1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * (C) Copyright 2000-2004
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 
7 #ifndef BLK_H
8 #define BLK_H
9 
10 #include <dm/uclass-id.h>
11 #include <efi.h>
12 
13 #ifdef CONFIG_SYS_64BIT_LBA
14 typedef uint64_t lbaint_t;
15 #define LBAFlength "ll"
16 #else
17 typedef ulong lbaint_t;
18 #define LBAFlength "l"
19 #endif
20 #define LBAF "%" LBAFlength "x"
21 #define LBAFU "%" LBAFlength "u"
22 
23 struct udevice;
24 
blk_enabled(void)25 static inline bool blk_enabled(void)
26 {
27 	return CONFIG_IS_ENABLED(BLK) || IS_ENABLED(CONFIG_SPL_LEGACY_BLOCK);
28 }
29 
30 #define BLK_VEN_SIZE		40
31 #define BLK_PRD_SIZE		20
32 #define BLK_REV_SIZE		8
33 
34 #define PART_FORMAT_PCAT	0x1
35 #define PART_FORMAT_GPT		0x2
36 
37 /*
38  * Identifies the partition table type (ie. MBR vs GPT GUID) signature
39  */
40 enum sig_type {
41 	SIG_TYPE_NONE,
42 	SIG_TYPE_MBR,
43 	SIG_TYPE_GUID,
44 
45 	SIG_TYPE_COUNT			/* Number of signature types */
46 };
47 
48 /*
49  * With driver model (CONFIG_BLK) this is uclass platform data, accessible
50  * with dev_get_uclass_plat(dev)
51  */
52 struct blk_desc {
53 	/*
54 	 * TODO: With driver model we should be able to use the parent
55 	 * device's uclass instead.
56 	 */
57 	enum uclass_id	uclass_id;	/* type of the interface */
58 	int		devnum;		/* device number */
59 	unsigned char	part_type;	/* partition type */
60 	unsigned char	target;		/* target SCSI ID */
61 	unsigned char	lun;		/* target LUN */
62 	unsigned char	hwpart;		/* HW partition, e.g. for eMMC */
63 	unsigned char	type;		/* device type */
64 	unsigned char	removable;	/* removable device */
65 	/* device can use 48bit addr (ATA/ATAPI v7) */
66 	bool	lba48;
67 	unsigned char	atapi;		/* Use ATAPI protocol */
68 	lbaint_t	lba;		/* number of blocks */
69 	unsigned long	blksz;		/* block size */
70 	int		log2blksz;	/* for convenience: log2(blksz) */
71 	char		vendor[BLK_VEN_SIZE + 1]; /* device vendor string */
72 	char		product[BLK_PRD_SIZE + 1]; /* device product number */
73 	char		revision[BLK_REV_SIZE + 1]; /* firmware revision */
74 	enum sig_type	sig_type;	/* Partition table signature type */
75 	union {
76 		uint32_t mbr_sig;	/* MBR integer signature */
77 		efi_guid_t guid_sig;	/* GPT GUID Signature */
78 	};
79 #if CONFIG_IS_ENABLED(BLK)
80 	/*
81 	 * For now we have a few functions which take struct blk_desc as a
82 	 * parameter. This field allows them to look up the associated
83 	 * device. Once these functions are removed we can drop this field.
84 	 */
85 	struct udevice *bdev;
86 #else
87 	unsigned long	(*block_read)(struct blk_desc *block_dev,
88 				      lbaint_t start,
89 				      lbaint_t blkcnt,
90 				      void *buffer);
91 	unsigned long	(*block_write)(struct blk_desc *block_dev,
92 				       lbaint_t start,
93 				       lbaint_t blkcnt,
94 				       const void *buffer);
95 	unsigned long	(*block_erase)(struct blk_desc *block_dev,
96 				       lbaint_t start,
97 				       lbaint_t blkcnt);
98 	void		*priv;		/* driver private struct pointer */
99 #endif
100 };
101 
102 #define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz))
103 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
104 	(PAD_SIZE(size, blk_desc->blksz))
105 
106 #if CONFIG_IS_ENABLED(BLOCK_CACHE)
107 
108 /**
109  * blkcache_init() - initialize the block cache list pointers
110  */
111 int blkcache_init(void);
112 
113 /**
114  * blkcache_read() - attempt to read a set of blocks from cache
115  *
116  * @param iftype - uclass_id_x for type of device
117  * @param dev - device index of particular type
118  * @param start - starting block number
119  * @param blkcnt - number of blocks to read
120  * @param blksz - size in bytes of each block
121  * @param buffer - buffer to contain cached data
122  *
123  * Return: - 1 if block returned from cache, 0 otherwise.
124  */
125 int blkcache_read(int iftype, int dev,
126 		  lbaint_t start, lbaint_t blkcnt,
127 		  unsigned long blksz, void *buffer);
128 
129 /**
130  * blkcache_fill() - make data read from a block device available
131  * to the block cache
132  *
133  * @param iftype - uclass_id_x for type of device
134  * @param dev - device index of particular type
135  * @param start - starting block number
136  * @param blkcnt - number of blocks available
137  * @param blksz - size in bytes of each block
138  * @param buffer - buffer containing data to cache
139  *
140  */
141 void blkcache_fill(int iftype, int dev,
142 		   lbaint_t start, lbaint_t blkcnt,
143 		   unsigned long blksz, void const *buffer);
144 
145 /**
146  * blkcache_invalidate() - discard the cache for a set of blocks
147  * because of a write or device (re)initialization.
148  *
149  * @iftype - UCLASS_ID_ for type of device, or -1 for any
150  * @dev - device index of particular type, if @iftype is not -1
151  */
152 void blkcache_invalidate(int iftype, int dev);
153 
154 /**
155  * blkcache_configure() - configure block cache
156  *
157  * @param blocks - maximum blocks per entry
158  * @param entries - maximum entries in cache
159  */
160 void blkcache_configure(unsigned blocks, unsigned entries);
161 
162 /*
163  * statistics of the block cache
164  */
165 struct block_cache_stats {
166 	unsigned hits;
167 	unsigned misses;
168 	unsigned entries; /* current entry count */
169 	unsigned max_blocks_per_entry;
170 	unsigned max_entries;
171 };
172 
173 /**
174  * get_blkcache_stats() - return statistics and reset
175  *
176  * @param stats - statistics are copied here
177  */
178 void blkcache_stats(struct block_cache_stats *stats);
179 
180 /** blkcache_free() - free all memory allocated to the block cache */
181 void blkcache_free(void);
182 
183 #else
184 
blkcache_read(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void * buffer)185 static inline int blkcache_read(int iftype, int dev,
186 				lbaint_t start, lbaint_t blkcnt,
187 				unsigned long blksz, void *buffer)
188 {
189 	return 0;
190 }
191 
blkcache_fill(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void const * buffer)192 static inline void blkcache_fill(int iftype, int dev,
193 				 lbaint_t start, lbaint_t blkcnt,
194 				 unsigned long blksz, void const *buffer) {}
195 
blkcache_invalidate(int iftype,int dev)196 static inline void blkcache_invalidate(int iftype, int dev) {}
197 
blkcache_free(void)198 static inline void blkcache_free(void) {}
199 
200 #endif
201 
202 #if CONFIG_IS_ENABLED(BLK)
203 struct udevice;
204 
205 /* Operations on block devices */
206 struct blk_ops {
207 	/**
208 	 * read() - read from a block device
209 	 *
210 	 * @dev:	Device to read from
211 	 * @start:	Start block number to read (0=first)
212 	 * @blkcnt:	Number of blocks to read
213 	 * @buffer:	Destination buffer for data read
214 	 * @return number of blocks read, or -ve error number (see the
215 	 * IS_ERR_VALUE() macro
216 	 */
217 	unsigned long (*read)(struct udevice *dev, lbaint_t start,
218 			      lbaint_t blkcnt, void *buffer);
219 
220 	/**
221 	 * write() - write to a block device
222 	 *
223 	 * @dev:	Device to write to
224 	 * @start:	Start block number to write (0=first)
225 	 * @blkcnt:	Number of blocks to write
226 	 * @buffer:	Source buffer for data to write
227 	 * @return number of blocks written, or -ve error number (see the
228 	 * IS_ERR_VALUE() macro
229 	 */
230 	unsigned long (*write)(struct udevice *dev, lbaint_t start,
231 			       lbaint_t blkcnt, const void *buffer);
232 
233 	/**
234 	 * erase() - erase a section of a block device
235 	 *
236 	 * @dev:	Device to (partially) erase
237 	 * @start:	Start block number to erase (0=first)
238 	 * @blkcnt:	Number of blocks to erase
239 	 * @return number of blocks erased, or -ve error number (see the
240 	 * IS_ERR_VALUE() macro
241 	 */
242 	unsigned long (*erase)(struct udevice *dev, lbaint_t start,
243 			       lbaint_t blkcnt);
244 
245 	/**
246 	 * select_hwpart() - select a particular hardware partition
247 	 *
248 	 * Some devices (e.g. MMC) can support partitioning at the hardware
249 	 * level. This is quite separate from the normal idea of
250 	 * software-based partitions. MMC hardware partitions must be
251 	 * explicitly selected. Once selected only the region of the device
252 	 * covered by that partition is accessible.
253 	 *
254 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
255 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
256 	 *
257 	 * @dev:	Block device to update
258 	 * @hwpart:	Hardware partition number to select. 0 means the raw
259 	 *		device, 1 is the first partition, 2 is the second, etc.
260 	 * @return 0 if OK, -ve on error
261 	 */
262 	int (*select_hwpart)(struct udevice *dev, int hwpart);
263 };
264 
265 #define blk_get_ops(dev)	((struct blk_ops *)(dev)->driver->ops)
266 
267 /*
268  * These functions should take struct udevice instead of struct blk_desc,
269  * but this is convenient for migration to driver model. Add a 'd' prefix
270  * to the function operations, so that blk_read(), etc. can be reserved for
271  * functions with the correct arguments.
272  */
273 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
274 			lbaint_t blkcnt, void *buffer);
275 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
276 			 lbaint_t blkcnt, const void *buffer);
277 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
278 			 lbaint_t blkcnt);
279 
280 /**
281  * blk_read() - Read from a block device
282  *
283  * @dev: Device to read from
284  * @start: Start block for the read
285  * @blkcnt: Number of blocks to read
286  * @buf: Place to put the data
287  * @return number of blocks read (which may be less than @blkcnt),
288  * or -ve on error. This never returns 0 unless @blkcnt is 0
289  */
290 long blk_read(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
291 	      void *buffer);
292 
293 /**
294  * blk_write() - Write to a block device
295  *
296  * @dev: Device to write to
297  * @start: Start block for the write
298  * @blkcnt: Number of blocks to write
299  * @buf: Data to write
300  * @return number of blocks written (which may be less than @blkcnt),
301  * or -ve on error. This never returns 0 unless @blkcnt is 0
302  */
303 long blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
304 	       const void *buffer);
305 
306 /**
307  * blk_erase() - Erase part of a block device
308  *
309  * @dev: Device to erase
310  * @start: Start block for the erase
311  * @blkcnt: Number of blocks to erase
312  * @return number of blocks erased (which may be less than @blkcnt),
313  * or -ve on error. This never returns 0 unless @blkcnt is 0
314  */
315 long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
316 
317 /**
318  * blk_find_device() - Find a block device
319  *
320  * This function does not activate the device. The device will be returned
321  * whether or not it is activated.
322  *
323  * @uclass_id:	Interface type (enum uclass_id_t)
324  * @devnum:	Device number (specific to each interface type)
325  * @devp:	the device, if found
326  * Return: 0 if found, -ENODEV if no device found, or other -ve error value
327  */
328 int blk_find_device(int uclass_id, int devnum, struct udevice **devp);
329 
330 /**
331  * blk_get_device() - Find and probe a block device ready for use
332  *
333  * @uclass_id:	Interface type (enum uclass_id_t)
334  * @devnum:	Device number (specific to each interface type)
335  * @devp:	the device, if found
336  * Return: 0 if found, -ENODEV if no device found, or other -ve error value
337  */
338 int blk_get_device(int uclass_id, int devnum, struct udevice **devp);
339 
340 /**
341  * blk_first_device() - Find the first device for a given interface
342  *
343  * The device is probed ready for use
344  *
345  * @devnum:	Device number (specific to each interface type)
346  * @devp:	the device, if found
347  * Return: 0 if found, -ENODEV if no device, or other -ve error value
348  */
349 int blk_first_device(int uclass_id, struct udevice **devp);
350 
351 /**
352  * blk_next_device() - Find the next device for a given interface
353  *
354  * This can be called repeatedly after blk_first_device() to iterate through
355  * all devices of the given interface type.
356  *
357  * The device is probed ready for use
358  *
359  * @devp:	On entry, the previous device returned. On exit, the next
360  *		device, if found
361  * Return: 0 if found, -ENODEV if no device, or other -ve error value
362  */
363 int blk_next_device(struct udevice **devp);
364 
365 /**
366  * blk_create_device() - Create a new block device
367  *
368  * @parent:	Parent of the new device
369  * @drv_name:	Driver name to use for the block device
370  * @name:	Name for the device
371  * @uclass_id:	Interface type (enum uclass_id_t)
372  * @devnum:	Device number, specific to the interface type, or -1 to
373  *		allocate the next available number
374  * @blksz:	Block size of the device in bytes (typically 512)
375  * @lba:	Total number of blocks of the device
376  * @devp:	the new device (which has not been probed)
377  */
378 int blk_create_device(struct udevice *parent, const char *drv_name,
379 		      const char *name, int uclass_id, int devnum, int blksz,
380 		      lbaint_t lba, struct udevice **devp);
381 
382 /**
383  * blk_create_devicef() - Create a new named block device
384  *
385  * @parent:	Parent of the new device
386  * @drv_name:	Driver name to use for the block device
387  * @name:	Name for the device (parent name is prepended)
388  * @uclass_id:	Interface type (enum uclass_id_t)
389  * @devnum:	Device number, specific to the interface type, or -1 to
390  *		allocate the next available number
391  * @blksz:	Block size of the device in bytes (typically 512)
392  * @lba:	Total number of blocks of the device
393  * @devp:	the new device (which has not been probed)
394  */
395 int blk_create_devicef(struct udevice *parent, const char *drv_name,
396 		       const char *name, int uclass_id, int devnum, int blksz,
397 		       lbaint_t lba, struct udevice **devp);
398 
399 /**
400  * blk_probe_or_unbind() - Try to probe
401  *
402  * Try to probe the device, primarily for enumerating partitions.
403  * If it fails, the device itself is unbound since it means that it won't
404  * work any more.
405  *
406  * @dev:	The device to probe
407  * Return:	0 if OK, -ve on error
408  */
409 int blk_probe_or_unbind(struct udevice *dev);
410 
411 /**
412  * blk_unbind_all() - Unbind all device of the given interface type
413  *
414  * The devices are removed and then unbound.
415  *
416  * @uclass_id:	Interface type to unbind
417  * Return: 0 if OK, -ve on error
418  */
419 int blk_unbind_all(int uclass_id);
420 
421 /**
422  * blk_find_max_devnum() - find the maximum device number for an interface type
423  *
424  * Finds the last allocated device number for an interface type @uclass_id. The
425  * next number is safe to use for a newly allocated device.
426  *
427  * @uclass_id:	Interface type to scan
428  * Return: maximum device number found, or -ENODEV if none, or other -ve on
429  * error
430  */
431 int blk_find_max_devnum(enum uclass_id uclass_id);
432 
433 /**
434  * blk_next_free_devnum() - get the next device number for an interface type
435  *
436  * Finds the next number that is safe to use for a newly allocated device for
437  * an interface type @uclass_id.
438  *
439  * @uclass_id:	Interface type to scan
440  * Return: next device number safe to use, or -ve on error
441  */
442 int blk_next_free_devnum(enum uclass_id uclass_id);
443 
444 /**
445  * blk_select_hwpart() - select a hardware partition
446  *
447  * Select a hardware partition if the device supports it (typically MMC does)
448  *
449  * @dev:	Device to update
450  * @hwpart:	Partition number to select
451  * Return: 0 if OK, -ve on error
452  */
453 int blk_select_hwpart(struct udevice *dev, int hwpart);
454 
455 /**
456  * blk_find_from_parent() - find a block device by looking up its parent
457  *
458  * All block devices have a parent 'media' device which provides the block
459  * driver for the block device, ensuring that access to the underlying medium
460  * is available.
461  *
462  * The block device is not activated by this function. See
463  * blk_get_from_parent() for that.
464  *
465  * @parent: Media device
466  * @devp: Returns the associated block device, if any
467  * Returns: 0 if OK, -ENODEV if @parent is not a media device and has no
468  * UCLASS_BLK child
469  */
470 int blk_find_from_parent(struct udevice *parent, struct udevice **devp);
471 
472 /**
473  * blk_get_from_parent() - obtain a block device by looking up its parent
474  *
475  * All block devices have a parent 'media' device which provides the block
476  * driver for the block device, ensuring that access to the underlying medium
477  * is available.
478  *
479  * The block device is probed and ready for use.
480  *
481  * @parent: Media device
482  * @devp: Returns the associated block device, if any
483  * Returns: 0 if OK, -ENODEV if @parent is not a media device and has no
484  * UCLASS_BLK child
485  */
486 int blk_get_from_parent(struct udevice *parent, struct udevice **devp);
487 
488 /**
489  * blk_get_devtype() - Get the device type of a block device
490  *
491  * @dev:	Block device to check
492  * Return: device tree, i.e. the uclass name of its parent, e.g. "mmc"
493  */
494 const char *blk_get_devtype(struct udevice *dev);
495 
496 /**
497  * blk_get_by_device() - Get the block device descriptor for the given device
498  * @dev:	Instance of a storage device (the parent of the block device)
499  *
500  * Return: With block device descriptor on success , NULL if there is no such
501  *	   block device.
502  */
503 struct blk_desc *blk_get_by_device(struct udevice *dev);
504 
505 #else
506 #include <errno.h>
507 /*
508  * These functions should take struct udevice instead of struct blk_desc,
509  * but this is convenient for migration to driver model. Add a 'd' prefix
510  * to the function operations, so that blk_read(), etc. can be reserved for
511  * functions with the correct arguments.
512  */
blk_dread(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,void * buffer)513 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
514 			      lbaint_t blkcnt, void *buffer)
515 {
516 	ulong blks_read;
517 	if (blkcache_read(block_dev->uclass_id, block_dev->devnum,
518 			  start, blkcnt, block_dev->blksz, buffer))
519 		return blkcnt;
520 
521 	/*
522 	 * We could check if block_read is NULL and return -ENOSYS. But this
523 	 * bloats the code slightly (cause some board to fail to build), and
524 	 * it would be an error to try an operation that does not exist.
525 	 */
526 	blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
527 	if (blks_read == blkcnt)
528 		blkcache_fill(block_dev->uclass_id, block_dev->devnum,
529 			      start, blkcnt, block_dev->blksz, buffer);
530 
531 	return blks_read;
532 }
533 
blk_dwrite(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,const void * buffer)534 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
535 			       lbaint_t blkcnt, const void *buffer)
536 {
537 	blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
538 	return block_dev->block_write(block_dev, start, blkcnt, buffer);
539 }
540 
blk_derase(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt)541 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
542 			       lbaint_t blkcnt)
543 {
544 	blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
545 	return block_dev->block_erase(block_dev, start, blkcnt);
546 }
547 
548 /**
549  * struct blk_driver - Driver for block interface types
550  *
551  * This provides access to the block devices for each interface type. One
552  * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
553  * type that is to be supported.
554  *
555  * @uclass_idname:	Interface type name
556  * @uclass_id:		Interface type
557  * @max_devs:		Maximum number of devices supported
558  * @desc:		Pointer to list of devices for this interface type,
559  *			or NULL to use @get_dev() instead
560  */
561 struct blk_driver {
562 	const char *uclass_idname;
563 	enum uclass_id uclass_id;
564 	int max_devs;
565 	struct blk_desc *desc;
566 	/**
567 	 * get_dev() - get a pointer to a block device given its number
568 	 *
569 	 * Each interface allocates its own devices and typically
570 	 * struct blk_desc is contained with the interface's data structure.
571 	 * There is no global numbering for block devices. This method allows
572 	 * the device for an interface type to be obtained when @desc is NULL.
573 	 *
574 	 * @devnum:	Device number (0 for first device on that interface,
575 	 *		1 for second, etc.
576 	 * @descp:	Returns pointer to the block device on success
577 	 * @return 0 if OK, -ve on error
578 	 */
579 	int (*get_dev)(int devnum, struct blk_desc **descp);
580 
581 	/**
582 	 * select_hwpart() - Select a hardware partition
583 	 *
584 	 * Some devices (e.g. MMC) can support partitioning at the hardware
585 	 * level. This is quite separate from the normal idea of
586 	 * software-based partitions. MMC hardware partitions must be
587 	 * explicitly selected. Once selected only the region of the device
588 	 * covered by that partition is accessible.
589 	 *
590 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
591 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
592 	 * Partition 0 is the main user-data partition.
593 	 *
594 	 * @desc:	Block device descriptor
595 	 * @hwpart:	Hardware partition number to select. 0 means the main
596 	 *		user-data partition, 1 is the first partition, 2 is
597 	 *		the second, etc.
598 	 * @return 0 if OK, other value for an error
599 	 */
600 	int (*select_hwpart)(struct blk_desc *desc, int hwpart);
601 };
602 
603 /*
604  * Declare a new U-Boot legacy block driver. New drivers should use driver
605  * model (UCLASS_BLK).
606  */
607 #define U_BOOT_LEGACY_BLK(__name)					\
608 	ll_entry_declare(struct blk_driver, __name, blk_driver)
609 
610 struct blk_driver *blk_driver_lookup_type(int uclass_id);
611 
612 #endif /* !CONFIG_BLK */
613 
614 /**
615  * blk_get_devnum_by_uclass_idname() - Get a block device by type and number
616  *
617  * This looks through the available block devices of the given type, returning
618  * the one with the given @devnum.
619  *
620  * @uclass_id:	Block device type
621  * @devnum:	Device number
622  * Return: point to block device descriptor, or NULL if not found
623  */
624 struct blk_desc *blk_get_devnum_by_uclass_id(enum uclass_id uclass_id, int devnum);
625 
626 /**
627  * blk_get_devnum_by_uclass_id() - Get a block device by type name, and number
628  *
629  * This looks up the block device type based on @uclass_idname, then calls
630  * blk_get_devnum_by_uclass_id().
631  *
632  * @uclass_idname:	Block device type name
633  * @devnum:		Device number
634  * Return: point to block device descriptor, or NULL if not found
635  */
636 struct blk_desc *blk_get_devnum_by_uclass_idname(const char *uclass_idname,
637 					    int devnum);
638 
639 /**
640  * blk_dselect_hwpart() - select a hardware partition
641  *
642  * This selects a hardware partition (such as is supported by MMC). The block
643  * device size may change as this effectively points the block device to a
644  * partition at the hardware level. See the select_hwpart() method above.
645  *
646  * @desc:	Block device descriptor for the device to select
647  * @hwpart:	Partition number to select
648  * Return: 0 if OK, -ve on error
649  */
650 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
651 
652 /**
653  * blk_list_part() - list the partitions for block devices of a given type
654  *
655  * This looks up the partition type for each block device of type @uclass_id,
656  * then displays a list of partitions.
657  *
658  * @uclass_id:	Block device type
659  * Return: 0 if OK, -ENODEV if there is none of that type
660  */
661 int blk_list_part(enum uclass_id uclass_id);
662 
663 /**
664  * blk_list_devices() - list the block devices of a given type
665  *
666  * This lists each block device of the type @uclass_id, showing the capacity
667  * as well as type-specific information.
668  *
669  * @uclass_id:	Block device type
670  */
671 void blk_list_devices(enum uclass_id uclass_id);
672 
673 /**
674  * blk_show_device() - show information about a given block device
675  *
676  * This shows the block device capacity as well as type-specific information.
677  *
678  * @uclass_id:	Block device type
679  * @devnum:	Device number
680  * Return: 0 if OK, -ENODEV for invalid device number
681  */
682 int blk_show_device(enum uclass_id uclass_id, int devnum);
683 
684 /**
685  * blk_print_device_num() - show information about a given block device
686  *
687  * This is similar to blk_show_device() but returns an error if the block
688  * device type is unknown.
689  *
690  * @uclass_id:	Block device type
691  * @devnum:	Device number
692  * Return: 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
693  * device is not connected
694  */
695 int blk_print_device_num(enum uclass_id uclass_id, int devnum);
696 
697 /**
698  * blk_print_part_devnum() - print the partition information for a device
699  *
700  * @uclass_id:	Block device type
701  * @devnum:	Device number
702  * Return: 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
703  * the interface type is not supported, other -ve on other error
704  */
705 int blk_print_part_devnum(enum uclass_id uclass_id, int devnum);
706 
707 /**
708  * blk_read_devnum() - read blocks from a device
709  *
710  * @uclass_id:	Block device type
711  * @devnum:	Device number
712  * @start:	Start block number to read (0=first)
713  * @blkcnt:	Number of blocks to read
714  * @buffer:	Address to write data to
715  * Return: number of blocks read, or -ve error number on error
716  */
717 ulong blk_read_devnum(enum uclass_id uclass_id, int devnum, lbaint_t start,
718 		      lbaint_t blkcnt, void *buffer);
719 
720 /**
721  * blk_write_devnum() - write blocks to a device
722  *
723  * @uclass_id:	Block device type
724  * @devnum:	Device number
725  * @start:	Start block number to write (0=first)
726  * @blkcnt:	Number of blocks to write
727  * @buffer:	Address to read data from
728  * Return: number of blocks written, or -ve error number on error
729  */
730 ulong blk_write_devnum(enum uclass_id uclass_id, int devnum, lbaint_t start,
731 		       lbaint_t blkcnt, const void *buffer);
732 
733 /**
734  * blk_select_hwpart_devnum() - select a hardware partition
735  *
736  * This is similar to blk_dselect_hwpart() but it looks up the interface and
737  * device number.
738  *
739  * @uclass_id:	Block device type
740  * @devnum:	Device number
741  * @hwpart:	Partition number to select
742  * Return: 0 if OK, -ve on error
743  */
744 int blk_select_hwpart_devnum(enum uclass_id uclass_id, int devnum, int hwpart);
745 
746 /**
747  * blk_get_uclass_name() - Get the name of an interface type
748  *
749  * @uclass_id: Interface type to check
750  * Return: name of interface, or NULL if none
751  */
752 const char *blk_get_uclass_name(enum uclass_id uclass_id);
753 
754 /**
755  * blk_common_cmd() - handle common commands with block devices
756  *
757  * @args: Number of arguments to the command (argv[0] is the command itself)
758  * @argv: Command arguments
759  * @uclass_id: Interface type
760  * @cur_devnump: Current device number for this interface type
761  * Return: 0 if OK, CMD_RET_ERROR on error
762  */
763 int blk_common_cmd(int argc, char *const argv[], enum uclass_id uclass_id,
764 		   int *cur_devnump);
765 
766 enum blk_flag_t {
767 	BLKF_FIXED	= 1 << 0,
768 	BLKF_REMOVABLE	= 1 << 1,
769 	BLKF_BOTH	= BLKF_FIXED | BLKF_REMOVABLE,
770 };
771 
772 /**
773  * blk_first_device_err() - Get the first block device
774  *
775  * The device returned is probed if necessary, and ready for use
776  *
777  * @flags: Indicates type of device to return
778  * @devp: Returns pointer to the first device in that uclass, or NULL if none
779  * Return: 0 if found, -ENODEV if not found, other -ve on error
780  */
781 int blk_first_device_err(enum blk_flag_t flags, struct udevice **devp);
782 
783 /**
784  * blk_next_device_err() - Get the next block device
785  *
786  * The device returned is probed if necessary, and ready for use
787  *
788  * @flags: Indicates type of device to return
789  * @devp: On entry, pointer to device to lookup. On exit, returns pointer
790  * to the next device in the uclass if no error occurred, or -ENODEV if
791  * there is no next device.
792  * Return: 0 if found, -ENODEV if not found, other -ve on error
793  */
794 int blk_next_device_err(enum blk_flag_t flags, struct udevice **devp);
795 
796 /**
797  * blk_find_first() - Return the first matching block device
798  * @flags: Indicates type of device to return
799  * @devp:	Returns pointer to device, or NULL on error
800  *
801  * The device is not prepared for use - this is an internal function.
802  * The function uclass_get_device_tail() can be used to probe the device.
803  *
804  * Note that some devices are considered removable until they have been probed
805  *
806  * @return 0 if found, -ENODEV if not found
807  */
808 int blk_find_first(enum blk_flag_t flags, struct udevice **devp);
809 
810 /**
811  * blk_find_next() - Return the next matching block device
812  * @flags: Indicates type of device to return
813  * @devp: On entry, pointer to device to lookup. On exit, returns pointer
814  * to the next device in the same uclass, or NULL if none
815  *
816  * The device is not prepared for use - this is an internal function.
817  * The function uclass_get_device_tail() can be used to probe the device.
818  *
819  * Note that some devices are considered removable until they have been probed
820  *
821  * @return 0 if found, -ENODEV if not found
822  */
823 int blk_find_next(enum blk_flag_t flags, struct udevice **devp);
824 
825 /**
826  * blk_foreach() - iterate through block devices
827  *
828  * This creates a for() loop which works through the available block devices in
829  * order from start to end.
830  *
831  * If for some reason the uclass cannot be found, this does nothing.
832  *
833  * @_flags: Indicates type of device to return
834  * @_pos: struct udevice * to hold the current device. Set to NULL when there
835  * are no more devices.
836  */
837 #define blk_foreach(_flags, _pos) \
838 	for (int _ret = blk_find_first(_flags, &_pos); !_ret && _pos; \
839 	     _ret = blk_find_next(_flags, &_pos))
840 
841 /**
842  * blk_foreach_probe() - Helper function to iteration through block devices
843  *
844  * This creates a for() loop which works through the available devices in
845  * a uclass in order from start to end. Devices are probed if necessary,
846  * and ready for use.
847  *
848  * @flags: Indicates type of device to return
849  * @dev: struct udevice * to hold the current device. Set to NULL when there
850  * are no more devices.
851  */
852 #define blk_foreach_probe(flags, pos)	\
853 	for (int _ret = blk_first_device_err(flags, &(pos)); \
854 	     !_ret && pos; \
855 	     _ret = blk_next_device_err(flags, &(pos)))
856 
857 /**
858  * blk_count_devices() - count the number of devices of a particular type
859  *
860  * @flags: Indicates type of device to find
861  * Return: number of devices matching those flags
862  */
863 int blk_count_devices(enum blk_flag_t flag);
864 
865 #endif
866