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linux-next/include/uapi/linux/mmc/ioctl.h
Jon Hunter a5f5774c55 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>
2015-10-26 16:00:00 +01:00

75 lines
2.2 KiB
C

#ifndef LINUX_MMC_IOCTL_H
#define LINUX_MMC_IOCTL_H
#include <linux/types.h>
struct mmc_ioc_cmd {
/* Implies direction of data. true = write, false = read */
int write_flag;
/* Application-specific command. true = precede with CMD55 */
int is_acmd;
__u32 opcode;
__u32 arg;
__u32 response[4]; /* CMD response */
unsigned int flags;
unsigned int blksz;
unsigned int blocks;
/*
* Sleep at least postsleep_min_us useconds, and at most
* postsleep_max_us useconds *after* issuing command. Needed for
* some read commands for which cards have no other way of indicating
* they're ready for the next command (i.e. there is no equivalent of
* a "busy" indicator for read operations).
*/
unsigned int postsleep_min_us;
unsigned int postsleep_max_us;
/*
* Override driver-computed timeouts. Note the difference in units!
*/
unsigned int data_timeout_ns;
unsigned int cmd_timeout_ms;
/*
* For 64-bit machines, the next member, ``__u64 data_ptr``, wants to
* be 8-byte aligned. Make sure this struct is the same size when
* built for 32-bit.
*/
__u32 __pad;
/* DAT buffer */
__u64 data_ptr;
};
#define mmc_ioc_cmd_set_data(ic, ptr) ic.data_ptr = (__u64)(unsigned long) ptr
/**
* 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
* is enforced per ioctl call. For larger data transfers, use the normal
* block device operations.
*/
#define MMC_IOC_MAX_BYTES (512L * 256)
#define MMC_IOC_MAX_CMDS 255
#endif /* LINUX_MMC_IOCTL_H */