diff options
| author | Jon Hunter | 2015-09-22 10:27:53 +0100 |
|---|---|---|
| committer | Ulf Hansson | 2015-10-26 16:00:00 +0100 |
| commit | a5f5774c55a2e3ed75f4d6c5556b7bfcb726e6f0 (patch) | |
| tree | 59d6825b63a06eb28f83cce482df405f5228e3ac /include/uapi/linux | |
| parent | aaa58d0e932c518bdb1d9dc767876d7a8c68e17e (diff) | |
mmc: block: Add new ioctl to send multi commands
Certain eMMC devices allow vendor specific device information to be read
via a sequence of vendor commands. These vendor commands must be issued
in sequence and an atomic fashion. One way to support this would be to
add an ioctl function for sending a sequence of commands to the device
atomically as proposed here. These multi commands are simple array of
the existing mmc_ioc_cmd structure.
The structure passed via the ioctl uses a __u64 type to specify the number
of commands (so that the structure is aligned on a 64-bit boundary) and a
zero length array as a header for list of commands to be issued. The
maximum number of commands that can be sent is determined by
MMC_IOC_MAX_CMDS (which defaults to 255 and should be more than
sufficient).
This based upon work by Seshagiri Holi <sholi@nvidia.com>.
Signed-off-by: Seshagiri Holi <sholi@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/mmc/ioctl.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/include/uapi/linux/mmc/ioctl.h b/include/uapi/linux/mmc/ioctl.h index 1f5e68923929..7e385b83b9d8 100644 --- a/include/uapi/linux/mmc/ioctl.h +++ b/include/uapi/linux/mmc/ioctl.h @@ -45,8 +45,24 @@ struct mmc_ioc_cmd { }; #define mmc_ioc_cmd_set_data(ic, ptr) ic.data_ptr = (__u64)(unsigned long) ptr -#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd) +/** + * struct mmc_ioc_multi_cmd - multi command information + * @num_of_cmds: Number of commands to send. Must be equal to or less than + * MMC_IOC_MAX_CMDS. + * @cmds: Array of commands with length equal to 'num_of_cmds' + */ +struct mmc_ioc_multi_cmd { + __u64 num_of_cmds; + struct mmc_ioc_cmd cmds[0]; +}; +#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd) +/* + * MMC_IOC_MULTI_CMD: Used to send an array of MMC commands described by + * the structure mmc_ioc_multi_cmd. The MMC driver will issue all + * commands in array in sequence to card. + */ +#define MMC_IOC_MULTI_CMD _IOWR(MMC_BLOCK_MAJOR, 1, struct mmc_ioc_multi_cmd) /* * Since this ioctl is only meant to enhance (and not replace) normal access * to the mmc bus device, an upper data transfer limit of MMC_IOC_MAX_BYTES @@ -54,4 +70,5 @@ struct mmc_ioc_cmd { * block device operations. */ #define MMC_IOC_MAX_BYTES (512L * 256) +#define MMC_IOC_MAX_CMDS 255 #endif /* LINUX_MMC_IOCTL_H */ |