ 3.2 */
	#define MMC_VDD_32_33 0x00100000 /* VDD voltage 3.2 ~ 3.3 */
	#define MMC_VDD_33_34 0x00200000 /* VDD voltage 3.3 ~ 3.4 */
	#define MMC_VDD_34_35 0x00400000 /* VDD voltage 3.4 ~ 3.5 */
	#define MMC_VDD_35_36 0x00800000 /* VDD voltage 3.5 ~ 3.6 */

	unsigned long caps; /* Host capabilities */

	#define MMC_CAP_4_BIT_DATA (1 << 0) /* Can the host do 4 bit transfers */
	#define MMC_CAP_MMC_HIGHSPEED (1 << 1) /* Can do MMC high-speed timing */
	#define MMC_CAP_SD_HIGHSPEED (1 << 2) /* Can do SD high-speed timing */
	#define MMC_CAP_SDIO_IRQ (1 << 3) /* Can signal pending SDIO IRQs */
	#define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */
	#define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */
	#define MMC_CAP_8_BIT_DATA (1 << 6) /* Can the host do 8 bit transfers */
	#define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */
	#define MMC_CAP_NONREMOVABLE (1 << 8) /* Nonremovable e.g. eMMC */
	#define MMC_CAP_WAIT_WHILE_BUSY (1 << 9) /* Waits while card is busy */
	#define MMC_CAP_ERASE (1 << 10) /* Allow erase/trim commands */
	#define MMC_CAP_1_8V_DDR (1 << 11) /* can support */
	/* DDR mode at 1.8V */
	#define MMC_CAP_1_2V_DDR (1 << 12) /* can support */
	/* DDR mode at 1.2V */
	#define MMC_CAP_POWER_OFF_CARD (1 << 13) /* Can power off after boot */
	#define MMC_CAP_BUS_WIDTH_TEST (1 << 14) /* CMD14/CMD19 bus width ok */
	#define MMC_CAP_UHS_SDR12 (1 << 15) /* Host supports UHS SDR12 mode */
	#define MMC_CAP_UHS_SDR25 (1 << 16) /* Host supports UHS SDR25 mode */
	#define MMC_CAP_UHS_SDR50 (1 << 17) /* Host supports UHS SDR50 mode */
	#define MMC_CAP_UHS_SDR104 (1 << 18) /* Host supports UHS SDR104 mode */
	#define MMC_CAP_UHS_DDR50 (1 << 19) /* Host supports UHS DDR50 mode */
	#define MMC_CAP_SET_XPC_330 (1 << 20) /* Host supports >150mA current at 3.3V */
	#define MMC_CAP_SET_XPC_300 (1 << 21) /* Host supports >150mA current at 3.0V */
	#define MMC_CAP_SET_XPC_180 (1 << 22) /* Host supports >150mA current at 1.8V */
	#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
	#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
	#define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */
	#define MMC_CAP_MAX_CURRENT_200 (1 << 26) /* Host max current limit is 200mA */
	#define MMC_CAP_MAX_CURRENT_400 (1 << 27) /* Host max current limit is 400mA */
	#define MMC_CAP_MAX_CURRENT_600 (1 << 28) /* Host max current limit is 600mA */
	#define MMC_CAP_MAX_CURRENT_800 (1 << 29) /* Host max current limit is 800mA */
	#define MMC_CAP_CMD23 (1 << 30) /* CMD23 supported. */
	#define MMC_CAP_HW_RESET (1 << 31) /* Hardware reset */

	unsigned int caps2; /* More host capabilities */

	#define MMC_CAP2_BOOTPART_NOACC (1 << 0) /* Boot partition no access */
	#define MMC_CAP2_CACHE_CTRL (1 << 1) /* Allow cache control */
	#define MMC_CAP2_POWEROFF_NOTIFY (1 << 2) /* Notify poweroff supported */
	#define MMC_CAP2_NO_MULTI_READ (1 << 3) /* Multiblock reads don't work */
	#define MMC_CAP2_NO_SLEEP_CMD (1 << 4) /* Don't allow sleep command */
	#define MMC_CAP2_HS200_1_8V_SDR (1 << 5) /* can support */
	#define MMC_CAP2_HS200_1_2V_SDR (1 << 6) /* can support */
	#define MMC_CAP2_HS200 (MMC_CAP2_HS200_1_8V_SDR \| \
	MMC_CAP2_HS200_1_2V_SDR)

	mmc_pm_flag_t pm_caps; /* supported pm features */
	unsigned int power_notify_type;
	#define MMC_HOST_PW_NOTIFY_NONE 0
	#define MMC_HOST_PW_NOTIFY_SHORT 1
	#define MMC_HOST_PW_NOTIFY_LONG 2

	#ifdef CONFIG_MMC_CLKGATE
	int clk_requests; /* internal reference counter */
	unsigned int clk_delay; /* number of MCI clk hold cycles */
	bool clk_gated; /* clock gated */
	struct delayed_work clk_gate_work; /* delayed clock gate */
	unsigned int clk_old; /* old clock value cache */
	spinlock_t clk_lock; /* lock for clk fields */
	struct mutex clk_gate_mutex; /* mutex for clock gating */
	struct device_attribute clkgate_delay_attr;
	unsigned long clkgate_delay;
	#endif

	/* host specific block data */
	unsigned int max_seg_size; /* see blk_queue_max_segment_size */
	unsigned short max_segs; /* see blk_queue_max_segments */
	unsigned short unused;
	unsigned int max_req_size; /* maximum number of bytes in one req */
	unsigned int max_blk_size; /* maximum size of one mmc block */
	unsigned int max_blk_count; /* maximum number of blocks in one req */
	unsigned int max_discard_to; /* max. discard timeout in ms */

	/* private data */
	spinlock_t lock; /* lock for claim and bus ops */

	struct mmc_ios ios; /* current io bus settings */
	u32 ocr; /* the current OCR setting */

	/* group bitfields together to minimize padding */
	unsigned int use_spi_crc:1;
	unsigned int claimed:1; /* host exclusively claimed */
	unsigned int bus_dead:1; /* bus has been released */
	#ifdef CONFIG_MMC_DEBUG
	unsigned int removed:1; /* host is being removed */
	#endif

	/* Only used with MMC_CAP_DISABLE */
	int enabled; /* host is enabled */
	int rescan_disable; /* disable card detection */
	int nesting_cnt; /* "enable" nesting count */
	int en_dis_recurs; /* detect recursion */
	unsigned int disable_delay; /* disable delay in msecs */
	struct delayed_work disable; /* disabling work */

	struct mmc_card card; / device attached to this host */

	wait_queue_head_t wq;
	struct task_struct claimer; / task that has host claimed */
	int claim_cnt; /* "claim" nesting count */

	struct delayed_work detect;
	int detect_change; /* card detect flag */
	struct mmc_hotplug hotplug;

	const struct mmc_bus_ops bus_ops; / current bus driver */
	unsigned int bus_refs; /* reference counter */

	unsigned int sdio_irqs;
	struct task_struct *sdio_irq_thread;
	atomic_t sdio_irq_thread_abort;

	mmc_pm_flag_t pm_flags; /* requested pm features */

	#ifdef CONFIG_LEDS_TRIGGERS
	struct led_trigger led; / activity led */
	#endif

	#ifdef CONFIG_REGULATOR
	bool regulator_enabled; /* regulator state */
	#endif

	struct dentry *debugfs_root;

	struct mmc_async_req areq; / active async req */

	#ifdef CONFIG_FAIL_MMC_REQUEST
	struct fault_attr fail_mmc_request;
	#endif

	unsigned int actual_clock; /* Actual HC clock rate */

	unsigned long private[0] ____cacheline_aligned;
	};

	extern struct mmc_host mmc_alloc_host(int extra, struct device );
	extern int mmc_add_host(struct mmc_host *);
	extern void mmc_remove_host(struct mmc_host *);
	extern void mmc_free_host(struct mmc_host *);

	static inline void mmc_priv(struct mmc_host host)
	{
	return (void *)host->private;
	}

	#define mmc_host_is_spi(host) ((host)->caps & MMC_CAP_SPI)

	#define mmc_dev(x) ((x)->parent)
	#define mmc_classdev(x) (&(x)->class_dev)
	#define mmc_hostname(x) (dev_name(&(x)->class_dev))

	extern int mmc_suspend_host(struct mmc_host *);
	extern int mmc_resume_host(struct mmc_host *);

	extern int mmc_power_save_host(struct mmc_host *host);
	extern int mmc_power_restore_host(struct mmc_host *host);

	extern void mmc_detect_change(struct mmc_host *, unsigned long delay);
	extern void mmc_request_done(struct mmc_host , struct mmc_request );

	extern int mmc_cache_ctrl(struct mmc_host *, u8);

	static inline void mmc_signal_sdio_irq(struct mmc_host *host)
	{
	host->ops->enable_sdio_irq(host, 0);
	wake_up_process(host->sdio_irq_thread);
	}

	struct regulator;

	#ifdef CONFIG_REGULATOR
	int mmc_regulator_get_ocrmask(struct regulator *supply);
	int mmc_regulator_set_ocr(struct mmc_host *mmc,
	struct regulator *supply,
	unsigned short vdd_bit);
	#else
	static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
	{
	return 0;
	}

	static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
	struct regulator *supply,
	unsigned short vdd_bit)
	{
	return 0;
	}
	#endif

	int mmc_card_awake(struct mmc_host *host);
	int mmc_card_sleep(struct mmc_host *host);
	int mmc_card_can_sleep(struct mmc_host *host);

	int mmc_host_enable(struct mmc_host *host);
	int mmc_host_disable(struct mmc_host *host);
	int mmc_host_lazy_disable(struct mmc_host *host);
	int mmc_pm_notify(struct notifier_block notify_block, unsigned long, void );

	static inline void mmc_set_disable_delay(struct mmc_host *host,
	unsigned int disable_delay)
	{
	host->disable_delay = disable_delay;
	}

	/* Module parameter */
	extern int mmc_assume_removable;

	static inline int mmc_card_is_removable(struct mmc_host *host)
	{
	return !(host->caps & MMC_CAP_NONREMOVABLE) && mmc_assume_removable;
	}

	static inline int mmc_card_keep_power(struct mmc_host *host)
	{
	return host->pm_flags & MMC_PM_KEEP_POWER;
	}

	static inline int mmc_card_wake_sdio_irq(struct mmc_host *host)
	{
	return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
	}

	static inline int mmc_host_cmd23(struct mmc_host *host)
	{
	return host->caps & MMC_CAP_CMD23;
	}

	static inline int mmc_boot_partition_access(struct mmc_host *host)
	{
	return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
	}

	#endif /* LINUX_MMC_HOST_H */