usb: gadget: uvc: Replace snprintf() with the safer scnprintf() variant

There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Daniel Scally <dan.scally@ideasonboard.com>
Cc: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20231213164246.1021885-5-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Make bmControls attr read/write

For the Processing Unit and Camera Terminal descriptors defined in
the UVC Gadget we currently hard-code values into their bmControls
fields, which enumerates which controls the gadget is able to
support. This isn't appropriate since only the userspace companion
program to the kernel driver will know which controls are supported.
Make the configfs attributes that point to those fields read/write
so userspace can set them to appropriate values.

Document the new behaviour at the same time so the functionality is
clear.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230309105825.216745-1-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: fix missing mutex_unlock() if kstrtou8() fails

If kstrtou8() fails, the mutex_unlock() is missed, move kstrtou8()
before mutex_lock() to fix it up.

Fixes: 0525210c9840 ("usb: gadget: uvc: Allow definition of XUs in configfs")
Fixes: b3c839bd8a07 ("usb: gadget: uvc: Make bSourceID read/write")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230213070926.776447-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Allow linking function to string descs

Currently the string descriptors for the IAD and VideoStreaming
Interfaces are hardcoded into f_uvc. Now that we can create arbitrary
string descriptors, add a mechanism to define string descriptors for
the IAD, VC and VS interfaces by linking to the appropriate directory
at function level.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-11-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Allow linking XUs to string descriptors

Add .allow_link() and .drop_link() callbacks to allow users to link
an extension unit descriptor to a string descriptor.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-9-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Allow definition of XUs in configfs

The UVC gadget at present has no support for extension units. Add the
infrastructure to uvc_configfs.c that allows users to create XUs via
configfs. These will be stored in a new child of uvcg_control_grp_type
with the name "extensions".

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-4-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Generalise helper functions for reuse

The __uvcg_*frm_intrv() helper functions can be helpful when adding
support for similar attributes. Generalise the functions and
move them higher in the file for better coverage.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-3-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Make bSourceID read/write

At the moment, the UVC function graph is hardcoded IT -> PU -> OT.
To add XU support we need the ability to insert the XU descriptors
into the chain. To facilitate that, make the output terminal's
bSourceID attribute writeable so that we can configure its source.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-2-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Allow creating new color matching descriptors

Allow users to create new color matching descriptors in addition to
the default one. These must be associated with a UVC format in order
to be transmitted to the host, which is achieved by symlinking from
the format to the newly created color matching descriptor - extend
the uncompressed and mjpeg formats to support that linking operation.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230202114142.300858-7-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Make color matching attributes read/write

In preparation for allowing more than the default color matching
descriptor, make the color matching attributes writeable.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230202114142.300858-6-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Copy color matching descriptor for each frame

As currently implemented the default color matching descriptor is
appended after _all_ the formats and frames that the gadget is
configured with. According to the UVC specifications however this
is supposed to be on a per-format basis (section 3.9.2.6):

"Only one instance is allowed for a given format and if present,
the Color Matching descriptor shall be placed following the Video
and Still Image Frame descriptors for that format."

Associate the default color matching descriptor with struct
uvcg_format and copy it once-per-format instead of once only.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230202114142.300858-4-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Add struct for color matching in configs

Color matching descriptors are meant to be a per-format piece of data
and we need to be able to support different descriptors for different
formats. As a preliminary step towards that goal, switch the default
color matching configfs functionality to point to an instance of a
new struct uvcg_color_matching. Use the same default values for its
attributes as the currently hard-coded ones so that the interface to
userspace is consistent.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230202114142.300858-3-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Add new enable_interrupt_ep attribute

Add a new attribute to the default control config group that allows
users to specify whether they want to enable the optional interrupt
endpoint for the VideoControl interface.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230130105045.120886-3-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: usb: Remove "default" from color matching attributes

Color matching attributes in the configfs for UVC are named with the
phrase "default". The implication of that is that they will only be
used _with_ the default color matching descriptor, and that will
shortly no longer be the case.

Remove the "default" from the color matching descriptor attribute
variables.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Link: https://lore.kernel.org/r/20221213083736.2284536-2-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Rename bmInterfaceFlags -> bmInterlaceFlags

In the specification documents for the Uncompressed and MJPEG USB
Video Payloads, the field name is bmInterlaceFlags - it has been
misnamed within the kernel.

Although renaming the field does break the kernel's interface to
userspace it should be low-risk in this instance. The field is read
only and hardcoded to 0, so there was never any value in anyone
reading it. A search of the uvc-gadget application and all the
forks that I could find for it did not reveal any users either.

Fixes: cdda479f15cd ("USB gadget: video class function driver")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20221206161203.1562827-1-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: fix changing interface name via configfs

When setting the function name, it is always truncated by one char since
snprintf is always including the null-termination in the len parameter.
We use strscpy and fix the size setting to use len + 1 instead.

Fixes: 324e4f85070f ("usb: gadget: uvc: allow changing interface name via configfs")
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220707115612.2760569-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: track frames in format entries

Just like the header is tracking the formats in a linked list, in this
patch we track the frames in a linked list of the formats. It
simplifies the parsing of the configfs structure.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>

Link: https://lore.kernel.org/r/20220421211427.3400834-6-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: move structs to common header

The functions and structs of the configfs interface should also be used
by the uvc gadget driver. This patch prepares the stack by moving the
common structs and functions to the common header file.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>

Link: https://lore.kernel.org/r/20220421211427.3400834-5-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: prevent index variables to start from 0

Some configfs variables like bDefaultFrameIndex are always starting by
1. This patch adds a check to prevent setting those variables to 0.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>

Link: https://lore.kernel.org/r/20220421211427.3400834-4-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: allow changing interface name via configfs

Add a configfs entry, "function_name", to change the iInterface field
for VideoControl. This name is used on host devices for user selection,
useful when multiple cameras are present. The default will remain "UVC
Camera".

Signed-off-by: Dan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20220401160447.5919-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Drop unnecessary NULL checks after container_of

The parameters passed to allow_link and drop_link functions are never NULL.
That means the result of container_of() on those parameters is also
never NULL, even though the reference into the structure points to the
first element of the structure. Remove the unnecessary NULL checks.

This change was made automatically with the following Coccinelle script.
A now obsolete 'out:' label was removed manually.

@@
type t;
identifier v;
statement s;
@@

<+...
(
t v = container_of(...);
|
v = container_of(...);
)
...
when != v
- if (\( !v \| v == NULL \) ) s
...+>

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Felipe Balbi <balbi@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210424145443.170413-1-linux@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Updating bcdUVC field to 0x0110

Command Verifier during UVC Descriptor Tests (Class Video Control
Interface Descriptor Test Video) complains about:

Video Control Interface Header bcdUVC is 0x0100. USB Video Class
specification 1.0 has been replaced by 1.1 specification
(UVC: 6.2.26) Class Video Control Interface Descriptor bcdUVC is not 1.1

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Reviewed-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20210315065926.30152-1-pawell@gli-login.cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Change Andrzej Pietrasiewicz's e-mail address

My @samusung.com address is going to cease existing soon, so change it to
an address which can actually be used to contact me.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: Remove dead branch code

'num' is a u8 variable, it never greater than 255,
So the if branch is dead code and can be removed.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: uvc: configfs: Use %u to print unsigned int values

The driver uses the %d format to print unsigned int values. The correct
format is %u. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>

usb: gadget: uvc: configfs: Simplify attributes macros

Several macros used to define attributes and their access functions take
multiple arguments to specify endianness and string conversion
functions, based on the size of the attribute. This can be simplified by
passing the number of bits explicitly, and constructing the name of the
functions internally.

The UVCG_OPTS_ATTR macro can be simplified further as all fields it
deals with are unsigned int.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>

usb: gadget: uvc: configfs: Fix operation on big endian platforms

USB descriptors are stored in little endian, requiring the use of
conversion macros. Those macros are incorrectly used for values stored
in native endian structures within the driver. Operation on big endian
platforms is thus broken. Fix it by removing the conversion macros where
they're not needed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>

usb: gadget: uvc: configfs: Sort frame intervals upon writing

There is an issue where the host is unable to tell the gadget what frame
rate it wants if the dwFrameIntervals in the interface descriptors are
not in ascending order. This means that when instantiating a uvc gadget
via configfs the user must make sure the dwFrameIntervals are in
ascending order.

Instead of silently failing the breaking of this rule, we sort the
dwFrameIntervals upon writing to configfs.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

usb: gadget: uvc: configfs: Prevent format changes after linking header

While checks are in place to avoid attributes and children of a format
being manipulated after the format is linked into the streaming header,
the linked flag was never actually set, invalidating the protections.
Update the flag as appropriate in the header link calls.

Signed-off-by: Joel Pepper <joel.pepper@rwth-aachen.de>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

usb: gadget: uvc: configfs: Add bFrameIndex attributes

- Add bFrameIndex as a UVCG_FRAME_ATTR_RO for each frame size.
- Automatically assign ascending bFrameIndex to each frame in a format.

Before all "bFrameindex" attributes were set to "1" with no way to
configure the gadget otherwise. This resulted in the host always
negotiating for bFrameIndex 1 (i.e. the first frame size of the gadget).
After the negotiation the host driver will set the user or application
selected frame size, while the gadget is actually set to the first frame
size.

Now, when the containing format is linked into the streaming header,
iterate over all child frame descriptors and assign ascending indices.
The automatically assigned indices can be read from the new read only
bFrameIndex configfs attribute in each frame descriptor item.

Signed-off-by: Joel Pepper <joel.pepper@rwth-aachen.de>
[Simplified documentation, renamed function, blank space update]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Add bFormatIndex attributes

The UVC format description are numbered using the descriptor's
bFormatIndex field. The index is used in UVC requests, and is thus
needed to handle requests in userspace. Make it dynamically discoverable
by exposing it in a bFormatIndex configfs attribute of the uncompressed
and mjpeg format config items.

The bFormatIndex value exposed through the attribute is stored in the
config item private data. However, that value is never set: the driver
instead computes the bFormatIndex value when linking the stream class
header in the configfs hierarchy and stores it directly in the class
descriptors in a separate structure. In order to expose the value
through the configfs attribute, store it in the config item private data
as well. This results in a small code simplification.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Add interface number attributes

The video control and video streaming interface numbers are needed in
the UVC gadget userspace stack to reply to UVC requests. They are
hardcoded to fixed values at the moment, preventing configurations with
multiple functions.

To fix this, make them dynamically discoverable by userspace through
read-only configfs attributes in <function>/control/bInterfaceNumber and
<function>/streaming/bInterfaceNumber respectively.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Allocate groups dynamically

The UVC configfs implementation creates all groups as global static
variables. This prevents creation of multiple UVC function instances,
as they would all require their own configfs group instances.

Fix this by allocating all groups dynamically. To avoid duplicating code
around, extend the config_item_type structure with group name and
children, and implement helper functions to create children
automatically for most groups.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Drop leaked references to config items

Some of the .allow_link() and .drop_link() operations implementations
call config_group_find_item() and then leak the reference to the
returned item. Fix this by dropping those references where needed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Add section header comments

The UVC configfs implementation is large and difficult to navigate. Add
a bit more air to the code to make it easier to read.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Don't wrap groups unnecessarily

Various configfs groups (represented by config_group) are wrapped in
structures that they're the only member of. This allows adding other
data fields to groups, but it unnecessarily makes the code more complex.
Remove the outer structures and use config_group directly to simplify
the code. Groups can still be wrapped individually in the future if
other data fields need to be added.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: configfs: Move function to avoid forward declaration

The to_f_uvc_opts() function is forward-declared without needing to, as
its definition can simply be moved up in the file. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: function: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: make config_item_type structures const

Make these structures const as they are only passed to the const
argument of the functions config_{group/item}_init_type_name.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

usb: gadget: uvc: Missing files for configfs interface

Commit 76e0da34c7ce ("usb-gadget/uvc: use per-attribute show and store
methods") caused a stringification of an undefined macro argument "aname",
so three UVC parameters (streaming_interval, streaming_maxpacket and
streaming_maxburst) were named "aname".

Add the definition of "aname" to the main macro and name the filenames as
originaly intended.

Signed-off-by: Petr Cvek <petr.cvek@tul.cz>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

fs: configfs: don't return anything from drop_link

Documentation/filesystems/configfs/configfs.txt says:

"When unlink(2) is called on the symbolic link, the source item is
notified via the ->drop_link() method. Like the ->drop_item() method,
this is a void function and cannot return failure."

The ->drop_item() is indeed a void function, the ->drop_link() is
actually not. This, together with the fact that the value of ->drop_link()
is silently ignored suggests, that it is the ->drop_link() return
type that should be corrected and changed to void.

This patch changes drop_link() signature and all its users.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
[hch: reverted reformatting of some code]
Signed-off-by: Christoph Hellwig <hch@lst.de>

usb: gadget: uvc: Fix return value in case of error

If this memory allocation fail, we will return 0, which means success.
Return -ENOMEM instead.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

configfs: switch ->default groups to a linked list

Replace the current NULL-terminated array of default groups with a linked
list. This gets rid of lots of nasty code to size and/or dynamically
allocate the array.

While we're at it also provide a conveniant helper to remove the default
groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org> [drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>

usb: gadget: uvc: fix permissions of configfs attributes

76e0da3 "usb-gadget/uvc: use per-attribute show and store methods"
removed write permission for writeable attributes. Correct attribute
permissions.

Fixes: 76e0da3 "usb-gadget/uvc: use per-attribute show and store methods"
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb-gadget/uvc: use per-attribute show and store methods

UVC is a little different from other configfs consumers in that it wants
different function and field names from the exposed attribute name, so
it keeps it's local macros to define attributes instead of using the common
ones.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

usb: gadget: uvc: comments for iterating over streaming hierarchy

The purpose of the functions and their parametrs might not be obvious
to the reader, so explain it.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: use explicit type instead of void *

The first parameter of __uvcg_iter_strm_cls() is always used in
the context of struct uvcg_streaming_header, so change the
function prototype accordingly.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: preserve the address passed to kfree()

__uvcg_fill_strm() called from __uvcg_iter_stream_cls()
might have advanced the "data" even if __uvcg_iter_stream_cls()
returns an error, so use a backup copy as an argument to kfree().

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: cleanup UVCG_FRAME_ATTR macro

1) Change "conv" an "vnoc" to "to_cpu_endian" to "to_little_endian".
2) No need to check the "limit" because that is already handled in
kstrtoXX so delete that parameter along with the check.
3) By using a "bits" parameter, we can combine the "uxx" parameter and
the "str2u" parameters.
4) The kstrtou##bits() conversion does not need to be done under the
mutex so move it to the start of the function.
5) Change the name of "identity_conv" to "noop_conversion".

Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: memory leak in uvcg_frame_make()

We need to add a kfree(h) on an error path.

Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: remove an impossible condition

"num" is a u32 so "(num > 0xFFFFFFFF)" is never true. Also the range
is already checked in kstrtou32().

Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: fix some error codes

We're basically saying ERR_CAST(NULL) and PTR_ERR(NULL) here, which is
nonsensical.

Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: to_uvcg_control_header() can be static

drivers/usb/gadget/function/uvc_configfs.c:46:28: sparse: symbol 'to_uvcg_control_header' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:138:25: sparse: symbol 'uvcg_control_header_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:164:6: sparse: symbol 'uvcg_control_header_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:721:20: sparse: symbol 'to_uvcg_format' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:798:30: sparse: symbol 'to_uvcg_streaming_header' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:950:25: sparse: symbol 'uvcg_streaming_header_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:976:6: sparse: symbol 'uvcg_streaming_header_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1020:19: sparse: symbol 'to_uvcg_frame' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1265:25: sparse: symbol 'uvcg_frame_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1315:6: sparse: symbol 'uvcg_frame_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1338:26: sparse: symbol 'to_uvcg_uncompressed' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1548:25: sparse: symbol 'uvcg_uncompressed_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1586:6: sparse: symbol 'uvcg_uncompressed_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1610:19: sparse: symbol 'to_uvcg_mjpeg' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1761:25: sparse: symbol 'uvcg_mjpeg_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1793:6: sparse: symbol 'uvcg_mjpeg_drop' was not declared. Should it be static?

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: configfs support in uvc function

Add support for using the uvc function as a component of USB gadgets composed
with configfs.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>