mirror of
https://github.com/apache/nuttx.git
synced 2026-08-15 09:23:20 +00:00
6b3f7e0939
Adds initial documentation to the IOCTL commands of wireless character devices. Signed-off-by: Kevin Witteveen (MartiniMarter) <kevinwit1999@gmail.com>
53 lines
No EOL
1.9 KiB
ReStructuredText
53 lines
No EOL
1.9 KiB
ReStructuredText
==========================
|
|
Wireless character drivers
|
|
==========================
|
|
|
|
.. toctree::
|
|
:maxdepth: 1
|
|
|
|
lpwan/index.rst
|
|
|
|
IOCTL Interface
|
|
===============
|
|
|
|
Before this interface, the IOCTL API for character-driven RF devices lacked
|
|
a common interface across different modulation technologies,
|
|
such as LoRa, FSK, and OOK. The result was, driver-specific IOCTL commands
|
|
were created even when they could be shared across multiple radios.
|
|
This fragmentation made application portability more difficult to maintain.
|
|
|
|
To solve this issue, groups of commands have been created that are "selected"
|
|
by using ``WLIOC_SETMODU``.
|
|
See image below for a representation.
|
|
|
|
.. figure:: wireless_ioctl_white.drawio.png
|
|
|
|
.. note:: This image does not show all features. This is purely a
|
|
representation of command relations under WLIOC_SETMODU.
|
|
|
|
read()
|
|
------
|
|
|
|
Reading a radio will take a ``wlioc_rx_hdr_s``, where information about the
|
|
payload will be read and written to.
|
|
|
|
- ``FAR uint8_t *payload_buffer`` Pointer to **user buffer**. This is where
|
|
the payload will be written to.
|
|
- ``size_t payload_length`` **Initially**: User must set this to the size
|
|
of ``payload_buffer``. **After reading**: This will become the amount of
|
|
bytes written to the ``payload_buffer``.
|
|
- ``uint8_t error`` When greater than 0, there are errors detected in the
|
|
payload. The payload can still be returned, which allows the user to repair
|
|
it if desired.
|
|
- ``int32_t rssi_dbm`` The Received Signal Strength Indicator in
|
|
1/100 decibel-milliwatts of the received signal.
|
|
When unsupported, this returns ``INT32_MIN``.
|
|
- ``int32_t snr_db`` The signal to noise ratio in 1/100 decibels of the
|
|
received signal. When unsupported, this returns ``INT32_MIN``.
|
|
|
|
write()
|
|
-------
|
|
|
|
Writing to a radio will attempt to send the given bytes. The radio must be
|
|
configured before doing so.
|
|
Unlike ``read()``, this will simply take uint8_t bytes as payload. |