The modem pipe APIs include synchronous calls to open/close,
which internally use a fixed timeout of 10 seconds. The timeout
should be configurable through the APIs, anywhere from K_NO_WAIT
to K_FOREVER.
This commit adds timeout parameters to the open/close APIs, and
updates in-tree usage of the open/close APIs to explicitly
provide the previously implicit timeout of 10 seconds.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
Changed the `api` field in the `modem_pipe` structure to be
a pointer to constant.
This ensures that the `api` field remains immutable after
initialization.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
The design of the pipe is overly complicated compared to the
in-tree and planned future use of the pipe module.
The pipe is currently designed to protect against multiple
threads calling any API simultaineously. This is not neccesary
as only one thread ever calls open/close/transmit/receive at
once, while the notification APIs are potentially called by a
different thread.
This commit removes the synchronization of calls to the open/
close/receive/transmit APIs. It also uses a k_event for thread
safe event and state handling instead of a k_mutex and k_condvar.
The callback is proteced by a k_sem as it modified using the
attach/release APIs, which can be called simultaneously to a
thread invoking the callback.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
Add transmit idle event to modem_pipe_event enum. This will
allow modules to await transmit idle before trying to transmit
more data, instead of blindly calling modem_pipe_transmit in
a loop until all data has been accepted.
This will reduce the time spent trying to transmit data while
the backend is blocked.
Similarly to the RECEIVE_READY event, backends will call
modem_pipe_notify_transmit_idle() to indicate that transmit
is idle, and the TRANSMIT_IDLE event will be reinvoked when
the modem pipe is attached to synchronize the state of the
pipe with the user of it.
Additionally, the TRANSMIT_IDLE event is also invoked when the
modem is opened to further help synchronization with the user
of the pipe.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
This PR adds a mechanism to avoid calling open() or close()
on pipes which are already opened or closed respectively.
This optimization can help simplify backends implementing
the modem_pipe API by avoiding duplicated boilerplate code.
The TTY backend test suite has been updated to match the
new behavior.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This PR makes the modem_pipe instances track if they have
data ready to receive, and invoke the RECEIVE_READY event
every time they are attached if the backend implementing
the pipe has notified that receive is ready.
This mechanism ensures that modules attaching to a pipe
get the async RECEIVE_READY event immediately after
attaching to a pipe if there is data ready, instead of
having to poll the pipe, or worse, wait until newer data
becomes available.
The addition revealed a timing issue in the cmux test
suite. Specifically the CMUX instance now immediately
receives the response to a command which the CMUX
instance has not sent yet, causing it to drop the
response.
The CMUX test suite now uses the transaction
mechanism of the mock_pipe to wait for the command
before sending the response.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This PR adds the following modem modules to the subsys/modem
folder:
- chat: Light implementation of the Linux chat program, used to
send and receive text based commands statically created
scripts.
- cmux: Implementation of the CMUX protocol
- pipe: Thread-safe async data-in/data-out binding layer between
modem modules.
- ppp: Implementation of the PPP protocol, binding the Zephyr PPP
L2 stack with the data-in/data-out pipe.
These modules use the abstract pipes to communicate between each
other. To bind them with the hardware, the following backends
are provided:
- TTY: modem pipe <-> POSIX TTY file
- UART: modem pipe <-> UART, async and ISR APIs supported
The backends are used to abstract away the physical layer, UART,
TTY, IPC, I2C, SPI etc, to a modem modules friendly pipe.
Signed-off-by: Bjarki Arge Andreasen <baa@trackunit.com>
