1.\" 2.\" Copyright (c) 1997 3.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer as 11.\" the first lines of this file unmodified. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" $Id: psm.4,v 1.11 1998/01/24 12:14:13 yokota Exp $ 28.\" 29.Dd December 3, 1997 30.Dt PSM 4 i386 31.Os FreeBSD 32.Sh NAME 33.Nm psm 34.Nd 35PS/2 mouse style pointing device driver 36.Sh SYNOPSIS 37.Cd "options" \&"PSM_HOOKAPM\&" 38.Cd "options" \&"PSM_RESETAFTERSUSPEND\&" 39.Cd "options" \&"KBD_RESETDELAY=N\&" 40.Cd "options" \&"KBD_MAXWAIT=N\&" 41.Cd "options" \&"PSM_DEBUG=N\&" 42.Cd "options" \&"KBDIO_DEBUG=N\&" 43.Cd "device psm0 at isa? port" \&"IO_KBD\&" conflicts tty irq 12 vector psmintr 44.Sh DESCRIPTION 45The 46.Nm 47driver provides support for the PS/2 mouse style pointing device. 48Currently there can be only one 49.Nm 50device node in the system. 51.Em port \&"IO_KBD\&" 52and 53.Em conflicts 54are required, 55as the PS/2 mouse port is located 56at the auxiliary port of the keyboard controller; the 57.Nm 58driver has to share the same I/O ports with the keyboard driver. 59Note also that there is currently no provision of changing the 60.Em irq 61number. 62.Pp 63Basic PS/2 style pointing device has two or three buttons. 64Some devices may have a roller or a wheel and/or additional buttons. 65.Ss Device Resolution 66The PS/2 style pointing device usually has several grades of resolution, 67that is, sensitivity of movement. They are typically 25, 50, 100 and 200 68pulse per inch. Some devices may have finer resolution. 69The current resolution can be changed at runtime. The 70.Nm 71driver allows the user to initially set the resolution 72via the driver flag 73.Pq see Sx DRIVER CONFIGURATION 74or change it later via the 75.Xr ioctl 2 76command 77.Dv MOUSE_SETMODE 78.Pq see Sx IOCTLS . 79.Ss Report Rate 80Frequency, or report rate, at which the device sends movement 81and button state reports to the host system is also configurable. 82The PS/2 style pointing device typically supports 10, 20, 40, 60, 80, 100 83and 200 reports per second. 8460 or 100 appears to be the default value for many devices. 85Note that when there is no movement and no button has changed its state, 86the device won't send anything to the host system. 87The report rate can be changed via an ioctl call. 88.Ss Operation Levels 89The 90.Nm 91driver has three levels of operation. 92The current operation level can be set via an ioctl call. 93.Pp 94At the level zero the basic support is provided; the device driver will report 95horizontal and vertical movement of the attached device 96and state of up to three buttons. 97The movement and status are encoded in a series of fixed-length data packets 98.Pq see Sx Data Packet Format . 99This is the default level of operation and the driver is initially 100at this level when opened by the user program. 101.Pp 102The operation level one, the `extended' level, supports a roller (or wheel), 103if any, and up to 11 buttons. 104The movement of the roller is reported as movement along the Z axis. 1058 byte data packets are sent to the user program at this level. 106.Pp 107At the operation level two, data from the pointing device is passed to the 108user program as is. 109Modern PS/2 type pointing devices often use proprietary data format. 110Therefore, the user program is expected to have 111intimate knowledge about the format from a particular device when operating 112the driver at this level. 113This level is called `native' level. 114.Ss Data Packet Format 115Data packets read from the 116.Nm 117driver are formatted differently at each operation level. 118.Pp 119A data packet from the PS/2 mouse style pointing device 120is three bytes long at the operation level zero: 121.Pp 122.Bl -tag -width Byte_1 -compact 123.It Byte 1 124.Bl -tag -width bit_7 -compact 125.It bit 7 126One indicates overflow in the vertical movement count. 127.It bit 6 128One indicates overflow in the horizontal movement count. 129.It bit 5 130Set if the vertical movement count is negative. 131.It bit 4 132Set if the horizontal movement count is negative. 133.It bit 3 134Always one. 135.\" The ALPS GlidePoint clears this bit when the user `taps' the surface of 136.\" the pad, otherwise the bit is set. 137.\" Most, if not all, other devices always set this bit. 138.It bit 2 139Middle button status; set if pressed. For devices without the middle 140button, this bit is always zero. 141.It bit 1 142Right button status; set if pressed. 143.It bit 0 144Left button status; set if pressed. 145.El 146.It Byte 2 147Horizontal movement count in two's compliment; 148-256 through 255. 149Note that the sign bit is in the first byte. 150.It Byte 3 151Vertical movement count in two's compliment; 152-256 through 255. 153Note that the sign bit is in the first byte. 154.El 155.Pp 156At the level one, a data packet is encoded 157in the standard format 158.Dv MOUSE_PROTO_SYSMOUSE 159as defined in 160.Xr mouse 4 . 161.Pp 162At the level two, native level, there is no standard on the size and format 163of the data packet. 164.Ss Acceleration 165The 166.Nm 167driver can somewhat `accelerate' the movement of the pointing device. 168The faster you move the device, the further the pointer 169travels on the screen. 170The driver has an internal variable which governs the effect of 171the acceleration. Its value can be modified via the driver flag 172or via an ioctl call. 173.Ss Device Number 174The minor device number of the 175.Nm 176is made up of: 177.Bd -literal -offset indent 178minor = (`unit' << 1) | `non-blocking' 179.Ed 180.Pp 181where `unit' is the device number (usually 0) and the `non-blocking' bit 182is set to indicate ``don't block waiting for mouse input, 183return immediately''. 184The `non-blocking' bit should be set for \fIXFree86\fP, 185therefore the minor device number usually used for \fIXFree86\fP is 1. 186See 187.Sx FILES 188for device node names. 189.Sh DRIVER CONFIGURATION 190.Ss Kernel Configuration Options 191There are following kernel configuration options to control the 192.Nm 193driver. 194They may be set in the kernel configuration file 195.Pq see Xr config 8 . 196.Bl -tag -width MOUSE 197.It Em PSM_HOOKAPM 198The built-in PS/2 pointing device of some laptop computers is somehow 199not operable immediately after the system `resumes' from 200the power saving mode, 201though it will eventually become available. 202There are reports that 203stimulating the device by performing I/O will help 204waking up the device quickly. This option will add a piece of code 205to the 206.Nm 207driver to hook 208the APM `resume' event and exercise some harmless I/O operations to the 209device. 210.It Em PSM_RESETAFTERSUSPEND 211This option adds more drastic action for the above problem. 212It will make the 213.Nm 214driver to reset the pointing device after the APM resume event. 215It has no effect unless the 216.Em PSM_HOOKAPM 217option is enabled as well. 218.It Em KBD_RESETDELAY=X, KBD_MAXWAIT=Y 219The 220.Nm 221driver will attempt to reset the pointing device during the boot process. 222It sometimes takes a long while before the device will respond after 223reset. These options control how long the driver should wait before 224it eventually gives up waiting. The driver will wait 225.Fa X 226* 227.Fa Y 228msecs at most. If the driver seems unable to detect your pointing 229device, you may want to increase these values. The default values are 230200 msec for 231.Fa X 232and 5 233for 234.Fa Y . 235.It Em PSM_DEBUG=N, KBDIO_DEBUG=N 236Sets the debug level to 237.Fa N . 238The default debug level is zero. See 239.Sx DIAGNOSTICS 240for debug logging. 241.El 242.Ss Driver Flags 243The 244.Nm 245driver accepts the following driver flags. Set them in the 246kernel configuration file or in the User Configuration Menu at 247the boot time 248.Pq see Xr boot 8 . 249.Pp 250.Bl -tag -width MOUSE 251.It bit 0..3 RESOLUTION 252This flag specifies the resolution of the pointing device. 253It must be zero through four. The greater the value 254is, the finer resolution the device will select. 255Actual resolution selected by this field varies according to the model 256of the device. Typical resolutions are: 257.Pp 258.Bl -tag -width 0_(medium_high)__ -compact 259.It Em 1 (low) 26025 pulse per inch (ppi) 261.It Em 2 (medium low) 26250 ppi 263.It Em 3 (medium high) 264100 ppi 265.It Em 4 (high) 266200 ppi 267.El 268.Pp 269Leaving this flag zero will selects the default resolution for the 270device (whatever it is). 271.It bit 4..7 ACCELERATION 272This flag controls the amount of acceleration effect. 273The smaller the value of this flag is, more sensitive the movement becomes. 274The minimum value allowed, thus the value for the most sensitive setting, 275is one. Setting this flag to zero will completely disables the 276acceleration effect. 277.It bit 8 NOCHECKSYNC 278The 279.Nm 280driver tries to detect the first byte of the data packet by checking 281the bit pattern of that byte. Although 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.El 292.Sh IOCTLS 293There are a few 294.Xr ioctl 2 295commands for mouse drivers. 296These commands and related structures and constants are defined in 297.Ao Pa machine/mouse.h Ac . 298General description of the commands is given in 299.Xr mouse 4 . 300This section explains the features specific to the 301.Nm 302driver. 303.Pp 304.Bl -tag -width MOUSE -compact 305.It Dv MOUSE_GETLEVEL Ar int *level 306.It Dv MOUSE_SETLEVEL Ar int *level 307These commands manipulate the operation level of the 308.Nm 309driver. 310.Pp 311.It Dv MOUSE_GETHWINFO Ar mousehw_t *hw 312Returns the hardware information of the attached device in the following 313structure. 314.Bd -literal 315typedef struct mousehw { 316 int buttons; /* number of buttons */ 317 int iftype; /* I/F type */ 318 int type; /* mouse/track ball/pad... */ 319 int model; /* I/F dependent model ID */ 320 int hwid; /* I/F dependent hardware ID */ 321} mousehw_t; 322.Ed 323.Pp 324The 325.Dv buttons 326field holds the number of buttons on the device. 327The 328.Nm 329driver currently can detect the 3 button mouse from Logitech and report 330accordingly. 331The 3 button mouse from the other manufacturer may or may not be 332reported correctly. However, it will not affect the operation of 333the driver. 334.Pp 335The 336.Dv iftype 337is always 338.Dv MOUSE_IF_PS2 . 339.Pp 340The 341.Dv type 342tells the device type: 343.Dv MOUSE_MOUSE , 344.Dv MOUSE_TRACKBALL , 345.Dv MOUSE_STICK , 346.Dv MOUSE_PAD , 347or 348.Dv MOUSE_UNKNOWN . 349The user should not heavily rely on this field, as the 350driver may not always, in fact it is very rarely able to, identify 351the device type. 352.Pp 353The 354.Dv model 355is always 356.Dv MOUSE_MODEL_GENERIC 357at the operation level 0. 358It may be 359.Dv MOUSE_MODEL_GENERIC 360or one of 361.Dv MOUSE_MODEL_XXX 362constants at higher operation levels. 363Again the 364.Nm 365driver may or may not set an appropriate value in this field. 366.Pp 367The 368.Dv hwid 369is the ID value returned by the device. 370Known IDs include: 371.Pp 372.Bl -tag -width 0__ -compact 373.It Em 0 374Mouse (Microsoft, Logitech and many other manufacturers) 375.It Em 2 376Microsoft Ballpoint mouse 377.It Em 3 378Microsoft IntelliMouse 379.El 380.Pp 381.It Dv MOUSE_GETMODE Ar mousemode_t *mode 382The command gets the current operation parameters of the mouse 383driver. 384.Bd -literal 385typedef struct mousemode { 386 int protocol; /* MOUSE_PROTO_XXX */ 387 int rate; /* report rate (per sec), -1 if unknown */ 388 int resolution; /* MOUSE_RES_XXX, -1 if unknown */ 389 int accelfactor; /* acceleration factor */ 390 int level; /* driver operation level */ 391 int packetsize; /* the length of the data packet */ 392 unsigned char syncmask[2]; /* sync. bits */ 393} mousemode_t; 394.Ed 395.Pp 396The 397.Dv protocol 398is 399.Dv MOUSE_PROTO_PS2 400at the operation level zero and two. 401.Dv MOUSE_PROTO_SYSMOUSE 402at the operation level one. 403.Pp 404The 405.Dv rate 406is the status report rate (reports/sec) at which the device will send 407movement report to the host computer. 408Typical supported values are 10, 20, 40, 60, 80, 100 and 200. 409Some mice may accept other arbitrary values too. 410.Pp 411The 412.Dv resolution 413of the pointing device must be one of 414.Dv MOUSE_RES_XXX 415constants or a positive value. The greater the value 416is, the finer resolution the mouse will select. 417Actual resolution selected by the 418.Dv MOUSE_RES_XXX 419constant varies according to the model of mouse. Typical resolutions are: 420.Pp 421.Bl -tag -width MOUSE_RES_MEDIUMHIGH__ -compact 422.It Dv MOUSE_RES_LOW 42325 ppi 424.It Dv MOUSE_RES_MEDIUMLOW 42550 ppi 426.It Dv MOUSE_RES_MEDIUMHIGH 427100 ppi 428.It Dv MOUSE_RES_HIGH 429200 ppi 430.El 431.Pp 432The 433.Dv accelfactor 434field holds a value to control acceleration feature 435.Pq see Sx Acceleration . 436It must be zero or greater. If it is zero, acceleration is disabled. 437.Pp 438The 439.Dv packetsize 440field specifies the length of the data packet. It depends on the 441operation level and the model of the pointing device. 442.Pp 443.Bl -tag -width level_0__ -compact 444.It Em level 0 4453 bytes 446.It Em level 1 4478 bytes 448.It Em level 2 449Depends on the model of the device 450.El 451.Pp 452The array 453.Dv syncmask 454holds a bit mask and pattern to detect the first byte of the 455data packet. 456.Dv syncmask[0] 457is the bit mask to be ANDed with a byte. If the result is equal to 458.Dv syncmask[1] , 459the byte is likely to be the first byte of the data packet. 460Note that this detection method is not 100% reliable, 461thus, should be taken only as an advisory measure. 462.Pp 463.It Dv MOUSE_SETMODE Ar mousemode_t *mode 464The command changes the current operation parameters of the mouse driver 465as specified in 466.Ar mode . 467Only 468.Dv rate , 469.Dv resolution , 470.Dv level 471and 472.Dv accelfactor 473may be modifiable. Setting values in the other field does not generate 474error and has no effect. 475.Pp 476If you do not want to change the current setting of a field, put -1 477there. 478You may also put zero in 479.Dv resolution 480and 481.Dv rate , 482and the default value for the fields will be selected. 483.\" .Pp 484.\" .It Dv MOUSE_GETVARS Ar mousevar_t *vars 485.\" .It Dv MOUSE_SETVARS Ar mousevar_t *vars 486.\" These commands are not supported by the 487.\" .Nm 488.\" driver. 489.Pp 490.It Dv MOUSE_READDATA Ar mousedata_t *data 491.\" The command reads the raw data from the device. 492.\" .Bd -literal 493.\" typedef struct mousedata { 494.\" int len; /* # of data in the buffer */ 495.\" int buf[16]; /* data buffer */ 496.\" } mousedata_t; 497.\" .Ed 498.\" .Pp 499.\" Upon returning to the user program, the driver will place the number 500.\" of valid data bytes in the buffer in the 501.\" .Dv len 502.\" field. 503.\" .Pp 504.It Dv MOUSE_READSTATE Ar mousedata_t *state 505.\" The command reads the hardware settings from the device. 506.\" Upon returning to the user program, the driver will place the number 507.\" of valid data bytes in the buffer in the 508.\" .Dv len 509.\" field. It is usually 3 bytes. 510.\" The buffer is formatted as follows: 511.\" .Pp 512.\" .Bl -tag -width Byte_1 -compact 513.\" .It Byte 1 514.\" .Bl -tag -width bit_6 -compact 515.\" .It bit 7 516.\" Reserved. 517.\" .It bit 6 518.\" 0 - stream mode, 1 - remote mode. 519.\" In the stream mode, the pointing device sends the device status 520.\" whenever its state changes. In the remote mode, the host computer 521.\" must request the status to be sent. 522.\" The 523.\" .Nm 524.\" driver puts the device in the stream mode. 525.\" .It bit 5 526.\" Set if the pointing device is currently enabled. Otherwise zero. 527.\" .It bit 4 528.\" 0 - 1:1 scaling, 1 - 2:1 scaling. 529.\" 1:1 scaling is the default. 530.\" .It bit 3 531.\" Reserved. 532.\" .It bit 2 533.\" Left button status; set if pressed. 534.\" .It bit 1 535.\" Middle button status; set if pressed. 536.\" .It bit 0 537.\" Right button status; set if pressed. 538.\" .El 539.\" .It Byte 2 540.\" .Bl -tag -width bit_6_0 -compact 541.\" .It bit 7 542.\" Reserved. 543.\" .It bit 6..0 544.\" Resolution code: zero through three. Actual resolution for 545.\" the resolution code varies from one device to another. 546.\" .El 547.\" .It Byte 3 548.\" The status report rate (reports/sec) at which the device will send 549.\" movement report to the host computer. 550.\" .El 551These commands are not currently supported by the 552.Nm 553driver. 554.Pp 555.It Dv MOUSE_GETSTATE Ar mousestatus_t *status 556The command returns the current state of buttons and 557movement counts as described in 558.Xr mouse 4 . 559.El 560.Sh FILES 561.Bl -tag -width /dev/npsm0 -compact 562.It Pa /dev/psm0 563`non-blocking' device node in the system without 564.Em devfs , 565`blocking' under 566.Em devfs . 567.It Pa /dev/npsm0 568`non-blocking' device node under 569.Em devfs . 570.El 571.Sh EXAMPLE 572.Dl "options" \&"PSM_HOOKAPM\&" 573.Dl "device psm0 at isa? port" \&"IO_KBD\&" conflicts tty irq 12 vector psmintr 574.Pp 575Add the 576.Nm 577driver to the kernel with the optional code to stimulate the pointing device 578after the `resume' event. 579.Pp 580.Dl "device psm0 at isa? port" \&"IO_KBD\&" conflicts tty flags 0x024 irq 12 581.Dl vector psmintr 582.Pp 583Set the device resolution high (4) and the acceleration factor to 2. 584.Sh DIAGNOSTICS 585.Pp 586At debug level 0, little information is logged except for the following 587line during boot process: 588.Bd -literal -offset indent 589psm0: device ID X 590.Ed 591.Pp 592where 593.Fa X 594the device ID code returned by the found pointing device. 595See 596.Dv MOUSE_GETINFO 597for known IDs. 598.Pp 599At debug level 1 more information will be logged 600while the driver probes the auxiliary port (mouse port). 601Messages are logged with the LOG_KERN facility at the LOG_DEBUG level 602.Pq see Xr syslogd 8 . 603.Bd -literal -offset indent 604psm0: current command byte:xxxx 605kbdio: TEST_AUX_PORT status:0000 606kbdio: RESET_AUX return code:00fa 607kbdio: RESET_AUX status:00aa 608kbdio: RESET_AUX ID:0000 609[...] 610psm: status 00 02 64 611psm0 at 0x60-0x64 irq 12 on motherboard 612psm0: model AAAA, device ID X, N buttons 613psm0: config:00000www, flags:0000uuuu, packet size:M 614psm0: syncmask:xx, syncbits:yy 615.Ed 616.Pp 617The first line shows the command byte value of the keyboard 618controller just before the auxiliary port is probed. 619It usually is 4D, 45, 47 or 65, depending on how the motherboard BIOS 620initialized the keyboard controller upon power-up. 621.Pp 622The second line shows the result of the keyboard controller's 623test on the auxiliary port interface, with zero indicating 624no error; note that some controllers report no error even if 625the port does not exist in the system, however. 626.Pp 627The third through fifth lines show the reset status of the pointing device. 628The functioning device should return the sequence of FA AA <ID>. 629The ID code is described above. 630.Pp 631The seventh line shows the current hardware settings. 632.\" See 633.\" .Dv MOUSE_READSTATE 634.\" for definitions. 635These bytes are formatted as follows: 636.Pp 637.Bl -tag -width Byte_1 -compact 638.It Byte 1 639.Bl -tag -width bit_6 -compact 640.It bit 7 641Reserved. 642.It bit 6 6430 - stream mode, 1 - remote mode. 644In the stream mode, the pointing device sends the device status 645whenever its state changes. In the remote mode, the host computer 646must request the status to be sent. 647The 648.Nm 649driver puts the device in the stream mode. 650.It bit 5 651Set if the pointing device is currently enabled. Otherwise zero. 652.It bit 4 6530 - 1:1 scaling, 1 - 2:1 scaling. 6541:1 scaling is the default. 655.It bit 3 656Reserved. 657.It bit 2 658Left button status; set if pressed. 659.It bit 1 660Middle button status; set if pressed. 661.It bit 0 662Right button status; set if pressed. 663.El 664.It Byte 2 665.Bl -tag -width bit_6_0 -compact 666.It bit 7 667Reserved. 668.It bit 6..0 669Resolution code: zero through three. Actual resolution for 670the resolution code varies from one device to another. 671.El 672.It Byte 3 673The status report rate (reports/sec) at which the device will send 674movement report to the host computer. 675.El 676.Pp 677Note that the pointing device will not be enabled until the 678.Nm 679driver is opened by the user program. 680.Pp 681The rest of the lines show the device ID code, the number of detected 682buttons and internal variables. 683.Pp 684At debug level 2, much more detailed information is logged. 685.Sh CAVEATS 686Many pad devices behave as if the first (left) button were pressed if 687the user `taps' the surface of the pad. 688In contrast, some ALPS GlidePoint pad models treat the tapping action 689as fourth button events. 690.Pp 691Some PS/2 mouse models from MouseSystems require to be put in the 692high resolution mode to work properly. Use the driver flag to 693set resolution. 694.Pp 695There is not a guaranteed way to re-synchronize with the first byte 696of the packet once we are out of synchronization with the data 697stream. However, if you are using the \fIXFree86\fP server and experiencing 698the problem, you may be able to make the X server synchronize with the mouse 699by switching away to a virtual terminal and getting back to the X server, 700unless the X server is accessing the mouse via 701.Xr moused 1 . 702Clicking any button without moving the mouse may also work. 703.Sh BUGS 704The ioctl command 705.Dv MOUSEIOCREAD 706has been removed. It was never functional anyway. 707.Sh SEE ALSO 708.Xr ioctl 2 , 709.Xr syslog 3 , 710.Xr mouse 4 , 711.Xr mse 4 , 712.Xr sysmouse 4 , 713.Xr moused 8 , 714.Xr syslogd 8 715.\".Sh HISTORY 716.Sh AUTHORS 717The 718.Nm 719driver is based on the work done by quite a number of people, including 720.An Eric Forsberg , 721.An Sandi Donno , 722.An Rick Macklem , 723.An Andrew Herbert , 724.An Charles Hannum , 725.An Shoji Yuen 726and 727.An Kazutaka Yokota 728to name the few. 729.Pp 730This manual page was written by 731.An Kazutaka Yokota Aq yokota@FreeBSD.org . 732