patch-2.1.56 linux/Documentation/parport.txt

• Lines: 94
• Date: Tue Sep 16 12:22:45 1997
• Orig file: v2.1.55/linux/Documentation/parport.txt
• Orig date: Wed Apr 23 19:01:14 1997

diff -u --recursive --new-file v2.1.55/linux/Documentation/parport.txt linux/Documentation/parport.txt
@@ -6,12 +6,61 @@
 detection of your hardware.  This is particularly useful if you want
 to use IRQs, since in general these can't be autoprobed successfully.
 
+The parport code is split into two parts: generic (which deals with
+port-sharing) and architecture-dependent (which deals with actually
+using the port).
+
+Parport as modules
+==================
+
 If you load the parport code as a module, say
 
-	# insmod parport.o io=0x378,0x278 irq=7,5
+	# insmod parport.o
+
+to load the generic parport code.  You then must load the
+architecture-dependent code with (for example):
+
+	# insmod parport_pc.o io=0x378,0x278 irq=7,5
+
+to tell the parport code that you want two PC-style ports, one at
+0x378 using IRQ 7, and one at 0x278 using IRQ 5.  Currently, PC-style
+(parport_pc) and ARC onboard (parport_arc) parallel ports are
+supported.
+
+Kerneld
+-------
+
+If you use kerneld, you will find it useful to edit /etc/conf.modules.
+Here is an example of the lines that need to be added:
+
+	alias parport_lowlevel parport_pc
+	options parport_pc io=0x378,0x278 irq=7,5
+
+Kerneld, in conjunction with parport, will automatically load
+parport_pc whenever a parallel port device driver (such as lp) is
+loaded.
+
+Parport probe [optional]
+-------------
 
-to tell the parport code that you want two ports, one at 0x378 using
-IRQ 7, and one at 0x278 using IRQ 5. 
+Once the architecture-dependent part of the parport code is loaded
+into the kernel, you insert the parport_probe module with:
+
+	# insmod parport_probe.o
+
+This will perform an IEEE1284 probe of any attached devices and log a
+message similar to:
+
+	parport0: Printer, BJC-210 (Canon)
+
+Additionally, if you use kerneld, you can add to /etc/conf.modules the
+following lines, to have the probe happen automatically:
+
+	post-install parport modprobe parport_probe
+	pre-remove parport modprobe -r parport_probe
+
+Parport, but not as modules
+===========================
 
 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
@@ -20,12 +69,15 @@
 	parport=0x378,7 parport=0x278,5
 
 You can have many `parport=...' statements, one for each port you want
-to add.  Adding `parport=0' or just `parport=' to the command-line
-will disable parport support entirely.
+to add.  Adding `parport=0' to the kernel command-line will disable
+parport support entirely.
+
+Device drivers
+==============
 
 Once the parport code is initialised, you can attach device drivers to
-ports.  Normally this happens automatically; if the lp driver is
-loaded it will create one lp device for each port found.  You can
+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:
 
@@ -57,3 +109,8 @@
  * If your BIOS allows you to engage "ECP mode", you may find that
    your port's IRQ can be autoprobed, without having to specify any 
    parameters.
+
+
+--
+Philip.Blundell@pobox.com
+tim@cyberelk.demon.co.uk