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-rw-r--r--Documentation/ABI/testing/sysfs-driver-hid-roccat-pyra98
-rw-r--r--Documentation/input/ntrig.txt126
2 files changed, 224 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-hid-roccat-pyra b/Documentation/ABI/testing/sysfs-driver-hid-roccat-pyra
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1What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/actual_cpi
2Date: August 2010
3Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
4Description: It is possible to switch the cpi setting of the mouse with the
5 press of a button.
6 When read, this file returns the raw number of the actual cpi
7 setting reported by the mouse. This number has to be further
8 processed to receive the real dpi value.
9
10 VALUE DPI
11 1 400
12 2 800
13 4 1600
14
15 This file is readonly.
16
17What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/actual_profile
18Date: August 2010
19Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
20Description: When read, this file returns the number of the actual profile in
21 range 0-4.
22 This file is readonly.
23
24What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/firmware_version
25Date: August 2010
26Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
27Description: When read, this file returns the raw integer version number of the
28 firmware reported by the mouse. Using the integer value eases
29 further usage in other programs. To receive the real version
30 number the decimal point has to be shifted 2 positions to the
31 left. E.g. a returned value of 138 means 1.38
32 This file is readonly.
33
34What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/profile_settings
35Date: August 2010
36Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
37Description: The mouse can store 5 profiles which can be switched by the
38 press of a button. A profile is split in settings and buttons.
39 profile_settings holds informations like resolution, sensitivity
40 and light effects.
41 When written, this file lets one write the respective profile
42 settings back to the mouse. The data has to be 13 bytes long.
43 The mouse will reject invalid data.
44 Which profile to write is determined by the profile number
45 contained in the data.
46 This file is writeonly.
47
48What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/profile[1-5]_settings
49Date: August 2010
50Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
51Description: The mouse can store 5 profiles which can be switched by the
52 press of a button. A profile is split in settings and buttons.
53 profile_settings holds informations like resolution, sensitivity
54 and light effects.
55 When read, these files return the respective profile settings.
56 The returned data is 13 bytes in size.
57 This file is readonly.
58
59What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/profile_buttons
60Date: August 2010
61Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
62Description: The mouse can store 5 profiles which can be switched by the
63 press of a button. A profile is split in settings and buttons.
64 profile_buttons holds informations about button layout.
65 When written, this file lets one write the respective profile
66 buttons back to the mouse. The data has to be 19 bytes long.
67 The mouse will reject invalid data.
68 Which profile to write is determined by the profile number
69 contained in the data.
70 This file is writeonly.
71
72What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/profile[1-5]_buttons
73Date: August 2010
74Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
75Description: The mouse can store 5 profiles which can be switched by the
76 press of a button. A profile is split in settings and buttons.
77 profile_buttons holds informations about button layout.
78 When read, these files return the respective profile buttons.
79 The returned data is 19 bytes in size.
80 This file is readonly.
81
82What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/startup_profile
83Date: August 2010
84Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
85Description: The integer value of this attribute ranges from 0-4.
86 When read, this attribute returns the number of the profile
87 that's active when the mouse is powered on.
88 This file is readonly.
89
90What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/settings
91Date: August 2010
92Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
93Description: When read, this file returns the settings stored in the mouse.
94 The size of the data is 3 bytes and holds information on the
95 startup_profile.
96 When written, this file lets write settings back to the mouse.
97 The data has to be 3 bytes long. The mouse will reject invalid
98 data.
diff --git a/Documentation/input/ntrig.txt b/Documentation/input/ntrig.txt
new file mode 100644
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@@ -0,0 +1,126 @@
1N-Trig touchscreen Driver
2-------------------------
3 Copyright (c) 2008-2010 Rafi Rubin <rafi@seas.upenn.edu>
4 Copyright (c) 2009-2010 Stephane Chatty
5
6This driver provides support for N-Trig pen and multi-touch sensors. Single
7and multi-touch events are translated to the appropriate protocols for
8the hid and input systems. Pen events are sufficiently hid compliant and
9are left to the hid core. The driver also provides additional filtering
10and utility functions accessible with sysfs and module parameters.
11
12This driver has been reported to work properly with multiple N-Trig devices
13attached.
14
15
16Parameters
17----------
18
19Note: values set at load time are global and will apply to all applicable
20devices. Adjusting parameters with sysfs will override the load time values,
21but only for that one device.
22
23The following parameters are used to configure filters to reduce noise:
24
25activate_slack number of fingers to ignore before processing events
26
27activation_height size threshold to activate immediately
28activation_width
29
30min_height size threshold bellow which fingers are ignored
31min_width both to decide activation and during activity
32
33deactivate_slack the number of "no contact" frames to ignore before
34 propagating the end of activity events
35
36When the last finger is removed from the device, it sends a number of empty
37frames. By holding off on deactivation for a few frames we can tolerate false
38erroneous disconnects, where the sensor may mistakenly not detect a finger that
39is still present. Thus deactivate_slack addresses problems where a users might
40see breaks in lines during drawing, or drop an object during a long drag.
41
42
43Additional sysfs items
44----------------------
45
46These nodes just provide easy access to the ranges reported by the device.
47sensor_logical_height the range for positions reported during activity
48sensor_logical_width
49
50sensor_physical_height internal ranges not used for normal events but
51sensor_physical_width useful for tuning
52
53All N-Trig devices with product id of 1 report events in the ranges of
54X: 0-9600
55Y: 0-7200
56However not all of these devices have the same physical dimensions. Most
57seem to be 12" sensors (Dell Latitude XT and XT2 and the HP TX2), and
58at least one model (Dell Studio 17) has a 17" sensor. The ratio of physical
59to logical sizes is used to adjust the size based filter parameters.
60
61
62Filtering
63---------
64
65With the release of the early multi-touch firmwares it became increasingly
66obvious that these sensors were prone to erroneous events. Users reported
67seeing both inappropriately dropped contact and ghosts, contacts reported
68where no finger was actually touching the screen.
69
70Deactivation slack helps prevent dropped contact for single touch use, but does
71not address the problem of dropping one of more contacts while other contacts
72are still active. Drops in the multi-touch context require additional
73processing and should be handled in tandem with tacking.
74
75As observed ghost contacts are similar to actual use of the sensor, but they
76seem to have different profiles. Ghost activity typically shows up as small
77short lived touches. As such, I assume that the longer the continuous stream
78of events the more likely those events are from a real contact, and that the
79larger the size of each contact the more likely it is real. Balancing the
80goals of preventing ghosts and accepting real events quickly (to minimize
81user observable latency), the filter accumulates confidence for incoming
82events until it hits thresholds and begins propagating. In the interest in
83minimizing stored state as well as the cost of operations to make a decision,
84I've kept that decision simple.
85
86Time is measured in terms of the number of fingers reported, not frames since
87the probability of multiple simultaneous ghosts is expected to drop off
88dramatically with increasing numbers. Rather than accumulate weight as a
89function of size, I just use it as a binary threshold. A sufficiently large
90contact immediately overrides the waiting period and leads to activation.
91
92Setting the activation size thresholds to large values will result in deciding
93primarily on activation slack. If you see longer lived ghosts, turning up the
94activation slack while reducing the size thresholds may suffice to eliminate
95the ghosts while keeping the screen quite responsive to firm taps.
96
97Contacts continue to be filtered with min_height and min_width even after
98the initial activation filter is satisfied. The intent is to provide
99a mechanism for filtering out ghosts in the form of an extra finger while
100you actually are using the screen. In practice this sort of ghost has
101been far less problematic or relatively rare and I've left the defaults
102set to 0 for both parameters, effectively turning off that filter.
103
104I don't know what the optimal values are for these filters. If the defaults
105don't work for you, please play with the parameters. If you do find other
106values more comfortable, I would appreciate feedback.
107
108The calibration of these devices does drift over time. If ghosts or contact
109dropping worsen and interfere with the normal usage of your device, try
110recalibrating it.
111
112
113Calibration
114-----------
115
116The N-Trig windows tools provide calibration and testing routines. Also an
117unofficial unsupported set of user space tools including a calibrator is
118available at:
119http://code.launchpad.net/~rafi-seas/+junk/ntrig_calib
120
121
122Tracking
123--------
124
125As of yet, all tested N-Trig firmwares do not track fingers. When multiple
126contacts are active they seem to be sorted primarily by Y position.