This PR makes the modem_chat wait until a chat script chat
request has been sent before accepting responses to said
request.
This helps ensure that an unsolicitet response is not mistaken
for a response to a request, which is especially problematic
if the chat script chat is using an any match.
For example, start chat script sending AT+CGMI, expecting the
modem name as a response followed by OK
> start script, waiting for response immediately
> start sending "AT+CGMI"
> receive "+CEREG 1,0" while sending
> script accepts "+CEREG 1,0" as the response to "AT+CGMI"
> "AT+CGMI" sent
> receive "QUECTEL BG95"
> receive "OK"
script handler got "+CEREG 1,0" instead of "QUECTEL BG95"
After this PR:
> start script
> start sending AT+CGMI
> receive "+CEREG 1,0" while sending
> "AT+CGMI" sent
> start waiting for response
> receive "QUECTEL BG95"
> script accepts "QUECTEL BG95" as response to "AT+CGMI"
> receive "OK"
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
This optimization aggregates frame headers before adding to the ring buffer
and computes the FCS of the frame header in one operation.
This approach improves execution efficiency and reduces memory footprint.
This code adjustment aligns with the changes proposed in https://github.com/zephyrproject-rtos/zephyr/pull/67062.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
Implement transmit idle notification for TTY backend. Since TTY
has an "infinite" transmit buffer, we invoke transmit idle
immediately after writing the data to the TTY file.
The test suite for the TTY backend has been updated to match the
new behavior.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
Make async and interrupt driven UART backends notify transmit
idle when transmit is idle.
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>
Some modems don't start sending resync flags as described in
3G TS 27.010 V2.0.0 5.2.5, which results in the CMUX being
stuck in resync mode for said modems.
This patch simplifies the resync mechanism to simply drop
invalid frames, and wait for atleast two consequtive frame
flags (stop+start).
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
DLCI receive buffer may overrun if data is not processed fast
enough. This error was not reported before this patch, resulting
in unexplained missing bytes.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
The CMUX resync mechanism can get stuck between states
MODEM_CMUX_RECEIVE_STATE_RESYNC_0 and
MODEM_CMUX_RECEIVE_STATE_RESYNC_1 if the resync flags, which are
sent only once in state MODEM_CMUX_RECEIVE_STATE_SOF, are not
responded to, or the response is lost.
This patch ensures resync flags are sent from states
MODEM_CMUX_RECEIVE_STATE_SOF, MODEM_CMUX_RECEIVE_STATE_RESYNC_1
and MODEM_CMUX_RECEIVE_STATE_RESYNC_2 if its determined that the
resync flags are not being responded to.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
The chat module contains an array of three lists of matches,
one of which are static, two of which are contained within the
currently running script. The current match, which is an
object stored in one of the three lists, is stored in its own
pointer in the chat module context.
A memory error occurs when the script is stopped, while the
chat module is using one of the matches stored withing the
script. This commit clears the match pointer when the script
is stopped if the match is stored within the script.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
In cases where the data is bigger than 127 bytes,
the first bit of the second byte of the data length field
used to always be set.
This is wrong as according to the 3GPP 27.010 spec
only the first bit of the first byte is the EA bit;
all the others denote the data length.
Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>
Added missing command and message handling for use existing
modem cmux for DCE role.
DCE CMUX connection can be now initialized from DTE side.
Signed-off-by: Juha Heiskanen <juha.heiskanen@nordicsemi.no>
The UART flush is not relevant for the async UART implementation.
UART drivers should handle this internally.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
Use single ring buffer and protect it with a spinlock as it is
shared between backend and UART thread (ISR). This is simpler
than the double ring buffer setup.
The receive idle timeout has also been made configurable
instead of being a hardcoded value.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
The current implementation only waits for the RX disabled event
to determine if the UART is closed. It should wait for all RX
buffers to be released, and the TX to be done as well.
We now also call uart_tx_abort() when closing the pipe.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
Possible NULL pointer dereferences where discovered by static
code analysis, they are addressed in this commit.
Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>
This commit reuses the string "Unknown %s frame type" for two
log messages, as suggested by ycsin.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit resets the state of the CMUX receive state
machine when the CMUX instance is attached to a pipe.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit adds logging for CMUX frames and commands and
their data, for both transmit and receive. It also removes
the superseded LOG_DBG() lines like "Received frame".
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit resets the receive ring buffer for each DLCI
pipe when they are opened. They may have old data stored
from last time they where opened.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit adds a check to the async connect and disconnect
functions to validate the CMUX is not already connected
or disconnected respectively. This was already part of the
sync connect and disconnect functions, so the sync functions
now simply wrap the async functions to avoid duplicate code.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit increases the buffer used for commands
in the control channel within an instance of the
modem_cmux module. The buffer was not large enough to
store an MSC command if the optional break signals
where included. This commit fixes the issue and
updates the test suite to use the max size MSC message.
Signed-off-by: Bjarki Arge Andreasen <baa@trackunit.com>
This commit sets the C/R (command/response) bit when UIH
CMUX frames are sent from the modem_cmux module. This bit
is ignored by some modems like the Quectel BG95, as there
is no defined response to this specific CMUX frame type.
However, other modems, like the TELIT ME910, require the
bit to be set (command). If the bit is not set, the modem
will simply ignore the frame completely.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
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 commit optimizes the performance of the script chats by
storing the size of requests with the chat script chat, negating
the need to use strlen() within the modem_chat module every time
a chat script chat request is sent.
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit adds one new feature, modem_chat_run_script(),
which synchronously runs a script.
The existing function modem_chat_script_run() is async,
and doesn't follow the naming convention created for the
other modem modules, specifically, all functions are sync,
unless appended with _async.
To preserve backwards compatibility, the existing function
modem_chat_script_run() will remain until deprecated. It
simply calls modem_chat_run_script_async().
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 commit adds support for partial matches for the modem_chat
module. A match is a combination of an expected response to a
request along with delimiters to use and a handler for the
parsed response.
The usual behavior of the modem_chat script is to continue to
the next step when any expected response is received. The partial
flag indicates that the script should not proceed to the next
step if the response matches the match. This is useful for
commands which respond with an unspecified number of lines,
followed by an "OK". This flag allows the script to essentially
run in a "while" loop until OK is received.
Along with this addition, a more scalable macro for initializing
the modem_chat match struct, MODEM_CHAT_MATCH_INITIALIZER().
Without this macro, we will need 4 different macros to initialize
the 4 variants of a chat_match, and 8 when the next feature is
added...
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
This commit delegates the modem_pipe_notify_closed() call
resulting from the UART async API UART_RX_DISABLED event
to the workqueue. This is neccesary as the async UART
callback may be called from ISR context.
modem_pipe_notify_closed() must be called from outside of
the ISR context as it takes a mutex.
The commit also adds a missing break to the async UART
callback, and adds a missing dependency to the Kconfig
for the UART backends, RING_BUFFER=y
Signed-off-by: Bjarki Arge Andreasen <bjarkix123@gmail.com>
The backend currently returns the pipe closed event immediately
after calling uart_rx_disable() which is not the correct behavior.
the pipe closed event should be called when the UART_RX_DISABLED
event is raised by the UART driver.
With this fix, back-to-back open/close/open... will work as
expected, where before the second open would often fail since
the UART was not actually disabled yet.
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>
