|
@@ -1,15 +1,18 @@
|
|
|
-The `parport' code provides parallel-port support under Linux. This
|
|
|
+Parport
|
|
|
++++++++
|
|
|
+
|
|
|
+The ``parport`` code provides parallel-port support under Linux. This
|
|
|
includes the ability to share one port between multiple device
|
|
|
drivers.
|
|
|
|
|
|
-You can pass parameters to the parport code to override its automatic
|
|
|
+You can pass parameters to the ``parport`` code to override its automatic
|
|
|
detection of your hardware. This is particularly useful if you want
|
|
|
to use IRQs, since in general these can't be autoprobed successfully.
|
|
|
-By default IRQs are not used even if they _can_ be probed. This is
|
|
|
+By default IRQs are not used even if they **can** be probed. This is
|
|
|
because there are a lot of people using the same IRQ for their
|
|
|
parallel port and a sound card or network card.
|
|
|
|
|
|
-The parport code is split into two parts: generic (which deals with
|
|
|
+The ``parport`` code is split into two parts: generic (which deals with
|
|
|
port-sharing) and architecture-dependent (which deals with actually
|
|
|
using the port).
|
|
|
|
|
@@ -17,21 +20,21 @@ using the port).
|
|
|
Parport as modules
|
|
|
==================
|
|
|
|
|
|
-If you load the parport code as a module, say
|
|
|
+If you load the `parport`` code as a module, say::
|
|
|
|
|
|
# insmod parport
|
|
|
|
|
|
-to load the generic parport code. You then must load the
|
|
|
-architecture-dependent code with (for example):
|
|
|
+to load the generic ``parport`` code. You then must load the
|
|
|
+architecture-dependent code with (for example)::
|
|
|
|
|
|
# insmod parport_pc io=0x3bc,0x378,0x278 irq=none,7,auto
|
|
|
|
|
|
-to tell the parport code that you want three PC-style ports, one at
|
|
|
+to tell the ``parport`` code that you want three PC-style ports, one at
|
|
|
0x3bc with no IRQ, one at 0x378 using IRQ 7, and one at 0x278 with an
|
|
|
-auto-detected IRQ. Currently, PC-style (parport_pc), Sun `bpp',
|
|
|
+auto-detected IRQ. Currently, PC-style (``parport_pc``), Sun ``bpp``,
|
|
|
Amiga, Atari, and MFC3 hardware is supported.
|
|
|
|
|
|
-PCI parallel I/O card support comes from parport_pc. Base I/O
|
|
|
+PCI parallel I/O card support comes from ``parport_pc``. Base I/O
|
|
|
addresses should not be specified for supported PCI cards since they
|
|
|
are automatically detected.
|
|
|
|
|
@@ -40,151 +43,154 @@ modprobe
|
|
|
--------
|
|
|
|
|
|
If you use modprobe , you will find it useful to add lines as below to a
|
|
|
-configuration file in /etc/modprobe.d/ directory:.
|
|
|
+configuration file in /etc/modprobe.d/ directory::
|
|
|
|
|
|
alias parport_lowlevel parport_pc
|
|
|
options parport_pc io=0x378,0x278 irq=7,auto
|
|
|
|
|
|
-modprobe will load parport_pc (with the options "io=0x378,0x278 irq=7,auto")
|
|
|
-whenever a parallel port device driver (such as lp) is loaded.
|
|
|
+modprobe will load ``parport_pc`` (with the options ``io=0x378,0x278 irq=7,auto``)
|
|
|
+whenever a parallel port device driver (such as ``lp``) is loaded.
|
|
|
|
|
|
Note that these are example lines only! You shouldn't in general need
|
|
|
-to specify any options to parport_pc in order to be able to use a
|
|
|
+to specify any options to ``parport_pc`` in order to be able to use a
|
|
|
parallel port.
|
|
|
|
|
|
|
|
|
Parport probe [optional]
|
|
|
--------------
|
|
|
+------------------------
|
|
|
|
|
|
-In 2.2 kernels there was a module called parport_probe, which was used
|
|
|
+In 2.2 kernels there was a module called ``parport_probe``, which was used
|
|
|
for collecting IEEE 1284 device ID information. This has now been
|
|
|
enhanced and now lives with the IEEE 1284 support. When a parallel
|
|
|
port is detected, the devices that are connected to it are analysed,
|
|
|
-and information is logged like this:
|
|
|
+and information is logged like this::
|
|
|
|
|
|
parport0: Printer, BJC-210 (Canon)
|
|
|
|
|
|
-The probe information is available from files in /proc/sys/dev/parport/.
|
|
|
+The probe information is available from files in ``/proc/sys/dev/parport/``.
|
|
|
|
|
|
|
|
|
Parport linked into the kernel statically
|
|
|
=========================================
|
|
|
|
|
|
-If you compile the parport code into the kernel, then you can use
|
|
|
+If you compile the ``parport`` code into the kernel, then you can use
|
|
|
kernel boot parameters to get the same effect. Add something like the
|
|
|
-following to your LILO command line:
|
|
|
+following to your LILO command line::
|
|
|
|
|
|
parport=0x3bc parport=0x378,7 parport=0x278,auto,nofifo
|
|
|
|
|
|
-You can have many `parport=...' statements, one for each port you want
|
|
|
-to add. Adding `parport=0' to the kernel command-line will disable
|
|
|
-parport support entirely. Adding `parport=auto' to the kernel
|
|
|
-command-line will make parport use any IRQ lines or DMA channels that
|
|
|
+You can have many ``parport=...`` statements, one for each port you want
|
|
|
+to add. Adding ``parport=0`` to the kernel command-line will disable
|
|
|
+parport support entirely. Adding ``parport=auto`` to the kernel
|
|
|
+command-line will make ``parport`` use any IRQ lines or DMA channels that
|
|
|
it auto-detects.
|
|
|
|
|
|
|
|
|
Files in /proc
|
|
|
==============
|
|
|
|
|
|
-If you have configured the /proc filesystem into your kernel, you will
|
|
|
-see a new directory entry: /proc/sys/dev/parport. In there will be a
|
|
|
+If you have configured the ``/proc`` filesystem into your kernel, you will
|
|
|
+see a new directory entry: ``/proc/sys/dev/parport``. In there will be a
|
|
|
directory entry for each parallel port for which parport is
|
|
|
configured. In each of those directories are a collection of files
|
|
|
describing that parallel port.
|
|
|
|
|
|
-The /proc/sys/dev/parport directory tree looks like:
|
|
|
-
|
|
|
-parport
|
|
|
-|-- default
|
|
|
-| |-- spintime
|
|
|
-| `-- timeslice
|
|
|
-|-- parport0
|
|
|
-| |-- autoprobe
|
|
|
-| |-- autoprobe0
|
|
|
-| |-- autoprobe1
|
|
|
-| |-- autoprobe2
|
|
|
-| |-- autoprobe3
|
|
|
-| |-- devices
|
|
|
-| | |-- active
|
|
|
-| | `-- lp
|
|
|
-| | `-- timeslice
|
|
|
-| |-- base-addr
|
|
|
-| |-- irq
|
|
|
-| |-- dma
|
|
|
-| |-- modes
|
|
|
-| `-- spintime
|
|
|
-`-- parport1
|
|
|
- |-- autoprobe
|
|
|
- |-- autoprobe0
|
|
|
- |-- autoprobe1
|
|
|
- |-- autoprobe2
|
|
|
- |-- autoprobe3
|
|
|
- |-- devices
|
|
|
- | |-- active
|
|
|
- | `-- ppa
|
|
|
- | `-- timeslice
|
|
|
- |-- base-addr
|
|
|
- |-- irq
|
|
|
- |-- dma
|
|
|
- |-- modes
|
|
|
- `-- spintime
|
|
|
-
|
|
|
-
|
|
|
-File: Contents:
|
|
|
-
|
|
|
-devices/active A list of the device drivers using that port. A "+"
|
|
|
- will appear by the name of the device currently using
|
|
|
- the port (it might not appear against any). The
|
|
|
- string "none" means that there are no device drivers
|
|
|
- using that port.
|
|
|
-
|
|
|
-base-addr Parallel port's base address, or addresses if the port
|
|
|
- has more than one in which case they are separated
|
|
|
- with tabs. These values might not have any sensible
|
|
|
- meaning for some ports.
|
|
|
-
|
|
|
-irq Parallel port's IRQ, or -1 if none is being used.
|
|
|
-
|
|
|
-dma Parallel port's DMA channel, or -1 if none is being
|
|
|
- used.
|
|
|
-
|
|
|
-modes Parallel port's hardware modes, comma-separated,
|
|
|
- meaning:
|
|
|
-
|
|
|
- PCSPP PC-style SPP registers are available.
|
|
|
- TRISTATE Port is bidirectional.
|
|
|
- COMPAT Hardware acceleration for printers is
|
|
|
- available and will be used.
|
|
|
- EPP Hardware acceleration for EPP protocol
|
|
|
- is available and will be used.
|
|
|
- ECP Hardware acceleration for ECP protocol
|
|
|
- is available and will be used.
|
|
|
- DMA DMA is available and will be used.
|
|
|
-
|
|
|
- Note that the current implementation will only take
|
|
|
- advantage of COMPAT and ECP modes if it has an IRQ
|
|
|
- line to use.
|
|
|
-
|
|
|
-autoprobe Any IEEE-1284 device ID information that has been
|
|
|
- acquired from the (non-IEEE 1284.3) device.
|
|
|
-
|
|
|
-autoprobe[0-3] IEEE 1284 device ID information retrieved from
|
|
|
- daisy-chain devices that conform to IEEE 1284.3.
|
|
|
-
|
|
|
-spintime The number of microseconds to busy-loop while waiting
|
|
|
- for the peripheral to respond. You might find that
|
|
|
- adjusting this improves performance, depending on your
|
|
|
- peripherals. This is a port-wide setting, i.e. it
|
|
|
- applies to all devices on a particular port.
|
|
|
-
|
|
|
-timeslice The number of milliseconds that a device driver is
|
|
|
- allowed to keep a port claimed for. This is advisory,
|
|
|
- and driver can ignore it if it must.
|
|
|
-
|
|
|
-default/* The defaults for spintime and timeslice. When a new
|
|
|
- port is registered, it picks up the default spintime.
|
|
|
- When a new device is registered, it picks up the
|
|
|
- default timeslice.
|
|
|
+The ``/proc/sys/dev/parport`` directory tree looks like::
|
|
|
+
|
|
|
+ parport
|
|
|
+ |-- default
|
|
|
+ | |-- spintime
|
|
|
+ | `-- timeslice
|
|
|
+ |-- parport0
|
|
|
+ | |-- autoprobe
|
|
|
+ | |-- autoprobe0
|
|
|
+ | |-- autoprobe1
|
|
|
+ | |-- autoprobe2
|
|
|
+ | |-- autoprobe3
|
|
|
+ | |-- devices
|
|
|
+ | | |-- active
|
|
|
+ | | `-- lp
|
|
|
+ | | `-- timeslice
|
|
|
+ | |-- base-addr
|
|
|
+ | |-- irq
|
|
|
+ | |-- dma
|
|
|
+ | |-- modes
|
|
|
+ | `-- spintime
|
|
|
+ `-- parport1
|
|
|
+ |-- autoprobe
|
|
|
+ |-- autoprobe0
|
|
|
+ |-- autoprobe1
|
|
|
+ |-- autoprobe2
|
|
|
+ |-- autoprobe3
|
|
|
+ |-- devices
|
|
|
+ | |-- active
|
|
|
+ | `-- ppa
|
|
|
+ | `-- timeslice
|
|
|
+ |-- base-addr
|
|
|
+ |-- irq
|
|
|
+ |-- dma
|
|
|
+ |-- modes
|
|
|
+ `-- spintime
|
|
|
+
|
|
|
+======================= =======================================================
|
|
|
+File Contents
|
|
|
+======================= =======================================================
|
|
|
+``devices/active`` A list of the device drivers using that port. A "+"
|
|
|
+ will appear by the name of the device currently using
|
|
|
+ the port (it might not appear against any). The
|
|
|
+ string "none" means that there are no device drivers
|
|
|
+ using that port.
|
|
|
+
|
|
|
+``base-addr`` Parallel port's base address, or addresses if the port
|
|
|
+ has more than one in which case they are separated
|
|
|
+ with tabs. These values might not have any sensible
|
|
|
+ meaning for some ports.
|
|
|
+
|
|
|
+``irq`` Parallel port's IRQ, or -1 if none is being used.
|
|
|
+
|
|
|
+``dma`` Parallel port's DMA channel, or -1 if none is being
|
|
|
+ used.
|
|
|
+
|
|
|
+``modes`` Parallel port's hardware modes, comma-separated,
|
|
|
+ meaning:
|
|
|
+
|
|
|
+ =============== =======================================
|
|
|
+ PCSPP PC-style SPP registers are available.
|
|
|
+ TRISTATE Port is bidirectional.
|
|
|
+ COMPAT Hardware acceleration for printers is
|
|
|
+ available and will be used.
|
|
|
+ EPP Hardware acceleration for EPP protocol
|
|
|
+ is available and will be used.
|
|
|
+ ECP Hardware acceleration for ECP protocol
|
|
|
+ is available and will be used.
|
|
|
+ DMA DMA is available and will be used.
|
|
|
+ =============== =======================================
|
|
|
+
|
|
|
+ Note that the current implementation will only take
|
|
|
+ advantage of COMPAT and ECP modes if it has an IRQ
|
|
|
+ line to use.
|
|
|
+
|
|
|
+``autoprobe`` Any IEEE-1284 device ID information that has been
|
|
|
+ acquired from the (non-IEEE 1284.3) device.
|
|
|
+
|
|
|
+``autoprobe[0-3]`` IEEE 1284 device ID information retrieved from
|
|
|
+ daisy-chain devices that conform to IEEE 1284.3.
|
|
|
+
|
|
|
+``spintime`` The number of microseconds to busy-loop while waiting
|
|
|
+ for the peripheral to respond. You might find that
|
|
|
+ adjusting this improves performance, depending on your
|
|
|
+ peripherals. This is a port-wide setting, i.e. it
|
|
|
+ applies to all devices on a particular port.
|
|
|
+
|
|
|
+``timeslice`` The number of milliseconds that a device driver is
|
|
|
+ allowed to keep a port claimed for. This is advisory,
|
|
|
+ and driver can ignore it if it must.
|
|
|
+
|
|
|
+``default/*`` The defaults for spintime and timeslice. When a new
|
|
|
+ port is registered, it picks up the default spintime.
|
|
|
+ When a new device is registered, it picks up the
|
|
|
+ default timeslice.
|
|
|
+======================= =======================================================
|
|
|
|
|
|
Device drivers
|
|
|
==============
|
|
@@ -193,31 +199,31 @@ Once the parport code is initialised, you can attach device drivers to
|
|
|
specific ports. Normally this happens automatically; if the lp driver
|
|
|
is loaded it will create one lp device for each port found. You can
|
|
|
override this, though, by using parameters either when you load the lp
|
|
|
-driver:
|
|
|
+driver::
|
|
|
|
|
|
# insmod lp parport=0,2
|
|
|
|
|
|
-or on the LILO command line:
|
|
|
+or on the LILO command line::
|
|
|
|
|
|
lp=parport0 lp=parport2
|
|
|
|
|
|
-Both the above examples would inform lp that you want /dev/lp0 to be
|
|
|
-the first parallel port, and /dev/lp1 to be the _third_ parallel port,
|
|
|
+Both the above examples would inform lp that you want ``/dev/lp0`` to be
|
|
|
+the first parallel port, and /dev/lp1 to be the **third** parallel port,
|
|
|
with no lp device associated with the second port (parport1). Note
|
|
|
that this is different to the way older kernels worked; there used to
|
|
|
be a static association between the I/O port address and the device
|
|
|
-name, so /dev/lp0 was always the port at 0x3bc. This is no longer the
|
|
|
-case - if you only have one port, it will default to being /dev/lp0,
|
|
|
+name, so ``/dev/lp0`` was always the port at 0x3bc. This is no longer the
|
|
|
+case - if you only have one port, it will default to being ``/dev/lp0``,
|
|
|
regardless of base address.
|
|
|
|
|
|
Also:
|
|
|
|
|
|
* If you selected the IEEE 1284 support at compile time, you can say
|
|
|
- `lp=auto' on the kernel command line, and lp will create devices
|
|
|
+ ``lp=auto`` on the kernel command line, and lp will create devices
|
|
|
only for those ports that seem to have printers attached.
|
|
|
|
|
|
- * If you give PLIP the `timid' parameter, either with `plip=timid' on
|
|
|
- the command line, or with `insmod plip timid=1' when using modules,
|
|
|
+ * If you give PLIP the ``timid`` parameter, either with ``plip=timid`` on
|
|
|
+ the command line, or with ``insmod plip timid=1`` when using modules,
|
|
|
it will avoid any ports that seem to be in use by other devices.
|
|
|
|
|
|
* IRQ autoprobing works only for a few port types at the moment.
|
|
@@ -229,39 +235,41 @@ If you are having problems printing, please go through these steps to
|
|
|
try to narrow down where the problem area is.
|
|
|
|
|
|
When reporting problems with parport, really you need to give all of
|
|
|
-the messages that parport_pc spits out when it initialises. There are
|
|
|
+the messages that ``parport_pc`` spits out when it initialises. There are
|
|
|
several code paths:
|
|
|
|
|
|
-o polling
|
|
|
-o interrupt-driven, protocol in software
|
|
|
-o interrupt-driven, protocol in hardware using PIO
|
|
|
-o interrupt-driven, protocol in hardware using DMA
|
|
|
+- polling
|
|
|
+- interrupt-driven, protocol in software
|
|
|
+- interrupt-driven, protocol in hardware using PIO
|
|
|
+- interrupt-driven, protocol in hardware using DMA
|
|
|
|
|
|
-The kernel messages that parport_pc logs give an indication of which
|
|
|
+The kernel messages that ``parport_pc`` logs give an indication of which
|
|
|
code path is being used. (They could be a lot better actually..)
|
|
|
|
|
|
For normal printer protocol, having IEEE 1284 modes enabled or not
|
|
|
should not make a difference.
|
|
|
|
|
|
To turn off the 'protocol in hardware' code paths, disable
|
|
|
-CONFIG_PARPORT_PC_FIFO. Note that when they are enabled they are not
|
|
|
-necessarily _used_; it depends on whether the hardware is available,
|
|
|
+``CONFIG_PARPORT_PC_FIFO``. Note that when they are enabled they are not
|
|
|
+necessarily **used**; it depends on whether the hardware is available,
|
|
|
enabled by the BIOS, and detected by the driver.
|
|
|
|
|
|
-So, to start with, disable CONFIG_PARPORT_PC_FIFO, and load parport_pc
|
|
|
-with 'irq=none'. See if printing works then. It really should,
|
|
|
+So, to start with, disable ``CONFIG_PARPORT_PC_FIFO``, and load ``parport_pc``
|
|
|
+with ``irq=none``. See if printing works then. It really should,
|
|
|
because this is the simplest code path.
|
|
|
|
|
|
-If that works fine, try with 'io=0x378 irq=7' (adjust for your
|
|
|
+If that works fine, try with ``io=0x378 irq=7`` (adjust for your
|
|
|
hardware), to make it use interrupt-driven in-software protocol.
|
|
|
|
|
|
-If _that_ works fine, then one of the hardware modes isn't working
|
|
|
-right. Enable CONFIG_PARPORT_PC_FIFO (no, it isn't a module option,
|
|
|
+If **that** works fine, then one of the hardware modes isn't working
|
|
|
+right. Enable ``CONFIG_FIFO`` (no, it isn't a module option,
|
|
|
and yes, it should be), set the port to ECP mode in the BIOS and note
|
|
|
-the DMA channel, and try with:
|
|
|
+the DMA channel, and try with::
|
|
|
|
|
|
io=0x378 irq=7 dma=none (for PIO)
|
|
|
io=0x378 irq=7 dma=3 (for DMA)
|
|
|
---
|
|
|
+
|
|
|
+----------
|
|
|
+
|
|
|
philb@gnu.org
|
|
|
tim@cyberelk.net
|