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 <bouncebuf.h>
11 #include <dm/uclass-id.h>
12 #include <efi.h>
13 
14 #ifdef CONFIG_SYS_64BIT_LBA
15 typedef uint64_t lbaint_t;
16 #define LBAFlength "ll"
17 #else
18 typedef ulong lbaint_t;
19 #define LBAFlength "l"
20 #endif
21 #define LBAF "%" LBAFlength "x"
22 #define LBAFU "%" LBAFlength "u"
23 
24 #define DEFAULT_BLKSZ		512
25 
26 struct udevice;
27 
blk_enabled(void)28 static inline bool blk_enabled(void)
29 {
30 	return CONFIG_IS_ENABLED(BLK) || IS_ENABLED(CONFIG_SPL_LEGACY_BLOCK);
31 }
32 
33 #define BLK_VEN_SIZE		40
34 #define BLK_PRD_SIZE		20
35 #define BLK_REV_SIZE		8
36 
37 #define PART_FORMAT_PCAT	0x1
38 #define PART_FORMAT_GPT		0x2
39 
40 /*
41  * Identifies the partition table type (ie. MBR vs GPT GUID) signature
42  */
43 enum sig_type {
44 	SIG_TYPE_NONE,
45 	SIG_TYPE_MBR,
46 	SIG_TYPE_GUID,
47 
48 	SIG_TYPE_COUNT			/* Number of signature types */
49 };
50 
51 /*
52  * With driver model (CONFIG_BLK) this is uclass platform data, accessible
53  * with dev_get_uclass_plat(dev)
54  */
55 struct blk_desc {
56 	/*
57 	 * TODO: With driver model we should be able to use the parent
58 	 * device's uclass instead.
59 	 */
60 	enum uclass_id	uclass_id;	/* type of the interface */
61 	int		devnum;		/* device number */
62 	unsigned char	part_type;	/* partition type */
63 	unsigned char	target;		/* target SCSI ID */
64 	unsigned char	lun;		/* target LUN */
65 	unsigned char	hwpart;		/* HW partition, e.g. for eMMC */
66 	unsigned char	type;		/* device type */
67 	unsigned char	removable;	/* removable device */
68 	/* device can use 48bit addr (ATA/ATAPI v7) */
69 	bool	lba48;
70 	unsigned char	atapi;		/* Use ATAPI protocol */
71 	unsigned char	bb;		/* Use bounce buffer */
72 	lbaint_t	lba;		/* number of blocks */
73 	unsigned long	blksz;		/* block size */
74 	int		log2blksz;	/* for convenience: log2(blksz) */
75 	char		vendor[BLK_VEN_SIZE + 1]; /* device vendor string */
76 	char		product[BLK_PRD_SIZE + 1]; /* device product number */
77 	char		revision[BLK_REV_SIZE + 1]; /* firmware revision */
78 	enum sig_type	sig_type;	/* Partition table signature type */
79 	union {
80 		uint32_t mbr_sig;	/* MBR integer signature */
81 		efi_guid_t guid_sig;	/* GPT GUID Signature */
82 	};
83 #if CONFIG_IS_ENABLED(BLK)
84 	/*
85 	 * For now we have a few functions which take struct blk_desc as a
86 	 * parameter. This field allows them to look up the associated
87 	 * device. Once these functions are removed we can drop this field.
88 	 */
89 	struct udevice *bdev;
90 #else
91 	unsigned long	(*block_read)(struct blk_desc *block_dev,
92 				      lbaint_t start,
93 				      lbaint_t blkcnt,
94 				      void *buffer);
95 	unsigned long	(*block_write)(struct blk_desc *block_dev,
96 				       lbaint_t start,
97 				       lbaint_t blkcnt,
98 				       const void *buffer);
99 	unsigned long	(*block_erase)(struct blk_desc *block_dev,
100 				       lbaint_t start,
101 				       lbaint_t blkcnt);
102 	void		*priv;		/* driver private struct pointer */
103 #endif
104 };
105 
106 #define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz))
107 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
108 	(PAD_SIZE(size, blk_desc->blksz))
109 
110 #if CONFIG_IS_ENABLED(BLOCK_CACHE)
111 /**
112  * blkcache_read() - attempt to read a set of blocks from cache
113  *
114  * @param iftype - uclass_id_x for type of device
115  * @param dev - device index of particular type
116  * @param start - starting block number
117  * @param blkcnt - number of blocks to read
118  * @param blksz - size in bytes of each block
119  * @param buffer - buffer to contain cached data
120  *
121  * Return: - 1 if block returned from cache, 0 otherwise.
122  */
123 int blkcache_read(int iftype, int dev,
124 		  lbaint_t start, lbaint_t blkcnt,
125 		  unsigned long blksz, void *buffer);
126 
127 /**
128  * blkcache_fill() - make data read from a block device available
129  * to the block cache
130  *
131  * @param iftype - uclass_id_x for type of device
132  * @param dev - device index of particular type
133  * @param start - starting block number
134  * @param blkcnt - number of blocks available
135  * @param blksz - size in bytes of each block
136  * @param buffer - buffer containing data to cache
137  *
138  */
139 void blkcache_fill(int iftype, int dev,
140 		   lbaint_t start, lbaint_t blkcnt,
141 		   unsigned long blksz, void const *buffer);
142 
143 /**
144  * blkcache_invalidate() - discard the cache for a set of blocks
145  * because of a write or device (re)initialization.
146  *
147  * @iftype - UCLASS_ID_ for type of device, or -1 for any
148  * @dev - device index of particular type, if @iftype is not -1
149  */
150 void blkcache_invalidate(int iftype, int dev);
151 
152 /**
153  * blkcache_configure() - configure block cache
154  *
155  * @param blocks - maximum blocks per entry
156  * @param entries - maximum entries in cache
157  */
158 void blkcache_configure(unsigned blocks, unsigned entries);
159 
160 /*
161  * statistics of the block cache
162  */
163 struct block_cache_stats {
164 	unsigned hits;
165 	unsigned misses;
166 	unsigned entries; /* current entry count */
167 	unsigned max_blocks_per_entry;
168 	unsigned max_entries;
169 };
170 
171 /**
172  * get_blkcache_stats() - return statistics and reset
173  *
174  * @param stats - statistics are copied here
175  */
176 void blkcache_stats(struct block_cache_stats *stats);
177 
178 /** blkcache_free() - free all memory allocated to the block cache */
179 void blkcache_free(void);
180 
181 #else
182 
blkcache_read(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void * buffer)183 static inline int blkcache_read(int iftype, int dev,
184 				lbaint_t start, lbaint_t blkcnt,
185 				unsigned long blksz, void *buffer)
186 {
187 	return 0;
188 }
189 
blkcache_fill(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void const * buffer)190 static inline void blkcache_fill(int iftype, int dev,
191 				 lbaint_t start, lbaint_t blkcnt,
192 				 unsigned long blksz, void const *buffer) {}
193 
blkcache_invalidate(int iftype,int dev)194 static inline void blkcache_invalidate(int iftype, int dev) {}
195 
blkcache_free(void)196 static inline void blkcache_free(void) {}
197 
198 #endif
199 
200 struct udevice;
201 
202 /* Operations on block devices */
203 struct blk_ops {
204 	/**
205 	 * read() - read from a block device
206 	 *
207 	 * @dev:	Device to read from
208 	 * @start:	Start block number to read (0=first)
209 	 * @blkcnt:	Number of blocks to read
210 	 * @buffer:	Destination buffer for data read
211 	 * @return number of blocks read, or -ve error number (see the
212 	 * IS_ERR_VALUE() macro
213 	 */
214 	unsigned long (*read)(struct udevice *dev, lbaint_t start,
215 			      lbaint_t blkcnt, void *buffer);
216 
217 	/**
218 	 * write() - write to a block device
219 	 *
220 	 * @dev:	Device to write to
221 	 * @start:	Start block number to write (0=first)
222 	 * @blkcnt:	Number of blocks to write
223 	 * @buffer:	Source buffer for data to write
224 	 * @return number of blocks written, or -ve error number (see the
225 	 * IS_ERR_VALUE() macro
226 	 */
227 	unsigned long (*write)(struct udevice *dev, lbaint_t start,
228 			       lbaint_t blkcnt, const void *buffer);
229 
230 	/**
231 	 * erase() - erase a section of a block device
232 	 *
233 	 * @dev:	Device to (partially) erase
234 	 * @start:	Start block number to erase (0=first)
235 	 * @blkcnt:	Number of blocks to erase
236 	 * @return number of blocks erased, or -ve error number (see the
237 	 * IS_ERR_VALUE() macro
238 	 */
239 	unsigned long (*erase)(struct udevice *dev, lbaint_t start,
240 			       lbaint_t blkcnt);
241 
242 	/**
243 	 * select_hwpart() - select a particular hardware partition
244 	 *
245 	 * Some devices (e.g. MMC) can support partitioning at the hardware
246 	 * level. This is quite separate from the normal idea of
247 	 * software-based partitions. MMC hardware partitions must be
248 	 * explicitly selected. Once selected only the region of the device
249 	 * covered by that partition is accessible.
250 	 *
251 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
252 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
253 	 *
254 	 * @dev:	Block device to update
255 	 * @hwpart:	Hardware partition number to select. 0 means the raw
256 	 *		device, 1 is the first partition, 2 is the second, etc.
257 	 * @return 0 if OK, -ve on error
258 	 */
259 	int (*select_hwpart)(struct udevice *dev, int hwpart);
260 
261 #if IS_ENABLED(CONFIG_BOUNCE_BUFFER)
262 	/**
263 	 * buffer_aligned() - test memory alignment of block operation buffer
264 	 *
265 	 * Some devices have limited DMA capabilities and require that the
266 	 * buffers passed to them fit specific properties. This optional
267 	 * callback can be used to indicate whether a buffer alignment is
268 	 * suitable for the device DMA or not, and trigger use of generic
269 	 * bounce buffer implementation to help use of unsuitable buffers
270 	 * at the expense of performance degradation.
271 	 *
272 	 * @dev:	Block device associated with the request
273 	 * @state:	Bounce buffer state
274 	 * @return 1 if OK, 0 if unaligned
275 	 */
276 	int (*buffer_aligned)(struct udevice *dev, struct bounce_buffer *state);
277 #endif	/* CONFIG_BOUNCE_BUFFER */
278 };
279 
280 #if CONFIG_IS_ENABLED(BLK)
281 
282 /*
283  * These functions should take struct udevice instead of struct blk_desc,
284  * but this is convenient for migration to driver model. Add a 'd' prefix
285  * to the function operations, so that blk_read(), etc. can be reserved for
286  * functions with the correct arguments.
287  */
288 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
289 			lbaint_t blkcnt, void *buffer);
290 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
291 			 lbaint_t blkcnt, const void *buffer);
292 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
293 			 lbaint_t blkcnt);
294 
295 #endif /* BLK */
296 
297 /**
298  * blk_read() - Read from a block device
299  *
300  * @dev: Device to read from
301  * @start: Start block for the read
302  * @blkcnt: Number of blocks to read
303  * @buf: Place to put the data
304  * @return number of blocks read (which may be less than @blkcnt),
305  * or -ve on error. This never returns 0 unless @blkcnt is 0
306  */
307 long blk_read(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
308 	      void *buffer);
309 
310 /**
311  * blk_write() - Write to a block device
312  *
313  * @dev: Device to write to
314  * @start: Start block for the write
315  * @blkcnt: Number of blocks to write
316  * @buf: Data to write
317  * @return number of blocks written (which may be less than @blkcnt),
318  * or -ve on error. This never returns 0 unless @blkcnt is 0
319  */
320 long blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
321 	       const void *buffer);
322 
323 /**
324  * blk_erase() - Erase part of a block device
325  *
326  * @dev: Device to erase
327  * @start: Start block for the erase
328  * @blkcnt: Number of blocks to erase
329  * @return number of blocks erased (which may be less than @blkcnt),
330  * or -ve on error. This never returns 0 unless @blkcnt is 0
331  */
332 long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
333 
334 /**
335  * blk_find_device() - Find a block device
336  *
337  * This function does not activate the device. The device will be returned
338  * whether or not it is activated.
339  *
340  * @uclass_id:	Interface type (enum uclass_id_t)
341  * @devnum:	Device number (specific to each interface type)
342  * @devp:	the device, if found
343  * Return: 0 if found, -ENODEV if no device found, or other -ve error value
344  */
345 int blk_find_device(int uclass_id, int devnum, struct udevice **devp);
346 
347 /**
348  * blk_get_device() - Find and probe a block device ready for use
349  *
350  * @uclass_id:	Interface type (enum uclass_id_t)
351  * @devnum:	Device number (specific to each interface type)
352  * @devp:	the device, if found
353  * Return: 0 if found, -ENODEV if no device found, or other -ve error value
354  */
355 int blk_get_device(int uclass_id, int devnum, struct udevice **devp);
356 
357 /**
358  * blk_first_device() - Find the first device for a given interface
359  *
360  * The device is probed ready for use
361  *
362  * @devnum:	Device number (specific to each interface type)
363  * @devp:	the device, if found
364  * Return: 0 if found, -ENODEV if no device, or other -ve error value
365  */
366 int blk_first_device(int uclass_id, struct udevice **devp);
367 
368 /**
369  * blk_next_device() - Find the next device for a given interface
370  *
371  * This can be called repeatedly after blk_first_device() to iterate through
372  * all devices of the given interface type.
373  *
374  * The device is probed ready for use
375  *
376  * @devp:	On entry, the previous device returned. On exit, the next
377  *		device, if found
378  * Return: 0 if found, -ENODEV if no device, or other -ve error value
379  */
380 int blk_next_device(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 /**
506  * blk_get_desc() - Get the block device descriptor for the given device number
507  *
508  * @uclass_id:	Interface type
509  * @devnum:	Device number (0 = first)
510  * @descp:	Returns block device descriptor on success
511  * Return: 0 on success, -ENODEV if there is no such device and no device
512  * with a higher device number, -ENOENT if there is no such device but there
513  * is one with a higher number, or other -ve on other error.
514  */
515 int blk_get_desc(enum uclass_id uclass_id, int devnum, struct blk_desc **descp);
516 
517 #if !CONFIG_IS_ENABLED(BLK)
518 
519 #include <errno.h>
520 
521 /*
522  * These functions should take struct udevice instead of struct blk_desc,
523  * but this is convenient for migration to driver model. Add a 'd' prefix
524  * to the function operations, so that blk_read(), etc. can be reserved for
525  * functions with the correct arguments.
526  */
blk_dread(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,void * buffer)527 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
528 			      lbaint_t blkcnt, void *buffer)
529 {
530 	ulong blks_read;
531 	if (blkcache_read(block_dev->uclass_id, block_dev->devnum,
532 			  start, blkcnt, block_dev->blksz, buffer))
533 		return blkcnt;
534 
535 	/*
536 	 * We could check if block_read is NULL and return -ENOSYS. But this
537 	 * bloats the code slightly (cause some board to fail to build), and
538 	 * it would be an error to try an operation that does not exist.
539 	 */
540 	blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
541 	if (blks_read == blkcnt)
542 		blkcache_fill(block_dev->uclass_id, block_dev->devnum,
543 			      start, blkcnt, block_dev->blksz, buffer);
544 
545 	return blks_read;
546 }
547 
blk_dwrite(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,const void * buffer)548 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
549 			       lbaint_t blkcnt, const void *buffer)
550 {
551 	blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
552 	return block_dev->block_write(block_dev, start, blkcnt, buffer);
553 }
554 
blk_derase(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt)555 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
556 			       lbaint_t blkcnt)
557 {
558 	blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
559 	return block_dev->block_erase(block_dev, start, blkcnt);
560 }
561 
562 /**
563  * struct blk_driver - Driver for block interface types
564  *
565  * This provides access to the block devices for each interface type. One
566  * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
567  * type that is to be supported.
568  *
569  * @uclass_idname:	Interface type name
570  * @uclass_id:		Interface type
571  * @max_devs:		Maximum number of devices supported
572  * @desc:		Pointer to list of devices for this interface type,
573  *			or NULL to use @get_dev() instead
574  */
575 struct blk_driver {
576 	const char *uclass_idname;
577 	enum uclass_id uclass_id;
578 	int max_devs;
579 	struct blk_desc *desc;
580 	/**
581 	 * get_dev() - get a pointer to a block device given its number
582 	 *
583 	 * Each interface allocates its own devices and typically
584 	 * struct blk_desc is contained with the interface's data structure.
585 	 * There is no global numbering for block devices. This method allows
586 	 * the device for an interface type to be obtained when @desc is NULL.
587 	 *
588 	 * @devnum:	Device number (0 for first device on that interface,
589 	 *		1 for second, etc.
590 	 * @descp:	Returns pointer to the block device on success
591 	 * @return 0 if OK, -ve on error
592 	 */
593 	int (*get_dev)(int devnum, struct blk_desc **descp);
594 
595 	/**
596 	 * select_hwpart() - Select a hardware partition
597 	 *
598 	 * Some devices (e.g. MMC) can support partitioning at the hardware
599 	 * level. This is quite separate from the normal idea of
600 	 * software-based partitions. MMC hardware partitions must be
601 	 * explicitly selected. Once selected only the region of the device
602 	 * covered by that partition is accessible.
603 	 *
604 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
605 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
606 	 * Partition 0 is the main user-data partition.
607 	 *
608 	 * @desc:	Block device descriptor
609 	 * @hwpart:	Hardware partition number to select. 0 means the main
610 	 *		user-data partition, 1 is the first partition, 2 is
611 	 *		the second, etc.
612 	 * @return 0 if OK, other value for an error
613 	 */
614 	int (*select_hwpart)(struct blk_desc *desc, int hwpart);
615 };
616 
617 /*
618  * Declare a new U-Boot legacy block driver. New drivers should use driver
619  * model (UCLASS_BLK).
620  */
621 #define U_BOOT_LEGACY_BLK(__name)					\
622 	ll_entry_declare(struct blk_driver, __name, blk_driver)
623 
624 struct blk_driver *blk_driver_lookup_type(int uclass_id);
625 
626 #endif /* !CONFIG_BLK */
627 
628 /**
629  * blk_get_devnum_by_uclass_idname() - Get a block device by type and number
630  *
631  * This looks through the available block devices of the given type, returning
632  * the one with the given @devnum.
633  *
634  * @uclass_id:	Block device type
635  * @devnum:	Device number
636  * Return: point to block device descriptor, or NULL if not found
637  */
638 struct blk_desc *blk_get_devnum_by_uclass_id(enum uclass_id uclass_id, int devnum);
639 
640 /**
641  * blk_get_devnum_by_uclass_idname() - Get block device by type name and number
642  *
643  * This looks up the block device type based on @uclass_idname, then calls
644  * blk_get_devnum_by_uclass_id().
645  *
646  * @uclass_idname:	Block device type name
647  * @devnum:		Device number
648  * Return: point to block device descriptor, or NULL if not found
649  */
650 struct blk_desc *blk_get_devnum_by_uclass_idname(const char *uclass_idname,
651 						 int devnum);
652 
653 /**
654  * blk_dselect_hwpart() - select a hardware partition
655  *
656  * This selects a hardware partition (such as is supported by MMC). The block
657  * device size may change as this effectively points the block device to a
658  * partition at the hardware level. See the select_hwpart() method above.
659  *
660  * @desc:	Block device descriptor for the device to select
661  * @hwpart:	Partition number to select
662  * Return: 0 if OK, -ve on error
663  */
664 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
665 
666 /**
667  * blk_list_part() - list the partitions for block devices of a given type
668  *
669  * This looks up the partition type for each block device of type @uclass_id,
670  * then displays a list of partitions.
671  *
672  * @uclass_id:	Block device type
673  * Return: 0 if OK, -ENODEV if there is none of that type
674  */
675 int blk_list_part(enum uclass_id uclass_id);
676 
677 /**
678  * blk_list_devices() - list the block devices of a given type
679  *
680  * This lists each block device of the type @uclass_id, showing the capacity
681  * as well as type-specific information.
682  *
683  * @uclass_id:	Block device type
684  */
685 void blk_list_devices(enum uclass_id uclass_id);
686 
687 /**
688  * blk_show_device() - show information about a given block device
689  *
690  * This shows the block device capacity as well as type-specific information.
691  *
692  * @uclass_id:	Block device type
693  * @devnum:	Device number
694  * Return: 0 if OK, -ENODEV for invalid device number
695  */
696 int blk_show_device(enum uclass_id uclass_id, int devnum);
697 
698 /**
699  * blk_print_device_num() - show information about a given block device
700  *
701  * This is similar to blk_show_device() but returns an error if the block
702  * device type is unknown.
703  *
704  * @uclass_id:	Block device type
705  * @devnum:	Device number
706  * Return: 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
707  * device is not connected
708  */
709 int blk_print_device_num(enum uclass_id uclass_id, int devnum);
710 
711 /**
712  * blk_print_part_devnum() - print the partition information for a device
713  *
714  * @uclass_id:	Block device type
715  * @devnum:	Device number
716  * Return: 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
717  * the interface type is not supported, other -ve on other error
718  */
719 int blk_print_part_devnum(enum uclass_id uclass_id, int devnum);
720 
721 /**
722  * blk_select_hwpart_devnum() - select a hardware partition
723  *
724  * This is similar to blk_dselect_hwpart() but it looks up the interface and
725  * device number.
726  *
727  * @uclass_id:	Block device type
728  * @devnum:	Device number
729  * @hwpart:	Partition number to select
730  * Return: 0 if OK, -ve on error
731  */
732 int blk_select_hwpart_devnum(enum uclass_id uclass_id, int devnum, int hwpart);
733 
734 /**
735  * blk_get_uclass_name() - Get the name of an interface type
736  *
737  * @uclass_id: Interface type to check
738  * Return: name of interface, or NULL if none
739  */
740 const char *blk_get_uclass_name(enum uclass_id uclass_id);
741 
742 /**
743  * blk_common_cmd() - handle common commands with block devices
744  *
745  * @args: Number of arguments to the command (argv[0] is the command itself)
746  * @argv: Command arguments
747  * @uclass_id: Interface type
748  * @cur_devnump: Current device number for this interface type
749  * Return: 0 if OK, CMD_RET_ERROR on error
750  */
751 int blk_common_cmd(int argc, char *const argv[], enum uclass_id uclass_id,
752 		   int *cur_devnump);
753 
754 enum blk_flag_t {
755 	BLKF_FIXED	= 1 << 0,
756 	BLKF_REMOVABLE	= 1 << 1,
757 	BLKF_BOTH	= BLKF_FIXED | BLKF_REMOVABLE,
758 };
759 
760 /**
761  * blk_first_device_err() - Get the first block device
762  *
763  * The device returned is probed if necessary, and ready for use
764  *
765  * @flags: Indicates type of device to return
766  * @devp: Returns pointer to the first device in that uclass, or NULL if none
767  * Return: 0 if found, -ENODEV if not found, other -ve on error
768  */
769 int blk_first_device_err(enum blk_flag_t flags, struct udevice **devp);
770 
771 /**
772  * blk_next_device_err() - Get the next block device
773  *
774  * The device returned is probed if necessary, and ready for use
775  *
776  * @flags: Indicates type of device to return
777  * @devp: On entry, pointer to device to lookup. On exit, returns pointer
778  * to the next device in the uclass if no error occurred, or -ENODEV if
779  * there is no next device.
780  * Return: 0 if found, -ENODEV if not found, other -ve on error
781  */
782 int blk_next_device_err(enum blk_flag_t flags, struct udevice **devp);
783 
784 /**
785  * blk_foreach_probe() - Helper function to iteration through block devices
786  *
787  * This creates a for() loop which works through the available devices in
788  * a uclass in order from start to end. Devices are probed if necessary,
789  * and ready for use.
790  *
791  * @flags: Indicates type of device to return
792  * @dev: struct udevice * to hold the current device. Set to NULL when there
793  * are no more devices.
794  */
795 #define blk_foreach_probe(flags, pos)	\
796 	for (int _ret = blk_first_device_err(flags, &(pos)); \
797 	     !_ret && pos; \
798 	     _ret = blk_next_device_err(flags, &(pos)))
799 
800 /**
801  * blk_count_devices() - count the number of devices of a particular type
802  *
803  * @flags: Indicates type of device to find
804  * Return: number of devices matching those flags
805  */
806 int blk_count_devices(enum blk_flag_t flag);
807 
808 #endif
809