From e24328974a88aa8541e94e8bb8dfa2ade1b3c45d Mon Sep 17 00:00:00 2001 From: Donggeun Yoo Date: Wed, 2 Sep 2026 00:21:26 +0900 Subject: iio: proximity: vl53l0x-i2c: claim direct mode for raw reads vl53l0x_read_raw() starts a single-shot ranging measurement and reads back the result. Once the triggered buffer is enabled the sensor runs in continuous mode and its data-ready interrupt is routed to the trigger, so a concurrent in_distance_raw read disturbs the streaming setup and never gets its completion, returning -ETIMEDOUT. The original submission claimed direct mode here, but it was dropped during review because the driver had no buffer support at the time [1]. Continuous (buffered) mode was later added without restoring the claim [2], reintroducing the conflict. Reject direct reads while buffered capture is active by claiming direct mode around the measurement, as the vl53l1x sibling already does. Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support") Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1] Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2] Signed-off-by: Donggeun Yoo Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- Documentation/input/devices/appletouch.rst | 94 ++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 Documentation/input/devices/appletouch.rst (limited to 'Documentation/input/devices/appletouch.rst') diff --git a/Documentation/input/devices/appletouch.rst b/Documentation/input/devices/appletouch.rst new file mode 100644 index 000000000..c94470e66 --- /dev/null +++ b/Documentation/input/devices/appletouch.rst @@ -0,0 +1,94 @@ +.. include:: + +---------------------------------- +Apple Touchpad Driver (appletouch) +---------------------------------- + +:Copyright: |copy| 2005 Stelian Pop + +appletouch is a Linux kernel driver for the USB touchpad found on post +February 2005 and October 2005 Apple Aluminium Powerbooks. + +This driver is derived from Johannes Berg's appletrackpad driver [#f1]_, +but it has been improved in some areas: + + * appletouch is a full kernel driver, no userspace program is necessary + * appletouch can be interfaced with the synaptics X11 driver, in order + to have touchpad acceleration, scrolling, etc. + +Credits go to Johannes Berg for reverse-engineering the touchpad protocol, +Frank Arnold for further improvements, and Alex Harper for some additional +information about the inner workings of the touchpad sensors. Michael +Hanselmann added support for the October 2005 models. + +Usage +----- + +In order to use the touchpad in the basic mode, compile the driver and load +the module. A new input device will be detected and you will be able to read +the mouse data from /dev/input/mice (using gpm, or X11). + +In X11, you can configure the touchpad to use the synaptics X11 driver, which +will give additional functionalities, like acceleration, scrolling, 2 finger +tap for middle button mouse emulation, 3 finger tap for right button mouse +emulation, etc. In order to do this, make sure you're using a recent version of +the synaptics driver (tested with 0.14.2, available from [#f2]_), and configure +a new input device in your X11 configuration file (take a look below for an +example). For additional configuration, see the synaptics driver documentation:: + + Section "InputDevice" + Identifier "Synaptics Touchpad" + Driver "synaptics" + Option "SendCoreEvents" "true" + Option "Device" "/dev/input/mice" + Option "Protocol" "auto-dev" + Option "LeftEdge" "0" + Option "RightEdge" "850" + Option "TopEdge" "0" + Option "BottomEdge" "645" + Option "MinSpeed" "0.4" + Option "MaxSpeed" "1" + Option "AccelFactor" "0.02" + Option "FingerLow" "0" + Option "FingerHigh" "30" + Option "MaxTapMove" "20" + Option "MaxTapTime" "100" + Option "HorizScrollDelta" "0" + Option "VertScrollDelta" "30" + Option "SHMConfig" "on" + EndSection + + Section "ServerLayout" + ... + InputDevice "Mouse" + InputDevice "Synaptics Touchpad" + ... + EndSection + +Fuzz problems +------------- + +The touchpad sensors are very sensitive to heat, and will generate a lot of +noise when the temperature changes. This is especially true when you power-on +the laptop for the first time. + +The appletouch driver tries to handle this noise and auto adapt itself, but it +is not perfect. If finger movements are not recognized anymore, try reloading +the driver. + +You can activate debugging using the 'debug' module parameter. A value of 0 +deactivates any debugging, 1 activates tracing of invalid samples, 2 activates +full tracing (each sample is being traced):: + + modprobe appletouch debug=1 + +or:: + + echo "1" > /sys/module/appletouch/parameters/debug + + +.. Links: + +.. [#f1] http://johannes.sipsolutions.net/PowerBook/touchpad/ + +.. [#f2] ``_ -- cgit v1.3.1