Group some variables based on their sizes to reduce hole and avoid padding.
On x86_64, this shrinks the size of 'struct hid_input'
from 72 to 64 bytes.
It saves a few bytes of memory and is more cache-line friendly.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Some digitizers (notably XP-Pen Artist 24) do not report the Invert
usage when erasing. This causes the device to be permanently stuck with
the BTN_TOOL_RUBBER tool after sending Eraser, as Invert is the only
usage that can release the tool. In this state, Touch and Inrange are
no longer reported to userspace, rendering the pen unusable.
Prior to commit 87562fcd13 ("HID: input: remove the need for
HID_QUIRK_INVERT"), BTN_TOOL_RUBBER was never set and Eraser events were
simply translated into BTN_TOUCH without causing an inconsistent state.
Introduce HID_QUIRK_NOINVERT for such digitizers and detect them during
hidinput_configure_usage(). This quirk causes the tool to be released
as soon as Eraser is reported as not set. Set BTN_TOOL_RUBBER in
input->keybit when mapping Eraser.
Fixes: 87562fcd13 ("HID: input: remove the need for HID_QUIRK_INVERT")
Co-developed-by: Nils Fuhler <nils@nilsfuhler.de>
Signed-off-by: Nils Fuhler <nils@nilsfuhler.de>
Signed-off-by: Illia Ostapyshyn <ostapyshyn@sra.uni-hannover.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Add an introduction about HID meant for the casual programmer
that is trying either to fix his device or to understand
what is going wrong.
Signed-off-by: Marco Morandini <marco.morandini@polimi.it>
Co-authored-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
More and more drivers rely on devres to manage their resources, however
if bus' probe() and release() methods are not trivial and control some
of resources as well (for example enable or disable clocks, or attach
device to a power domain), we need to make sure that driver-allocated
resources are released immediately after driver's remove() method
returns, and not postponed until driver core gets around to releasing
resources.
In case of HID we should not try to close the report and release
associated memory until after all devres callbacks are executed. To fix
that we open a new devres group before calling driver's probe() and
explicitly release it when we return from driver's remove().
This is similar to what we did for I2C bus in commit 5b5475826c ("i2c:
ensure timely release of driver-allocated resources"). It is tempting to
try and move this into driver core, but actually doing so is challenging,
we need to split bus' remove() method into pre- and post-remove methods,
which would make the logic even less clear.
Reported-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230505232417.1377393-1-swboyd@chromium.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
"Digitizer" is a generic usage that may be used by various devices but
which is particularly used by non-display pen tablets. This patch adds the
usage to the list of values matched by the IS_INPUT_APPLICATION() macro
that determines if an input device should be allocated or not.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Link: https://lore.kernel.org/r/20221019151832.44522-1-jason.gerecke@wacom.com
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Our HID device need KEY_CAMERA_FOCUS event to control camera,
but this event is non-existent in current HID driver.
So we add this event in hid-input.c.
Signed-off-by: fengqi <fengqi@xiaomi.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Presently, when a report is processed, its proposed size, provided by
the user of the API (as Report Size * Report Count) is compared against
the subsystem default HID_MAX_BUFFER_SIZE (16k). However, some
low-level HID drivers allocate a reduced amount of memory to their
buffers (e.g. UHID only allocates UHID_DATA_MAX (4k) buffers), rending
this check inadequate in some cases.
In these circumstances, if the received report ends up being smaller
than the proposed report size, the remainder of the buffer is zeroed.
That is, the space between sizeof(csize) (size of the current report)
and the rsize (size proposed i.e. Report Size * Report Count), which can
be handled up to HID_MAX_BUFFER_SIZE (16k). Meaning that memset()
shoots straight past the end of the buffer boundary and starts zeroing
out in-use values, often resulting in calamity.
This patch introduces a new variable into 'struct hid_ll_driver' where
individual low-level drivers can over-ride the default maximum value of
HID_MAX_BUFFER_SIZE (16k) with something more sympathetic to the
interface.
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Initial support of HID-BPF (Benjamin Tissoires)
The history is a little long for this series, as it was intended to be
sent for v6.2. However some last minute issues forced us to postpone it
to v6.3.
Conflicts:
* drivers/hid/i2c-hid/Kconfig:
commit bf7660dab3 ("HID: stop drivers from selecting CONFIG_HID")
conflicts with commit 2afac81dd1 ("HID: fix I2C_HID not selected
when I2C_HID_OF_ELAN is")
the resolution is simple enough: just drop the "default" and "select"
lines as the new commit from Arnd is doing
In certain circumstances, such as when creating I2C-connected HID
devices, we want to pass and retain some quirks (axis inversion, etc).
The source of such quirks may be device tree, or DMI data, or something
else not readily available to the HID core itself and therefore cannot
be reconstructed easily. To allow this, introduce "initial_quirks" field
in hid_device structure and use it when determining the final set of
quirks.
This fixes the problem with i2c-hid setting up device-tree sourced
quirks too late and losing them on device rebind, and also allows to
sever the tie between hid-code and i2c-hid when applying DMI-based
quirks.
Fixes: b60d3c803d ("HID: i2c-hid-of: Expose the touchscreen-inverted properties")
Fixes: a2f416bf06 ("HID: multitouch: Add quirks for flipped axes")
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Tested-by: Allen Ballway <ballway@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Alistair Francis <alistair@alistair23.me>
Link: https://lore.kernel.org/r/Y+LYwu3Zs13hdVDy@google.com
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
The custom "debug" module parameter is fairly inflexible.
It can only manage debugging for all calls dbg_hid() at the same time.
Furthermore it creates a mismatch between calls to hid_dbg() which can
be managed by CONFIG_DYNAMIC_DEBUG and dbg_hid() which is managed by the
module parameter.
Furthermore the change to pr_debug() allows the debugging statements to
be completely compiled-out if desired.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20221223-hid-dbg-v1-1-5dcf8794f7f9@weissschuh.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Nothing is nor should be modifying these structs so mark them as const.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As there are no external users this implementation detail does not need
to be exported.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As there are no external users this implementation detail does not need
to be exported.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As there are no external users this implementation detail does not need
to be exported.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As no external users remain this implementation detail does not need to
be exported anymore.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As the last user was removed we can delete this function.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
By making hid_is_usb() a non-inline function the lowlevel usbhid driver
does not have to be exported anymore.
Also mark the argument as const as it is not modified.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
HID descriptors with Battery System (0x85) Charging (0x44) usage are
ignored and POWER_SUPPLY_STATUS_DISCHARGING is always reported to user
space, even when the device is charging.
Map this usage and when it is reported set the right charging status.
In addition, add KUnit tests to make sure that the charging status is
correctly set and reported. They can be run with the usual command:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/hid
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Declare an entry point that can use fmod_ret BPF programs, and
also an API to access and change the incoming data.
A simpler implementation would consist in just calling
hid_bpf_device_event() for any incoming event and let users deal
with the fact that they will be called for any event of any device.
The goal of HID-BPF is to partially replace drivers, so this situation
can be problematic because we might have programs which will step on
each other toes.
For that, we add a new API hid_bpf_attach_prog() that can be called
from a syscall and we manually deal with a jump table in hid-bpf.
Whenever we add a program to the jump table (in other words, when we
attach a program to a HID device), we keep the number of time we added
this program in the jump table so we can release it whenever there are
no other users.
HID devices have an RCU protected list of available programs in the
jump table, and those programs are called one after the other thanks
to bpf_tail_call().
To achieve the detection of users losing their fds on the programs we
attached, we add 2 tracing facilities on bpf_prog_release() (for when
a fd is closed) and bpf_free_inode() (for when a pinned program gets
unpinned).
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This allows to export the type in BTF and so in the automatically
generated vmlinux.h. It will also add some static checks on the users
when we change the ll driver API (see not below).
Note that we need to also do change in the ll_driver API, but given
that this will have a wider impact outside of this tree, we leave this
as a TODO for the future.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220902132938.2409206-11-benjamin.tissoires@redhat.com
When we are dealing with eBPF, we need to have access to the report type.
Currently our implementation differs from the USB standard, making it
impossible for users to know the exact value besides hardcoding it
themselves.
And instead of a blank define, convert it as an enum.
Note that we need to also do change in the ll_driver API, but given
that this will have a wider impact outside of this tree, we leave this
as a TODO for the future.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220902132938.2409206-10-benjamin.tissoires@redhat.com
This unique identifier is currently used only for ensuring uniqueness in
sysfs. However, this could be handful for userspace to refer to a specific
hid_device by this id.
2 use cases are in my mind: LEDs (and their naming convention), and
HID-BPF.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220902132938.2409206-9-benjamin.tissoires@redhat.com
Multitouch devices in hybrid mode are reporting multiple times the
same collection. We should accommodate for this in our handling
of priorities by defining the slots they belong to.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
HID_QUIRK_INVERT is kind of complex to deal with and was bogus.
Furthermore, it didn't make sense to use a global per struct hid_device
quirk for something dynamic as the current state.
Store the current tool information in the report itself, and re-order
the processing of the fields to enforce having all the tablet "state"
fields before getting to In Range and other input fields.
This way, we now have all the information whether a tool is present
or not while processing In Range.
This new behavior enforces that only one tool gets forwarded to userspace
at the same time, and that if either eraser or invert is set, we enforce
BTN_TOOL_RUBBER.
Note that the release of the previous tool now happens in its own EV_SYN
report so userspace doesn't get confused by having 2 tools.
These changes are tested in the following hid-tools regression tests:
https://gitlab.freedesktop.org/libevdev/hid-tools/-/merge_requests/127
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
When a device exposes both Invert and InRange, Invert must be processed
before InRange. If we keep the order of the device and we process them
out of order, InRange will first set BTN_TOOL_PEN, and then Invert will
set BTN_TOOL_RUBBER. Userspace knows how to deal with that situation,
but fixing it in the kernel is now easier.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This will be used in a later commit:
we build a list of input fields (and usage_index) that is ordered based
on a usage priority.
Changing the usage priority allows to re-order the processed list, meaning
that we can enforce some usages to be process before others.
For instance, before processing InRange in the HID tablets, we need to
know if we are using the eraser (side or button). Enforcing a higher
(lower number) priority for Invert allows to force the input stack to
process that field before.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This is a preparatory patch for being able to process the usages
out of order. We split the retrieval of the data in a separate function
and also split out the processing of the usages depending if the field
is an array or a variable.
No functional changes from this patch.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This is a preparation patch for rethinking the generic processing
of HID reports.
We can actually pre-allocate all of our memory instead of dynamically
allocating/freeing it whenever we parse a report.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
- support for USI style pens (Tero Kristo, Mika Westerberg)
- quirk for devices that need inverted X/Y axes (Alistair Francis)
- small core code cleanups and deduplication (Benjamin Tissoires)
Add a HID_QUIRK_X_INVERT/HID_QUIRK_Y_INVERT quirk that can be used
to invert the X/Y values.
Signed-off-by: Alistair Francis <alistair@alistair23.me>
[bentiss: silence checkpatch warning]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211208124045.61815-2-alistair@alistair23.me
This function is not called outside of hid-input.c so we can make it
static.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211210111138.1248187-5-tero.kristo@linux.intel.com
Since we are going to have more MSC events too, add map_msc() that can
be used to fill in necessary fields and avoid boilerplate code.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211210111138.1248187-2-tero.kristo@linux.intel.com
We don't gain much by having them as inline, and it
actually prevents us to attach a probe to those helpers.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211202095334.14399-5-benjamin.tissoires@redhat.com
There is a lot of duplication of code in the HID low level drivers.
Better have everything in one place so we can eventually extend it
in a generic way.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211202095334.14399-4-benjamin.tissoires@redhat.com
A number of HID drivers already call hid_is_using_ll_driver() but only
for the detection of if this is a USB device or not. Make this more
obvious by creating hid_is_usb() and calling the function that way.
Also converts the existing hid_is_using_ll_driver() functions to use the
new call.
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Cc: stable@vger.kernel.org
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211201183503.2373082-1-gregkh@linuxfoundation.org
- patch series that ensures that hid-multitouch driver disables touch and
button-press reporting on hid-mt devices during suspend when the device is
not configured as a wakeup-source, from Hans de Goede
- device unbinding locking fix from Dmitry Torokhov
- support for programmable buttons (mapping to KEY_MACRO# event codes)
from Thomas Weißschuh
- various other small fixes and code style improvements
Add a hid_hw_may_wakeup() function, which is the equivalent of
device_may_wakeup() for hid devices.
In most cases this just returns device_may_wakeup(hdev->dev.parent), but for
some ll-drivers this is not correct. E.g. usb_hid_driver instantiated hid
devices have their parent set to the usb-interface to which the usb_hid_driver
is bound, but the power/wakeup* sysfs attributes are part of the usb-device,
which is the usb-interface's parent.
For these special cases a new may_wakeup callback is added to
hid_ll_driver, so that ll-drivers can override the default behavior.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Map them to KEY_MACRO# event codes.
These buttons are defined by HID as follows:
"The user defines the function of these buttons to control software applications or GUI objects."
This matches the semantics of the KEY_MACRO# input event codes that Linux supports.
Also add support for HID "Named Array" collections.
Also add hid-debug support for KEY_MACRO#.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
In hid_submit_ctrl(), the way of calculating the report length doesn't
take into account that report->size can be zero. When running the
syzkaller reproducer, a report of size 0 causes hid_submit_ctrl) to
calculate transfer_buffer_length as 16384. When this urb is passed to
the usb core layer, KMSAN reports an info leak of 16384 bytes.
To fix this, first modify hid_report_len() to account for the zero
report size case by using DIV_ROUND_UP for the division. Then, call it
from hid_submit_ctrl().
Reported-by: syzbot+7c2bb71996f95a82524c@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This is the capacity in percentage, relative to design capacity.
Specifically, it is present in Apple Magic Mouse 2.
In contrast, usage 00850064 is also the capacity in percentage, but is
relative to full capacity. It is not mapped here because I don't have
such device.
Signed-off-by: John Chen <johnchen902@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Plantronics Blackwire 3220 Series (047f:c056) sends HID reports twice
for each volume key press. This patch adds a quirk to hid-plantronics
for this product ID, which will ignore the second volume key press if
it happens within 5 ms from the last one that was handled.
The patch was tested on the mentioned model only, it shouldn't affect
other models, however, this quirk might be needed for them too.
Auto-repeat (when a key is held pressed) is not affected, because the
rate is about 3 times per second, which is far less frequent than once
in 5 ms.
Fixes: 81bb773fae ("HID: plantronics: Update to map volume up/down controls")
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Correct kernel-doc notation in HID header files (include/linux/hid*.h).
Add notation (comments) where it is missing.
Use the documented "Return:" notation for function return values.
Fix a few typos/spellos.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Currently the maximum HID report size which can be buffered by the kernel is
8KB. This is sufficient for the vast majority of HID devices on the market, as
most HID reports are fairly small.
However, some unusual devices such as the Elgate Stream Deck exist which use a
report size slightly over 8KB for the image data that is sent to the device.
Reports these large cannot be buffered by the regular HID subsystem currently,
thus the only way to use such device is to bypass the HID subsystem entirely.
This increases the maximum HID report size to 16KB, which should cover all
sanely designed HID devices.
Signed-off-by: Dean Camera <dean@fourwalledcubicle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There are styluses that only report their battery status when they are
touching the touchscreen; additionally we currently suppress battery
reports if capacity has not changed. To help userspace recognize how long
ago the device reported battery status, let's send the change event through
if either capacity has changed, or at least 30 seconds have passed since
last report we've let through.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
