xref: /linux/include/linux/mmc/host.h (revision 7aacf86b75bc5523d20fd9127104384fce51ce9c)
1 /*
2  *  linux/include/linux/mmc/host.h
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  *  Host driver specific definitions.
9  */
10 #ifndef LINUX_MMC_HOST_H
11 #define LINUX_MMC_HOST_H
12 
13 #include <linux/sched.h>
14 #include <linux/device.h>
15 #include <linux/fault-inject.h>
16 
17 #include <linux/mmc/core.h>
18 #include <linux/mmc/card.h>
19 #include <linux/mmc/pm.h>
20 #include <linux/dma-direction.h>
21 
22 struct mmc_ios {
23 	unsigned int	clock;			/* clock rate */
24 	unsigned short	vdd;
25 
26 /* vdd stores the bit number of the selected voltage range from below. */
27 
28 	unsigned char	bus_mode;		/* command output mode */
29 
30 #define MMC_BUSMODE_OPENDRAIN	1
31 #define MMC_BUSMODE_PUSHPULL	2
32 
33 	unsigned char	chip_select;		/* SPI chip select */
34 
35 #define MMC_CS_DONTCARE		0
36 #define MMC_CS_HIGH		1
37 #define MMC_CS_LOW		2
38 
39 	unsigned char	power_mode;		/* power supply mode */
40 
41 #define MMC_POWER_OFF		0
42 #define MMC_POWER_UP		1
43 #define MMC_POWER_ON		2
44 #define MMC_POWER_UNDEFINED	3
45 
46 	unsigned char	bus_width;		/* data bus width */
47 
48 #define MMC_BUS_WIDTH_1		0
49 #define MMC_BUS_WIDTH_4		2
50 #define MMC_BUS_WIDTH_8		3
51 
52 	unsigned char	timing;			/* timing specification used */
53 
54 #define MMC_TIMING_LEGACY	0
55 #define MMC_TIMING_MMC_HS	1
56 #define MMC_TIMING_SD_HS	2
57 #define MMC_TIMING_UHS_SDR12	3
58 #define MMC_TIMING_UHS_SDR25	4
59 #define MMC_TIMING_UHS_SDR50	5
60 #define MMC_TIMING_UHS_SDR104	6
61 #define MMC_TIMING_UHS_DDR50	7
62 #define MMC_TIMING_MMC_DDR52	8
63 #define MMC_TIMING_MMC_HS200	9
64 #define MMC_TIMING_MMC_HS400	10
65 
66 	unsigned char	signal_voltage;		/* signalling voltage (1.8V or 3.3V) */
67 
68 #define MMC_SIGNAL_VOLTAGE_330	0
69 #define MMC_SIGNAL_VOLTAGE_180	1
70 #define MMC_SIGNAL_VOLTAGE_120	2
71 
72 	unsigned char	drv_type;		/* driver type (A, B, C, D) */
73 
74 #define MMC_SET_DRIVER_TYPE_B	0
75 #define MMC_SET_DRIVER_TYPE_A	1
76 #define MMC_SET_DRIVER_TYPE_C	2
77 #define MMC_SET_DRIVER_TYPE_D	3
78 
79 	bool enhanced_strobe;			/* hs400es selection */
80 };
81 
82 struct mmc_host;
83 
84 struct mmc_host_ops {
85 	/*
86 	 * It is optional for the host to implement pre_req and post_req in
87 	 * order to support double buffering of requests (prepare one
88 	 * request while another request is active).
89 	 * pre_req() must always be followed by a post_req().
90 	 * To undo a call made to pre_req(), call post_req() with
91 	 * a nonzero err condition.
92 	 */
93 	void	(*post_req)(struct mmc_host *host, struct mmc_request *req,
94 			    int err);
95 	void	(*pre_req)(struct mmc_host *host, struct mmc_request *req);
96 	void	(*request)(struct mmc_host *host, struct mmc_request *req);
97 
98 	/*
99 	 * Avoid calling the next three functions too often or in a "fast
100 	 * path", since underlaying controller might implement them in an
101 	 * expensive and/or slow way. Also note that these functions might
102 	 * sleep, so don't call them in the atomic contexts!
103 	 */
104 
105 	/*
106 	 * Notes to the set_ios callback:
107 	 * ios->clock might be 0. For some controllers, setting 0Hz
108 	 * as any other frequency works. However, some controllers
109 	 * explicitly need to disable the clock. Otherwise e.g. voltage
110 	 * switching might fail because the SDCLK is not really quiet.
111 	 */
112 	void	(*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
113 
114 	/*
115 	 * Return values for the get_ro callback should be:
116 	 *   0 for a read/write card
117 	 *   1 for a read-only card
118 	 *   -ENOSYS when not supported (equal to NULL callback)
119 	 *   or a negative errno value when something bad happened
120 	 */
121 	int	(*get_ro)(struct mmc_host *host);
122 
123 	/*
124 	 * Return values for the get_cd callback should be:
125 	 *   0 for a absent card
126 	 *   1 for a present card
127 	 *   -ENOSYS when not supported (equal to NULL callback)
128 	 *   or a negative errno value when something bad happened
129 	 */
130 	int	(*get_cd)(struct mmc_host *host);
131 
132 	void	(*enable_sdio_irq)(struct mmc_host *host, int enable);
133 	void	(*ack_sdio_irq)(struct mmc_host *host);
134 
135 	/* optional callback for HC quirks */
136 	void	(*init_card)(struct mmc_host *host, struct mmc_card *card);
137 
138 	int	(*start_signal_voltage_switch)(struct mmc_host *host, struct mmc_ios *ios);
139 
140 	/* Check if the card is pulling dat[0:3] low */
141 	int	(*card_busy)(struct mmc_host *host);
142 
143 	/* The tuning command opcode value is different for SD and eMMC cards */
144 	int	(*execute_tuning)(struct mmc_host *host, u32 opcode);
145 
146 	/* Prepare HS400 target operating frequency depending host driver */
147 	int	(*prepare_hs400_tuning)(struct mmc_host *host, struct mmc_ios *ios);
148 	/* Prepare enhanced strobe depending host driver */
149 	void	(*hs400_enhanced_strobe)(struct mmc_host *host,
150 					 struct mmc_ios *ios);
151 	int	(*select_drive_strength)(struct mmc_card *card,
152 					 unsigned int max_dtr, int host_drv,
153 					 int card_drv, int *drv_type);
154 	void	(*hw_reset)(struct mmc_host *host);
155 	void	(*card_event)(struct mmc_host *host);
156 
157 	/*
158 	 * Optional callback to support controllers with HW issues for multiple
159 	 * I/O. Returns the number of supported blocks for the request.
160 	 */
161 	int	(*multi_io_quirk)(struct mmc_card *card,
162 				  unsigned int direction, int blk_size);
163 };
164 
165 struct mmc_async_req {
166 	/* active mmc request */
167 	struct mmc_request	*mrq;
168 	/*
169 	 * Check error status of completed mmc request.
170 	 * Returns 0 if success otherwise non zero.
171 	 */
172 	enum mmc_blk_status (*err_check)(struct mmc_card *, struct mmc_async_req *);
173 };
174 
175 /**
176  * struct mmc_slot - MMC slot functions
177  *
178  * @cd_irq:		MMC/SD-card slot hotplug detection IRQ or -EINVAL
179  * @handler_priv:	MMC/SD-card slot context
180  *
181  * Some MMC/SD host controllers implement slot-functions like card and
182  * write-protect detection natively. However, a large number of controllers
183  * leave these functions to the CPU. This struct provides a hook to attach
184  * such slot-function drivers.
185  */
186 struct mmc_slot {
187 	int cd_irq;
188 	bool cd_wake_enabled;
189 	void *handler_priv;
190 };
191 
192 /**
193  * mmc_context_info - synchronization details for mmc context
194  * @is_done_rcv		wake up reason was done request
195  * @is_new_req		wake up reason was new request
196  * @is_waiting_last_req	mmc context waiting for single running request
197  * @wait		wait queue
198  */
199 struct mmc_context_info {
200 	bool			is_done_rcv;
201 	bool			is_new_req;
202 	bool			is_waiting_last_req;
203 	wait_queue_head_t	wait;
204 };
205 
206 struct regulator;
207 struct mmc_pwrseq;
208 
209 struct mmc_supply {
210 	struct regulator *vmmc;		/* Card power supply */
211 	struct regulator *vqmmc;	/* Optional Vccq supply */
212 };
213 
214 struct mmc_host {
215 	struct device		*parent;
216 	struct device		class_dev;
217 	int			index;
218 	const struct mmc_host_ops *ops;
219 	struct mmc_pwrseq	*pwrseq;
220 	unsigned int		f_min;
221 	unsigned int		f_max;
222 	unsigned int		f_init;
223 	u32			ocr_avail;
224 	u32			ocr_avail_sdio;	/* SDIO-specific OCR */
225 	u32			ocr_avail_sd;	/* SD-specific OCR */
226 	u32			ocr_avail_mmc;	/* MMC-specific OCR */
227 #ifdef CONFIG_PM_SLEEP
228 	struct notifier_block	pm_notify;
229 #endif
230 	u32			max_current_330;
231 	u32			max_current_300;
232 	u32			max_current_180;
233 
234 #define MMC_VDD_165_195		0x00000080	/* VDD voltage 1.65 - 1.95 */
235 #define MMC_VDD_20_21		0x00000100	/* VDD voltage 2.0 ~ 2.1 */
236 #define MMC_VDD_21_22		0x00000200	/* VDD voltage 2.1 ~ 2.2 */
237 #define MMC_VDD_22_23		0x00000400	/* VDD voltage 2.2 ~ 2.3 */
238 #define MMC_VDD_23_24		0x00000800	/* VDD voltage 2.3 ~ 2.4 */
239 #define MMC_VDD_24_25		0x00001000	/* VDD voltage 2.4 ~ 2.5 */
240 #define MMC_VDD_25_26		0x00002000	/* VDD voltage 2.5 ~ 2.6 */
241 #define MMC_VDD_26_27		0x00004000	/* VDD voltage 2.6 ~ 2.7 */
242 #define MMC_VDD_27_28		0x00008000	/* VDD voltage 2.7 ~ 2.8 */
243 #define MMC_VDD_28_29		0x00010000	/* VDD voltage 2.8 ~ 2.9 */
244 #define MMC_VDD_29_30		0x00020000	/* VDD voltage 2.9 ~ 3.0 */
245 #define MMC_VDD_30_31		0x00040000	/* VDD voltage 3.0 ~ 3.1 */
246 #define MMC_VDD_31_32		0x00080000	/* VDD voltage 3.1 ~ 3.2 */
247 #define MMC_VDD_32_33		0x00100000	/* VDD voltage 3.2 ~ 3.3 */
248 #define MMC_VDD_33_34		0x00200000	/* VDD voltage 3.3 ~ 3.4 */
249 #define MMC_VDD_34_35		0x00400000	/* VDD voltage 3.4 ~ 3.5 */
250 #define MMC_VDD_35_36		0x00800000	/* VDD voltage 3.5 ~ 3.6 */
251 
252 	u32			caps;		/* Host capabilities */
253 
254 #define MMC_CAP_4_BIT_DATA	(1 << 0)	/* Can the host do 4 bit transfers */
255 #define MMC_CAP_MMC_HIGHSPEED	(1 << 1)	/* Can do MMC high-speed timing */
256 #define MMC_CAP_SD_HIGHSPEED	(1 << 2)	/* Can do SD high-speed timing */
257 #define MMC_CAP_SDIO_IRQ	(1 << 3)	/* Can signal pending SDIO IRQs */
258 #define MMC_CAP_SPI		(1 << 4)	/* Talks only SPI protocols */
259 #define MMC_CAP_NEEDS_POLL	(1 << 5)	/* Needs polling for card-detection */
260 #define MMC_CAP_8_BIT_DATA	(1 << 6)	/* Can the host do 8 bit transfers */
261 #define MMC_CAP_AGGRESSIVE_PM	(1 << 7)	/* Suspend (e)MMC/SD at idle  */
262 #define MMC_CAP_NONREMOVABLE	(1 << 8)	/* Nonremovable e.g. eMMC */
263 #define MMC_CAP_WAIT_WHILE_BUSY	(1 << 9)	/* Waits while card is busy */
264 #define MMC_CAP_ERASE		(1 << 10)	/* Allow erase/trim commands */
265 #define MMC_CAP_3_3V_DDR	(1 << 11)	/* Host supports eMMC DDR 3.3V */
266 #define MMC_CAP_1_8V_DDR	(1 << 12)	/* Host supports eMMC DDR 1.8V */
267 #define MMC_CAP_1_2V_DDR	(1 << 13)	/* Host supports eMMC DDR 1.2V */
268 #define MMC_CAP_POWER_OFF_CARD	(1 << 14)	/* Can power off after boot */
269 #define MMC_CAP_BUS_WIDTH_TEST	(1 << 15)	/* CMD14/CMD19 bus width ok */
270 #define MMC_CAP_UHS_SDR12	(1 << 16)	/* Host supports UHS SDR12 mode */
271 #define MMC_CAP_UHS_SDR25	(1 << 17)	/* Host supports UHS SDR25 mode */
272 #define MMC_CAP_UHS_SDR50	(1 << 18)	/* Host supports UHS SDR50 mode */
273 #define MMC_CAP_UHS_SDR104	(1 << 19)	/* Host supports UHS SDR104 mode */
274 #define MMC_CAP_UHS_DDR50	(1 << 20)	/* Host supports UHS DDR50 mode */
275 #define MMC_CAP_NO_BOUNCE_BUFF	(1 << 21)	/* Disable bounce buffers on host */
276 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
277 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
278 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
279 #define MMC_CAP_CD_WAKE		(1 << 28)	/* Enable card detect wake */
280 #define MMC_CAP_CMD_DURING_TFR	(1 << 29)	/* Commands during data transfer */
281 #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
282 #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */
283 
284 	u32			caps2;		/* More host capabilities */
285 
286 #define MMC_CAP2_BOOTPART_NOACC	(1 << 0)	/* Boot partition no access */
287 #define MMC_CAP2_FULL_PWR_CYCLE	(1 << 2)	/* Can do full power cycle */
288 #define MMC_CAP2_HS200_1_8V_SDR	(1 << 5)        /* can support */
289 #define MMC_CAP2_HS200_1_2V_SDR	(1 << 6)        /* can support */
290 #define MMC_CAP2_HS200		(MMC_CAP2_HS200_1_8V_SDR | \
291 				 MMC_CAP2_HS200_1_2V_SDR)
292 #define MMC_CAP2_CD_ACTIVE_HIGH	(1 << 10)	/* Card-detect signal active high */
293 #define MMC_CAP2_RO_ACTIVE_HIGH	(1 << 11)	/* Write-protect signal active high */
294 #define MMC_CAP2_PACKED_RD	(1 << 12)	/* Allow packed read */
295 #define MMC_CAP2_PACKED_WR	(1 << 13)	/* Allow packed write */
296 #define MMC_CAP2_PACKED_CMD	(MMC_CAP2_PACKED_RD | \
297 				 MMC_CAP2_PACKED_WR)
298 #define MMC_CAP2_NO_PRESCAN_POWERUP (1 << 14)	/* Don't power up before scan */
299 #define MMC_CAP2_HS400_1_8V	(1 << 15)	/* Can support HS400 1.8V */
300 #define MMC_CAP2_HS400_1_2V	(1 << 16)	/* Can support HS400 1.2V */
301 #define MMC_CAP2_HS400		(MMC_CAP2_HS400_1_8V | \
302 				 MMC_CAP2_HS400_1_2V)
303 #define MMC_CAP2_HSX00_1_2V	(MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V)
304 #define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
305 #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18)	/* No physical write protect pin, assume that card is always read-write */
306 #define MMC_CAP2_NO_SDIO	(1 << 19)	/* Do not send SDIO commands during initialization */
307 #define MMC_CAP2_HS400_ES	(1 << 20)	/* Host supports enhanced strobe */
308 #define MMC_CAP2_NO_SD		(1 << 21)	/* Do not send SD commands during initialization */
309 #define MMC_CAP2_NO_MMC		(1 << 22)	/* Do not send (e)MMC commands during initialization */
310 
311 	mmc_pm_flag_t		pm_caps;	/* supported pm features */
312 
313 	/* host specific block data */
314 	unsigned int		max_seg_size;	/* see blk_queue_max_segment_size */
315 	unsigned short		max_segs;	/* see blk_queue_max_segments */
316 	unsigned short		unused;
317 	unsigned int		max_req_size;	/* maximum number of bytes in one req */
318 	unsigned int		max_blk_size;	/* maximum size of one mmc block */
319 	unsigned int		max_blk_count;	/* maximum number of blocks in one req */
320 	unsigned int		max_busy_timeout; /* max busy timeout in ms */
321 
322 	/* private data */
323 	spinlock_t		lock;		/* lock for claim and bus ops */
324 
325 	struct mmc_ios		ios;		/* current io bus settings */
326 
327 	/* group bitfields together to minimize padding */
328 	unsigned int		use_spi_crc:1;
329 	unsigned int		claimed:1;	/* host exclusively claimed */
330 	unsigned int		bus_dead:1;	/* bus has been released */
331 #ifdef CONFIG_MMC_DEBUG
332 	unsigned int		removed:1;	/* host is being removed */
333 #endif
334 	unsigned int		can_retune:1;	/* re-tuning can be used */
335 	unsigned int		doing_retune:1;	/* re-tuning in progress */
336 	unsigned int		retune_now:1;	/* do re-tuning at next req */
337 	unsigned int		retune_paused:1; /* re-tuning is temporarily disabled */
338 
339 	int			rescan_disable;	/* disable card detection */
340 	int			rescan_entered;	/* used with nonremovable devices */
341 
342 	int			need_retune;	/* re-tuning is needed */
343 	int			hold_retune;	/* hold off re-tuning */
344 	unsigned int		retune_period;	/* re-tuning period in secs */
345 	struct timer_list	retune_timer;	/* for periodic re-tuning */
346 
347 	bool			trigger_card_event; /* card_event necessary */
348 
349 	struct mmc_card		*card;		/* device attached to this host */
350 
351 	wait_queue_head_t	wq;
352 	struct task_struct	*claimer;	/* task that has host claimed */
353 	int			claim_cnt;	/* "claim" nesting count */
354 
355 	struct delayed_work	detect;
356 	int			detect_change;	/* card detect flag */
357 	struct mmc_slot		slot;
358 
359 	const struct mmc_bus_ops *bus_ops;	/* current bus driver */
360 	unsigned int		bus_refs;	/* reference counter */
361 
362 	unsigned int		sdio_irqs;
363 	struct task_struct	*sdio_irq_thread;
364 	struct delayed_work	sdio_irq_work;
365 	bool			sdio_irq_pending;
366 	atomic_t		sdio_irq_thread_abort;
367 
368 	mmc_pm_flag_t		pm_flags;	/* requested pm features */
369 
370 	struct led_trigger	*led;		/* activity led */
371 
372 #ifdef CONFIG_REGULATOR
373 	bool			regulator_enabled; /* regulator state */
374 #endif
375 	struct mmc_supply	supply;
376 
377 	struct dentry		*debugfs_root;
378 
379 	struct mmc_async_req	*areq;		/* active async req */
380 	struct mmc_context_info	context_info;	/* async synchronization info */
381 
382 	/* Ongoing data transfer that allows commands during transfer */
383 	struct mmc_request	*ongoing_mrq;
384 
385 #ifdef CONFIG_FAIL_MMC_REQUEST
386 	struct fault_attr	fail_mmc_request;
387 #endif
388 
389 	unsigned int		actual_clock;	/* Actual HC clock rate */
390 
391 	unsigned int		slotno;	/* used for sdio acpi binding */
392 
393 	int			dsr_req;	/* DSR value is valid */
394 	u32			dsr;	/* optional driver stage (DSR) value */
395 
396 	unsigned long		private[0] ____cacheline_aligned;
397 };
398 
399 struct device_node;
400 
401 struct mmc_host *mmc_alloc_host(int extra, struct device *);
402 int mmc_add_host(struct mmc_host *);
403 void mmc_remove_host(struct mmc_host *);
404 void mmc_free_host(struct mmc_host *);
405 int mmc_of_parse(struct mmc_host *host);
406 int mmc_of_parse_voltage(struct device_node *np, u32 *mask);
407 
408 static inline void *mmc_priv(struct mmc_host *host)
409 {
410 	return (void *)host->private;
411 }
412 
413 #define mmc_host_is_spi(host)	((host)->caps & MMC_CAP_SPI)
414 
415 #define mmc_dev(x)	((x)->parent)
416 #define mmc_classdev(x)	(&(x)->class_dev)
417 #define mmc_hostname(x)	(dev_name(&(x)->class_dev))
418 
419 int mmc_power_save_host(struct mmc_host *host);
420 int mmc_power_restore_host(struct mmc_host *host);
421 
422 void mmc_detect_change(struct mmc_host *, unsigned long delay);
423 void mmc_request_done(struct mmc_host *, struct mmc_request *);
424 void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq);
425 
426 static inline void mmc_signal_sdio_irq(struct mmc_host *host)
427 {
428 	host->ops->enable_sdio_irq(host, 0);
429 	host->sdio_irq_pending = true;
430 	if (host->sdio_irq_thread)
431 		wake_up_process(host->sdio_irq_thread);
432 }
433 
434 void sdio_run_irqs(struct mmc_host *host);
435 void sdio_signal_irq(struct mmc_host *host);
436 
437 #ifdef CONFIG_REGULATOR
438 int mmc_regulator_get_ocrmask(struct regulator *supply);
439 int mmc_regulator_set_ocr(struct mmc_host *mmc,
440 			struct regulator *supply,
441 			unsigned short vdd_bit);
442 int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios);
443 #else
444 static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
445 {
446 	return 0;
447 }
448 
449 static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
450 				 struct regulator *supply,
451 				 unsigned short vdd_bit)
452 {
453 	return 0;
454 }
455 
456 static inline int mmc_regulator_set_vqmmc(struct mmc_host *mmc,
457 					  struct mmc_ios *ios)
458 {
459 	return -EINVAL;
460 }
461 #endif
462 
463 u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
464 int mmc_regulator_get_supply(struct mmc_host *mmc);
465 
466 static inline int mmc_card_is_removable(struct mmc_host *host)
467 {
468 	return !(host->caps & MMC_CAP_NONREMOVABLE);
469 }
470 
471 static inline int mmc_card_keep_power(struct mmc_host *host)
472 {
473 	return host->pm_flags & MMC_PM_KEEP_POWER;
474 }
475 
476 static inline int mmc_card_wake_sdio_irq(struct mmc_host *host)
477 {
478 	return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
479 }
480 
481 /* TODO: Move to private header */
482 static inline int mmc_card_hs(struct mmc_card *card)
483 {
484 	return card->host->ios.timing == MMC_TIMING_SD_HS ||
485 		card->host->ios.timing == MMC_TIMING_MMC_HS;
486 }
487 
488 /* TODO: Move to private header */
489 static inline int mmc_card_uhs(struct mmc_card *card)
490 {
491 	return card->host->ios.timing >= MMC_TIMING_UHS_SDR12 &&
492 		card->host->ios.timing <= MMC_TIMING_UHS_DDR50;
493 }
494 
495 void mmc_retune_timer_stop(struct mmc_host *host);
496 
497 static inline void mmc_retune_needed(struct mmc_host *host)
498 {
499 	if (host->can_retune)
500 		host->need_retune = 1;
501 }
502 
503 static inline bool mmc_can_retune(struct mmc_host *host)
504 {
505 	return host->can_retune == 1;
506 }
507 
508 static inline enum dma_data_direction mmc_get_dma_dir(struct mmc_data *data)
509 {
510 	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
511 }
512 
513 int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error);
514 int mmc_abort_tuning(struct mmc_host *host, u32 opcode);
515 
516 #endif /* LINUX_MMC_HOST_H */
517