- add SPDX header;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
Documentation/networking/index.rst | 1 +
.../networking/{PLIP.txt => plip.rst} | 43 +++++++++++--------
drivers/net/plip/Kconfig | 2 +-
3 files changed, 27 insertions(+), 19 deletions(-)
rename Documentation/networking/{PLIP.txt => plip.rst} (92%)
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 696181a96e3c..18bb10239cad 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -92,6 +92,7 @@ Contents:
packet_mmap
phonet
pktgen
+ plip
.. only:: subproject and html
diff --git a/Documentation/networking/PLIP.txt b/Documentation/networking/plip.rst
similarity index 92%
rename from Documentation/networking/PLIP.txt
rename to Documentation/networking/plip.rst
index ad7e3f7c3bbf..0eda745050ff 100644
--- a/Documentation/networking/PLIP.txt
+++ b/Documentation/networking/plip.rst
@@ -1,4 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================================================
PLIP: The Parallel Line Internet Protocol Device
+================================================
Donald Becker (becker@xxxxxxxxx)
I.D.A. Supercomputing Research Center, Bowie MD 20715
@@ -83,7 +87,7 @@ When the PLIP driver is used in IRQ mode, the timeout used for triggering a
data transfer (the maximal time the PLIP driver would allow the other side
before announcing a timeout, when trying to handshake a transfer of some
data) is, by default, 500usec. As IRQ delivery is more or less immediate,
-this timeout is quite sufficient.
+this timeout is quite sufficient.
When in IRQ-less mode, the PLIP driver polls the parallel port HZ times
per second (where HZ is typically 100 on most platforms, and 1024 on an
@@ -115,7 +119,7 @@ printer "null" cable to transfer data four bits at a time using
data bit outputs connected to status bit inputs.
The second data transfer method relies on both machines having
-bi-directional parallel ports, rather than output-only ``printer''
+bi-directional parallel ports, rather than output-only ``printer``
ports. This allows byte-wide transfers and avoids reconstructing
nibbles into bytes, leading to much faster transfers.
@@ -132,7 +136,7 @@ bits with standard status register implementation.
A cable that implements this protocol is available commercially as a
"Null Printer" or "Turbo Laplink" cable. It can be constructed with
-two DB-25 male connectors symmetrically connected as follows:
+two DB-25 male connectors symmetrically connected as follows::
STROBE output 1*
D0->ERROR 2 - 15 15 - 2
@@ -146,7 +150,8 @@ two DB-25 male connectors symmetrically connected as follows:
SLCTIN 17 - 17
extra grounds are 18*,19*,20*,21*,22*,23*,24*
GROUND 25 - 25
-* Do not connect these pins on either end
+
+ * Do not connect these pins on either end
If the cable you are using has a metallic shield it should be
connected to the metallic DB-25 shell at one end only.
@@ -155,14 +160,14 @@ Parallel Transfer Mode 1
========================
The second data transfer method relies on both machines having
-bi-directional parallel ports, rather than output-only ``printer''
+bi-directional parallel ports, rather than output-only ``printer``
ports. This allows byte-wide transfers, and avoids reconstructing
nibbles into bytes. This cable should not be used on unidirectional
-``printer'' (as opposed to ``parallel'') ports or when the machine
+``printer`` (as opposed to ``parallel``) ports or when the machine
isn't configured for PLIP, as it will result in output driver
conflicts and the (unlikely) possibility of damage.
-The cable for this transfer mode should be constructed as follows:
+The cable for this transfer mode should be constructed as follows::
STROBE->BUSY 1 - 11
D0->D0 2 - 2
@@ -179,7 +184,8 @@ The cable for this transfer mode should be constructed as follows:
GND->ERROR 18 - 15
extra grounds are 19*,20*,21*,22*,23*,24*
GROUND 25 - 25
-* Do not connect these pins on either end
+
+ * Do not connect these pins on either end
Once again, if the cable you are using has a metallic shield it should
be connected to the metallic DB-25 shell at one end only.
@@ -188,7 +194,7 @@ PLIP Mode 0 transfer protocol
=============================
The PLIP driver is compatible with the "Crynwr" parallel port transfer
-standard in Mode 0. That standard specifies the following protocol:
+standard in Mode 0. That standard specifies the following protocol::
send header nibble '0x8'
count-low octet
@@ -196,20 +202,21 @@ standard in Mode 0. That standard specifies the following protocol:
... data octets
checksum octet
-Each octet is sent as
+Each octet is sent as::
+
<wait for rx. '0x1?'> <send 0x10+(octet&0x0F)>
<wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)>
To start a transfer the transmitting machine outputs a nibble 0x08.
That raises the ACK line, triggering an interrupt in the receiving
machine. The receiving machine disables interrupts and raises its own ACK
-line.
+line.
-Restated:
+Restated::
-(OUT is bit 0-4, OUT.j is bit j from OUT. IN likewise)
-Send_Byte:
- OUT := low nibble, OUT.4 := 1
- WAIT FOR IN.4 = 1
- OUT := high nibble, OUT.4 := 0
- WAIT FOR IN.4 = 0
+ (OUT is bit 0-4, OUT.j is bit j from OUT. IN likewise)
+ Send_Byte:
+ OUT := low nibble, OUT.4 := 1
+ WAIT FOR IN.4 = 1
+ OUT := high nibble, OUT.4 := 0
+ WAIT FOR IN.4 = 0
diff --git a/drivers/net/plip/Kconfig b/drivers/net/plip/Kconfig
index b41035be2d51..e03556d1d0c2 100644
--- a/drivers/net/plip/Kconfig
+++ b/drivers/net/plip/Kconfig
@@ -21,7 +21,7 @@ config PLIP
bits at a time (mode 0) or with special PLIP cables, to be used on
bidirectional parallel ports only, which can transmit 8 bits at a
time (mode 1); you can find the wiring of these cables in
- <file:Documentation/networking/PLIP.txt>. The cables can be up to
+ <file:Documentation/networking/plip.rst>. The cables can be up to
15m long. Mode 0 works also if one of the machines runs DOS/Windows
and has some PLIP software installed, e.g. the Crynwr PLIP packet
driver (<http://oak.oakland.edu/simtel.net/msdos/pktdrvr-pre.html>)
--
2.25.4
