Commit 8006479c authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: implement proper locking in input core



Also add some kerneldoc documentation to input.h
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 501cc54c
This diff is collapsed.
......@@ -845,7 +845,7 @@ struct ff_rumble_effect {
* defining effect parameters
*
* This structure is sent through ioctl from the application to the driver.
* To create a new effect aplication should set its @id to -1; the kernel
* To create a new effect application should set its @id to -1; the kernel
* will return assigned @id which can later be used to update or delete
* this effect.
*
......@@ -925,9 +925,82 @@ struct ff_effect {
#define BIT(x) (1UL<<((x)%BITS_PER_LONG))
#define LONG(x) ((x)/BITS_PER_LONG)
/**
* struct input_dev - represents an input device
* @name: name of the device
* @phys: physical path to the device in the system hierarchy
* @uniq: unique identification code for the device (if device has it)
* @id: id of the device (struct input_id)
* @evbit: bitmap of types of events supported by the device (EV_KEY,
* EV_REL, etc.)
* @keybit: bitmap of keys/buttons this device has
* @relbit: bitmap of relative axes for the device
* @absbit: bitmap of absolute axes for the device
* @mscbit: bitmap of miscellaneous events supported by the device
* @ledbit: bitmap of leds present on the device
* @sndbit: bitmap of sound effects supported by the device
* @ffbit: bitmap of force feedback effects supported by the device
* @swbit: bitmap of switches present on the device
* @keycodemax: size of keycode table
* @keycodesize: size of elements in keycode table
* @keycode: map of scancodes to keycodes for this device
* @setkeycode: optional method to alter current keymap, used to implement
* sparse keymaps. If not supplied default mechanism will be used
* @getkeycode: optional method to retrieve current keymap. If not supplied
* default mechanism will be used
* @ff: force feedback structure associated with the device if device
* supports force feedback effects
* @repeat_key: stores key code of the last key pressed; used to implement
* software autorepeat
* @timer: timer for software autorepeat
* @sync: set to 1 when there were no new events since last EV_SYNC
* @abs: current values for reports from absolute axes
* @rep: current values for autorepeat parameters (delay, rate)
* @key: reflects current state of device's keys/buttons
* @led: reflects current state of device's LEDs
* @snd: reflects current state of sound effects
* @sw: reflects current state of device's switches
* @absmax: maximum values for events coming from absolute axes
* @absmin: minimum values for events coming from absolute axes
* @absfuzz: describes noisiness for axes
* @absflat: size of the center flat position (used by joydev)
* @open: this method is called when the very first user calls
* input_open_device(). The driver must prepare the device
* to start generating events (start polling thread,
* request an IRQ, submit URB, etc.)
* @close: this method is called when the very last user calls
* input_close_device().
* @flush: purges the device. Most commonly used to get rid of force
* feedback effects loaded into the device when disconnecting
* from it
* @event: event handler for events sent _to_ the device, like EV_LED
* or EV_SND. The device is expected to carry out the requested
* action (turn on a LED, play sound, etc.) The call is protected
* by @event_lock and must not sleep
* @grab: input handle that currently has the device grabbed (via
* EVIOCGRAB ioctl). When a handle grabs a device it becomes sole
* recipient for all input events coming from the device
* @event_lock: this spinlock is is taken when input core receives
* and processes a new event for the device (in input_event()).
* Code that accesses and/or modifies parameters of a device
* (such as keymap or absmin, absmax, absfuzz, etc.) after device
* has been registered with input core must take this lock.
* @mutex: serializes calls to open(), close() and flush() methods
* @users: stores number of users (input handlers) that opened this
* device. It is used by input_open_device() and input_close_device()
* to make sure that dev->open() is only called when the first
* user opens device and dev->close() is called when the very
* last user closes the device
* @going_away: marks devices that are in a middle of unregistering and
* causes input_open_device*() fail with -ENODEV.
* @dev: driver model's view of this device
* @h_list: list of input handles associated with the device. When
* accessing the list dev->mutex must be held
* @node: used to place the device onto input_dev_list
*/
struct input_dev {
void *private;
void *private; /* do not use */
const char *name;
const char *phys;
......@@ -955,8 +1028,6 @@ struct input_dev {
unsigned int repeat_key;
struct timer_list timer;
int state;
int sync;
int abs[ABS_MAX + 1];
......@@ -979,8 +1050,11 @@ struct input_dev {
struct input_handle *grab;
struct mutex mutex; /* serializes open and close operations */
spinlock_t event_lock;
struct mutex mutex;
unsigned int users;
int going_away;
struct device dev;
union { /* temporarily so while we switching to struct device */
......@@ -1046,7 +1120,9 @@ struct input_handle;
/**
* struct input_handler - implements one of interfaces for input devices
* @private: driver-specific data
* @event: event handler
* @event: event handler. This method is being called by input core with
* interrupts disabled and dev->event_lock spinlock held and so
* it may not sleep
* @connect: called when attaching a handler to an input device
* @disconnect: disconnects a handler from input device
* @start: starts handler for given handle. This function is called by
......@@ -1058,10 +1134,18 @@ struct input_handle;
* @name: name of the handler, to be shown in /proc/bus/input/handlers
* @id_table: pointer to a table of input_device_ids this driver can
* handle
* @blacklist: prointer to a table of input_device_ids this driver should
* @blacklist: pointer to a table of input_device_ids this driver should
* ignore even if they match @id_table
* @h_list: list of input handles associated with the handler
* @node: for placing the driver onto input_handler_list
*
* Input handlers attach to input devices and create input handles. There
* are likely several handlers attached to any given input device at the
* same time. All of them will get their copy of input event generated by
* the device.
*
* Note that input core serializes calls to connect() and disconnect()
* methods.
*/
struct input_handler {
......@@ -1083,6 +1167,18 @@ struct input_handler {
struct list_head node;
};
/**
* struct input_handle - links input device with an input handler
* @private: handler-specific data
* @open: counter showing whether the handle is 'open', i.e. should deliver
* events from its device
* @name: name given to the handle by handler that created it
* @dev: input device the handle is attached to
* @handler: handler that works with the device through this handle
* @d_node: used to put the handle on device's list of attached handles
* @h_node: used to put the handle on handler's list of handles from which
* it gets events
*/
struct input_handle {
void *private;
......@@ -1205,7 +1301,7 @@ extern struct class input_class;
* @max_effects: maximum number of effects supported by device
* @effects: pointer to an array of effects currently loaded into device
* @effect_owners: array of effect owners; when file handle owning
* an effect gets closed the effcet is automatically erased
* an effect gets closed the effect is automatically erased
*
* Every force-feedback device must implement upload() and playback()
* methods; erase() is optional. set_gain() and set_autocenter() need
......
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