Add FunctionFS support.
It allows certain USB functions to be provided from userspace, e.g. MTP,
PTP, adb.
The functions provided by the gadget itself are enumerated in
/sys/class/ccg0/functions. The functions which can be supplied
from userspace must be enumerated in /sys/class/ccg0/f_fs/user_functions.
No other userspace functions can be used than specified in the above mentioned
file, but just specifying them there is not enough to activate them.
The userspace functions in order to be activated need also be enumerated
in /sys/class/ccg0/functions.
An example sequence of operations can be as follows:
$ echo 0 > /sys/class/ccg_usb/ccg0/enable
$ echo -n 0x2d01 > /sys/module/g_ccg/parameters/idProduct
$ echo -n MyDevice > /sys/module/g_ccg/parameters/iSerialNumber
$ echo -n 0x1d6b > /sys/module/g_ccg/parameters/idVendor
$ echo -n Manufacturer > /sys/module/g_ccg/parameters/iManufacturer
$ echo -n Product > /sys/module/g_ccg/parameters/iProduct
$ echo -n bcdDevice > /sys/module/g_ccg/parameters/bcdDevice
$ echo adb,mtp,ptp > /sys/class/ccg_usb/ccg0/f_fs/user_functions
$ echo mass_storage,ptp > /sys/class/ccg_usb/ccg0/functions
$ echo /file.img > /sys/class/ccg_usb/ccg0/f_mass_storage/lun/file
$ mkdir -p /dev/usbgadget/ptp
$ mount -t functionfs ptp /dev/usbgadget/ptp
$ ./ptp &
$ echo 1 > /sys/class/ccg_usb/ccg0/enable
The above example declares that adb, mtp and ptp functions can be supplied
from userspace through FunctionFS. But of them all only ptp is actually
activated, together with mass_storage, the latter being implemented in
the gadget itself (in kernel, not in userspace). The list of functions
can be modified at runtime while the gadget is not enabled, that is,
after
$ echo 0 > /sys/class/ccg_usb/ccg0/enable
The FunctionFS function is implicitly handled by the gadget, that is,
if a userspace function name is provided in
/sys/class/ccg_usb/ccg0/functions, then the FunctionFS function
is activated.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Configurable Gadget driver is a composite driver that allows
userspace to change at runtime the list of functions enabled in
its configuration and to configure these functions. It supports
multiple functions: acm, rndis, and mass storage.
It is usually controlled by a daemon that changes the configuration
based on user settings. For example, rndis is enabled when the user
enables sharing the phone data connection.
As an example on how to use it, the following shell commands will
make the gadget disconnect from the host and make it be re-enumerated
as a composite with 1 rndis and 2 acm interfaces, and a different
product id:
echo 0 > /sys/class/ccg_usb/ccg0/enable
echo rndis,acm > /sys/class/ccg_usb/ccg0/functions
echo 2 > /sys/class/ccg_usb/ccg0/f_acm/instances
echo -n 0x2d01 > /sys/module/g_ccg/parameters/idProduct
echo 1 > /sys/class/ccg_usb/ccg0/enable
The driver requires a gadget controller that supports software
control of the D+ pullup and the controller driver must support
disabling the pullup during composite_bind.
Signed-off-by: Mike Lockwood <lockwood@android.com>
Signed-off-by: Benoit Goby <benoit@android.com>
[import from android.c, implement review comments, remove adb,mtp,ptp,accessory]
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
