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authorJiri Slaby <jslaby@suse.cz>2022-04-11 14:01:40 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-14 19:24:23 +0300
commite26595034dada8a1e6c10f0e0187f43edec72698 (patch)
tree10c289557fea4ad9ca766ec9d45f7e2567c3b1a6 /Documentation/driver-api/serial
parent1a4a8f6bbac07e3270805009c69e89c7de801df1 (diff)
downloadlinux-e26595034dada8a1e6c10f0e0187f43edec72698.tar.xz
Documentation: tty: move n_gsm to tty
We have n_tty documented in Documentation/driver-api/tty/. n_gsm belongs there too, so move from serial/ to tty/ too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220411110143.10019-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/driver-api/serial')
-rw-r--r--Documentation/driver-api/serial/index.rst1
-rw-r--r--Documentation/driver-api/serial/n_gsm.rst159
2 files changed, 0 insertions, 160 deletions
diff --git a/Documentation/driver-api/serial/index.rst b/Documentation/driver-api/serial/index.rst
index 7eb21a695fc3..4ebdb86cd6b6 100644
--- a/Documentation/driver-api/serial/index.rst
+++ b/Documentation/driver-api/serial/index.rst
@@ -17,7 +17,6 @@ Serial drivers
:maxdepth: 1
moxa-smartio
- n_gsm
serial-iso7816
serial-rs485
diff --git a/Documentation/driver-api/serial/n_gsm.rst b/Documentation/driver-api/serial/n_gsm.rst
deleted file mode 100644
index 49956509ad73..000000000000
--- a/Documentation/driver-api/serial/n_gsm.rst
+++ /dev/null
@@ -1,159 +0,0 @@
-==============================
-GSM 0710 tty multiplexor HOWTO
-==============================
-
-This line discipline implements the GSM 07.10 multiplexing protocol
-detailed in the following 3GPP document:
-
- https://www.3gpp.org/ftp/Specs/archive/07_series/07.10/0710-720.zip
-
-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
-^^^^^^^^^^^^^^^^^^^^^
-
-1.1 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.
-
-1.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.
-
-1.4 obtain base gsmtty number for the used serial port.
-
-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
-
- int ldisc = N_GSM0710;
- struct gsm_config c;
- struct termios configuration;
- uint32_t first;
-
- /* open the serial port connected to the modem */
- fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
-
- /* configure the serial port : speed, flow control ... */
-
- /* send the AT commands to switch the modem to CMUX mode
- and check that it's successful (should return OK) */
- write(fd, "AT+CMUX=0\r", 10);
-
- /* experience showed that some modems need some time before
- being able to answer to the first MUX packet so a delay
- may be needed here in some case */
- sleep(3);
-
- /* use n_gsm line discipline */
- ioctl(fd, TIOCSETD, &ldisc);
-
- /* get n_gsm configuration */
- ioctl(fd, GSMIOC_GETCONF, &c);
- /* we are initiator and need encoding 0 (basic) */
- c.initiator = 1;
- c.encapsulation = 0;
- /* our modem defaults to a maximum size of 127 bytes */
- c.mru = 127;
- c.mtu = 127;
- /* set the new configuration */
- ioctl(fd, GSMIOC_SETCONF, &c);
- /* get first gsmtty device node */
- ioctl(fd, GSMIOC_GETFIRST, &first);
- printf("first muxed line: /dev/gsmtty%i\n", first);
-
- /* and wait for ever to keep the line discipline enabled */
- daemon(0,0);
- pause();
-
-1.5 use these devices as plain serial ports.
-
- for example, it's possible:
-
- - and 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.
-
- 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
- this situation either reset the modem if your hardware allows that or send
- 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.
-
-2. config requester
-^^^^^^^^^^^^^^^^^^^^^
-
-2.1 receive string "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.
-
-2.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.
-
-2.4 obtain base gsmtty number for the used serial port::
-
- #include <stdio.h>
- #include <stdint.h>
- #include <linux/gsmmux.h>
- #include <linux/tty.h>
- #define DEFAULT_SPEED B115200
- #define SERIAL_PORT /dev/ttyS0
-
- int ldisc = N_GSM0710;
- struct gsm_config c;
- struct termios configuration;
- uint32_t first;
-
- /* open the serial port */
- fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
-
- /* configure the serial port : speed, flow control ... */
-
- /* get serial data and check "AT+CMUX=command" parameter ... */
-
- /* use n_gsm line discipline */
- ioctl(fd, TIOCSETD, &ldisc);
-
- /* get n_gsm configuration */
- ioctl(fd, GSMIOC_GETCONF, &c);
- /* we are requester and need encoding 0 (basic) */
- c.initiator = 0;
- c.encapsulation = 0;
- /* our modem defaults to a maximum size of 127 bytes */
- c.mru = 127;
- c.mtu = 127;
- /* set the new configuration */
- ioctl(fd, GSMIOC_SETCONF, &c);
- /* get first gsmtty device node */
- ioctl(fd, GSMIOC_GETFIRST, &first);
- printf("first muxed line: /dev/gsmtty%i\n", first);
-
- /* and wait for ever to keep the line discipline enabled */
- daemon(0,0);
- pause();
-
-Additional Documentation
-------------------------
-More practical details on the protocol and how it's supported by industrial
-modems can be found in the following documents :
-
-- http://www.telit.com/module/infopool/download.php?id=616
-- http://www.u-blox.com/images/downloads/Product_Docs/LEON-G100-G200-MuxImplementation_ApplicationNote_%28GSM%20G1-CS-10002%29.pdf
-- http://www.sierrawireless.com/Support/Downloads/AirPrime/WMP_Series/~/media/Support_Downloads/AirPrime/Application_notes/CMUX_Feature_Application_Note-Rev004.ashx
-- http://wm.sim.com/sim/News/photo/2010721161442.pdf
-
-11-03-08 - Eric BĂ©nard - <eric@eukrea.com>