Documentation/admin-guide/parport.rst

4 The ``parport`` code provides parallel-port support under Linux.  This
10 to use IRQs, since in general these can't be autoprobed successfully.
13 parallel port and a sound card or network card.
16 port-sharing) and architecture-dependent (which deals with actually
28 architecture-dependent code with (for example)::
32 to tell the ``parport`` code that you want three PC-style ports, one at
34 auto-detected IRQ.  Currently, PC-style (``parport_pc``), Sun ``bpp``,
37 PCI parallel I/O card support comes from ``parport_pc``.  Base I/O
43 --------
46 configuration file in /etc/modprobe.d/ directory::
52 whenever a parallel port device driver (such as ``lp``) is loaded.
54 Note that these are example lines only!  You shouldn't in general need
55 to specify any options to ``parport_pc`` in order to be able to use a
56 parallel port.
60 ------------------------
62 In 2.2 kernels there was a module called ``parport_probe``, which was used
64 enhanced and now lives with the IEEE 1284 support.  When a parallel
68 	parport0: Printer, BJC-210 (Canon)
70 The probe information is available from files in ``/proc/sys/dev/parport/``.
83 to add.  Adding ``parport=0`` to the kernel command-line will disable
85 command-line will make ``parport`` use any IRQ lines or DMA channels that
86 it auto-detects.
89 Files in /proc
93 see a new directory entry: ``/proc/sys/dev/parport``.  In there will be a
94 directory entry for each parallel port for which parport is
95 configured.  In each of those directories are a collection of files
96 describing that parallel port.
101 	|-- default
102 	|   |-- spintime
103 	|   `-- timeslice
104 	|-- parport0
105 	|   |-- autoprobe
106 	|   |-- autoprobe0
107 	|   |-- autoprobe1
108 	|   |-- autoprobe2
109 	|   |-- autoprobe3
110 	|   |-- devices
111 	|   |   |-- active
112 	|   |   `-- lp
113 	|   |       `-- timeslice
114 	|   |-- base-addr
115 	|   |-- irq
116 	|   |-- dma
117 	|   |-- modes
118 	|   `-- spintime
119 	`-- parport1
120 	|-- autoprobe
121 	|-- autoprobe0
122 	|-- autoprobe1
123 	|-- autoprobe2
124 	|-- autoprobe3
125 	|-- devices
126 	|   |-- active
127 	|   `-- ppa
128 	|       `-- timeslice
129 	|-- base-addr
130 	|-- irq
131 	|-- dma
132 	|-- modes
133 	`-- spintime
146 ``base-addr``		Parallel port's base address, or addresses if the port
147 			has more than one in which case they are separated
151 ``irq``			Parallel port's IRQ, or -1 if none is being used.
153 ``dma``			Parallel port's DMA channel, or -1 if none is being
156 ``modes``		Parallel port's hardware modes, comma-separated,
159 			- PCSPP
160 				PC-style SPP registers are available.
162 			- TRISTATE
165 			- COMPAT
169 			- EPP
173 			- ECP
177 			- DMA
184 ``autoprobe``		Any IEEE-1284 device ID information that has been
185 			acquired from the (non-IEEE 1284.3) device.
187 ``autoprobe[0-3]``	IEEE 1284 device ID information retrieved from
188 			daisy-chain devices that conform to IEEE 1284.3.
190 ``spintime``		The number of microseconds to busy-loop while waiting
193 			peripherals.  This is a port-wide setting, i.e. it
222 the first parallel port, and /dev/lp1 to be the **third** parallel port,
227 case - if you only have one port, it will default to being ``/dev/lp0``,
238    it will avoid any ports that seem to be in use by other devices.
252 - polling
253 - interrupt-driven, protocol in software
254 - interrupt-driven, protocol in hardware using PIO
255 - interrupt-driven, protocol in hardware using DMA
263 To turn off the 'protocol in hardware' code paths, disable
273 hardware), to make it use interrupt-driven in-software protocol.
277 and yes, it should be), set the port to ECP mode in the BIOS and note
283 ----------