597151d963
The new API now covers the entire character driver protocol, while hiding all the message details. It should therefore be used by all new character drivers. All existing drivers that already made use of libchardriver have been changed to use the new API. As one of the most important API changes, support for scatter and gather transfers has been removed, as several key drivers already did not support this, and it could be supported at the safecopy level instead (for a future readv/writev). Additional changes include: - respond to block device open requests to avoid hanging VFS threads; - add support for sef_cancel. Change-Id: I1bab6c1cb66916c71b87aeb1db54a9bdf171fe6b |
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Makefile | ||
README.txt | ||
tsl2550.c |
TSL2550 Driver (Ambient Light Sensor) ===================================== Overview -------- This is the driver for the ambient light sensor commonly found on the WeatherCape expansion board for the BeagleBone. Interface --------- This driver implements the character device interface. It supports reading through /dev/tsl2550b{1,3}s39. When read from, it returns a string containing a data label, a colon, and the sensor value. Example output of `cat /dev/tsl2550b3s39`: ILLUMINANCE : 830 Illuminance is expressed in lux. Valid values are 0 to 1846. Limitations ----------- Extended mode isn't implemented. Normal mode should be sufficient for most applications. Testing the Code ---------------- The driver should have been started by a script in /etc/rc.capes/ If not, this is how you start up an instance: cd /dev && MAKEDEV tsl2550b3s39 /bin/service up /usr/sbin/tsl2550 -label tsl2550.3.39 -dev /dev/tsl2550b3s39 \ -args 'bus=3 address=0x39' Getting the sensor value: cat /dev/tsl2550b3s39 Killing an instance: /bin/service down tsl2550.3.39