From e2ba573120feadfb365467f0cdae2918926efabc Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 4 Apr 2017 17:51:04 -0700 Subject: Input: create a book with Linux Input documentation Now that all files under Documentation/input follows the ReST markup language, rename them to *.rst and create a book for the Linux Input subsystem. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Dmitry Torokhov --- Documentation/input/event-codes.rst | 404 ++++++++++++++++++++++++++++++++++++ 1 file changed, 404 insertions(+) create mode 100644 Documentation/input/event-codes.rst (limited to 'Documentation/input/event-codes.rst') diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst new file mode 100644 index 000000000000..92db50954169 --- /dev/null +++ b/Documentation/input/event-codes.rst @@ -0,0 +1,404 @@ +================= +Input event codes +================= + + +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. + +Event types +=========== + +Event 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. + +* EV_FF_STATUS: + + - Used to receive force feedback device status. + +Event codes +=========== + +Event codes define the precise type of event. + +EV_SYN +------ + +EV_SYN event values are undefined. Their usage is defined only by when they are +sent in the evdev event stream. + +* SYN_REPORT: + + - 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. + +* SYN_CONFIG: + + - TBD + +* SYN_MT_REPORT: + + - Used to synchronize and separate touch events. See the + multi-touch-protocol.txt document for more information. + +* SYN_DROPPED: + + - 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 +------ + +EV_KEY events take the form KEY_ or BTN_. 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_ is used for keyboard keys, and +BTN_ is used for other types of momentary switch events. + +A few EV_KEY codes have special meanings: + +* BTN_TOOL_: + + - 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_ + code should be set to a value of 1. When the tool is no longer interacting + with the input device, the BTN_TOOL_ code should be reset to 0. All + trackpads, tablets, and touchscreens should use at least one BTN_TOOL_ + code when events are generated. + +* BTN_TOUCH: + + 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_ 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. + +* BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, BTN_TOOL_TRIPLETAP, BTN_TOOL_QUADTAP: + + - 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_ 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_ + 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 +------ + +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: + +* REL_WHEEL, REL_HWHEEL: + + - These codes are used for vertical and horizontal scroll wheels, + respectively. + +EV_ABS +------ + +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: + +* ABS_DISTANCE: + + - 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. + - BTN_TOOL_ should be set to 1 when the tool comes into detectable + proximity and set to 0 when the tool leaves detectable proximity. + BTN_TOOL_ signals the type of tool that is currently detected by the + hardware and is otherwise independent of ABS_DISTANCE and/or BTN_TOUCH. + +* ABS_MT_: + + - Used to describe multitouch input events. Please see + multi-touch-protocol.txt for details. + +EV_SW +----- + +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 +------ + +EV_MSC events are used for input and output events that do not fall under other +categories. + +A few EV_MSC codes have special meaning: + +* MSC_TIMESTAMP: + + - Used to report the number of microseconds since the last reset. This event + should be coded as an uint32 value, which is allowed to wrap around with + no special consequence. It is assumed that the time difference between two + consecutive events is reliable on a reasonable time scale (hours). + A reset to zero can happen, in which case the time since the last event is + unknown. If the device does not provide this information, the driver must + not provide it to user space. + +EV_LED +------ + +EV_LED events are used for input and output to set and query the state of +various LEDs on devices. + +EV_REP +------ + +EV_REP events are used for specifying autorepeating events. + +EV_SND +------ + +EV_SND events are used for sending sound commands to simple sound output +devices. + +EV_FF +----- + +EV_FF events are used to initialize a force feedback capable device and to cause +such device to feedback. + +EV_PWR +------ + +EV_PWR events are a special type of event used specifically for power +management. Its usage is not well defined. To be addressed later. + +Device properties +================= + +Normally, userspace sets up an input device based on the data it emits, +i.e., the event types. In the case of two devices emitting the same event +types, additional information can be provided in the form of device +properties. + +INPUT_PROP_DIRECT + INPUT_PROP_POINTER +-------------------------------------- + +The INPUT_PROP_DIRECT property indicates that device coordinates should be +directly mapped to screen coordinates (not taking into account trivial +transformations, such as scaling, flipping and rotating). Non-direct input +devices require non-trivial transformation, such as absolute to relative +transformation for touchpads. Typical direct input devices: touchscreens, +drawing tablets; non-direct devices: touchpads, mice. + +The INPUT_PROP_POINTER property indicates that the device is not transposed +on the screen and thus requires use of an on-screen pointer to trace user's +movements. Typical pointer devices: touchpads, tablets, mice; non-pointer +device: touchscreen. + +If neither INPUT_PROP_DIRECT or INPUT_PROP_POINTER are set, the property is +considered undefined and the device type should be deduced in the +traditional way, using emitted event types. + +INPUT_PROP_BUTTONPAD +-------------------- + +For touchpads where the button is placed beneath the surface, such that +pressing down on the pad causes a button click, this property should be +set. Common in clickpad notebooks and macbooks from 2009 and onwards. + +Originally, the buttonpad property was coded into the bcm5974 driver +version field under the name integrated button. For backwards +compatibility, both methods need to be checked in userspace. + +INPUT_PROP_SEMI_MT +------------------ + +Some touchpads, most common between 2008 and 2011, can detect the presence +of multiple contacts without resolving the individual positions; only the +number of contacts and a rectangular shape is known. For such +touchpads, the semi-mt property should be set. + +Depending on the device, the rectangle may enclose all touches, like a +bounding box, or just some of them, for instance the two most recent +touches. The diversity makes the rectangle of limited use, but some +gestures can normally be extracted from it. + +If INPUT_PROP_SEMI_MT is not set, the device is assumed to be a true MT +device. + +INPUT_PROP_TOPBUTTONPAD +----------------------- + +Some laptops, most notably the Lenovo 40 series provide a trackstick +device but do not have physical buttons associated with the trackstick +device. Instead, the top area of the touchpad is marked to show +visual/haptic areas for left, middle, right buttons intended to be used +with the trackstick. + +If INPUT_PROP_TOPBUTTONPAD is set, userspace should emulate buttons +accordingly. This property does not affect kernel behavior. +The kernel does not provide button emulation for such devices but treats +them as any other INPUT_PROP_BUTTONPAD device. + +INPUT_PROP_ACCELEROMETER +------------------------ + +Directional axes on this device (absolute and/or relative x, y, z) represent +accelerometer data. All other axes retain their meaning. A device must not mix +regular directional axes and accelerometer axes on the same event node. + +Guidelines +========== + +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. + +Mice +---- + +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. + +Touchscreens +------------ + +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_ events should be reported where possible. + +For new hardware, INPUT_PROP_DIRECT should be set. + +Trackpads +--------- + +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_ should +be used to report the number of touches active on the trackpad. + +For new hardware, INPUT_PROP_POINTER should be set. + +Tablets +------- + +BTN_TOOL_ 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. + +For new hardware, both INPUT_PROP_DIRECT and INPUT_PROP_POINTER should be set. -- cgit v1.2.3 From ad6493800b08791bd7ea1a578b8c8b14dfecec0d Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Sat, 15 Apr 2017 15:16:50 -0700 Subject: Input: docs - freshen up introduction Stop saying that API is experimental and that only USB is supported, acknowledge that evdev is the preferred interface, and remove paragraph encouraging people sending snail mail to Vojtech :) along with his email. Signed-off-by: Dmitry Torokhov --- Documentation/input/event-codes.rst | 2 + Documentation/input/input.rst | 253 +++++++++++++--------------- Documentation/input/joydev/joystick-api.rst | 2 + Documentation/input/joydev/joystick.rst | 2 + 4 files changed, 127 insertions(+), 132 deletions(-) (limited to 'Documentation/input/event-codes.rst') diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst index 92db50954169..00b88f113bda 100644 --- a/Documentation/input/event-codes.rst +++ b/Documentation/input/event-codes.rst @@ -1,3 +1,5 @@ +.. _input-event-codes: + ================= Input event codes ================= diff --git a/Documentation/input/input.rst b/Documentation/input/input.rst index ac7669ad3e76..3b3a22975106 100644 --- a/Documentation/input/input.rst +++ b/Documentation/input/input.rst @@ -1,25 +1,20 @@ .. include:: -=================== -Linux Input drivers -=================== +============ +Introduction +============ :Copyright: |copy| 1999-2001 Vojtech Pavlik - Sponsored by SuSE -Should you need to contact me, the author, you can do so either by e-mail -- mail your message to , or by paper mail: Vojtech Pavlik, -Simunkova 1594, Prague 8, 182 00 Czech Republic - -Introduction +Architecture ============ -This is a collection of drivers that is designed to support all input -devices under Linux. While it is currently used only on for USB input -devices, future use (say 2.5/2.6) is expected to expand to replace -most of the existing input system, which is why it lives in -drivers/input/ instead of drivers/usb/. +Input subsystem a collection of drivers that is designed to support +all input devices under Linux. Most of the drivers reside in +drivers/input, although quite a few live in drivers/hid and +drivers/platform. -The centre of the input drivers is the input module, which must be +The core of the input subsystem is the input module, which must be loaded before any other of the input modules - it serves as a way of communication between two groups of modules: @@ -32,9 +27,9 @@ events (keystrokes, mouse movements) to the input module. Event handlers -------------- -These modules get events from input and pass them where needed via -various interfaces - keystrokes to the kernel, mouse movements via a -simulated PS/2 interface to GPM and X and so on. +These modules get events from input core and pass them where needed +via various interfaces - keystrokes to the kernel, mouse movements via +a simulated PS/2 interface to GPM and X, and so on. Simple Usage ============ @@ -45,19 +40,18 @@ kernel):: input mousedev - keybdev usbcore uhci_hcd or ohci_hcd or ehci_hcd usbhid + hid_generic After this, the USB keyboard will work straight away, and the USB mouse will be available as a character device on major 13, minor 63:: crw-r--r-- 1 root root 13, 63 Mar 28 22:45 mice -This device has to be created. - -The commands to create it by hand are:: +This device usually created automatically by the system. The commands +to create it by hand are:: cd /dev mkdir input @@ -81,100 +75,50 @@ When you do all of the above, you can use your USB mouse and keyboard. Detailed Description ==================== -Device drivers +Event handlers -------------- -Device drivers are the modules that generate events. The events are -however not useful without being handled, so you also will need to use some -of the modules from section 3.2. - -usbhid -~~~~~~ - -usbhid is the largest and most complex driver of the whole suite. It -handles all HID devices, and because there is a very wide variety of them, -and because the USB HID specification isn't simple, it needs to be this big. - -Currently, it handles USB mice, joysticks, gamepads, steering wheels -keyboards, trackballs and digitizers. - -However, USB uses HID also for monitor controls, speaker controls, UPSs, -LCDs and many other purposes. - -The monitor and speaker controls should be easy to add to the hid/input -interface, but for the UPSs and LCDs it doesn't make much sense. For this, -the hiddev interface was designed. See Documentation/hid/hiddev.txt -for more information about it. - -The usage of the usbhid module is very simple, it takes no parameters, -detects everything automatically and when a HID device is inserted, it -detects it appropriately. - -However, because the devices vary wildly, you might happen to have a -device that doesn't work well. In that case #define DEBUG at the beginning -of hid-core.c and send me the syslog traces. +Event handlers distribute the events from the devices to userspace and +in-kernel consumers, as needed. -usbmouse -~~~~~~~~ - -For embedded systems, for mice with broken HID descriptors and just any -other use when the big usbhid wouldn't be a good choice, there is the -usbmouse driver. It handles USB mice only. It uses a simpler HIDBP -protocol. This also means the mice must support this simpler protocol. Not -all do. If you don't have any strong reason to use this module, use usbhid -instead. - -usbkbd -~~~~~~ - -Much like usbmouse, this module talks to keyboards with a simplified -HIDBP protocol. It's smaller, but doesn't support any extra special keys. -Use usbhid instead if there isn't any special reason to use this. - -wacom +evdev ~~~~~ -This is a driver for Wacom Graphire and Intuos tablets. Not for Wacom -PenPartner, that one is handled by the HID driver. Although the Intuos and -Graphire tablets claim that they are HID tablets as well, they are not and -thus need this specific driver. +``evdev`` is the generic input event interface. It passes the events +generated in the kernel straight to the program, with timestamps. The +event codes are the same on all architectures and are hardware +independent. -iforce -~~~~~~ +This is the preferred interface for userspace to consume user +input, and all clients are encouraged to use it. -A driver for I-Force joysticks and wheels, both over USB and RS232. -It includes ForceFeedback support now, even though Immersion -Corp. considers the protocol a trade secret and won't disclose a word -about it. +See :ref:`event-interface` for notes on API. -Event handlers --------------- +The devices are in /dev/input:: -Event handlers distribute the events from the devices to userland and -kernel, as needed. + crw-r--r-- 1 root root 13, 64 Apr 1 10:49 event0 + crw-r--r-- 1 root root 13, 65 Apr 1 10:50 event1 + crw-r--r-- 1 root root 13, 66 Apr 1 10:50 event2 + crw-r--r-- 1 root root 13, 67 Apr 1 10:50 event3 + ... -keybdev -~~~~~~~ +There are two ranges of minors: 64 through 95 is the static legacy +range. If there are more than 32 input devices in a system, additional +evdev nodes are created with minors starting with 256. -keybdev is currently a rather ugly hack that translates the input -events into architecture-specific keyboard raw mode (Xlated AT Set2 on -x86), and passes them into the handle_scancode function of the -keyboard.c module. This works well enough on all architectures that -keybdev can generate rawmode on, other architectures can be added to -it. +keyboard +~~~~~~~~ -The right way would be to pass the events to keyboard.c directly, -best if keyboard.c would itself be an event handler. This is done in -the input patch, available on the webpage mentioned below. +``keyboard`` is in-kernel input handler ad is a part of VT code. It +consumes keyboard keystrokes and handles user input for VT consoles. mousedev ~~~~~~~~ -mousedev is also a hack to make programs that use mouse input +``mousedev`` is a hack to make legacy programs that use mouse input work. It takes events from either mice or digitizers/tablets and makes a PS/2-style (a la /dev/psaux) mouse device available to the -userland. Ideally, the programs could use a more reasonable interface, -for example evdev +userland. Mousedev devices in /dev/input (as shown above) are:: @@ -190,8 +134,9 @@ Mousedev devices in /dev/input (as shown above) are:: Each ``mouse`` device is assigned to a single mouse or digitizer, except the last one - ``mice``. This single character device is shared by all mice and digitizers, and even if none are connected, the device is -present. This is useful for hotplugging USB mice, so that programs -can open the device even when no mice are present. +present. This is useful for hotplugging USB mice, so that older programs +that do not handle hotplug can open the device even when no mice are +present. CONFIG_INPUT_MOUSEDEV_SCREEN_[XY] in the kernel configuration are the size of your screen (in pixels) in XFree86. This is needed if you @@ -208,11 +153,10 @@ mouse and ExplorerPS/2 if you want to use extra (up to 5) buttons. joydev ~~~~~~ -Joydev implements v0.x and v1.x Linux joystick api, much like -drivers/char/joystick/joystick.c used to in earlier versions. See -joystick-api.txt in the Documentation subdirectory for details. As -soon as any joystick is connected, it can be accessed in /dev/input -on:: +``joydev`` implements v0.x and v1.x Linux joystick API. See +:ref:`joystick-api` for details. + +As soon as any joystick is connected, it can be accessed in /dev/input on:: crw-r--r-- 1 root root 13, 0 Apr 1 10:50 js0 crw-r--r-- 1 root root 13, 1 Apr 1 10:50 js1 @@ -220,56 +164,99 @@ on:: crw-r--r-- 1 root root 13, 3 Apr 1 10:50 js3 ... -And so on up to js31. +And so on up to js31 in legacy range, and additional nodes with minors +above 256 if there are more joystick devices. -evdev -~~~~~ +Device drivers +-------------- -evdev is the generic input event interface. It passes the events -generated in the kernel straight to the program, with timestamps. The -API is still evolving, but should be usable now. It's described in -section 5. +Device drivers are the modules that generate events. -This should be the way for GPM and X to get keyboard and mouse -events. It allows for multihead in X without any specific multihead -kernel support. The event codes are the same on all architectures and -are hardware independent. +hid-generic +~~~~~~~~~~~ -The devices are in /dev/input:: +``hid-generic`` is one of the largest and most complex driver of the +whole suite. It handles all HID devices, and because there is a very +wide variety of them, and because the USB HID specification isn't +simple, it needs to be this big. - crw-r--r-- 1 root root 13, 64 Apr 1 10:49 event0 - crw-r--r-- 1 root root 13, 65 Apr 1 10:50 event1 - crw-r--r-- 1 root root 13, 66 Apr 1 10:50 event2 - crw-r--r-- 1 root root 13, 67 Apr 1 10:50 event3 - ... +Currently, it handles USB mice, joysticks, gamepads, steering wheels +keyboards, trackballs and digitizers. + +However, USB uses HID also for monitor controls, speaker controls, UPSs, +LCDs and many other purposes. + +The monitor and speaker controls should be easy to add to the hid/input +interface, but for the UPSs and LCDs it doesn't make much sense. For this, +the hiddev interface was designed. See Documentation/hid/hiddev.txt +for more information about it. + +The usage of the usbhid module is very simple, it takes no parameters, +detects everything automatically and when a HID device is inserted, it +detects it appropriately. -And so on up to event31. +However, because the devices vary wildly, you might happen to have a +device that doesn't work well. In that case #define DEBUG at the beginning +of hid-core.c and send me the syslog traces. + +usbmouse +~~~~~~~~ + +For embedded systems, for mice with broken HID descriptors and just any +other use when the big usbhid wouldn't be a good choice, there is the +usbmouse driver. It handles USB mice only. It uses a simpler HIDBP +protocol. This also means the mice must support this simpler protocol. Not +all do. If you don't have any strong reason to use this module, use usbhid +instead. + +usbkbd +~~~~~~ + +Much like usbmouse, this module talks to keyboards with a simplified +HIDBP protocol. It's smaller, but doesn't support any extra special keys. +Use usbhid instead if there isn't any special reason to use this. + +psmouse +~~~~~~~ + +This is driver for all flavors of pointing devices using PS/2 +protocol, including Synaptics and ALPS touchpads, Intellimouse +Explorer devices, Logitech PS/2 mice and so on. + +atkbd +~~~~~ + +This is driver for PS/2 (AT) keyboards. + +iforce +~~~~~~ + +A driver for I-Force joysticks and wheels, both over USB and RS232. +It includes Force Feedback support now, even though Immersion +Corp. considers the protocol a trade secret and won't disclose a word +about it. Verifying if it works ===================== Typing a couple keys on the keyboard should be enough to check that -a USB keyboard works and is correctly connected to the kernel keyboard +a keyboard works and is correctly connected to the kernel keyboard driver. Doing a ``cat /dev/input/mouse0`` (c, 13, 32) will verify that a mouse is also emulated; characters should appear if you move it. You can test the joystick emulation with the ``jstest`` utility, -available in the joystick package (see Documentation/input/joystick.txt). +available in the joystick package (see :ref:`joystick-doc`). -You can test the event devices with the ``evtest`` utility available -in the LinuxConsole project CVS archive (see the URL below). +You can test the event devices with the ``evtest`` utility. + +.. _event-interface: Event interface =============== -Should you want to add event device support into any application (X, gpm, -svgalib ...) I will be happy to provide you any help I -can. Here goes a description of the current state of things, which is going -to be extended, but not changed incompatibly as time goes: - -You can use blocking and nonblocking reads, also select() on the +You can use blocking and nonblocking reads, and also select() on the /dev/input/eventX devices, and you'll always get a whole number of input events on a read. Their layout is:: @@ -290,3 +277,5 @@ list is in include/uapi/linux/input-event-codes.h. ``value`` is the value the event carries. Either a relative change for EV_REL, absolute new value for EV_ABS (joysticks ...), or 0 for EV_KEY for release, 1 for keypress and 2 for autorepeat. + +See :ref:`input-event-codes` for more information about various even codes. diff --git a/Documentation/input/joydev/joystick-api.rst b/Documentation/input/joydev/joystick-api.rst index 42edcfc6e8af..95803e2e8cd0 100644 --- a/Documentation/input/joydev/joystick-api.rst +++ b/Documentation/input/joydev/joystick-api.rst @@ -1,3 +1,5 @@ +.. _joystick-api: + ===================== Programming Interface ===================== diff --git a/Documentation/input/joydev/joystick.rst b/Documentation/input/joydev/joystick.rst index b90705eb69b1..9746fd76cc58 100644 --- a/Documentation/input/joydev/joystick.rst +++ b/Documentation/input/joydev/joystick.rst @@ -1,5 +1,7 @@ .. include:: +.. _joystick-doc: + Introduction ============ -- cgit v1.2.3