Documentation/admin-guide/parport.rst

4 The ``parport`` code provides parallel-port support under Linux.  This
5 includes the ability to share one port between multiple device
12 because there are a lot of people using the same IRQ for their
16 port-sharing) and architecture-dependent (which deals with actually
28 architecture-dependent code with (for example)::
30 	# insmod parport_pc io=0x3bc,0x378,0x278 irq=none,7,auto
32 to tell the ``parport`` code that you want three PC-style ports, one at
33 0x3bc with no IRQ, one at 0x378 using IRQ 7, and one at 0x278 with an
34 auto-detected IRQ.  Currently, PC-style (``parport_pc``), Sun ``bpp``,
43 --------
49 	options parport_pc io=0x378,0x278 irq=7,auto
51 modprobe will load ``parport_pc`` (with the options ``io=0x378,0x278 irq=7,auto``)
52 whenever a parallel port device driver (such as ``lp``) is loaded.
60 ------------------------
63 for collecting IEEE 1284 device ID information.  This has now been
68 	parport0: Printer, BJC-210 (Canon)
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.
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
140 ``devices/active``	A list of the device drivers using that port.  A "+"
141 			will appear by the name of the device currently using
143 			string "none" means that there are no device drivers
146 ``base-addr``		Parallel port's base address, or addresses if the port
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
181 			advantage of COMPAT and ECP modes if it has an IRQ
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
196 ``timeslice``		The number of milliseconds that a device driver is
202 			When a new device is registered, it picks up the
206 Device drivers
209 Once the parport code is initialised, you can attach device drivers to
211 is loaded it will create one lp device for each port found.  You can
223 with no lp device associated with the second port (parport1).  Note
225 be a static association between the I/O port address and the device
227 case - if you only have one port, it will default to being ``/dev/lp0``,
240  * IRQ autoprobing works only for a few port types at the moment.
252 - polling
253 - interrupt-driven, protocol in software
254 - interrupt-driven, protocol in hardware using PIO
255 - interrupt-driven, protocol in hardware using DMA
269 with ``irq=none``. See if printing works then.  It really should,
272 If that works fine, try with ``io=0x378 irq=7`` (adjust for your
273 hardware), to make it use interrupt-driven in-software protocol.
280     io=0x378 irq=7 dma=none (for PIO)
281     io=0x378 irq=7 dma=3 (for DMA)
283 ----------