diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2011-04-18 13:29:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-04-18 13:29:03 -0700
commit96fd2d57b8252e16dfacf8941f7a74a6119197f5 (patch)
parent8a83f33100c691f5a576dba259cc05502dc358f0 (diff)
parentc36b58e8a9112017c2bcc322cc98e71241814303 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: xen-kbdfront - fix mouse getting stuck after save/restore Input: estimate number of events per packet Input: evdev - indicate buffer overrun with SYN_DROPPED Input: document event types and codes and their intended use Input: add KEY_IMAGES specifically for AL Image Browser Input: twl4030_keypad - fix potential NULL dereference in twl4030_kp_probe() Input: h3600_ts - fix error handling at connect Input: twl4030_keypad - avoid potential NULL-pointer dereference
8 files changed, 361 insertions, 26 deletions
diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt
new file mode 100644
index 00000000000..23fcb05175b
--- /dev/null
+++ b/Documentation/input/event-codes.txt
@@ -0,0 +1,262 @@
+The input protocol uses a map of types and codes to express input device values
+to userspace. This document describes the types and codes and how and when they
+may be used.
+A single hardware event generates multiple input events. Each input event
+contains the new value of a single data item. A special event type, EV_SYN, is
+used to separate input events into packets of input data changes occurring at
+the same moment in time. In the following, the term "event" refers to a single
+input event encompassing a type, code, and value.
+The input protocol is a stateful protocol. Events are emitted only when values
+of event codes have changed. However, the state is maintained within the Linux
+input subsystem; drivers do not need to maintain the state and may attempt to
+emit unchanged values without harm. Userspace may obtain the current state of
+event code values using the EVIOCG* ioctls defined in linux/input.h. The event
+reports supported by a device are also provided by sysfs in
+class/input/event*/device/capabilities/, and the properties of a device are
+provided in class/input/event*/device/properties.
+Types are groupings of codes under a logical input construct. Each type has a
+set of applicable codes to be used in generating events. See the Codes section
+for details on valid codes for each type.
+* EV_SYN:
+ - Used as markers to separate events. Events may be separated in time or in
+ space, such as with the multitouch protocol.
+* EV_KEY:
+ - Used to describe state changes of keyboards, buttons, or other key-like
+ devices.
+* EV_REL:
+ - Used to describe relative axis value changes, e.g. moving the mouse 5 units
+ to the left.
+* EV_ABS:
+ - Used to describe absolute axis value changes, e.g. describing the
+ coordinates of a touch on a touchscreen.
+* EV_MSC:
+ - Used to describe miscellaneous input data that do not fit into other types.
+* EV_SW:
+ - Used to describe binary state input switches.
+* EV_LED:
+ - Used to turn LEDs on devices on and off.
+* EV_SND:
+ - Used to output sound to devices.
+* EV_REP:
+ - Used for autorepeating devices.
+* EV_FF:
+ - Used to send force feedback commands to an input device.
+* EV_PWR:
+ - A special type for power button and switch input.
+ - Used to receive force feedback device status.
+Codes define the precise type of event.
+EV_SYN event values are undefined. Their usage is defined only by when they are
+sent in the evdev event stream.
+ - Used to synchronize and separate events into packets of input data changes
+ occurring at the same moment in time. For example, motion of a mouse may set
+ the REL_X and REL_Y values for one motion, then emit a SYN_REPORT. The next
+ motion will emit more REL_X and REL_Y values and send another SYN_REPORT.
+ - TBD
+ - Used to synchronize and separate touch events. See the
+ multi-touch-protocol.txt document for more information.
+ - Used to indicate buffer overrun in the evdev client's event queue.
+ Client should ignore all events up to and including next SYN_REPORT
+ event and query the device (using EVIOCG* ioctls) to obtain its
+ current state.
+EV_KEY events take the form KEY_<name> or BTN_<name>. For example, KEY_A is used
+to represent the 'A' key on a keyboard. When a key is depressed, an event with
+the key's code is emitted with value 1. When the key is released, an event is
+emitted with value 0. Some hardware send events when a key is repeated. These
+events have a value of 2. In general, KEY_<name> is used for keyboard keys, and
+BTN_<name> is used for other types of momentary switch events.
+A few EV_KEY codes have special meanings:
+* BTN_TOOL_<name>:
+ - These codes are used in conjunction with input trackpads, tablets, and
+ touchscreens. These devices may be used with fingers, pens, or other tools.
+ When an event occurs and a tool is used, the corresponding BTN_TOOL_<name>
+ code should be set to a value of 1. When the tool is no longer interacting
+ with the input device, the BTN_TOOL_<name> code should be reset to 0. All
+ trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name>
+ code when events are generated.
+ BTN_TOUCH is used for touch contact. While an input tool is determined to be
+ within meaningful physical contact, the value of this property must be set
+ to 1. Meaningful physical contact may mean any contact, or it may mean
+ contact conditioned by an implementation defined property. For example, a
+ touchpad may set the value to 1 only when the touch pressure rises above a
+ certain value. BTN_TOUCH may be combined with BTN_TOOL_<name> codes. For
+ example, a pen tablet may set BTN_TOOL_PEN to 1 and BTN_TOUCH to 0 while the
+ pen is hovering over but not touching the tablet surface.
+Note: For appropriate function of the legacy mousedev emulation driver,
+BTN_TOUCH must be the first evdev code emitted in a synchronization frame.
+Note: Historically a touch device with BTN_TOOL_FINGER and BTN_TOUCH was
+interpreted as a touchpad by userspace, while a similar device without
+BTN_TOOL_FINGER was interpreted as a touchscreen. For backwards compatibility
+with current userspace it is recommended to follow this distinction. In the
+future, this distinction will be deprecated and the device properties ioctl
+EVIOCGPROP, defined in linux/input.h, will be used to convey the device type.
+ - These codes denote one, two, three, and four finger interaction on a
+ trackpad or touchscreen. For example, if the user uses two fingers and moves
+ them on the touchpad in an effort to scroll content on screen,
+ BTN_TOOL_DOUBLETAP should be set to value 1 for the duration of the motion.
+ Note that all BTN_TOOL_<name> codes and the BTN_TOUCH code are orthogonal in
+ purpose. A trackpad event generated by finger touches should generate events
+ for one code from each group. At most only one of these BTN_TOOL_<name>
+ codes should have a value of 1 during any synchronization frame.
+Note: Historically some drivers emitted multiple of the finger count codes with
+a value of 1 in the same synchronization frame. This usage is deprecated.
+Note: In multitouch drivers, the input_mt_report_finger_count() function should
+be used to emit these codes. Please see multi-touch-protocol.txt for details.
+EV_REL events describe relative changes in a property. For example, a mouse may
+move to the left by a certain number of units, but its absolute position in
+space is unknown. If the absolute position is known, EV_ABS codes should be used
+instead of EV_REL codes.
+A few EV_REL codes have special meanings:
+ - These codes are used for vertical and horizontal scroll wheels,
+ respectively.
+EV_ABS events describe absolute changes in a property. For example, a touchpad
+may emit coordinates for a touch location.
+A few EV_ABS codes have special meanings:
+ - Used to describe the distance of a tool from an interaction surface. This
+ event should only be emitted while the tool is hovering, meaning in close
+ proximity of the device and while the value of the BTN_TOUCH code is 0. If
+ the input device may be used freely in three dimensions, consider ABS_Z
+ instead.
+* ABS_MT_<name>:
+ - Used to describe multitouch input events. Please see
+ multi-touch-protocol.txt for details.
+EV_SW events describe stateful binary switches. For example, the SW_LID code is
+used to denote when a laptop lid is closed.
+Upon binding to a device or resuming from suspend, a driver must report
+the current switch state. This ensures that the device, kernel, and userspace
+state is in sync.
+Upon resume, if the switch state is the same as before suspend, then the input
+subsystem will filter out the duplicate switch state reports. The driver does
+not need to keep the state of the switch at any time.
+EV_MSC events are used for input and output events that do not fall under other
+EV_LED events are used for input and output to set and query the state of
+various LEDs on devices.
+EV_REP events are used for specifying autorepeating events.
+EV_SND events are used for sending sound commands to simple sound output
+EV_FF events are used to initialize a force feedback capable device and to cause
+such device to feedback.
+EV_PWR events are a special type of event used specifically for power
+mangement. Its usage is not well defined. To be addressed later.
+The guidelines below ensure proper single-touch and multi-finger functionality.
+For multi-touch functionality, see the multi-touch-protocol.txt document for
+more information.
+REL_{X,Y} must be reported when the mouse moves. BTN_LEFT must be used to report
+the primary button press. BTN_{MIDDLE,RIGHT,4,5,etc.} should be used to report
+further buttons of the device. REL_WHEEL and REL_HWHEEL should be used to report
+scroll wheel events where available.
+ABS_{X,Y} must be reported with the location of the touch. BTN_TOUCH must be
+used to report when a touch is active on the screen.
+BTN_{MOUSE,LEFT,MIDDLE,RIGHT} must not be reported as the result of touch
+contact. BTN_TOOL_<name> events should be reported where possible.
+Legacy trackpads that only provide relative position information must report
+events like mice described above.
+Trackpads that provide absolute touch position must report ABS_{X,Y} for the
+location of the touch. BTN_TOUCH should be used to report when a touch is active
+on the trackpad. Where multi-finger support is available, BTN_TOOL_<name> should
+be used to report the number of touches active on the trackpad.
+BTN_TOOL_<name> events must be reported when a stylus or other tool is active on
+the tablet. ABS_{X,Y} must be reported with the location of the tool. BTN_TOUCH
+should be used to report when the tool is in contact with the tablet.
+BTN_{STYLUS,STYLUS2} should be used to report buttons on the tool itself. Any
+button may be used for buttons on the tablet except BTN_{MOUSE,LEFT}.
+BTN_{0,1,2,etc} are good generic codes for unlabeled buttons. Do not use
+meaningful buttons, like BTN_FORWARD, unless the button is labeled for that
+purpose on the device.
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 7f42d3a454d..88d8e4cb419 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -39,13 +39,13 @@ struct evdev {
struct evdev_client {
- int head;
- int tail;
+ unsigned int head;
+ unsigned int tail;
spinlock_t buffer_lock; /* protects access to buffer, head and tail */
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
- int bufsize;
+ unsigned int bufsize;
struct input_event buffer[];
@@ -55,16 +55,25 @@ static DEFINE_MUTEX(evdev_table_mutex);
static void evdev_pass_event(struct evdev_client *client,
struct input_event *event)
- /*
- * Interrupts are disabled, just acquire the lock.
- * Make sure we don't leave with the client buffer
- * "empty" by having client->head == client->tail.
- */
+ /* Interrupts are disabled, just acquire the lock. */
- do {
- client->buffer[client->head++] = *event;
- client->head &= client->bufsize - 1;
- } while (client->head == client->tail);
+ client->buffer[client->head++] = *event;
+ client->head &= client->bufsize - 1;
+ if (unlikely(client->head == client->tail)) {
+ /*
+ * This effectively "drops" all unconsumed events, leaving
+ * EV_SYN/SYN_DROPPED plus the newest event in the queue.
+ */
+ client->tail = (client->head - 2) & (client->bufsize - 1);
+ client->buffer[client->tail].time = event->time;
+ client->buffer[client->tail].type = EV_SYN;
+ client->buffer[client->tail].code = SYN_DROPPED;
+ client->buffer[client->tail].value = 0;
+ }
if (event->type == EV_SYN)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index d6e8bd8a851..ebbceedc92f 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1746,6 +1746,42 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
+static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
+ int mt_slots;
+ int i;
+ unsigned int events;
+ if (dev->mtsize) {
+ mt_slots = dev->mtsize;
+ } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
+ mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
+ dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
+ clamp(mt_slots, 2, 32);
+ } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
+ mt_slots = 2;
+ } else {
+ mt_slots = 0;
+ }
+ events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
+ for (i = 0; i < ABS_CNT; i++) {
+ if (test_bit(i, dev->absbit)) {
+ if (input_is_mt_axis(i))
+ events += mt_slots;
+ else
+ events++;
+ }
+ }
+ for (i = 0; i < REL_CNT; i++)
+ if (test_bit(i, dev->relbit))
+ events++;
+ return events;
#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
do { \
if (!test_bit(EV_##type, dev->evbit)) \
@@ -1793,6 +1829,10 @@ int input_register_device(struct input_dev *dev)
/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
+ if (!dev->hint_events_per_packet)
+ dev->hint_events_per_packet =
+ input_estimate_events_per_packet(dev);
* If delay and period are pre-set by the driver, then autorepeating
* is handled by the driver itself and we don't do it in input.c.
diff --git a/drivers/input/keyboard/twl4030_keypad.c b/drivers/input/keyboard/twl4030_keypad.c
index 09bef79d9da..a26922cf0e8 100644
--- a/drivers/input/keyboard/twl4030_keypad.c
+++ b/drivers/input/keyboard/twl4030_keypad.c
@@ -332,18 +332,20 @@ static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
static int __devinit twl4030_kp_probe(struct platform_device *pdev)
struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
- const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
+ const struct matrix_keymap_data *keymap_data;
struct twl4030_keypad *kp;
struct input_dev *input;
u8 reg;
int error;
- if (!pdata || !pdata->rows || !pdata->cols ||
+ if (!pdata || !pdata->rows || !pdata->cols || !pdata->keymap_data ||
pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
dev_err(&pdev->dev, "Invalid platform_data\n");
return -EINVAL;
+ keymap_data = pdata->keymap_data;
kp = kzalloc(sizeof(*kp), GFP_KERNEL);
input = input_allocate_device();
if (!kp || !input) {
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 7077f9bf5ea..62bae99424e 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -303,7 +303,7 @@ static void xenkbd_backend_changed(struct xenbus_device *dev,
enum xenbus_state backend_state)
struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
- int val;
+ int ret, val;
switch (backend_state) {
case XenbusStateInitialising:
@@ -316,6 +316,17 @@ static void xenkbd_backend_changed(struct xenbus_device *dev,
case XenbusStateInitWait:
+ ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+ "feature-abs-pointer", "%d", &val);
+ if (ret < 0)
+ val = 0;
+ if (val) {
+ ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
+ "request-abs-pointer", "1");
+ if (ret)
+ pr_warning("xenkbd: can't request abs-pointer");
+ }
xenbus_switch_state(dev, XenbusStateConnected);
diff --git a/drivers/input/touchscreen/h3600_ts_input.c b/drivers/input/touchscreen/h3600_ts_input.c
index efa06882de0..45f93d0f559 100644
--- a/drivers/input/touchscreen/h3600_ts_input.c
+++ b/drivers/input/touchscreen/h3600_ts_input.c
@@ -399,31 +399,34 @@ static int h3600ts_connect(struct serio *serio, struct serio_driver *drv)
IRQF_SHARED | IRQF_DISABLED, "h3600_action", &ts->dev)) {
printk(KERN_ERR "h3600ts.c: Could not allocate Action Button IRQ!\n");
err = -EBUSY;
- goto fail2;
+ goto fail1;
if (request_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, npower_button_handler,
IRQF_SHARED | IRQF_DISABLED, "h3600_suspend", &ts->dev)) {
printk(KERN_ERR "h3600ts.c: Could not allocate Power Button IRQ!\n");
err = -EBUSY;
- goto fail3;
+ goto fail2;
serio_set_drvdata(serio, ts);
err = serio_open(serio, drv);
if (err)
- return err;
+ goto fail3;
//h3600_flite_control(1, 25); /* default brightness */
- input_register_device(ts->dev);
+ err = input_register_device(ts->dev);
+ if (err)
+ goto fail4;
return 0;
-fail3: free_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, ts->dev);
+fail4: serio_close(serio);
+fail3: serio_set_drvdata(serio, NULL);
+ free_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, ts->dev);
fail2: free_irq(IRQ_GPIO_BITSY_ACTION_BUTTON, ts->dev);
-fail1: serio_set_drvdata(serio, NULL);
- input_free_device(input_dev);
+fail1: input_free_device(input_dev);
return err;
diff --git a/include/linux/input.h b/include/linux/input.h
index f3a7794a18c..771d6d85667 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -167,6 +167,7 @@ struct input_keymap_entry {
#define SYN_REPORT 0
#define SYN_CONFIG 1
#define SYN_MT_REPORT 2
+#define SYN_DROPPED 3
* Keys and buttons
@@ -553,8 +554,8 @@ struct input_keymap_entry {
#define KEY_DVD 0x185 /* Media Select DVD */
#define KEY_AUX 0x186
#define KEY_MP3 0x187
-#define KEY_AUDIO 0x188
-#define KEY_VIDEO 0x189
+#define KEY_AUDIO 0x188 /* AL Audio Browser */
+#define KEY_VIDEO 0x189 /* AL Movie Browser */
#define KEY_DIRECTORY 0x18a
#define KEY_LIST 0x18b
#define KEY_MEMO 0x18c /* Media Select Messages */
@@ -603,8 +604,9 @@ struct input_keymap_entry {
#define KEY_FRAMEFORWARD 0x1b5
#define KEY_CONTEXT_MENU 0x1b6 /* GenDesc - system context menu */
#define KEY_MEDIA_REPEAT 0x1b7 /* Consumer - transport control */
-#define KEY_10CHANNELSUP 0x1b8 /* 10 channels up (10+) */
-#define KEY_10CHANNELSDOWN 0x1b9 /* 10 channels down (10-) */
+#define KEY_10CHANNELSUP 0x1b8 /* 10 channels up (10+) */
+#define KEY_10CHANNELSDOWN 0x1b9 /* 10 channels down (10-) */
+#define KEY_IMAGES 0x1ba /* AL Image Browser */
#define KEY_DEL_EOL 0x1c0
#define KEY_DEL_EOS 0x1c1
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index b3ac06a4435..318bb82325a 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -48,6 +48,12 @@ static inline void input_mt_slot(struct input_dev *dev, int slot)
input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
+static inline bool input_is_mt_axis(int axis)
+ return axis == ABS_MT_SLOT ||
+ (axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST);
void input_mt_report_slot_state(struct input_dev *dev,
unsigned int tool_type, bool active);