Commit 7fb4028f authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

Documentation: tty: n_gsm, use power of ReST 



Reformat the whole document, so that automatic numbering and TOC is
properly generated.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220411110143.10019-7-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e937eb43

Documentation/driver-api/tty/n_gsm.rst

+74 −70
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ 
GSM 0710 tty multiplexor HOWTO

==============================



.. contents:: :local:



This line discipline implements the GSM 07.10 multiplexing protocol

detailed in the following 3GPP document:
@@ -11,28 +13,30 @@ This document give some hints on how to use this driver with GPRS and 3G 
modems connected to a physical serial port.



How to use it

-------------

1. config initiator

^^^^^^^^^^^^^^^^^^^^^

=============



Config Initiator

----------------



1.1 initialize the modem in 0710 mux mode (usually AT+CMUX= command) through

#. Initialize the modem in 0710 mux mode (usually ``AT+CMUX=`` command) through

   its serial port. Depending on the modem used, you can pass more or less

   parameters to this command.



1.2 switch the serial line to using the n_gsm line discipline by using

    TIOCSETD ioctl.

#. Switch the serial line to using the n_gsm line discipline by using

   ``TIOCSETD`` ioctl.



1.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.

#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.



1.4 obtain base gsmtty number for the used serial port.

#. Obtain base gsmtty number for the used serial port.



Major parts of the initialization program :

   Major parts of the initialization program

   (a good starting point is util-linux-ng/sys-utils/ldattach.c)::



      #include <stdio.h>

      #include <stdint.h>

      #include <linux/gsmmux.h>

      #include <linux/tty.h>



      #define DEFAULT_SPEED	B115200

      #define SERIAL_PORT	/dev/ttyS0
@@ -76,14 +80,14 @@ Major parts of the initialization program : 
      daemon(0,0);

      pause();



1.5 use these devices as plain serial ports.

#. Use these devices as plain serial ports.



   for example, it's possible:

   For example, it's possible:



   - and to use gnokii to send / receive SMS on ttygsm1

   - to use ppp to establish a datalink on ttygsm2

   - to use *gnokii* to send / receive SMS on ``ttygsm1``

   - to use *ppp* to establish a datalink on ``ttygsm2``



1.6 first close all virtual ports before closing the physical port.

#. First close all virtual ports before closing the physical port.



   Note that after closing the physical port the modem is still in multiplexing

   mode. This may prevent a successful re-opening of the port later. To avoid
@@ -91,20 +95,20 @@ Major parts of the initialization program : 
   a disconnect command frame manually before initializing the multiplexing mode

   for the second time. The byte sequence for the disconnect command frame is::



      0xf9, 0x03, 0xef, 0x03, 0xc3, 0x16, 0xf9.

      0xf9, 0x03, 0xef, 0x03, 0xc3, 0x16, 0xf9



2. config requester

^^^^^^^^^^^^^^^^^^^^^

Config Requester

----------------



2.1 receive string "AT+CMUX= command" through its serial port,initialize

    mux mode config

#. Receive ``AT+CMUX=`` command through its serial port, initialize mux mode

   config.



2.2 switch the serial line to using the n_gsm line discipline by using

    TIOCSETD ioctl.

#. Switch the serial line to using the *n_gsm* line discipline by using

   ``TIOCSETD`` ioctl.



2.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.

#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.



2.4 obtain base gsmtty number for the used serial port::

#. Obtain base gsmtty number for the used serial port::



        #include <stdio.h>

        #include <stdint.h>