treewide: Change AT command terminator to CR

Change default AT command terminator from <CRLF> to <CR> in
both the serial modem application and the host side.
This is aligned with 3GPP TS 27.007.

Jira: SLM-39

Signed-off-by: Tommi Rantanen <tommi.rantanen@nordicsemi.no>

Author: trantanen

app/Kconfig

@@ -29,7 +29,7 @@ config SM_EXTERNAL_XTAL
 #
 choice
 	prompt "Termination mode"
-	default SM_CR_LF_TERMINATION
+	default SM_CR_TERMINATION
 	help
 	  Sets the command terminator used by the serial terminal.
 	  Available options are:

app/overlay-ppp-cmux-linux.conf

@@ -7,7 +7,6 @@
 CONFIG_SM_SKIP_READY_MSG=y
 CONFIG_SM_CMUX=y
 CONFIG_SM_PPP=y
-CONFIG_SM_CR_TERMINATION=y
 
 CONFIG_MODEM_CMUX_MTU=127
 CONFIG_MODEM_CMUX_WORK_BUFFER_SIZE=536

doc/app/sm_description.rst

@@ -159,6 +159,7 @@ CONFIG_SM_AUTO_CONNECT - Connect to the network at start-up or reset
 
 CONFIG_SM_CR_TERMINATION - CR termination
    This option configures the application to accept AT commands ending with a carriage return.
+   This is the default AT command terminator.
 
    Select this option if you want to connect to the development kit using PuTTY.
    See `Testing and optimization`_  for instructions.
@@ -443,11 +444,10 @@ To connect to an nRF91 Series DK with a PC:
 
    .. note::
 
-      The default AT command terminator is a carriage return followed by a line feed (``\r\n``).
-      The Serial Terminal app supports this format.
-      If you want to use another terminal emulator, make sure that the configured AT command terminator corresponds to the line terminator of your terminal.
-      When using PuTTY, you must set the :ref:`CONFIG_SM_CR_TERMINATION <CONFIG_SM_CR_TERMINATION>` |SM| configuration option.
-      See :ref:`sm_config_options` for more details.
+      The default AT command terminator is a carriage return (``\r``).
+      The Serial Terminal app, PuTTY and many terminal emulators support this format by default.
+      However, make sure that the configured AT command terminator corresponds to the line terminator of your terminal.
+      See :ref:`sm_config_options` for more details on AT command terminator choices.
 
 .. sm_connecting_91dk_pc_instr_end
 

doc/lib/sm_host.rst

@@ -46,9 +46,9 @@ Optionally configure the following Kconfig options based on need:
 
 Use one of the following options to select the termination character:
 
-* ``CONFIG_SM_HOST_CR_TERMINATION`` - Enables ``<CR>`` as the termination character.
+* ``CONFIG_SM_HOST_CR_TERMINATION`` - Enables ``<CR>`` as the termination character, which is selected by default.
 * ``CONFIG_SM_HOST_LF_TERMINATION`` - Enables ``<LF>`` as the termination character.
-* ``CONFIG_SM_HOST_CR_LF_TERMINATION`` - Enables ``<CR+LF>`` as the termination character, which is selected by default.
+* ``CONFIG_SM_HOST_CR_LF_TERMINATION`` - Enables ``<CR+LF>`` as the termination character.
 
 You must configure the same termination character as that configured in |SM| on the nRF91 Series SiP.
 The library sends the termination character automatically after an AT command.

doc/migration_notes.rst

@@ -47,6 +47,8 @@ The following changes are mandatory to make your application work in the same wa
      * Renamed the file name from ``slm_`` to ``sm_`` and ``modem_slm`` to ``sm_host``.
      * Functions and other symbols in the code have been renamed accordingly making automatic patching to likely fail.
 
+   * Default AT command terminator changed from ``\r\n`` (``CONFIG_SM_CR_LF_TERMINATION`` and ``CONFIG_SM_HOST_CR_LF_TERMINATION``) to ``\r`` (``CONFIG_SM_CR_TERMINATION`` and ``CONFIG_SM_HOST_CR_TERMINATION``).
+
    * Rename the following AT commands:
 
      * ``AT#GPS`` to ``AT#GNSS``

lib/sm_host/Kconfig

@@ -55,7 +55,7 @@ config SM_HOST_SHELL
 
 choice
 	prompt "AT command terminator"
-	default SM_HOST_CR_LF_TERMINATION
+	default SM_HOST_CR_TERMINATION
 	help
 	  Sets the termination ending from the serial terminal
 	  Levels are: