xref: /freebsd/share/man/man4/psm.4 (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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2.\" Copyright (c) 1997
3.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
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27.\" $FreeBSD$
28.\"
29.Dd April 8, 2008
30.Dt PSM 4
31.Os
32.Sh NAME
33.Nm psm
34.Nd PS/2 mouse style pointing device driver
35.Sh SYNOPSIS
36.Cd "options KBD_RESETDELAY=N"
37.Cd "options KBD_MAXWAIT=N"
38.Cd "options PSM_DEBUG=N"
39.Cd "options KBDIO_DEBUG=N"
40.Cd "device psm"
41.Pp
42In
43.Pa /boot/device.hints :
44.Cd hint.psm.0.at="atkbdc"
45.Cd hint.psm.0.irq="12"
46.Sh DESCRIPTION
47The
48.Nm
49driver provides support for the PS/2 mouse style pointing device.
50Currently there can be only one
51.Nm
52device node in the system.
53As the PS/2 mouse port is located
54at the auxiliary port of the keyboard controller,
55the keyboard controller driver,
56.Nm atkbdc ,
57must also be configured in the kernel.
58Note that there is currently no provision of changing the
59.Em irq
60number.
61.Pp
62Basic PS/2 style pointing device has two or three buttons.
63Some devices may have a roller or a wheel and/or additional buttons.
64.Ss Device Resolution
65The PS/2 style pointing device usually has several grades of resolution,
66that is, sensitivity of movement.
67They are typically 25, 50, 100 and 200
68pulse per inch.
69Some devices may have finer resolution.
70The current resolution can be changed at runtime.
71The
72.Nm
73driver allows the user to initially set the resolution
74via the driver flag
75(see
76.Sx "DRIVER CONFIGURATION" )
77or change it later via the
78.Xr ioctl 2
79command
80.Dv MOUSE_SETMODE
81(see
82.Sx IOCTLS ) .
83.Ss Report Rate
84Frequency, or report rate, at which the device sends movement
85and button state reports to the host system is also configurable.
86The PS/2 style pointing device typically supports 10, 20, 40, 60, 80, 100
87and 200 reports per second.
8860 or 100 appears to be the default value for many devices.
89Note that when there is no movement and no button has changed its state,
90the device will not send anything to the host system.
91The report rate can be changed via an ioctl call.
92.Ss Operation Levels
93The
94.Nm
95driver has three levels of operation.
96The current operation level can be set via an ioctl call.
97.Pp
98At the level zero the basic support is provided; the device driver will report
99horizontal and vertical movement of the attached device
100and state of up to three buttons.
101The movement and status are encoded in a series of fixed-length data packets
102(see
103.Sx "Data Packet Format" ) .
104This is the default level of operation and the driver is initially
105at this level when opened by the user program.
106.Pp
107The operation level one, the `extended' level, supports a roller (or wheel),
108if any, and up to 11 buttons.
109The movement of the roller is reported as movement along the Z axis.
1108 byte data packets are sent to the user program at this level.
111.Pp
112At the operation level two, data from the pointing device is passed to the
113user program as is. Conversely, command from the user program is passed
114to the pointing device as is and the user program is responsible for
115status validation and error recovery.
116Modern PS/2 type pointing devices often use proprietary data format.
117Therefore, the user program is expected to have
118intimate knowledge about the format from a particular device when operating
119the driver at this level.
120This level is called `native' level.
121.Ss Data Packet Format
122Data packets read from the
123.Nm
124driver are formatted differently at each operation level.
125.Pp
126A data packet from the PS/2 mouse style pointing device
127is three bytes long at the operation level zero:
128.Pp
129.Bl -tag -width Byte_1 -compact
130.It Byte 1
131.Bl -tag -width bit_7 -compact
132.It bit 7
133One indicates overflow in the vertical movement count.
134.It bit 6
135One indicates overflow in the horizontal movement count.
136.It bit 5
137Set if the vertical movement count is negative.
138.It bit 4
139Set if the horizontal movement count is negative.
140.It bit 3
141Always one.
142.\" The ALPS GlidePoint clears this bit when the user `taps' the surface of
143.\" the pad, otherwise the bit is set.
144.\" Most, if not all, other devices always set this bit.
145.It bit 2
146Middle button status; set if pressed.
147For devices without the middle
148button, this bit is always zero.
149.It bit 1
150Right button status; set if pressed.
151.It bit 0
152Left button status; set if pressed.
153.El
154.It Byte 2
155Horizontal movement count in two's complement;
156-256 through 255.
157Note that the sign bit is in the first byte.
158.It Byte 3
159Vertical movement count in two's complement;
160-256 through 255.
161Note that the sign bit is in the first byte.
162.El
163.Pp
164At the level one, a data packet is encoded
165in the standard format
166.Dv MOUSE_PROTO_SYSMOUSE
167as defined in
168.Xr mouse 4 .
169.Pp
170At the level two, native level, there is no standard on the size and format
171of the data packet.
172.Ss Acceleration
173The
174.Nm
175driver can somewhat `accelerate' the movement of the pointing device.
176The faster you move the device, the further the pointer
177travels on the screen.
178The driver has an internal variable which governs the effect of
179the acceleration.
180Its value can be modified via the driver flag
181or via an ioctl call.
182.Ss Device Number
183The minor device number of the
184.Nm
185is made up of:
186.Bd -literal -offset indent
187minor = (`unit' << 1) | `non-blocking'
188.Ed
189.Pp
190where `unit' is the device number (usually 0) and the `non-blocking' bit
191is set to indicate ``do not block waiting for mouse input,
192return immediately''.
193The `non-blocking' bit should be set for \fIXFree86\fP,
194therefore the minor device number usually used for \fIXFree86\fP is 1.
195See
196.Sx FILES
197for device node names.
198.Sh DRIVER CONFIGURATION
199.Ss Kernel Configuration Options
200There are following kernel configuration options to control the
201.Nm
202driver.
203They may be set in the kernel configuration file
204(see
205.Xr config 8 ) .
206.Bl -tag -width MOUSE
207.It Em KBD_RESETDELAY=X , KBD_MAXWAIT=Y
208The
209.Nm
210driver will attempt to reset the pointing device during the boot process.
211It sometimes takes a long while before the device will respond after
212reset.
213These options control how long the driver should wait before
214it eventually gives up waiting.
215The driver will wait
216.Fa X
217*
218.Fa Y
219msecs at most.
220If the driver seems unable to detect your pointing
221device, you may want to increase these values.
222The default values are
223200 msec for
224.Fa X
225and 5
226for
227.Fa Y .
228.It Em PSM_DEBUG=N , KBDIO_DEBUG=N
229Sets the debug level to
230.Fa N .
231The default debug level is zero.
232See
233.Sx DIAGNOSTICS
234for debug logging.
235.El
236.Ss Driver Flags
237The
238.Nm
239driver accepts the following driver flags.
240Set them in
241.Pa /boot/device.hints
242(see
243.Sx EXAMPLES
244below).
245.Pp
246.Bl -tag -width MOUSE
247.It bit 0..3 RESOLUTION
248This flag specifies the resolution of the pointing device.
249It must be zero through four.
250The greater the value
251is, the finer resolution the device will select.
252Actual resolution selected by this field varies according to the model
253of the device.
254Typical resolutions are:
255.Pp
256.Bl -tag -width 0_(medium_high)__ -compact
257.It Em 1 (low)
25825 pulse per inch (ppi)
259.It Em 2 (medium low)
26050 ppi
261.It Em 3 (medium high)
262100 ppi
263.It Em 4 (high)
264200 ppi
265.El
266.Pp
267Leaving this flag zero will selects the default resolution for the
268device (whatever it is).
269.It bit 4..7 ACCELERATION
270This flag controls the amount of acceleration effect.
271The smaller the value of this flag is, more sensitive the movement becomes.
272The minimum value allowed, thus the value for the most sensitive setting,
273is one.
274Setting this flag to zero will completely disables the
275acceleration effect.
276.It bit 8 NOCHECKSYNC
277The
278.Nm
279driver tries to detect the first byte of the data packet by checking
280the bit pattern of that byte.
281Although this method should work with most
282PS/2 pointing devices, it may interfere with some devices which are not
283so compatible with known devices.
284If you think your pointing device is not functioning as expected,
285and the kernel frequently prints the following message to the console,
286.Bd -literal -offset indent
287psmintr: out of sync (xxxx != yyyy).
288.Ed
289.Pp
290set this flag to disable synchronization check and see if it helps.
291.It bit 9 NOIDPROBE
292The
293.Nm
294driver will not try to identify the model of the pointing device and
295will not carry out model-specific initialization.
296The device should always act like a standard PS/2 mouse without such
297initialization.
298Extra features, such as wheels and additional buttons, will not be
299recognized by the
300.Nm
301driver.
302.It bit 10 NORESET
303When this flag is set, the
304.Nm
305driver will not reset the pointing device when initializing the device.
306If the
307.Fx
308kernel
309is started after another OS has run, the pointing device will inherit
310settings from the previous OS.
311However, because there is no way for the
312.Nm
313driver to know the settings, the device and the driver may not
314work correctly.
315The flag should never be necessary under normal circumstances.
316.It bit 11 FORCETAP
317Some pad devices report as if the fourth button is pressed
318when the user `taps' the surface of the device (see
319.Sx CAVEATS ) .
320This flag will make the
321.Nm
322driver assume that the device behaves this way.
323Without the flag, the driver will assume this behavior
324for ALPS GlidePoint models only.
325.It bit 12 IGNOREPORTERROR
326This flag makes
327.Nm
328driver ignore certain error conditions when probing the PS/2 mouse port.
329It should never be necessary under normal circumstances.
330.It bit 13 HOOKRESUME
331The built-in PS/2 pointing device of some laptop computers is somehow
332not operable immediately after the system `resumes' from
333the power saving mode,
334though it will eventually become available.
335There are reports that
336stimulating the device by performing I/O will help
337waking up the device quickly.
338This flag will enable a piece of code in the
339.Nm
340driver to hook
341the `resume' event and exercise some harmless I/O operations on the
342device.
343.It bit 14 INITAFTERSUSPEND
344This flag adds more drastic action for the above problem.
345It will cause the
346.Nm
347driver to reset and re-initialize the pointing device
348after the `resume' event.
349It has no effect unless the
350.Em HOOKRESUME
351flag is set as well.
352.El
353.Sh LOADER TUNABLES
354Extended support for Synaptics touchpads can be enabled by setting
355.Va hw.psm.synaptics_support
356to
357.Em 1
358at boot-time.
359This will enable
360.Nm
361to handle packets from guest devices (sticks) and extra buttons.
362.Sh IOCTLS
363There are a few
364.Xr ioctl 2
365commands for mouse drivers.
366These commands and related structures and constants are defined in
367.In sys/mouse.h .
368General description of the commands is given in
369.Xr mouse 4 .
370This section explains the features specific to the
371.Nm
372driver.
373.Pp
374.Bl -tag -width MOUSE -compact
375.It Dv MOUSE_GETLEVEL Ar int *level
376.It Dv MOUSE_SETLEVEL Ar int *level
377These commands manipulate the operation level of the
378.Nm
379driver.
380.Pp
381.It Dv MOUSE_GETHWINFO Ar mousehw_t *hw
382Returns the hardware information of the attached device in the following
383structure.
384.Bd -literal
385typedef struct mousehw {
386    int buttons;    /* number of buttons */
387    int iftype;     /* I/F type */
388    int type;       /* mouse/track ball/pad... */
389    int model;      /* I/F dependent model ID */
390    int hwid;       /* I/F dependent hardware ID */
391} mousehw_t;
392.Ed
393.Pp
394The
395.Dv buttons
396field holds the number of buttons on the device.
397The
398.Nm
399driver currently can detect the 3 button mouse from Logitech and report
400accordingly.
401The 3 button mouse from the other manufacturer may or may not be
402reported correctly.
403However, it will not affect the operation of
404the driver.
405.Pp
406The
407.Dv iftype
408is always
409.Dv MOUSE_IF_PS2 .
410.Pp
411The
412.Dv type
413tells the device type:
414.Dv MOUSE_MOUSE ,
415.Dv MOUSE_TRACKBALL ,
416.Dv MOUSE_STICK ,
417.Dv MOUSE_PAD ,
418or
419.Dv MOUSE_UNKNOWN .
420The user should not heavily rely on this field, as the
421driver may not always, in fact it is very rarely able to, identify
422the device type.
423.Pp
424The
425.Dv model
426is always
427.Dv MOUSE_MODEL_GENERIC
428at the operation level 0.
429It may be
430.Dv MOUSE_MODEL_GENERIC
431or one of
432.Dv MOUSE_MODEL_XXX
433constants at higher operation levels.
434Again the
435.Nm
436driver may or may not set an appropriate value in this field.
437.Pp
438The
439.Dv hwid
440is the ID value returned by the device.
441Known IDs include:
442.Pp
443.Bl -tag -width 0__ -compact
444.It Em 0
445Mouse (Microsoft, Logitech and many other manufacturers)
446.It Em 2
447Microsoft Ballpoint mouse
448.It Em 3
449Microsoft IntelliMouse
450.El
451.Pp
452.It Dv MOUSE_SYN_GETHWINFO Ar synapticshw_t *synhw
453Retrieves extra information associated with Synaptics Touchpads.
454Only available when
455.Va hw.psm.synaptics_support
456has been enabled.
457.Bd -literal
458typedef struct synapticshw {
459    int infoMajor;	/* major hardware revision */
460    int infoMinor;	/* minor hardware revision */
461    int infoRot180;	/* touchpad is rotated */
462    int infoPortrait;	/* touchpad is a portrait */
463    int infoSensor;	/* sensor model */
464    int infoHardware;	/* hardware model */
465    int infoNewAbs;	/* supports the newabs format */
466    int capPen;		/* can detect a pen */
467    int infoSimpleC;	/* supports simple commands */
468    int infoGeometry;	/* touchpad dimensions */
469    int capExtended;	/* supports extended packets */
470    int capSleep;	/* can be suspended/resumed */
471    int capFourButtons;	/* has four buttons */
472    int capMultiFinger;	/* can detect multiple fingers */
473    int capPalmDetect;	/* can detect a palm */
474    int capPassthrough;	/* can passthrough guest packets */
475} synapticshw_t;
476.Ed
477.Pp
478See the
479.Em Synaptics TouchPad Interfacing Guide
480for more information about the fields in this structure.
481.Pp
482.It Dv MOUSE_GETMODE Ar mousemode_t *mode
483The command gets the current operation parameters of the mouse
484driver.
485.Bd -literal
486typedef struct mousemode {
487    int protocol;    /* MOUSE_PROTO_XXX */
488    int rate;        /* report rate (per sec), -1 if unknown */
489    int resolution;  /* MOUSE_RES_XXX, -1 if unknown */
490    int accelfactor; /* acceleration factor */
491    int level;       /* driver operation level */
492    int packetsize;  /* the length of the data packet */
493    unsigned char syncmask[2]; /* sync. bits */
494} mousemode_t;
495.Ed
496.Pp
497The
498.Dv protocol
499is
500.Dv MOUSE_PROTO_PS2
501at the operation level zero and two.
502.Dv MOUSE_PROTO_SYSMOUSE
503at the operation level one.
504.Pp
505The
506.Dv rate
507is the status report rate (reports/sec) at which the device will send
508movement report to the host computer.
509Typical supported values are 10, 20, 40, 60, 80, 100 and 200.
510Some mice may accept other arbitrary values too.
511.Pp
512The
513.Dv resolution
514of the pointing device must be one of
515.Dv MOUSE_RES_XXX
516constants or a positive value.
517The greater the value
518is, the finer resolution the mouse will select.
519Actual resolution selected by the
520.Dv MOUSE_RES_XXX
521constant varies according to the model of mouse.
522Typical resolutions are:
523.Pp
524.Bl -tag -width MOUSE_RES_MEDIUMHIGH__ -compact
525.It Dv MOUSE_RES_LOW
52625 ppi
527.It Dv MOUSE_RES_MEDIUMLOW
52850 ppi
529.It Dv MOUSE_RES_MEDIUMHIGH
530100 ppi
531.It Dv MOUSE_RES_HIGH
532200 ppi
533.El
534.Pp
535The
536.Dv accelfactor
537field holds a value to control acceleration feature
538(see
539.Sx Acceleration ) .
540It must be zero or greater.
541If it is zero, acceleration is disabled.
542.Pp
543The
544.Dv packetsize
545field specifies the length of the data packet.
546It depends on the
547operation level and the model of the pointing device.
548.Pp
549.Bl -tag -width level_0__ -compact
550.It Em level 0
5513 bytes
552.It Em level 1
5538 bytes
554.It Em level 2
555Depends on the model of the device
556.El
557.Pp
558The array
559.Dv syncmask
560holds a bit mask and pattern to detect the first byte of the
561data packet.
562.Dv syncmask[0]
563is the bit mask to be ANDed with a byte.
564If the result is equal to
565.Dv syncmask[1] ,
566the byte is likely to be the first byte of the data packet.
567Note that this detection method is not 100% reliable,
568thus, should be taken only as an advisory measure.
569.Pp
570.It Dv MOUSE_SETMODE Ar mousemode_t *mode
571The command changes the current operation parameters of the mouse driver
572as specified in
573.Ar mode .
574Only
575.Dv rate ,
576.Dv resolution ,
577.Dv level
578and
579.Dv accelfactor
580may be modifiable.
581Setting values in the other field does not generate
582error and has no effect.
583.Pp
584If you do not want to change the current setting of a field, put -1
585there.
586You may also put zero in
587.Dv resolution
588and
589.Dv rate ,
590and the default value for the fields will be selected.
591.\" .Pp
592.\" .It Dv MOUSE_GETVARS Ar mousevar_t *vars
593.\" .It Dv MOUSE_SETVARS Ar mousevar_t *vars
594.\" These commands are not supported by the
595.\" .Nm
596.\" driver.
597.Pp
598.It Dv MOUSE_READDATA Ar mousedata_t *data
599.\" The command reads the raw data from the device.
600.\" .Bd -literal
601.\" typedef struct mousedata {
602.\"     int len;        /* # of data in the buffer */
603.\"     int buf[16];    /* data buffer */
604.\" } mousedata_t;
605.\" .Ed
606.\" .Pp
607.\" Upon returning to the user program, the driver will place the number
608.\" of valid data bytes in the buffer in the
609.\" .Dv len
610.\" field.
611.\" .Pp
612.It Dv MOUSE_READSTATE Ar mousedata_t *state
613.\" The command reads the hardware settings from the device.
614.\" Upon returning to the user program, the driver will place the number
615.\" of valid data bytes in the buffer in the
616.\" .Dv len
617.\" field. It is usually 3 bytes.
618.\" The buffer is formatted as follows:
619.\" .Pp
620.\" .Bl -tag -width Byte_1 -compact
621.\" .It Byte 1
622.\" .Bl -tag -width bit_6 -compact
623.\" .It bit 7
624.\" Reserved.
625.\" .It bit 6
626.\" 0 - stream mode, 1 - remote mode.
627.\" In the stream mode, the pointing device sends the device status
628.\" whenever its state changes. In the remote mode, the host computer
629.\" must request the status to be sent.
630.\" The
631.\" .Nm
632.\" driver puts the device in the stream mode.
633.\" .It bit 5
634.\" Set if the pointing device is currently enabled. Otherwise zero.
635.\" .It bit 4
636.\" 0 - 1:1 scaling, 1 - 2:1 scaling.
637.\" 1:1 scaling is the default.
638.\" .It bit 3
639.\" Reserved.
640.\" .It bit 2
641.\" Left button status; set if pressed.
642.\" .It bit 1
643.\" Middle button status; set if pressed.
644.\" .It bit 0
645.\" Right button status; set if pressed.
646.\" .El
647.\" .It Byte 2
648.\" .Bl -tag -width bit_6_0 -compact
649.\" .It bit 7
650.\" Reserved.
651.\" .It bit 6..0
652.\" Resolution code: zero through three. Actual resolution for
653.\" the resolution code varies from one device to another.
654.\" .El
655.\" .It Byte 3
656.\" The status report rate (reports/sec) at which the device will send
657.\" movement report to the host computer.
658.\" .El
659These commands are not currently supported by the
660.Nm
661driver.
662.Pp
663.It Dv MOUSE_GETSTATUS Ar mousestatus_t *status
664The command returns the current state of buttons and
665movement counts as described in
666.Xr mouse 4 .
667.El
668.Sh FILES
669.Bl -tag -width /dev/npsm0 -compact
670.It Pa /dev/psm0
671`non-blocking' device node
672.It Pa /dev/bpsm0
673`blocking' device node under
674.Em devfs .
675.El
676.Sh EXAMPLES
677In order to install the
678.Nm
679driver, you need to add
680.Pp
681.Dl "device atkbdc"
682.Dl "device psm"
683.Pp
684to your kernel configuration file, and put the following lines to
685.Pa /boot/device.hints .
686.Pp
687.Dl hint.atkbdc.0.at="isa"
688.Dl hint.atkbdc.0.port="0x060"
689.Dl hint.psm.0.at="atkbdc"
690.Dl hint.psm.0.irq="12"
691.Pp
692If you add the following statement to
693.Pa /boot/device.hints ,
694.Pp
695.Dl hint.psm.0.flags="0x2000"
696.Pp
697you will add the optional code to stimulate the pointing device
698after the `resume' event.
699.Pp
700.Dl hint.psm.0.flags="0x24"
701.Pp
702The above line will set the device resolution high (4)
703and the acceleration factor to 2.
704.Sh DIAGNOSTICS
705At debug level 0, little information is logged except for the following
706line during boot process:
707.Bd -literal -offset indent
708psm0: device ID X
709.Ed
710.Pp
711where
712.Fa X
713the device ID code returned by the found pointing device.
714See
715.Dv MOUSE_GETINFO
716for known IDs.
717.Pp
718At debug level 1 more information will be logged
719while the driver probes the auxiliary port (mouse port).
720Messages are logged with the LOG_KERN facility at the LOG_DEBUG level
721(see
722.Xr syslogd 8 ) .
723.Bd -literal -offset indent
724psm0: current command byte:xxxx
725kbdio: TEST_AUX_PORT status:0000
726kbdio: RESET_AUX return code:00fa
727kbdio: RESET_AUX status:00aa
728kbdio: RESET_AUX ID:0000
729[...]
730psm: status 00 02 64
731psm0 irq 12 on isa
732psm0: model AAAA, device ID X, N buttons
733psm0: config:00000www, flags:0000uuuu, packet size:M
734psm0: syncmask:xx, syncbits:yy
735.Ed
736.Pp
737The first line shows the command byte value of the keyboard
738controller just before the auxiliary port is probed.
739It usually is 4D, 45, 47 or 65, depending on how the motherboard BIOS
740initialized the keyboard controller upon power-up.
741.Pp
742The second line shows the result of the keyboard controller's
743test on the auxiliary port interface, with zero indicating
744no error; note that some controllers report no error even if
745the port does not exist in the system, however.
746.Pp
747The third through fifth lines show the reset status of the pointing device.
748The functioning device should return the sequence of FA AA <ID>.
749The ID code is described above.
750.Pp
751The seventh line shows the current hardware settings.
752.\" See
753.\" .Dv MOUSE_READSTATE
754.\" for definitions.
755These bytes are formatted as follows:
756.Pp
757.Bl -tag -width Byte_1 -compact
758.It Byte 1
759.Bl -tag -width bit_6 -compact
760.It bit 7
761Reserved.
762.It bit 6
7630 - stream mode, 1 - remote mode.
764In the stream mode, the pointing device sends the device status
765whenever its state changes.
766In the remote mode, the host computer
767must request the status to be sent.
768The
769.Nm
770driver puts the device in the stream mode.
771.It bit 5
772Set if the pointing device is currently enabled.
773Otherwise zero.
774.It bit 4
7750 - 1:1 scaling, 1 - 2:1 scaling.
7761:1 scaling is the default.
777.It bit 3
778Reserved.
779.It bit 2
780Left button status; set if pressed.
781.It bit 1
782Middle button status; set if pressed.
783.It bit 0
784Right button status; set if pressed.
785.El
786.It Byte 2
787.Bl -tag -width bit_6_0 -compact
788.It bit 7
789Reserved.
790.It bit 6..0
791Resolution code: zero through three.
792Actual resolution for
793the resolution code varies from one device to another.
794.El
795.It Byte 3
796The status report rate (reports/sec) at which the device will send
797movement report to the host computer.
798.El
799.Pp
800Note that the pointing device will not be enabled until the
801.Nm
802driver is opened by the user program.
803.Pp
804The rest of the lines show the device ID code, the number of detected
805buttons and internal variables.
806.Pp
807At debug level 2, much more detailed information is logged.
808.Sh CAVEATS
809Many pad devices behave as if the first (left) button were pressed if
810the user `taps' the surface of the pad.
811In contrast, some pad products, e.g.\& some versions of ALPS GlidePoint
812and Interlink VersaPad, treat the tapping action
813as fourth button events.
814.Pp
815It is reported that Interlink VersaPad requires both
816.Em HOOKRESUME
817and
818.Em INITAFTERSUSPEND
819flags in order to recover from suspended state.
820These flags are automatically set when VersaPad is detected by the
821.Nm
822driver.
823.Pp
824Some PS/2 mouse models from MouseSystems require to be put in the
825high resolution mode to work properly.
826Use the driver flag to
827set resolution.
828.Pp
829There is not a guaranteed way to re-synchronize with the first byte
830of the packet once we are out of synchronization with the data
831stream.
832However, if you are using the \fIXFree86\fP server and experiencing
833the problem, you may be able to make the X server synchronize with the mouse
834by switching away to a virtual terminal and getting back to the X server,
835unless the X server is accessing the mouse via
836.Xr moused 8 .
837Clicking any button without moving the mouse may also work.
838.Sh SEE ALSO
839.Xr ioctl 2 ,
840.Xr syslog 3 ,
841.Xr atkbdc 4 ,
842.Xr mouse 4 ,
843.Xr mse 4 ,
844.Xr sysmouse 4 ,
845.Xr moused 8 ,
846.Xr syslogd 8
847.Rs
848.%T Synaptics TouchPad Interfacing Guide
849.%O http://www.synaptics.com/
850.Re
851.\".Sh HISTORY
852.Sh AUTHORS
853.An -nosplit
854The
855.Nm
856driver is based on the work done by quite a number of people, including
857.An Eric Forsberg ,
858.An Sandi Donno ,
859.An Rick Macklem ,
860.An Andrew Herbert ,
861.An Charles Hannum ,
862.An Shoji Yuen
863and
864.An Kazutaka Yokota
865to name the few.
866.Pp
867This manual page was written by
868.An Kazutaka Yokota Aq yokota@FreeBSD.org .
869.Sh BUGS
870The ioctl command
871.Dv MOUSEIOCREAD
872has been removed.
873It was never functional anyway.
874.Pp
875Enabling the extended support for Synaptics touchpads has been reported to
876cause problems with responsivity on some (newer) models of Synaptics
877hardware, particularly those with guest devices.
878