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author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2007-08-30 04:22:11 (GMT) |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2007-08-30 04:22:11 (GMT) |
commit | 8006479c9b75fb6594a7b746af3d7f1fbb68f18f (patch) | |
tree | 1c1cd28f3fec192fa3e15f3042b4f087b43806d4 /include | |
parent | 501cc54c4d2b0c2bbae1a6490b0e547be46fc09f (diff) | |
download | linux-fsl-qoriq-8006479c9b75fb6594a7b746af3d7f1fbb68f18f.tar.xz |
Input: implement proper locking in input core
Also add some kerneldoc documentation to input.h
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/input.h | 112 |
1 files changed, 104 insertions, 8 deletions
diff --git a/include/linux/input.h b/include/linux/input.h index adfbe4f..d09e5e8 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -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 |