1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * (C) Copyright 2000-2004
10 #include <dm/uclass-id.h>
13 #ifdef CONFIG_SYS_64BIT_LBA
14 typedef uint64_t lbaint_t;
15 #define LBAFlength "ll"
17 typedef ulong lbaint_t;
18 #define LBAFlength "l"
20 #define LBAF "%" LBAFlength "x"
21 #define LBAFU "%" LBAFlength "u"
25 static inline bool blk_enabled(void)
27 return CONFIG_IS_ENABLED(BLK) || IS_ENABLED(CONFIG_SPL_LEGACY_BLOCK);
30 #define BLK_VEN_SIZE 40
31 #define BLK_PRD_SIZE 20
32 #define BLK_REV_SIZE 8
34 #define PART_FORMAT_PCAT 0x1
35 #define PART_FORMAT_GPT 0x2
38 * Identifies the partition table type (ie. MBR vs GPT GUID) signature
45 SIG_TYPE_COUNT /* Number of signature types */
49 * With driver model (CONFIG_BLK) this is uclass platform data, accessible
50 * with dev_get_uclass_plat(dev)
54 * TODO: With driver model we should be able to use the parent
55 * device's uclass instead.
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 */
66 /* device can use 48bit addr (ATA/ATAPI v7) */
69 lbaint_t lba; /* number of blocks */
70 unsigned long blksz; /* block size */
71 int log2blksz; /* for convenience: log2(blksz) */
72 char vendor[BLK_VEN_SIZE + 1]; /* device vendor string */
73 char product[BLK_PRD_SIZE + 1]; /* device product number */
74 char revision[BLK_REV_SIZE + 1]; /* firmware revision */
75 enum sig_type sig_type; /* Partition table signature type */
77 uint32_t mbr_sig; /* MBR integer signature */
78 efi_guid_t guid_sig; /* GPT GUID Signature */
80 #if CONFIG_IS_ENABLED(BLK)
82 * For now we have a few functions which take struct blk_desc as a
83 * parameter. This field allows them to look up the associated
84 * device. Once these functions are removed we can drop this field.
88 unsigned long (*block_read)(struct blk_desc *block_dev,
92 unsigned long (*block_write)(struct blk_desc *block_dev,
96 unsigned long (*block_erase)(struct blk_desc *block_dev,
99 void *priv; /* driver private struct pointer */
103 #define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz))
104 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
105 (PAD_SIZE(size, blk_desc->blksz))
107 #if CONFIG_IS_ENABLED(BLOCK_CACHE)
110 * blkcache_init() - initialize the block cache list pointers
112 int blkcache_init(void);
115 * blkcache_read() - attempt to read a set of blocks from cache
117 * @param iftype - uclass_id_x for type of device
118 * @param dev - device index of particular type
119 * @param start - starting block number
120 * @param blkcnt - number of blocks to read
121 * @param blksz - size in bytes of each block
122 * @param buffer - buffer to contain cached data
124 * Return: - 1 if block returned from cache, 0 otherwise.
126 int blkcache_read(int iftype, int dev,
127 lbaint_t start, lbaint_t blkcnt,
128 unsigned long blksz, void *buffer);
131 * blkcache_fill() - make data read from a block device available
134 * @param iftype - uclass_id_x for type of device
135 * @param dev - device index of particular type
136 * @param start - starting block number
137 * @param blkcnt - number of blocks available
138 * @param blksz - size in bytes of each block
139 * @param buffer - buffer containing data to cache
142 void blkcache_fill(int iftype, int dev,
143 lbaint_t start, lbaint_t blkcnt,
144 unsigned long blksz, void const *buffer);
147 * blkcache_invalidate() - discard the cache for a set of blocks
148 * because of a write or device (re)initialization.
150 * @param iftype - uclass_id_x for type of device
151 * @param dev - device index of particular type
153 void blkcache_invalidate(int iftype, int dev);
156 * blkcache_configure() - configure block cache
158 * @param blocks - maximum blocks per entry
159 * @param entries - maximum entries in cache
161 void blkcache_configure(unsigned blocks, unsigned entries);
164 * statistics of the block cache
166 struct block_cache_stats {
169 unsigned entries; /* current entry count */
170 unsigned max_blocks_per_entry;
171 unsigned max_entries;
175 * get_blkcache_stats() - return statistics and reset
177 * @param stats - statistics are copied here
179 void blkcache_stats(struct block_cache_stats *stats);
183 static inline int blkcache_read(int iftype, int dev,
184 lbaint_t start, lbaint_t blkcnt,
185 unsigned long blksz, void *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) {}
194 static inline void blkcache_invalidate(int iftype, int dev) {}
198 #if CONFIG_IS_ENABLED(BLK)
201 /* Operations on block devices */
204 * read() - read from a block device
206 * @dev: Device to read from
207 * @start: Start block number to read (0=first)
208 * @blkcnt: Number of blocks to read
209 * @buffer: Destination buffer for data read
210 * @return number of blocks read, or -ve error number (see the
211 * IS_ERR_VALUE() macro
213 unsigned long (*read)(struct udevice *dev, lbaint_t start,
214 lbaint_t blkcnt, void *buffer);
217 * write() - write to a block device
219 * @dev: Device to write to
220 * @start: Start block number to write (0=first)
221 * @blkcnt: Number of blocks to write
222 * @buffer: Source buffer for data to write
223 * @return number of blocks written, or -ve error number (see the
224 * IS_ERR_VALUE() macro
226 unsigned long (*write)(struct udevice *dev, lbaint_t start,
227 lbaint_t blkcnt, const void *buffer);
230 * erase() - erase a section of a block device
232 * @dev: Device to (partially) erase
233 * @start: Start block number to erase (0=first)
234 * @blkcnt: Number of blocks to erase
235 * @return number of blocks erased, or -ve error number (see the
236 * IS_ERR_VALUE() macro
238 unsigned long (*erase)(struct udevice *dev, lbaint_t start,
242 * select_hwpart() - select a particular hardware partition
244 * Some devices (e.g. MMC) can support partitioning at the hardware
245 * level. This is quite separate from the normal idea of
246 * software-based partitions. MMC hardware partitions must be
247 * explicitly selected. Once selected only the region of the device
248 * covered by that partition is accessible.
250 * The MMC standard provides for two boot partitions (numbered 1 and 2),
251 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
253 * @dev: Block device to update
254 * @hwpart: Hardware partition number to select. 0 means the raw
255 * device, 1 is the first partition, 2 is the second, etc.
256 * @return 0 if OK, -ve on error
258 int (*select_hwpart)(struct udevice *dev, int hwpart);
261 #define blk_get_ops(dev) ((struct blk_ops *)(dev)->driver->ops)
264 * These functions should take struct udevice instead of struct blk_desc,
265 * but this is convenient for migration to driver model. Add a 'd' prefix
266 * to the function operations, so that blk_read(), etc. can be reserved for
267 * functions with the correct arguments.
269 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
270 lbaint_t blkcnt, void *buffer);
271 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
272 lbaint_t blkcnt, const void *buffer);
273 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
277 * blk_read() - Read from a block device
279 * @dev: Device to read from
280 * @start: Start block for the read
281 * @blkcnt: Number of blocks to read
282 * @buf: Place to put the data
283 * @return number of blocks read (which may be less than @blkcnt),
284 * or -ve on error. This never returns 0 unless @blkcnt is 0
286 long blk_read(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
290 * blk_write() - Write to a block device
292 * @dev: Device to write to
293 * @start: Start block for the write
294 * @blkcnt: Number of blocks to write
295 * @buf: Data to write
296 * @return number of blocks written (which may be less than @blkcnt),
297 * or -ve on error. This never returns 0 unless @blkcnt is 0
299 long blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
303 * blk_erase() - Erase part of a block device
305 * @dev: Device to erase
306 * @start: Start block for the erase
307 * @blkcnt: Number of blocks to erase
308 * @return number of blocks erased (which may be less than @blkcnt),
309 * or -ve on error. This never returns 0 unless @blkcnt is 0
311 long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
314 * blk_find_device() - Find a block device
316 * This function does not activate the device. The device will be returned
317 * whether or not it is activated.
319 * @uclass_id: Interface type (enum uclass_id_t)
320 * @devnum: Device number (specific to each interface type)
321 * @devp: the device, if found
322 * Return: 0 if found, -ENODEV if no device found, or other -ve error value
324 int blk_find_device(int uclass_id, int devnum, struct udevice **devp);
327 * blk_get_device() - Find and probe a block device ready for use
329 * @uclass_id: Interface type (enum uclass_id_t)
330 * @devnum: Device number (specific to each interface type)
331 * @devp: the device, if found
332 * Return: 0 if found, -ENODEV if no device found, or other -ve error value
334 int blk_get_device(int uclass_id, int devnum, struct udevice **devp);
337 * blk_first_device() - Find the first device for a given interface
339 * The device is probed ready for use
341 * @devnum: Device number (specific to each interface type)
342 * @devp: the device, if found
343 * Return: 0 if found, -ENODEV if no device, or other -ve error value
345 int blk_first_device(int uclass_id, struct udevice **devp);
348 * blk_next_device() - Find the next device for a given interface
350 * This can be called repeatedly after blk_first_device() to iterate through
351 * all devices of the given interface type.
353 * The device is probed ready for use
355 * @devp: On entry, the previous device returned. On exit, the next
357 * Return: 0 if found, -ENODEV if no device, or other -ve error value
359 int blk_next_device(struct udevice **devp);
362 * blk_create_device() - Create a new block device
364 * @parent: Parent of the new device
365 * @drv_name: Driver name to use for the block device
366 * @name: Name for the device
367 * @uclass_id: Interface type (enum uclass_id_t)
368 * @devnum: Device number, specific to the interface type, or -1 to
369 * allocate the next available number
370 * @blksz: Block size of the device in bytes (typically 512)
371 * @lba: Total number of blocks of the device
372 * @devp: the new device (which has not been probed)
374 int blk_create_device(struct udevice *parent, const char *drv_name,
375 const char *name, int uclass_id, int devnum, int blksz,
376 lbaint_t lba, struct udevice **devp);
379 * blk_create_devicef() - Create a new named block device
381 * @parent: Parent of the new device
382 * @drv_name: Driver name to use for the block device
383 * @name: Name for the device (parent name is prepended)
384 * @uclass_id: Interface type (enum uclass_id_t)
385 * @devnum: Device number, specific to the interface type, or -1 to
386 * allocate the next available number
387 * @blksz: Block size of the device in bytes (typically 512)
388 * @lba: Total number of blocks of the device
389 * @devp: the new device (which has not been probed)
391 int blk_create_devicef(struct udevice *parent, const char *drv_name,
392 const char *name, int uclass_id, int devnum, int blksz,
393 lbaint_t lba, struct udevice **devp);
396 * blk_probe_or_unbind() - Try to probe
398 * Try to probe the device, primarily for enumerating partitions.
399 * If it fails, the device itself is unbound since it means that it won't
402 * @dev: The device to probe
403 * Return: 0 if OK, -ve on error
405 int blk_probe_or_unbind(struct udevice *dev);
408 * blk_unbind_all() - Unbind all device of the given interface type
410 * The devices are removed and then unbound.
412 * @uclass_id: Interface type to unbind
413 * Return: 0 if OK, -ve on error
415 int blk_unbind_all(int uclass_id);
418 * blk_find_max_devnum() - find the maximum device number for an interface type
420 * Finds the last allocated device number for an interface type @uclass_id. The
421 * next number is safe to use for a newly allocated device.
423 * @uclass_id: Interface type to scan
424 * Return: maximum device number found, or -ENODEV if none, or other -ve on
427 int blk_find_max_devnum(enum uclass_id uclass_id);
430 * blk_next_free_devnum() - get the next device number for an interface type
432 * Finds the next number that is safe to use for a newly allocated device for
433 * an interface type @uclass_id.
435 * @uclass_id: Interface type to scan
436 * Return: next device number safe to use, or -ve on error
438 int blk_next_free_devnum(enum uclass_id uclass_id);
441 * blk_select_hwpart() - select a hardware partition
443 * Select a hardware partition if the device supports it (typically MMC does)
445 * @dev: Device to update
446 * @hwpart: Partition number to select
447 * Return: 0 if OK, -ve on error
449 int blk_select_hwpart(struct udevice *dev, int hwpart);
452 * blk_get_from_parent() - obtain a block device by looking up its parent
456 int blk_get_from_parent(struct udevice *parent, struct udevice **devp);
459 * blk_get_devtype() - Get the device type of a block device
461 * @dev: Block device to check
462 * Return: device tree, i.e. the uclass name of its parent, e.g. "mmc"
464 const char *blk_get_devtype(struct udevice *dev);
467 * blk_get_by_device() - Get the block device descriptor for the given device
468 * @dev: Instance of a storage device (the parent of the block device)
470 * Return: With block device descriptor on success , NULL if there is no such
473 struct blk_desc *blk_get_by_device(struct udevice *dev);
478 * These functions should take struct udevice instead of struct blk_desc,
479 * but this is convenient for migration to driver model. Add a 'd' prefix
480 * to the function operations, so that blk_read(), etc. can be reserved for
481 * functions with the correct arguments.
483 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
484 lbaint_t blkcnt, void *buffer)
487 if (blkcache_read(block_dev->uclass_id, block_dev->devnum,
488 start, blkcnt, block_dev->blksz, buffer))
492 * We could check if block_read is NULL and return -ENOSYS. But this
493 * bloats the code slightly (cause some board to fail to build), and
494 * it would be an error to try an operation that does not exist.
496 blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
497 if (blks_read == blkcnt)
498 blkcache_fill(block_dev->uclass_id, block_dev->devnum,
499 start, blkcnt, block_dev->blksz, buffer);
504 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
505 lbaint_t blkcnt, const void *buffer)
507 blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
508 return block_dev->block_write(block_dev, start, blkcnt, buffer);
511 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
514 blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
515 return block_dev->block_erase(block_dev, start, blkcnt);
519 * struct blk_driver - Driver for block interface types
521 * This provides access to the block devices for each interface type. One
522 * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
523 * type that is to be supported.
525 * @uclass_idname: Interface type name
526 * @uclass_id: Interface type
527 * @max_devs: Maximum number of devices supported
528 * @desc: Pointer to list of devices for this interface type,
529 * or NULL to use @get_dev() instead
532 const char *uclass_idname;
533 enum uclass_id uclass_id;
535 struct blk_desc *desc;
537 * get_dev() - get a pointer to a block device given its number
539 * Each interface allocates its own devices and typically
540 * struct blk_desc is contained with the interface's data structure.
541 * There is no global numbering for block devices. This method allows
542 * the device for an interface type to be obtained when @desc is NULL.
544 * @devnum: Device number (0 for first device on that interface,
546 * @descp: Returns pointer to the block device on success
547 * @return 0 if OK, -ve on error
549 int (*get_dev)(int devnum, struct blk_desc **descp);
552 * select_hwpart() - Select a hardware partition
554 * Some devices (e.g. MMC) can support partitioning at the hardware
555 * level. This is quite separate from the normal idea of
556 * software-based partitions. MMC hardware partitions must be
557 * explicitly selected. Once selected only the region of the device
558 * covered by that partition is accessible.
560 * The MMC standard provides for two boot partitions (numbered 1 and 2),
561 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
562 * Partition 0 is the main user-data partition.
564 * @desc: Block device descriptor
565 * @hwpart: Hardware partition number to select. 0 means the main
566 * user-data partition, 1 is the first partition, 2 is
568 * @return 0 if OK, other value for an error
570 int (*select_hwpart)(struct blk_desc *desc, int hwpart);
574 * Declare a new U-Boot legacy block driver. New drivers should use driver
575 * model (UCLASS_BLK).
577 #define U_BOOT_LEGACY_BLK(__name) \
578 ll_entry_declare(struct blk_driver, __name, blk_driver)
580 struct blk_driver *blk_driver_lookup_type(int uclass_id);
582 #endif /* !CONFIG_BLK */
585 * blk_get_devnum_by_uclass_idname() - Get a block device by type and number
587 * This looks through the available block devices of the given type, returning
588 * the one with the given @devnum.
590 * @uclass_id: Block device type
591 * @devnum: Device number
592 * Return: point to block device descriptor, or NULL if not found
594 struct blk_desc *blk_get_devnum_by_uclass_id(enum uclass_id uclass_id, int devnum);
597 * blk_get_devnum_by_uclass_id() - Get a block device by type name, and number
599 * This looks up the block device type based on @uclass_idname, then calls
600 * blk_get_devnum_by_uclass_id().
602 * @uclass_idname: Block device type name
603 * @devnum: Device number
604 * Return: point to block device descriptor, or NULL if not found
606 struct blk_desc *blk_get_devnum_by_uclass_idname(const char *uclass_idname,
610 * blk_dselect_hwpart() - select a hardware partition
612 * This selects a hardware partition (such as is supported by MMC). The block
613 * device size may change as this effectively points the block device to a
614 * partition at the hardware level. See the select_hwpart() method above.
616 * @desc: Block device descriptor for the device to select
617 * @hwpart: Partition number to select
618 * Return: 0 if OK, -ve on error
620 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
623 * blk_list_part() - list the partitions for block devices of a given type
625 * This looks up the partition type for each block device of type @uclass_id,
626 * then displays a list of partitions.
628 * @uclass_id: Block device type
629 * Return: 0 if OK, -ENODEV if there is none of that type
631 int blk_list_part(enum uclass_id uclass_id);
634 * blk_list_devices() - list the block devices of a given type
636 * This lists each block device of the type @uclass_id, showing the capacity
637 * as well as type-specific information.
639 * @uclass_id: Block device type
641 void blk_list_devices(enum uclass_id uclass_id);
644 * blk_show_device() - show information about a given block device
646 * This shows the block device capacity as well as type-specific information.
648 * @uclass_id: Block device type
649 * @devnum: Device number
650 * Return: 0 if OK, -ENODEV for invalid device number
652 int blk_show_device(enum uclass_id uclass_id, int devnum);
655 * blk_print_device_num() - show information about a given block device
657 * This is similar to blk_show_device() but returns an error if the block
658 * device type is unknown.
660 * @uclass_id: Block device type
661 * @devnum: Device number
662 * Return: 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
663 * device is not connected
665 int blk_print_device_num(enum uclass_id uclass_id, int devnum);
668 * blk_print_part_devnum() - print the partition information for a device
670 * @uclass_id: Block device type
671 * @devnum: Device number
672 * Return: 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
673 * the interface type is not supported, other -ve on other error
675 int blk_print_part_devnum(enum uclass_id uclass_id, int devnum);
678 * blk_read_devnum() - read blocks from a device
680 * @uclass_id: Block device type
681 * @devnum: Device number
682 * @start: Start block number to read (0=first)
683 * @blkcnt: Number of blocks to read
684 * @buffer: Address to write data to
685 * Return: number of blocks read, or -ve error number on error
687 ulong blk_read_devnum(enum uclass_id uclass_id, int devnum, lbaint_t start,
688 lbaint_t blkcnt, void *buffer);
691 * blk_write_devnum() - write blocks to a device
693 * @uclass_id: Block device type
694 * @devnum: Device number
695 * @start: Start block number to write (0=first)
696 * @blkcnt: Number of blocks to write
697 * @buffer: Address to read data from
698 * Return: number of blocks written, or -ve error number on error
700 ulong blk_write_devnum(enum uclass_id uclass_id, int devnum, lbaint_t start,
701 lbaint_t blkcnt, const void *buffer);
704 * blk_select_hwpart_devnum() - select a hardware partition
706 * This is similar to blk_dselect_hwpart() but it looks up the interface and
709 * @uclass_id: Block device type
710 * @devnum: Device number
711 * @hwpart: Partition number to select
712 * Return: 0 if OK, -ve on error
714 int blk_select_hwpart_devnum(enum uclass_id uclass_id, int devnum, int hwpart);
717 * blk_get_uclass_name() - Get the name of an interface type
719 * @uclass_id: Interface type to check
720 * Return: name of interface, or NULL if none
722 const char *blk_get_uclass_name(enum uclass_id uclass_id);
725 * blk_common_cmd() - handle common commands with block devices
727 * @args: Number of arguments to the command (argv[0] is the command itself)
728 * @argv: Command arguments
729 * @uclass_id: Interface type
730 * @cur_devnump: Current device number for this interface type
731 * Return: 0 if OK, CMD_RET_ERROR on error
733 int blk_common_cmd(int argc, char *const argv[], enum uclass_id uclass_id,
738 BLKF_REMOVABLE = 1 << 1,
739 BLKF_BOTH = BLKF_FIXED | BLKF_REMOVABLE,
743 * blk_first_device_err() - Get the first block device
745 * The device returned is probed if necessary, and ready for use
747 * @flags: Indicates type of device to return
748 * @devp: Returns pointer to the first device in that uclass, or NULL if none
749 * Return: 0 if found, -ENODEV if not found, other -ve on error
751 int blk_first_device_err(enum blk_flag_t flags, struct udevice **devp);
754 * blk_next_device_err() - Get the next block device
756 * The device returned is probed if necessary, and ready for use
758 * @flags: Indicates type of device to return
759 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
760 * to the next device in the uclass if no error occurred, or -ENODEV if
761 * there is no next device.
762 * Return: 0 if found, -ENODEV if not found, other -ve on error
764 int blk_next_device_err(enum blk_flag_t flags, struct udevice **devp);
767 * blk_find_first() - Return the first matching block device
768 * @flags: Indicates type of device to return
769 * @devp: Returns pointer to device, or NULL on error
771 * The device is not prepared for use - this is an internal function.
772 * The function uclass_get_device_tail() can be used to probe the device.
774 * Note that some devices are considered removable until they have been probed
776 * @return 0 if found, -ENODEV if not found
778 int blk_find_first(enum blk_flag_t flags, struct udevice **devp);
781 * blk_find_next() - Return the next matching block device
782 * @flags: Indicates type of device to return
783 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
784 * to the next device in the same uclass, or NULL if none
786 * The device is not prepared for use - this is an internal function.
787 * The function uclass_get_device_tail() can be used to probe the device.
789 * Note that some devices are considered removable until they have been probed
791 * @return 0 if found, -ENODEV if not found
793 int blk_find_next(enum blk_flag_t flags, struct udevice **devp);
796 * blk_foreach() - iterate through block devices
798 * This creates a for() loop which works through the available block devices in
799 * order from start to end.
801 * If for some reason the uclass cannot be found, this does nothing.
803 * @_flags: Indicates type of device to return
804 * @_pos: struct udevice * to hold the current device. Set to NULL when there
805 * are no more devices.
807 #define blk_foreach(_flags, _pos) \
808 for (int _ret = blk_find_first(_flags, &_pos); !_ret && _pos; \
809 _ret = blk_find_next(_flags, &_pos))
812 * blk_foreach_probe() - Helper function to iteration through block devices
814 * This creates a for() loop which works through the available devices in
815 * a uclass in order from start to end. Devices are probed if necessary,
818 * @flags: Indicates type of device to return
819 * @dev: struct udevice * to hold the current device. Set to NULL when there
820 * are no more devices.
822 #define blk_foreach_probe(flags, pos) \
823 for (int _ret = blk_first_device_err(flags, &(pos)); \
825 _ret = blk_next_device_err(flags, &(pos)))
828 * blk_count_devices() - count the number of devices of a particular type
830 * @flags: Indicates type of device to find
831 * Return: number of devices matching those flags
833 int blk_count_devices(enum blk_flag_t flag);