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Diffstat (limited to 'include/blk.h')
-rw-r--r-- | include/blk.h | 808 |
1 files changed, 808 insertions, 0 deletions
diff --git a/include/blk.h b/include/blk.h new file mode 100644 index 00000000000..8d1b70cabd3 --- /dev/null +++ b/include/blk.h @@ -0,0 +1,808 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * (C) Copyright 2000-2004 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + */ + +#ifndef BLK_H +#define BLK_H + +#include <bouncebuf.h> +#include <dm/uclass-id.h> +#include <efi.h> + +#ifdef CONFIG_SYS_64BIT_LBA +typedef uint64_t lbaint_t; +#define LBAFlength "ll" +#else +typedef ulong lbaint_t; +#define LBAFlength "l" +#endif +#define LBAF "%" LBAFlength "x" +#define LBAFU "%" LBAFlength "u" + +#define DEFAULT_BLKSZ 512 + +struct udevice; + +static inline bool blk_enabled(void) +{ + return CONFIG_IS_ENABLED(BLK) || IS_ENABLED(CONFIG_SPL_LEGACY_BLOCK); +} + +#define BLK_VEN_SIZE 40 +#define BLK_PRD_SIZE 20 +#define BLK_REV_SIZE 8 + +#define PART_FORMAT_PCAT 0x1 +#define PART_FORMAT_GPT 0x2 + +/* + * Identifies the partition table type (ie. MBR vs GPT GUID) signature + */ +enum sig_type { + SIG_TYPE_NONE, + SIG_TYPE_MBR, + SIG_TYPE_GUID, + + SIG_TYPE_COUNT /* Number of signature types */ +}; + +/* + * With driver model (CONFIG_BLK) this is uclass platform data, accessible + * with dev_get_uclass_plat(dev) + */ +struct blk_desc { + /* + * TODO: With driver model we should be able to use the parent + * device's uclass instead. + */ + enum uclass_id uclass_id; /* type of the interface */ + int devnum; /* device number */ + unsigned char part_type; /* partition type */ + unsigned char target; /* target SCSI ID */ + unsigned char lun; /* target LUN */ + unsigned char hwpart; /* HW partition, e.g. for eMMC */ + unsigned char type; /* device type */ + unsigned char removable; /* removable device */ + /* device can use 48bit addr (ATA/ATAPI v7) */ + bool lba48; + unsigned char atapi; /* Use ATAPI protocol */ + unsigned char bb; /* Use bounce buffer */ + lbaint_t lba; /* number of blocks */ + unsigned long blksz; /* block size */ + int log2blksz; /* for convenience: log2(blksz) */ + char vendor[BLK_VEN_SIZE + 1]; /* device vendor string */ + char product[BLK_PRD_SIZE + 1]; /* device product number */ + char revision[BLK_REV_SIZE + 1]; /* firmware revision */ + enum sig_type sig_type; /* Partition table signature type */ + union { + uint32_t mbr_sig; /* MBR integer signature */ + efi_guid_t guid_sig; /* GPT GUID Signature */ + }; +#if CONFIG_IS_ENABLED(BLK) + /* + * For now we have a few functions which take struct blk_desc as a + * parameter. This field allows them to look up the associated + * device. Once these functions are removed we can drop this field. + */ + struct udevice *bdev; +#else + unsigned long (*block_read)(struct blk_desc *block_dev, + lbaint_t start, + lbaint_t blkcnt, + void *buffer); + unsigned long (*block_write)(struct blk_desc *block_dev, + lbaint_t start, + lbaint_t blkcnt, + const void *buffer); + unsigned long (*block_erase)(struct blk_desc *block_dev, + lbaint_t start, + lbaint_t blkcnt); + void *priv; /* driver private struct pointer */ +#endif +}; + +#define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz)) +#define PAD_TO_BLOCKSIZE(size, blk_desc) \ + (PAD_SIZE(size, blk_desc->blksz)) + +#if CONFIG_IS_ENABLED(BLOCK_CACHE) +/** + * blkcache_read() - attempt to read a set of blocks from cache + * + * @param iftype - uclass_id_x for type of device + * @param dev - device index of particular type + * @param start - starting block number + * @param blkcnt - number of blocks to read + * @param blksz - size in bytes of each block + * @param buffer - buffer to contain cached data + * + * Return: - 1 if block returned from cache, 0 otherwise. + */ +int blkcache_read(int iftype, int dev, + lbaint_t start, lbaint_t blkcnt, + unsigned long blksz, void *buffer); + +/** + * blkcache_fill() - make data read from a block device available + * to the block cache + * + * @param iftype - uclass_id_x for type of device + * @param dev - device index of particular type + * @param start - starting block number + * @param blkcnt - number of blocks available + * @param blksz - size in bytes of each block + * @param buffer - buffer containing data to cache + * + */ +void blkcache_fill(int iftype, int dev, + lbaint_t start, lbaint_t blkcnt, + unsigned long blksz, void const *buffer); + +/** + * blkcache_invalidate() - discard the cache for a set of blocks + * because of a write or device (re)initialization. + * + * @iftype - UCLASS_ID_ for type of device, or -1 for any + * @dev - device index of particular type, if @iftype is not -1 + */ +void blkcache_invalidate(int iftype, int dev); + +/** + * blkcache_configure() - configure block cache + * + * @param blocks - maximum blocks per entry + * @param entries - maximum entries in cache + */ +void blkcache_configure(unsigned blocks, unsigned entries); + +/* + * statistics of the block cache + */ +struct block_cache_stats { + unsigned hits; + unsigned misses; + unsigned entries; /* current entry count */ + unsigned max_blocks_per_entry; + unsigned max_entries; +}; + +/** + * get_blkcache_stats() - return statistics and reset + * + * @param stats - statistics are copied here + */ +void blkcache_stats(struct block_cache_stats *stats); + +/** blkcache_free() - free all memory allocated to the block cache */ +void blkcache_free(void); + +#else + +static inline int blkcache_read(int iftype, int dev, + lbaint_t start, lbaint_t blkcnt, + unsigned long blksz, void *buffer) +{ + return 0; +} + +static inline void blkcache_fill(int iftype, int dev, + lbaint_t start, lbaint_t blkcnt, + unsigned long blksz, void const *buffer) {} + +static inline void blkcache_invalidate(int iftype, int dev) {} + +static inline void blkcache_free(void) {} + +#endif + +struct udevice; + +/* Operations on block devices */ +struct blk_ops { + /** + * read() - read from a block device + * + * @dev: Device to read from + * @start: Start block number to read (0=first) + * @blkcnt: Number of blocks to read + * @buffer: Destination buffer for data read + * @return number of blocks read, or -ve error number (see the + * IS_ERR_VALUE() macro + */ + unsigned long (*read)(struct udevice *dev, lbaint_t start, + lbaint_t blkcnt, void *buffer); + + /** + * write() - write to a block device + * + * @dev: Device to write to + * @start: Start block number to write (0=first) + * @blkcnt: Number of blocks to write + * @buffer: Source buffer for data to write + * @return number of blocks written, or -ve error number (see the + * IS_ERR_VALUE() macro + */ + unsigned long (*write)(struct udevice *dev, lbaint_t start, + lbaint_t blkcnt, const void *buffer); + + /** + * erase() - erase a section of a block device + * + * @dev: Device to (partially) erase + * @start: Start block number to erase (0=first) + * @blkcnt: Number of blocks to erase + * @return number of blocks erased, or -ve error number (see the + * IS_ERR_VALUE() macro + */ + unsigned long (*erase)(struct udevice *dev, lbaint_t start, + lbaint_t blkcnt); + + /** + * select_hwpart() - select a particular hardware partition + * + * Some devices (e.g. MMC) can support partitioning at the hardware + * level. This is quite separate from the normal idea of + * software-based partitions. MMC hardware partitions must be + * explicitly selected. Once selected only the region of the device + * covered by that partition is accessible. + * + * The MMC standard provides for two boot partitions (numbered 1 and 2), + * rpmb (3), and up to 4 addition general-purpose partitions (4-7). + * + * @dev: Block device to update + * @hwpart: Hardware partition number to select. 0 means the raw + * device, 1 is the first partition, 2 is the second, etc. + * @return 0 if OK, -ve on error + */ + int (*select_hwpart)(struct udevice *dev, int hwpart); + +#if IS_ENABLED(CONFIG_BOUNCE_BUFFER) + /** + * buffer_aligned() - test memory alignment of block operation buffer + * + * Some devices have limited DMA capabilities and require that the + * buffers passed to them fit specific properties. This optional + * callback can be used to indicate whether a buffer alignment is + * suitable for the device DMA or not, and trigger use of generic + * bounce buffer implementation to help use of unsuitable buffers + * at the expense of performance degradation. + * + * @dev: Block device associated with the request + * @state: Bounce buffer state + * @return 1 if OK, 0 if unaligned + */ + int (*buffer_aligned)(struct udevice *dev, struct bounce_buffer *state); +#endif /* CONFIG_BOUNCE_BUFFER */ +}; + +#if CONFIG_IS_ENABLED(BLK) + +/* + * These functions should take struct udevice instead of struct blk_desc, + * but this is convenient for migration to driver model. Add a 'd' prefix + * to the function operations, so that blk_read(), etc. can be reserved for + * functions with the correct arguments. + */ +unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt, void *buffer); +unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt, const void *buffer); +unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt); + +#endif /* BLK */ + +/** + * blk_read() - Read from a block device + * + * @dev: Device to read from + * @start: Start block for the read + * @blkcnt: Number of blocks to read + * @buf: Place to put the data + * @return number of blocks read (which may be less than @blkcnt), + * or -ve on error. This never returns 0 unless @blkcnt is 0 + */ +long blk_read(struct udevice *dev, lbaint_t start, lbaint_t blkcnt, + void *buffer); + +/** + * blk_write() - Write to a block device + * + * @dev: Device to write to + * @start: Start block for the write + * @blkcnt: Number of blocks to write + * @buf: Data to write + * @return number of blocks written (which may be less than @blkcnt), + * or -ve on error. This never returns 0 unless @blkcnt is 0 + */ +long blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt, + const void *buffer); + +/** + * blk_erase() - Erase part of a block device + * + * @dev: Device to erase + * @start: Start block for the erase + * @blkcnt: Number of blocks to erase + * @return number of blocks erased (which may be less than @blkcnt), + * or -ve on error. This never returns 0 unless @blkcnt is 0 + */ +long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt); + +/** + * blk_find_device() - Find a block device + * + * This function does not activate the device. The device will be returned + * whether or not it is activated. + * + * @uclass_id: Interface type (enum uclass_id_t) + * @devnum: Device number (specific to each interface type) + * @devp: the device, if found + * Return: 0 if found, -ENODEV if no device found, or other -ve error value + */ +int blk_find_device(int uclass_id, int devnum, struct udevice **devp); + +/** + * blk_get_device() - Find and probe a block device ready for use + * + * @uclass_id: Interface type (enum uclass_id_t) + * @devnum: Device number (specific to each interface type) + * @devp: the device, if found + * Return: 0 if found, -ENODEV if no device found, or other -ve error value + */ +int blk_get_device(int uclass_id, int devnum, struct udevice **devp); + +/** + * blk_first_device() - Find the first device for a given interface + * + * The device is probed ready for use + * + * @devnum: Device number (specific to each interface type) + * @devp: the device, if found + * Return: 0 if found, -ENODEV if no device, or other -ve error value + */ +int blk_first_device(int uclass_id, struct udevice **devp); + +/** + * blk_next_device() - Find the next device for a given interface + * + * This can be called repeatedly after blk_first_device() to iterate through + * all devices of the given interface type. + * + * The device is probed ready for use + * + * @devp: On entry, the previous device returned. On exit, the next + * device, if found + * Return: 0 if found, -ENODEV if no device, or other -ve error value + */ +int blk_next_device(struct udevice **devp); + +/** + * blk_create_devicef() - Create a new named block device + * + * @parent: Parent of the new device + * @drv_name: Driver name to use for the block device + * @name: Name for the device (parent name is prepended) + * @uclass_id: Interface type (enum uclass_id_t) + * @devnum: Device number, specific to the interface type, or -1 to + * allocate the next available number + * @blksz: Block size of the device in bytes (typically 512) + * @lba: Total number of blocks of the device + * @devp: the new device (which has not been probed) + */ +int blk_create_devicef(struct udevice *parent, const char *drv_name, + const char *name, int uclass_id, int devnum, int blksz, + lbaint_t lba, struct udevice **devp); + +/** + * blk_probe_or_unbind() - Try to probe + * + * Try to probe the device, primarily for enumerating partitions. + * If it fails, the device itself is unbound since it means that it won't + * work any more. + * + * @dev: The device to probe + * Return: 0 if OK, -ve on error + */ +int blk_probe_or_unbind(struct udevice *dev); + +/** + * blk_unbind_all() - Unbind all device of the given interface type + * + * The devices are removed and then unbound. + * + * @uclass_id: Interface type to unbind + * Return: 0 if OK, -ve on error + */ +int blk_unbind_all(int uclass_id); + +/** + * blk_find_max_devnum() - find the maximum device number for an interface type + * + * Finds the last allocated device number for an interface type @uclass_id. The + * next number is safe to use for a newly allocated device. + * + * @uclass_id: Interface type to scan + * Return: maximum device number found, or -ENODEV if none, or other -ve on + * error + */ +int blk_find_max_devnum(enum uclass_id uclass_id); + +/** + * blk_next_free_devnum() - get the next device number for an interface type + * + * Finds the next number that is safe to use for a newly allocated device for + * an interface type @uclass_id. + * + * @uclass_id: Interface type to scan + * Return: next device number safe to use, or -ve on error + */ +int blk_next_free_devnum(enum uclass_id uclass_id); + +/** + * blk_select_hwpart() - select a hardware partition + * + * Select a hardware partition if the device supports it (typically MMC does) + * + * @dev: Device to update + * @hwpart: Partition number to select + * Return: 0 if OK, -ve on error + */ +int blk_select_hwpart(struct udevice *dev, int hwpart); + +/** + * blk_find_from_parent() - find a block device by looking up its parent + * + * All block devices have a parent 'media' device which provides the block + * driver for the block device, ensuring that access to the underlying medium + * is available. + * + * The block device is not activated by this function. See + * blk_get_from_parent() for that. + * + * @parent: Media device + * @devp: Returns the associated block device, if any + * Returns: 0 if OK, -ENODEV if @parent is not a media device and has no + * UCLASS_BLK child + */ +int blk_find_from_parent(struct udevice *parent, struct udevice **devp); + +/** + * blk_get_from_parent() - obtain a block device by looking up its parent + * + * All block devices have a parent 'media' device which provides the block + * driver for the block device, ensuring that access to the underlying medium + * is available. + * + * The block device is probed and ready for use. + * + * @parent: Media device + * @devp: Returns the associated block device, if any + * Returns: 0 if OK, -ENODEV if @parent is not a media device and has no + * UCLASS_BLK child + */ +int blk_get_from_parent(struct udevice *parent, struct udevice **devp); + +/** + * blk_get_devtype() - Get the device type of a block device + * + * @dev: Block device to check + * Return: device tree, i.e. the uclass name of its parent, e.g. "mmc" + */ +const char *blk_get_devtype(struct udevice *dev); + +/** + * blk_get_by_device() - Get the block device descriptor for the given device + * @dev: Instance of a storage device (the parent of the block device) + * + * Return: With block device descriptor on success , NULL if there is no such + * block device. + */ +struct blk_desc *blk_get_by_device(struct udevice *dev); + +/** + * blk_get_desc() - Get the block device descriptor for the given device number + * + * @uclass_id: Interface type + * @devnum: Device number (0 = first) + * @descp: Returns block device descriptor on success + * Return: 0 on success, -ENODEV if there is no such device and no device + * with a higher device number, -ENOENT if there is no such device but there + * is one with a higher number, or other -ve on other error. + */ +int blk_get_desc(enum uclass_id uclass_id, int devnum, struct blk_desc **descp); + +#if !CONFIG_IS_ENABLED(BLK) + +#include <errno.h> + +/* + * These functions should take struct udevice instead of struct blk_desc, + * but this is convenient for migration to driver model. Add a 'd' prefix + * to the function operations, so that blk_read(), etc. can be reserved for + * functions with the correct arguments. + */ +static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt, void *buffer) +{ + ulong blks_read; + if (blkcache_read(block_dev->uclass_id, block_dev->devnum, + start, blkcnt, block_dev->blksz, buffer)) + return blkcnt; + + /* + * We could check if block_read is NULL and return -ENOSYS. But this + * bloats the code slightly (cause some board to fail to build), and + * it would be an error to try an operation that does not exist. + */ + blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer); + if (blks_read == blkcnt) + blkcache_fill(block_dev->uclass_id, block_dev->devnum, + start, blkcnt, block_dev->blksz, buffer); + + return blks_read; +} + +static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt, const void *buffer) +{ + blkcache_invalidate(block_dev->uclass_id, block_dev->devnum); + return block_dev->block_write(block_dev, start, blkcnt, buffer); +} + +static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start, + lbaint_t blkcnt) +{ + blkcache_invalidate(block_dev->uclass_id, block_dev->devnum); + return block_dev->block_erase(block_dev, start, blkcnt); +} + +/** + * struct blk_driver - Driver for block interface types + * + * This provides access to the block devices for each interface type. One + * driver should be provided using U_BOOT_LEGACY_BLK() for each interface + * type that is to be supported. + * + * @uclass_idname: Interface type name + * @uclass_id: Interface type + * @max_devs: Maximum number of devices supported + * @desc: Pointer to list of devices for this interface type, + * or NULL to use @get_dev() instead + */ +struct blk_driver { + const char *uclass_idname; + enum uclass_id uclass_id; + int max_devs; + struct blk_desc *desc; + /** + * get_dev() - get a pointer to a block device given its number + * + * Each interface allocates its own devices and typically + * struct blk_desc is contained with the interface's data structure. + * There is no global numbering for block devices. This method allows + * the device for an interface type to be obtained when @desc is NULL. + * + * @devnum: Device number (0 for first device on that interface, + * 1 for second, etc. + * @descp: Returns pointer to the block device on success + * @return 0 if OK, -ve on error + */ + int (*get_dev)(int devnum, struct blk_desc **descp); + + /** + * select_hwpart() - Select a hardware partition + * + * Some devices (e.g. MMC) can support partitioning at the hardware + * level. This is quite separate from the normal idea of + * software-based partitions. MMC hardware partitions must be + * explicitly selected. Once selected only the region of the device + * covered by that partition is accessible. + * + * The MMC standard provides for two boot partitions (numbered 1 and 2), + * rpmb (3), and up to 4 addition general-purpose partitions (4-7). + * Partition 0 is the main user-data partition. + * + * @desc: Block device descriptor + * @hwpart: Hardware partition number to select. 0 means the main + * user-data partition, 1 is the first partition, 2 is + * the second, etc. + * @return 0 if OK, other value for an error + */ + int (*select_hwpart)(struct blk_desc *desc, int hwpart); +}; + +/* + * Declare a new U-Boot legacy block driver. New drivers should use driver + * model (UCLASS_BLK). + */ +#define U_BOOT_LEGACY_BLK(__name) \ + ll_entry_declare(struct blk_driver, __name, blk_driver) + +struct blk_driver *blk_driver_lookup_type(int uclass_id); + +#endif /* !CONFIG_BLK */ + +/** + * blk_get_devnum_by_uclass_idname() - Get a block device by type and number + * + * This looks through the available block devices of the given type, returning + * the one with the given @devnum. + * + * @uclass_id: Block device type + * @devnum: Device number + * Return: point to block device descriptor, or NULL if not found + */ +struct blk_desc *blk_get_devnum_by_uclass_id(enum uclass_id uclass_id, int devnum); + +/** + * blk_get_devnum_by_uclass_idname() - Get block device by type name and number + * + * This looks up the block device type based on @uclass_idname, then calls + * blk_get_devnum_by_uclass_id(). + * + * @uclass_idname: Block device type name + * @devnum: Device number + * Return: point to block device descriptor, or NULL if not found + */ +struct blk_desc *blk_get_devnum_by_uclass_idname(const char *uclass_idname, + int devnum); + +/** + * blk_dselect_hwpart() - select a hardware partition + * + * This selects a hardware partition (such as is supported by MMC). The block + * device size may change as this effectively points the block device to a + * partition at the hardware level. See the select_hwpart() method above. + * + * @desc: Block device descriptor for the device to select + * @hwpart: Partition number to select + * Return: 0 if OK, -ve on error + */ +int blk_dselect_hwpart(struct blk_desc *desc, int hwpart); + +/** + * blk_list_part() - list the partitions for block devices of a given type + * + * This looks up the partition type for each block device of type @uclass_id, + * then displays a list of partitions. + * + * @uclass_id: Block device type + * Return: 0 if OK, -ENODEV if there is none of that type + */ +int blk_list_part(enum uclass_id uclass_id); + +/** + * blk_list_devices() - list the block devices of a given type + * + * This lists each block device of the type @uclass_id, showing the capacity + * as well as type-specific information. + * + * @uclass_id: Block device type + */ +void blk_list_devices(enum uclass_id uclass_id); + +/** + * blk_show_device() - show information about a given block device + * + * This shows the block device capacity as well as type-specific information. + * + * @uclass_id: Block device type + * @devnum: Device number + * Return: 0 if OK, -ENODEV for invalid device number + */ +int blk_show_device(enum uclass_id uclass_id, int devnum); + +/** + * blk_print_device_num() - show information about a given block device + * + * This is similar to blk_show_device() but returns an error if the block + * device type is unknown. + * + * @uclass_id: Block device type + * @devnum: Device number + * Return: 0 if OK, -ENODEV for invalid device number, -ENOENT if the block + * device is not connected + */ +int blk_print_device_num(enum uclass_id uclass_id, int devnum); + +/** + * blk_print_part_devnum() - print the partition information for a device + * + * @uclass_id: Block device type + * @devnum: Device number + * Return: 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if + * the interface type is not supported, other -ve on other error + */ +int blk_print_part_devnum(enum uclass_id uclass_id, int devnum); + +/** + * blk_select_hwpart_devnum() - select a hardware partition + * + * This is similar to blk_dselect_hwpart() but it looks up the interface and + * device number. + * + * @uclass_id: Block device type + * @devnum: Device number + * @hwpart: Partition number to select + * Return: 0 if OK, -ve on error + */ +int blk_select_hwpart_devnum(enum uclass_id uclass_id, int devnum, int hwpart); + +/** + * blk_get_uclass_name() - Get the name of an interface type + * + * @uclass_id: Interface type to check + * Return: name of interface, or NULL if none + */ +const char *blk_get_uclass_name(enum uclass_id uclass_id); + +/** + * blk_common_cmd() - handle common commands with block devices + * + * @args: Number of arguments to the command (argv[0] is the command itself) + * @argv: Command arguments + * @uclass_id: Interface type + * @cur_devnump: Current device number for this interface type + * Return: 0 if OK, CMD_RET_ERROR on error + */ +int blk_common_cmd(int argc, char *const argv[], enum uclass_id uclass_id, + int *cur_devnump); + +enum blk_flag_t { + BLKF_FIXED = 1 << 0, + BLKF_REMOVABLE = 1 << 1, + BLKF_BOTH = BLKF_FIXED | BLKF_REMOVABLE, +}; + +/** + * blk_first_device_err() - Get the first block device + * + * The device returned is probed if necessary, and ready for use + * + * @flags: Indicates type of device to return + * @devp: Returns pointer to the first device in that uclass, or NULL if none + * Return: 0 if found, -ENODEV if not found, other -ve on error + */ +int blk_first_device_err(enum blk_flag_t flags, struct udevice **devp); + +/** + * blk_next_device_err() - Get the next block device + * + * The device returned is probed if necessary, and ready for use + * + * @flags: Indicates type of device to return + * @devp: On entry, pointer to device to lookup. On exit, returns pointer + * to the next device in the uclass if no error occurred, or -ENODEV if + * there is no next device. + * Return: 0 if found, -ENODEV if not found, other -ve on error + */ +int blk_next_device_err(enum blk_flag_t flags, struct udevice **devp); + +/** + * blk_foreach_probe() - Helper function to iteration through block devices + * + * This creates a for() loop which works through the available devices in + * a uclass in order from start to end. Devices are probed if necessary, + * and ready for use. + * + * @flags: Indicates type of device to return + * @dev: struct udevice * to hold the current device. Set to NULL when there + * are no more devices. + */ +#define blk_foreach_probe(flags, pos) \ + for (int _ret = blk_first_device_err(flags, &(pos)); \ + !_ret && pos; \ + _ret = blk_next_device_err(flags, &(pos))) + +/** + * blk_count_devices() - count the number of devices of a particular type + * + * @flags: Indicates type of device to find + * Return: number of devices matching those flags + */ +int blk_count_devices(enum blk_flag_t flag); + +#endif |