18. Driver documentation for yealink usb-p1k phones¶
The p1k is a relatively cheap usb 1.1 phone with:
keyboard full support, yealink.ko / input event API
LCD full support, yealink.ko / sysfs API
LED full support, yealink.ko / sysfs API
dialtone full support, yealink.ko / sysfs API
ringtone full support, yealink.ko / sysfs API
audio playback full support, snd_usb_audio.ko / alsa API
audio record full support, snd_usb_audio.ko / alsa API
For vendor documentation see http://www.yealink.com
18.2. keyboard features¶
The current mapping in the kernel is provided by the map_p1k_to_key function:
Physical USB-P1K button layout input events up up IN OUT left, right down down pickup C hangup enter, backspace, escape 1 2 3 1, 2, 3 4 5 6 4, 5, 6, 7 8 9 7, 8, 9, * 0 # *, 0, #,
The “up” and “down” keys, are symbolised by arrows on the button. The “pickup” and “hangup” keys are symbolised by a green and red phone on the button.
18.3. LCD features¶
The LCD is divided and organised as a 3 line display:
|    in | | M  D  :  out | store NEW REP SU MO TU WE TH FR SA                         Line 1 Format (see below) : 18.e8.M8.88...188 Icon names : M D : IN OUT STORE Line 2 Format : ......... Icon name : NEW REP SU MO TU WE TH FR SA Line 3 Format : 888888888888
- Format description:
From a userspace perspective the world is separated into “digits” and “icons”. A digit can have a character set, an icon can only be ON or OFF.
'8' : Generic 7 segment digit with individual addressable segments Reduced capability 7 segment digit, when segments are hard wired together. '1' : 2 segments digit only able to produce a 1. 'e' : Most significant day of the month digit, able to produce at least 1 2 3. 'M' : Most significant minute digit, able to produce at least 0 1 2 3 4 5. Icons or pictograms: '.' : For example like AM, PM, SU, a 'dot' .. or other single segment elements.
18.4. Driver usage¶
For userland the following interfaces are available using the sysfs interface:
/sys/.../ line1 Read/Write, lcd line1 line2 Read/Write, lcd line2 line3 Read/Write, lcd line3 get_icons Read, returns a set of available icons. hide_icon Write, hide the element by writing the icon name. show_icon Write, display the element by writing the icon name. map_seg7 Read/Write, the 7 segments char set, common for all yealink phones. (see map_to_7segment.h) ringtone Write, upload binary representation of a ringtone, see yealink.c. status EXPERIMENTAL due to potential races between async. and sync usb calls.
Reading /sys/../lineX will return the format string with its current value.
Example:cat ./line3 888888888888 Linux Rocks!
Writing to /sys/../lineX will set the corresponding LCD line.
Excess characters are ignored.
If less characters are written than allowed, the remaining digits are unchanged.
The tab ‘t’and ‘n’ char does not overwrite the original content.
Writing a space to an icon will always hide its content.
Example:date +"%m.%e.%k:%M" | sed 's/^0/ /' > ./line1
Will update the LCD with the current date & time.
Reading will return all available icon names and its current settings:
cat ./get_icons on M on D on : IN OUT STORE NEW REP SU MO TU WE TH FR SA LED DIALTONE RINGTONE
18.4.3. show/hide icons¶
Writing to these files will update the state of the icon. Only one icon at a time can be updated.
If an icon is also on a ./lineX the corresponding value is updated with the first letter of the icon.
Example - light up the store icon:echo -n "STORE" > ./show_icon cat ./line1 18.e8.M8.88...188 S
Example - sound the ringtone for 10 seconds:echo -n RINGTONE > /sys/..../show_icon sleep 10 echo -n RINGTONE > /sys/..../hide_icon
18.5. Sound features¶
Sound is supported by the ALSA driver: snd_usb_audio
One 16-bit channel with sample and playback rates of 8000 Hz is the practical limit of the device.
Example - recording test:arecord -v -d 10 -r 8000 -f S16_LE -t wav foobar.wav
Example - playback test:aplay foobar.wav
Module yealink compiled and installed without any problem but phone is not initialized and does not react to any actions.
If you see something like: hiddev0: USB HID v1.00 Device [Yealink Network Technology Ltd. VOIP USB Phone in dmesg, it means that the hid driver has grabbed the device first. Try to load module yealink before any other usb hid driver. Please see the instructions provided by your distribution on module configuration.
Phone is working now (displays version and accepts keypad input) but I can’t find the sysfs files.
The sysfs files are located on the particular usb endpoint. On most distributions you can do: “find /sys/ -name get_icons” for a hint.
18.7. Credits & Acknowledgments¶
Olivier Vandorpe, for starting the usbb2k-api project doing much of the reverse engineering.
Martin Diehl, for pointing out how to handle USB memory allocation.
Dmitry Torokhov, for the numerous code reviews and suggestions.