[PATCHv3 00/11] USB improvements and cleanpus, g_multi install mode

Michal Nazarewicz
2010-06-02T12:47:21Z

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Hello again,

It's me again with a bunch of patches but this time I bring some new
functionality! Install mode! If you are interested only in this jump
near the end of the mail.

The first 7 patches are what I've posted previously. I'm resending it
again since those are required for later patches plus there were some
minor fixes. The patches are:

USB: gadget: g_mass_storage: static data instead of dynamic
allocation

A micro optimisation preventing a kmalloc call() which would
otherwise be always called at the very beginning for the same area
size.

This was submitted previously but Greg did not included it in his
quilt tree (unless I overlooked something) so I'll posting it
again for completeness. Sorry if that creates confusion.

In my opinion this is worth including as it simplifies the code
a bit and removes the call to kmalloc/kfree (hidden in
fsg_common_init) which in my opinion is a good thing as well.

USB: gadget: f_mass_storage: fsg_add() renamed to fsg_bind_config()
USB: gadget: f_fs: functionfs_add() renamed to
functionfs_bind_config()

All other USB composite functions use foo_bind_config() to add
function to USB configuration so changed the names for mass
storage and FunctionFS as well.

The inconstancy apparent in multifunction gadgets stroke me for
quite some time now. I was always reluctant to submit patch
thinking that it would be just stupid name change but finally
couldn't stand it. ;)

In case of mass storage the old (fsg_add()) function is still
available but marked deprecated. In case of FFS the old
(functionfs_add()) function has been removed.

USB: gadget: composite: usb_string_ids_*() functions added
USB: gadget: f_fs: use usb_string_ids_n()

usb_string_ids_n() and usb_string_ids_tab() functions added for batch
sting IDs requests.

This simplifies the code where one would call usb_string_id()
several times and each time has to check for error codes. With
usb_string_ids_n() one can get a whole bunch of IDs with one call
and with usb_string_ids_tab() fill an array full of usb_string
structures.

USB: gadget: g_multi: code clean up and refactoring
USB: gadget: g_multi: added documentation and INF files

g_multi clean up, fixes, etc. Also a bit of documentation for
g_multi and an INF file tested with Windows XP SP3. Hopefully,
someone will find it useful.

Then, there is this patch David didn't seem impressed with:

USB: gadget: g_multi: more configurable

Adds a Kconfig option for each function provided by the g_multi.
This may look like making g_multi complex but I see it more as
creating an gadget that can be used to test various functionality
as well as show that adding new functions is not so hard even in
a complex gadget since the code adds a clear separation of each
function so that one may easily see which parts are for each
function.

And, finally 3 new patches with the advertised install mode
functionality:

USB: gadget: composite: addad disconnect callback

Adds an disconnect callback to the composite framework which is
called whenever composite receives disconnect from the hardware
driver.

USB: gadget: f_mass_storage: added eject callback

Adds a pre- and post-eject callbacks. The first may prevent
eject from really happen even though no error is reported to the
host so host things it succeeded. The second is called after the
file is closed so one may use it for some funky stuff which is
otherwise impossible while mass storage function holds the file or
mounting another file.

USB: gadget: g_multi: Install Mode added

This adds the install mode to the g_multi. Not to repeat myself,
quote from documentation:

* Install mode

The install mode makes the gadget appear as a plain mass storage
device the first time it is connected (and after each
disconnect). This lets one develop an "autorun" CD-ROM image
with drivers and put it as the first logical unit.

** Workings of the install mode

As you may know, mass storage gadget may provide several logical
units and its easier to think of them as separate drives. When
install mode is enabled, g_multi forces the first logical unit
to be a read-only CD-ROM. When install mode is enabled but mass
storage itself is not then exactly one logical unit is set.

When an eject request is made on that logical unit, the file is
not really closed but the gadget switches it's mode to the full
flagged gadget with all the other functions. If mass storage is
among them, the firs logical unit will be the CD-ROM image with
drivers (which may be seen as a bad thing).

When gadget is disconnected and connected afterwards it will
work again in install mode. Some heuristics are used here -- if
disconnection (or suspend) happens no longer then 10 seconds
after last eject on the first logical unit then on next
enumeration gadget will claim to be full flagged otherwise it'll
stick to install mode.

** Interoperability with host

As said, the idea behind install mode is that hosts that require
drivers will be able to get them without the need for additional
CD-ROM or another medium provided with the device.

CD-ROM image should provide an "autorun" functionality witch
will install drivers and eject the emulated CD-ROM to switch
gadget into the other mode which will be handled by newly
installed drivers. If drivers are installed already, they
should "catch" the install mode device by product and vendor IDs
and issue an eject.

This mode is not very Linux-friendly though since Linux and
Linux based systems have no notion of autorun (which from
security point of view is a good thing) and there's no way of
adding some file on the image which will make gadget eject the
device.

Fortunately, there's USB_ModeSwitch and/or udev which should
handle it just fine. A single rule need to be added and
everything should work fine.

Documentation/usb/gadget_multi.txt | 221 +++++++++
Documentation/usb/gadget_multi_rndis.inf | 200 ++++++++
Documentation/usb/gadget_multi_serial.inf | 44 ++
drivers/usb/gadget/Kconfig | 88 +++-
drivers/usb/gadget/composite.c | 73 +++-
drivers/usb/gadget/f_fs.c | 36 +-
drivers/usb/gadget/f_mass_storage.c | 122 +++--
drivers/usb/gadget/g_ffs.c | 2 +-
drivers/usb/gadget/mass_storage.c | 17 +-
drivers/usb/gadget/multi.c | 744 ++++++++++++++++++++++-------
include/linux/usb/composite.h | 6 +
include/linux/usb/functionfs.h | 6 +-
12 files changed, 1278 insertions(+), 281 deletions(-)
create mode 100644 Documentation/usb/gadget_multi.txt
create mode 100644 Documentation/usb/gadget_multi_rndis.inf
create mode 100644 Documentation/usb/gadget_multi_serial.inf

--
Best regards, _ _
| Humble Liege of Serenely Enlightened Majesty of o' \,=./ `o
| Computer Science, Michał "mina86" Nazarewicz (o o)
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