The Toppy's USB protocol has not been officially documented by Topfield, but the basic features have been reverse engineered by others in order to write replacements for the official `Altair' download/upload program from Topfield.
Existing replacements for Altair suffer from the fact that they are ultimately built on top of ugen(4). This has a number of detrimental side-effects:
The utoppy driver provides a clean and stable interface to the Toppy protocol, and ensures that an interrupt caused by a signal does not leave the Toppy in an undefined state.
#include <dev/usb/utoppy.h>
The
utoppy
driver can be accessed through the
/dev/utoppyN
character device.
The primary means of controlling the driver is by issuing a series of
ioctl(2)
system calls followed by
read(2)
or
write(2)
system calls as appropriate.
The following ioctl(2) commands are supported by the utoppy driver:
UTOPPYIOTURBO
int *mode
UTOPPYIOREADFILE
or
UTOPPYIOWRITEFILE
commands (see below).
If
num
is non-zero, Turbo mode will be enabled.
Otherwise Turbo mode will be disabled.
In non-Turbo mode, the Toppy's
USB
interface is capable of sustaining around 5.6 Mbit/s during a file transfer.
With Turbo mode enabled, it can sustain just over 16 Mbit/s.
Of course, these figures are valid only if the Toppy is connected via a
USB
2.0 interface.
Performance using an older
USB
1 interface will be significantly lower.
UTOPPYIOCANCEL
void
UTOPPYIOREADDIR
,
UTOPPYIOREADFILE
,
or
UTOPPYIOWRITEFILE
command.
UTOPPYIOREBOOT
void
UTOPPYIOSTATS
struct utoppy_stats *stats
struct utoppy_stats {
uint64_t us_hdd_size; /* Size of the disk, in bytes */
uint64_t us_hdd_free; /* Free space, in bytes */
};
struct utoppy_rename *rename
struct utoppy_rename {
char *ur_old_path; /* Path to existing file */
char *ur_new_path; /* Path to new file */
};
char *path
path
.
char *path
path
.
char *path
path
.
After issuing this command, the directory contents must be read using
consecutive
read(2)
system calls.
Each
read(2)
will transfer one or more directory entries into the user-supplied buffer.
The buffer must be large enough to receive at least one directory entry.
When
read(2)
returns zero, all directory entries have been read.
A directory entry is described using the following data structure:
struct utoppy_dirent {
char ud_path[UTOPPY_MAX_FILENAME_LEN + 1];
enum {
UTOPPY_DIRENT_UNKNOWN,
UTOPPY_DIRENT_DIRECTORY,
UTOPPY_DIRENT_FILE
} ud_type;
off_t ud_size;
time_t ud_mtime;
uint32_t ud_attributes;
};
The ud_path field contains the name of the directory entry.
The ud_type field specifies whether the entry corresponds to a file or a sub-directory.
The ud_size field is valid for files only, and specifies the file's size in bytes.
The ud_mtime field describes the file or directory's modification time, specified as seconds from the Unix epoch. The timestamp is relative to the current timezone, so localtime(3) can be used to convert it into human readable form. Note that the Toppy sets directory timestamps to a predefined value so they are not particularly useful.
The ud_attributes field is not used at this time.
struct utoppy_readfile *
struct utoppy_readfile {
char *ur_path;
off_t ur_offset;
};
After issuing this command, the file must be read using consecutive read(2) system calls. When read(2) returns zero, the entire file has been read.
struct utoppy_writefile *
struct utoppy_writefile {
char *uw_path;
off_t uw_offset;
off_t uw_size;
time_t uw_mtime;
};
The uw_path field specifies the full pathname of the file to be written.
The uw_offset field specifies the file offset at which to start writing, assuming the file already exists. Otherwise, uw_offset must be zero.
The protocol requires that the Toppy must be informed of a file's size in advance of the file being written. This is accomplished using the uw_size field. It may be possible to work around this limitation in a future version of the driver.
The uw_mtime field specifies the file's timestamp expressed as seconds from the Unix epoch in the local timezone.
Due to limitations with the protocol, a
utoppy
device can be opened by only one application at a time.
Also, only a single
UTOPPYIOREADDIR
,
UTOPPYIOREADFILE
,
or
UTOPPYIOWRITEFILE
command can be in progress at any given time.
/dev/utoppy0