UATP(4)

UATP(4) | Kernel Interfaces Manual | UATP(4)

# NAME

uatp — USB Apple trackpad driver

# SYNOPSIS

uatp* at uhidev? reportid ?
wsmouse* at uatp? mux 0

# DESCRIPTION

The uatp driver provides support for the USB trackpads found in Apple laptops since 2005, exposed through wsmouse(4). Some USB Apple trackpads are standard USB HID mice supported by ums(4), but uatp supports more features. The following sysctl(8) variables control behavior of USB Apple trackpads:

hw.uatpN.two_finger_buttons
  Bit mask of buttons to emulate when two fingers are on the trackpad while the button is pressed.
hw.uatpN.three_finger_buttons
  Bit mask of buttons to emulate when three fingers are on the trackpad while the button is pressed.
hw.uatpN.multifinger_track
  What to do when multiple fingers are moved on the trackpad. If set to 0, ignore the input. If set to 1, move as if a single finger were at the mean position of the fingers. If set to 2, scroll. Note that scrolling is currently broken.
hw.uatpN.x_sensors
  Number of sensor columns detecting the x positions of fingers on the trackpad. The driver should detect this based on the model of hardware, so you should not have to set this, and likewise for the x ratio and y sensors and ratio.
hw.uatpN.x_ratio
  Ratio of the number of sensor columns in the trackpad to the number of distinct cursor x positions.
hw.uatpN.y_sensors
  Number of sensor rows detecting the y positions of fingers on the trackpad.
hw.uatpN.y_ratio
  Ratio of the number of sensor rows in the trackpad to the number of distinct cursor y positions.
hw.uatpN.sensor_threshold
  Nonnegative integer giving a lower bound on the “pressure” a sensor must report for the driver to recognize input from it.
hw.uatpN.sensor_normalizer
  Nonnegative integer to subtract from the “pressure” reported by a sensor when averaging them to estimate the pressure of a single finger.
hw.uatpN.palm_width
  If zero, palm detection is disabled. Otherwise, a positive integer giving the number of consecutive sensors wide or high that will be interpreted as a palm instead of a finger and therefore ignored.
hw.uatpN.old_raw_weight
hw.uatpN.old_smoothed_weight
hw.uatpN.new_raw_weight
  When a finger moves on the trackpad, the new smoothed (cursor) position is computed as a positive linear combination of the old raw (trackpad) position, the old smoothed position, and the new raw position. The weights of the linear combination are given by these sysctl knobs.
hw.uatpN.motion_threshold
  Threshold below which a difference in smoothed position will not be reported as an input event to userland.
hw.uatpN.motion_multiplier
  Positive integer by which a difference in smoothed position will be multiplied before passing it as an input event to userland.
hw.uatpN.motion_divisor
  Positive integer by which a difference in smoothed position will be divided, after multiplying it by the motion multiplier, before passing it as an input event to userland.
hw.uatpN.fast_motion_threshold
  Threshold above which to use the fast motion factors below.
hw.uatpN.fast_motion_multiplier
  Positive integer by which to multiply a large difference in smoothed position.
hw.uatpN.fast_motion_divisor
  Positive integer by which to divide a large difference in smoothed position, after multiplying it by the fast motion multiplier.
hw.uatpN.motion_delay
  Number of input packets before uatp reports motion to userland.
hw.uatpN.tap_limit_msec
  Positive integer giving the number of milliseconds of a finger's contact with the trackpad before it will not be considered a tap.
hw.uatpN.double_tap_limit_msec
  Positive integer giving the maximum number of milliseconds after a tap before a second tap will keep the button down.
hw.uatpN.one_finger_tap_buttons
  Bit mask of buttons that a one-finger tap will press.
hw.uatpN.two_finger_tap_buttons
  Bit mask of buttons that a two-finger tap will press.
hw.uatpN.three_finger_tap_buttons
  Bit mask of buttons that a three-finger tap will press.
hw.uatpN.tap_track_distance_limit
  Maximum distance in smoothed position that will be interpreted as a tap instead of motion.

# SEE ALSO

ums(4), wsmouse(4)

# HISTORY

The uatp driver first appeared in NetBSD 7.0.

# AUTHORS

The uatp driver was originally written by Taylor R. Campbell <riastradh@NetBSD.org>.

# BUGS

Sometimes, particularly when X starts up, the driver gets wedged in an interrupt storm and does not reset the device. Setting `hw.uatpN.sensor_threshold` to a large number, say 1000, and then back to its original value, can fix this.

Palm detection is not very robust.

Multi-touch scrolling is currently broken.

Pinch-to-zoom and other fancy multi-touch input is not implemented.

On suspending and resuming, uatp detaches and reattaches, and loses all sysctl settings in the process.

Do not submerge your uatp devices in water: USB adenosine triphosphate is unstable in water, and will hydrolyze to USB adenosine diphosphate and phosphate, which is a lower energy state that makes your mouse narcoleptic in X.

August 4, 2012 | NetBSD 7.0