docs: networking: convert generic-hdlc.txt to ReST

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/generic-hdlc.rst

@@ -1,14 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==================
 Generic HDLC layer
+==================
+
 Krzysztof Halasa <khc@pm.waw.pl>
 
 
 Generic HDLC layer currently supports:
+
 1. Frame Relay (ANSI, CCITT, Cisco and no LMI)
+
    - Normal (routed) and Ethernet-bridged (Ethernet device emulation)
      interfaces can share a single PVC.
    - ARP support (no InARP support in the kernel - there is an
      experimental InARP user-space daemon available on:
      http://www.kernel.org/pub/linux/utils/net/hdlc/).
+
 2. raw HDLC - either IP (IPv4) interface or Ethernet device emulation
 3. Cisco HDLC
 4. PPP
@@ -24,19 +32,24 @@ with IEEE 802.1Q (VLANs) and 802.1D (Ethernet bridging).
 Make sure the hdlc.o and the hardware driver are loaded. It should
 create a number of "hdlc" (hdlc0 etc) network devices, one for each
 WAN port. You'll need the "sethdlc" utility, get it from:
+
 	http://www.kernel.org/pub/linux/utils/net/hdlc/
 
-Compile sethdlc.c utility:
+Compile sethdlc.c utility::
+
 	gcc -O2 -Wall -o sethdlc sethdlc.c
+
 Make sure you're using a correct version of sethdlc for your kernel.
 
 Use sethdlc to set physical interface, clock rate, HDLC mode used,
 and add any required PVCs if using Frame Relay.
-Usually you want something like:
+Usually you want something like::
 
 	sethdlc hdlc0 clock int rate 128000
 	sethdlc hdlc0 cisco interval 10 timeout 25
-or
+
+or::
+
 	sethdlc hdlc0 rs232 clock ext
 	sethdlc hdlc0 fr lmi ansi
 	sethdlc hdlc0 create 99
@@ -49,46 +62,63 @@ any IP address to it) before using pvc devices.
 
 Setting interface:
 
-* v35 | rs232 | x21 | t1 | e1 - sets physical interface for a given port
-                                if the card has software-selectable interfaces
-  loopback - activate hardware loopback (for testing only)
-* clock ext - both RX clock and TX clock external
-* clock int - both RX clock and TX clock internal
-* clock txint - RX clock external, TX clock internal
-* clock txfromrx - RX clock external, TX clock derived from RX clock
-* rate - sets clock rate in bps (for "int" or "txint" clock only)
+* v35 | rs232 | x21 | t1 | e1
+    - sets physical interface for a given port
+      if the card has software-selectable interfaces
+  loopback
+    - activate hardware loopback (for testing only)
+* clock ext
+    - both RX clock and TX clock external
+* clock int
+    - both RX clock and TX clock internal
+* clock txint
+    - RX clock external, TX clock internal
+* clock txfromrx
+    - RX clock external, TX clock derived from RX clock
+* rate
+    - sets clock rate in bps (for "int" or "txint" clock only)
 
 
 Setting protocol:
 
 * hdlc - sets raw HDLC (IP-only) mode
+
   nrz / nrzi / fm-mark / fm-space / manchester - sets transmission code
+
   no-parity / crc16 / crc16-pr0 (CRC16 with preset zeros) / crc32-itu
+
   crc16-itu (CRC16 with ITU-T polynomial) / crc16-itu-pr0 - sets parity
 
 * hdlc-eth - Ethernet device emulation using HDLC. Parity and encoding
   as above.
 
 * cisco - sets Cisco HDLC mode (IP, IPv6 and IPX supported)
+
   interval - time in seconds between keepalive packets
+
   timeout - time in seconds after last received keepalive packet before
-            we assume the link is down
+	    we assume the link is down
 
 * ppp - sets synchronous PPP mode
 
 * x25 - sets X.25 mode
 
 * fr - Frame Relay mode
+
   lmi ansi / ccitt / cisco / none - LMI (link management) type
+
   dce - Frame Relay DCE (network) side LMI instead of default DTE (user).
+
   It has nothing to do with clocks!
-  t391 - link integrity verification polling timer (in seconds) - user
-  t392 - polling verification timer (in seconds) - network
-  n391 - full status polling counter - user
-  n392 - error threshold - both user and network
-  n393 - monitored events count - both user and network
+
+  - t391 - link integrity verification polling timer (in seconds) - user
+  - t392 - polling verification timer (in seconds) - network
+  - n391 - full status polling counter - user
+  - n392 - error threshold - both user and network
+  - n393 - monitored events count - both user and network
 
 Frame-Relay only:
+
 * create n | delete n - adds / deletes PVC interface with DLCI #n.
   Newly created interface will be named pvc0, pvc1 etc.
 
@@ -101,26 +131,34 @@ Frame-Relay only:
 Board-specific issues
 ---------------------
 
-n2.o and c101.o need parameters to work:
+n2.o and c101.o need parameters to work::
 
 	insmod n2 hw=io,irq,ram,ports[:io,irq,...]
-example:
+
+example::
+
 	insmod n2 hw=0x300,10,0xD0000,01
 
-or
+or::
+
 	insmod c101 hw=irq,ram[:irq,...]
-example:
+
+example::
+
 	insmod c101 hw=9,0xdc000
 
-If built into the kernel, these drivers need kernel (command line) parameters:
+If built into the kernel, these drivers need kernel (command line) parameters::
+
 	n2.hw=io,irq,ram,ports:...
-or
+
+or::
+
 	c101.hw=irq,ram:...
 
 
 
 If you have a problem with N2, C101 or PLX200SYN card, you can issue the
-"private" command to see port's packet descriptor rings (in kernel logs):
+"private" command to see port's packet descriptor rings (in kernel logs)::
 
 	sethdlc hdlc0 private
 

Documentation/networking/index.rst

@@ -59,6 +59,7 @@ Contents:
    filter
    fore200e
    framerelay
+   generic-hdlc
 
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