leandrof/u-boot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

dm: blk: Add comments to a few functions

Browse Source 
The block interface is not well documented in the code. Pick two important
functions and add comments.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Simon Glass 2016-02-29 15:25:41 -07:00
parent 5ec4f1a5f3
commit fb1b7be953
1 changed files with 30 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
include/part.h
View File

@ -53,12 +53,42 @@ typedef struct disk_partition {
/* Misc _get_dev functions */
#ifdef CONFIG_PARTITIONS
/**
* get_dev() - get a pointer to a block device given its type and 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, so the interface name must be provided.
*
* @ifname: Interface name (e.g. "ide", "scsi")
* @dev: Device number (0 for first device on that interface, 1 for
* second, etc.
* @return pointer to the block device, or NULL if not available, or an
* error occurred.
*/
struct blk_desc *get_dev(const char *ifname, int dev);
struct blk_desc *ide_get_dev(int dev);
struct blk_desc *sata_get_dev(int dev);
struct blk_desc *scsi_get_dev(int dev);
struct blk_desc *usb_stor_get_dev(int dev);
struct blk_desc *mmc_get_dev(int dev);
/**
* mmc_select_hwpart() - Select the MMC hardware partiion on an MMC device
*
* MMC devices 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_num: Block device number (struct blk_desc->dev value)
* @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, other value for an error
*/
int mmc_select_hwpart(int dev_num, int hwpart);
struct blk_desc *systemace_get_dev(int dev);
struct blk_desc *mg_disk_get_dev(int dev);