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path: root/drivers/hid/uhid.c
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2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-1/+1
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-27HID: introduce hid_is_using_ll_driverJason Gerecke1-1/+2
Although HID itself is transport-agnostic, occasionally a driver may want to interact with the low-level transport that a device is connected through. To do this, we need to know what kind of bus is in use. The first guess may be to look at the 'bus' field of the 'struct hid_device', but this field may be emulated in some cases (e.g. uhid). More ideally, we can check which ll_driver a device is using. This function introduces a 'hid_is_using_ll_driver' function and makes the 'struct hid_ll_driver' of the four most common transports accessible through hid.h. Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com> Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-08-31miscdevice: Add helper macro for misc device boilerplatePrasannaKumar Muralidharan1-12/+1
Many modules call misc_register and misc_deregister in its module init and exit methods without any additional code. This ends up being boilerplate. This patch adds helper macro module_misc_device(), that replaces module_init()/ module_exit() with template functions. This patch also converts drivers to use new macro. Change since v1: Add device.h include in miscdevice.h as module_driver macro was not available from other include files in some architectures. Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01HID: uhid: fix timeout when probe races with IORoderick Colenbrander1-9/+24
Many devices use userspace bluetooth stacks like BlueZ or Bluedroid in combination with uhid. If any of these stacks is used with a HID device for which the driver performs a HID request as part .probe (or technically another HID operation), this results in a deadlock situation. The deadlock results in a 5 second timeout for I/O operations in HID drivers, so isn't fatal, but none of the I/O operations have a chance of succeeding. The root cause for the problem is that uhid only allows for one request to be processed at a time per uhid instance and locks out other operations. This means that if a user space is creating a new HID device through 'UHID_CREATE', which ultimately triggers '.probe' through the HID layer. Then any HID request e.g. a read for calibration data would trigger a HID operation on uhid again, but it won't go out to userspace, because it is still stuck in UHID_CREATE. In addition bluetooth stacks are typically single threaded, so they wouldn't be able to handle any requests while waiting on uhid. Lucikly the UHID spec is somewhat flexible and allows for fixing the issue, without breaking user space. The idea which the patch implements as discussed with David Herrmann is to decouple adding of a hid device (which triggers .probe) from UHID_CREATE. The work will kick off roughly once UHID_CREATE completed (or else will wait a tiny bit of time in .probe for a lock). A HID driver has to call HID to call 'hid_hw_start()' as part of .probe once it is ready for I/O, which triggers UHID_START to user space. Any HID operations should function now within .probe and won't deadlock because userspace is stuck on UHID_CREATE. We verified this patch on Bluedroid with Android 6.0 and on desktop Linux with BlueZ stacks. Prior to the patch they had the deadlock issue. [jkosina@suse.cz: reword subject] Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com> Cc: stable@vger.kernel.org Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-03-22drivers/hid/uhid.c: check write() bitness using in_compat_syscallAndy Lutomirski1-1/+1
uhid changes the format expected in write() depending on bitness. It should check the syscall bitness directly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-01HID: uHID: fix excepted report typeBenjamin Tissoires1-1/+1
When uhid_get_report() or uhid_set_report() are called, they emit on the char device a UHID_GET_REPORT or UHID_SET_REPORT message. Then, the protocol says that the user space asnwers with UHID_GET_REPORT_REPLY or UHID_SET_REPORT_REPLY. Unfortunatelly, the current code waits for an event of type UHID_GET_REPORT or UHID_SET_REPORT instead of the reply one. Add 1 to UHID_GET_REPORT or UHID_SET_REPORT to actually wait for the reply, and validate the reply. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: report to user-space whether reports are numberedDavid Herrmann1-1/+20
This makes UHID_START include a "dev_flags" field that describes details of the hid-device in the kernel. The first flags we introduce describe whether a given report-type uses numbered reports. This is useful for transport layers that force report-numbers and therefore might have to prefix kernel-provided HID-messages with the report-number. Currently, only HoG needs this and the spec only talks about "global report numbers". That is, it's a global boolean not a per-type boolean. However, given the quirks we already have in kernel-space, a per-type value seems much more appropriate. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: implement SET_REPORTDavid Herrmann1-68/+138
We so far lacked support for hid_hw_raw_request(..., HID_REQ_SET_REPORT); Add support for it and simply forward the request to user-space. Note that SET_REPORT is synchronous, just like GET_REPORT, even though it does not provide any data back besides an error code. If a transport layer does SET_REPORT asynchronously, they can just ACK it immediately by writing an uhid_set_report_reply to uhid. This patch re-uses the synchronous uhid-report infrastructure to query user-space. Note that this means you cannot run SET_REPORT and GET_REPORT in parallel. However, that has always been a restriction of HID and due to its blocking nature, this is just fine. Maybe some future transport layer supports parallel requests (very unlikely), however, until then lets not over-complicate things and avoid request-lookup-tables. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: rename uhid_raw_request to uhid_hid_raw_requestDavid Herrmann1-16/+16
We use strict prefixed in uhid.c: uhid_char_*: implement char-dev callbacks uhid_dev_*: implement uhid device management and runtime uhid_hid_*: implement hid-dev callbacks uhid_raw_request is an hid callback, so rename it to uhid_hid_raw_request. While at it, move it closer to it's extracted helpers and keep the same order as in "struct hid_driver". Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: add ABI compatible UHID_GET_REPORT replacing UHID_FEATUREDavid Herrmann1-14/+14
The old hdev->hid_get_raw_report() was broken by design. It was never clear what kind of HW request it should trigger. Benjamin fixed that with the core HID cleanup, though we never really adjusted uhid. Unfortunately, our old UHID_FEATURE command was modelled around the broken hid_get_raw_report(). We converted it silently to the new GET_REPORT and nothing broke. Make this explicit by renaming UHID_FEATURE to UHID_GET_REPORT and UHID_FEATURE_ANSWER to UHID_GET_REPORT_REPLY. Note that this is 100% ABI compatible to UHID_FEATURE. This is just a rename. But we have to keep the old definitions around to not break API. >From now on, UHID_GET_REPORT must trigger a GET_REPORT request on the user-space hardware layer. All the ambiguity due to the weird "feature" name should be gone now. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: invert report_done and make non-atomicDavid Herrmann1-8/+7
All accesses to @report_done are protected by qlock (or report-contexts). No need to use an atomic. While at it, invert the logic and call it "report_running". This is similar to the uhid->running field and easier to read. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: turn report_id into u32David Herrmann1-3/+4
All accesses to @report_id are protected by @qlock. No need to use an atomic. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: avoid magic-numbers when setting stringsDavid Herrmann1-7/+7
Avoid hard-coding the target buffer sizes and use sizeof() instead. This also makes us future-proof to buffer-extensions later on. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: avoid dangling pointers in uhid contextDavid Herrmann1-5/+11
Avoid keeping uhid->rd_data and uhid->rd_size set in case uhid_dev_create2() fails. This is non-critical as we never flip uhid->running and thus never enter uhid_dev_destroy(). However, it's much nicer for debugging if pointers are only set if they point to valid data. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: forward create_req to create2_reqDavid Herrmann1-65/+25
Instead of hard-coding the uhid_dev_create() function twice, copy any create_req into a create2_req structure and forward it. We allocate uhid_create_req on the stack here, but that should be fine. Unlike uhid_create2_req it is fairly small (<1KB) and it's only used temporarily to swap entries. uhid_dev_create2() doesn't access it. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-25HID: uhid: simplify report-cb shutdownDavid Herrmann1-9/+2
The report-query is blocking, so when user-space destroys a device we have to wake up any blocking kernel context that is currently in the report-cb. We used some broken correlation between @report_done and @running so far. Replace it by a much more obvious use. We now wake up the report-cb if either @report_done or @running is set. wake_up() and wait_event() serve as implicit barriers (as they always do) so no need to use smp_rmb/wmb directly. Note that @report_done is never reset by anyone but the report-cb, thus it cannot flip twice while we wait for it. And whenever we set @running, we afterwards synchronously remove the HID device. Therefore, we wait for all report-cbs to finish before we return. This way, @running can never flip to true while we wait for it. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-05-27HID: uhid: Use kmemdup instead of kmalloc + memcpyBenoit Taine1-3/+2
This issue was reported by coccicheck using the semantic patch at scripts/coccinelle/api/memdup.cocci Signed-off-by: Benoit Taine <benoit.taine@lip6.fr> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-01HID: uhid: Add UHID_CREATE2 + UHID_INPUT2Petri Gynther1-0/+78
UHID_CREATE2: HID report descriptor data (rd_data) is an array in struct uhid_create2_req, instead of a pointer. Enables use from languages that don't support pointers, e.g. Python. UHID_INPUT2: Data array is the last field of struct uhid_input2_req. Enables userspace to write only the required bytes to kernel (ev.type + ev.u.input2.size + the part of the data array that matters), instead of the entire struct uhid_input2_req. Note: UHID_CREATE2 increases the total size of struct uhid_event slightly, thus increasing the size of messages that are queued for userspace. However, this won't affect the userspace processing of these events. [Jiri Kosina <jkosina@suse.cz>: adjust to hid_get_raw_report() and hid_output_raw_report() API changes] Signed-off-by: Petri Gynther <pgynther@google.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-03-14HID: remove hid_output_raw_report transport implementationsBenjamin Tissoires1-1/+0
Nobody calls hid_output_raw_report anymore, and nobody should. We can now remove the various implementation in the different transport drivers and the declarations. Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-17HID: uHID: implement .raw_requestBenjamin Tissoires1-0/+16
uHID is missing a SET_REPORT protocol implementation, but as .hid_get_raw_report() as been removed from struct hid_device, there were no means to access GET_REPORT in uhid. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-17HID: uhid: reintroduce uhid_hid_get_raw()Jiri Kosina1-0/+83
This reverts commit 4a76d370f0c0508b5d6580d15eae3d40b47d837c. Removing it was a mistake, as we need a means to access GET_REPORT. Reported-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-17HID: uHID: remove duplicated codeBenjamin Tissoires1-21/+1
uhid_hid_output_report() can be implemented through a simple call to uhid_hid_output_raw(). Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-17HID: uhid: remove uhid_hid_get_raw()Jiri Kosina1-83/+0
This function is now unused since cafebc058bf8 ("HID: remove hid_get_raw_report in struct hid_device"). Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-17HID: remove hid_get_raw_report in struct hid_deviceBenjamin Tissoires1-1/+0
dev->hid_get_raw_report(X) and hid_hw_raw_request(X, HID_REQ_GET_REPORT) are strictly equivalent. Switch the hid subsystem to the hid_hw notation and remove the field .hid_get_raw_report in struct hid_device. Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-01-29HID: Add the transport-driver function to the uhid driverFrank Praznik1-0/+27
Add the uhid_output_report transport-driver function to the uhid driver. Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com> Acked-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-11-27HID: uhid: fix leak for 64/32 UHID_CREATEDavid Herrmann1-1/+1
UHID allows short writes so user-space can omit unused fields. We automatically set them to 0 in the kernel. However, the 64/32 bit compat-handler didn't do that in the UHID_CREATE fallback. This will reveal random kernel heap data (of random size, even) to user-space. Fixes: befde0226a59 ('HID: uhid: make creating devices work on 64/32 systems') Reported-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-09-26HID: uhid: allocate static minorDavid Herrmann1-1/+2
udev has this nice feature of creating "dead" /dev/<node> device-nodes if it finds a devnode:<node> modalias. Once the node is accessed, the kernel automatically loads the module that provides the node. However, this requires udev to know the major:minor code to use for the node. This feature was introduced by: commit 578454ff7eab61d13a26b568f99a89a2c9edc881 Author: Kay Sievers <kay.sievers@vrfy.org> Date: Thu May 20 18:07:20 2010 +0200 driver core: add devname module aliases to allow module on-demand auto-loading However, uhid uses dynamic minor numbers so this doesn't actually work. We need to load uhid to know which minor it's going to use. Hence, allocate a static minor (just like uinput does) and we're good to go. Reported-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-09-06Merge branches 'for-3.12/devm', 'for-3.12/i2c-hid', 'for-3.12/i2c-hid-dt', ↵Jiri Kosina1-25/+1
'for-3.12/logitech', 'for-3.12/multitouch-win8', 'for-3.12/trasnport-driver-cleanup', 'for-3.12/uhid', 'for-3.12/upstream' and 'for-3.12/wiimote' into for-linus
2013-09-02HID: uhid: add devname module aliasMarcel Holtmann1-0/+1
For simple device node creation, add the devname module alias. Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-31HID: uhid: use generic hidinput_input_event()David Herrmann1-25/+0
HID core provides the same functionality and can convert the input event to a raw output report. We can thus drop UHID_OUTPUT_EV and rely on the mandatory UHID_OUTPUT. User-space wasn't able to do anything with UHID_OUTPUT_EV, anyway. They don't have access to the report fields. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-02-18HID: uhid: make creating devices work on 64/32 systemsDmitry Torokhov1-3/+92
Unfortunately UHID interface, as it was introduced, is broken with 32 bit userspace running on 64 bit kernels as it uses a pointer in its userspace facing API. Fix it by checking if we are executing compat task and munge the request appropriately. Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20HID: uhid: Fix sending events with invalid dataVinicius Costa Gomes1-1/+1
This was detected because events with invalid types were arriving to userspace. The code before this patch would only work for the first event in the queue (when uhid->tail is 0). Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org> Reviewed-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: silence gcc warningJiri Kosina1-1/+1
gcc is giving me: drivers/hid/uhid.c: In function ‘uhid_hid_get_raw’: drivers/hid/uhid.c:157: warning: ‘len’ may be used uninitialized in this function which is clearly bogus, as - when used as memcpy() argument, it's initialized properly - the code is structured in a way that either 'ret' or 'len' is always initialized, so the return statement always has an initialized value. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: implement feature requestsDavid Herrmann1-1/+119
HID standard allows sending a feature request to the device which is answered by an HID report. uhid implements this by sending a UHID_FEATURE event to user-space which then must answer with UHID_FEATURE_ANSWER. If it doesn't do this in a timely manner, the request is discarded silently. We serialize the feature requests, that is, there is always only a single active feature-request sent to user-space, other requests have to wait. HIDP and USB-HID do it the same way. Because we discard feature-requests silently, we must make sure to match a response to the corresponding request. We use sequence-IDs for this so user-space must copy the ID from the request into the answer. Feature-answers are ignored if they do not contain the same ID as the currently pending feature request. Internally, we must make sure that feature-requests are synchronized with UHID_DESTROY and close() events. We must not dead-lock when closing the HID device, either, so we have to use separate locks. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: forward raw output reports to user-spaceDavid Herrmann1-1/+33
Some drivers that use non-standard HID features require raw output reports sent to the device. We now forward these requests directly to user-space so the transport-level driver can correctly send it to the device or handle it correspondingly. There is no way to signal back whether the transmission was successful, moreover, there might be lots of messages coming out from the driver flushing the output-queue. However, there is currently no driver that causes this so we are safe. If some drivers need to transmit lots of data this way, we need a method to synchronize this and can implement another UHID_OUTPUT_SYNC event. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: forward output request to user-spaceDavid Herrmann1-0/+18
If the hid-driver wants to send standardized data to the device it uses a linux input_event. We forward this to the user-space transport-level driver so they can perform the requested action on the device. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: forward open/close events to user-spaceDavid Herrmann1-1/+6
HID core notifies us with *_open/*_close callbacks when there is an actual user of our device. We forward these to user-space so they can react on this. This allows user-space to skip I/O unless they receive an OPEN event. When they receive a CLOSE event they can stop I/O again to save energy. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: add UHID_START and UHID_STOP eventsDavid Herrmann1-1/+7
We send UHID_START and UHID_STOP events to user-space when the HID core starts/stops the device. This notifies user-space about driver readiness and data-I/O can start now. This directly forwards the callbacks from hid-core to user-space. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: forward hid report-descriptor to hid coreDavid Herrmann1-1/+3
When the uhid_hid_parse callback is called we simply forward it to hid_parse_report() with the data that we got in the UHID_CREATE event. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: allow feeding input data into uhid devicesDavid Herrmann1-0/+14
This adds a new event type UHID_INPUT which allows user-space to feed raw HID reports into the HID subsystem. We copy the data into kernel memory and directly feed it into the HID core. There is no error handling of the events couldn't be parsed so user-space should consider all events successfull unless read() returns an error. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: add UHID_CREATE and UHID_DESTROY eventsDavid Herrmann1-0/+144
UHID_CREATE and UHID_DESTROY are used to create and destroy a device on an open uhid char-device. Internally, we allocate and register an HID device with the HID core and immediately start the device. From now on events may be received or sent to the device. The UHID_CREATE event has a payload similar to the data used by Bluetooth-HIDP when creating a new connection. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: implement write() on uhid devicesDavid Herrmann1-1/+30
Similar to read() you can only write() a single event with one call to an uhid device. To write multiple events use writev() which is supported by uhid. We currently always return -EOPNOTSUPP but other events will be added in later patches. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: implement read() on uhid devicesDavid Herrmann1-1/+45
User-space can use read() to get a single event from uhid devices. read() does never return multiple events. This allows us to extend the event structure and still keep backwards compatibility. If user-space wants to get multiple events in one syscall, they should use the readv()/writev() syscalls which are supported by uhid. This introduces a new lock which helps us synchronizing simultaneous reads from user-space. We also correctly return -EINVAL/-EFAULT only on errors and retry the read() when some other thread captured the event faster than we did. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: allow poll()'ing on uhid devicesDavid Herrmann1-0/+7
As long as the internal buffer is not empty, we return POLLIN to user-space. uhid->head and uhid->tail are no atomics so the comparison may return inexact results. However, this doesn't matter here as user-space would need to poll() in two threads simultaneously to trigger this. And in this case it doesn't matter if a cached result is returned or the exact new result as user-space does not know which thread returns first from poll() and the following read(). So it is safe to compare the values without locking. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: add internal message bufferDavid Herrmann1-0/+65
When receiving messages from the HID subsystem, we need to process them and store them in an internal buffer so user-space can read() on the char device to retrieve the messages. This adds a static buffer for 32 messages to each uhid device. Each message is dynamically allocated so the uhid_device structure does not get too big. uhid_queue() adds a message to the buffer. If the buffer is full, the message is discarded. uhid_queue_event() is an helper for messages without payload. This also adds a public header: uhid.h. It contains the declarations for the user-space API. It is built around "struct uhid_event" which contains a type field which specifies the event type and each event can then add a variable-length payload. For now, there is only a dummy event but later patches will add new event types and payloads. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-18HID: uhid: introduce user-space I/O driver support for HIDDavid Herrmann1-0/+88
This adds a dummy driver that will support user-space I/O drivers for the HID subsystem. This allows to write transport-level drivers like USB-HID and Bluetooth-HID in user-space. Low-Energy Bluetooth needs this to feed HID data that is parsed in user-space back into the kernel. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>

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