About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / paride.txt




Custom Search

Based on kernel version 2.6.27. Page generated on 2008-10-13 09:53 EST.

1	
2			Linux and parallel port IDE devices
3	
4	PARIDE v1.03   (c) 1997-8  Grant Guenther <grant[AT]torque[DOT]net>
5	
6	1. Introduction
7	
8	Owing to the simplicity and near universality of the parallel port interface
9	to personal computers, many external devices such as portable hard-disk,
10	CD-ROM, LS-120 and tape drives use the parallel port to connect to their
11	host computer.  While some devices (notably scanners) use ad-hoc methods
12	to pass commands and data through the parallel port interface, most 
13	external devices are actually identical to an internal model, but with
14	a parallel-port adapter chip added in.  Some of the original parallel port
15	adapters were little more than mechanisms for multiplexing a SCSI bus.
16	(The Iomega PPA-3 adapter used in the ZIP drives is an example of this
17	approach).  Most current designs, however, take a different approach.
18	The adapter chip reproduces a small ISA or IDE bus in the external device
19	and the communication protocol provides operations for reading and writing
20	device registers, as well as data block transfer functions.  Sometimes,
21	the device being addressed via the parallel cable is a standard SCSI
22	controller like an NCR 5380.  The "ditto" family of external tape
23	drives use the ISA replicator to interface a floppy disk controller,
24	which is then connected to a floppy-tape mechanism.  The vast majority
25	of external parallel port devices, however, are now based on standard
26	IDE type devices, which require no intermediate controller.  If one
27	were to open up a parallel port CD-ROM drive, for instance, one would
28	find a standard ATAPI CD-ROM drive, a power supply, and a single adapter
29	that interconnected a standard PC parallel port cable and a standard
30	IDE cable.  It is usually possible to exchange the CD-ROM device with
31	any other device using the IDE interface. 
32	
33	The document describes the support in Linux for parallel port IDE
34	devices.  It does not cover parallel port SCSI devices, "ditto" tape
35	drives or scanners.  Many different devices are supported by the 
36	parallel port IDE subsystem, including:
37	
38		MicroSolutions backpack CD-ROM
39		MicroSolutions backpack PD/CD
40		MicroSolutions backpack hard-drives
41		MicroSolutions backpack 8000t tape drive
42		SyQuest EZ-135, EZ-230 & SparQ drives
43		Avatar Shark
44		Imation Superdisk LS-120
45		Maxell Superdisk LS-120
46		FreeCom Power CD 
47		Hewlett-Packard 5GB and 8GB tape drives
48		Hewlett-Packard 7100 and 7200 CD-RW drives
49	
50	as well as most of the clone and no-name products on the market.
51	
52	To support such a wide range of devices, PARIDE, the parallel port IDE
53	subsystem, is actually structured in three parts.   There is a base
54	paride module which provides a registry and some common methods for
55	accessing the parallel ports.  The second component is a set of 
56	high-level drivers for each of the different types of supported devices: 
57	
58		pd	IDE disk
59		pcd	ATAPI CD-ROM
60		pf	ATAPI disk
61		pt	ATAPI tape
62		pg	ATAPI generic
63	
64	(Currently, the pg driver is only used with CD-R drives).
65	
66	The high-level drivers function according to the relevant standards.
67	The third component of PARIDE is a set of low-level protocol drivers
68	for each of the parallel port IDE adapter chips.  Thanks to the interest
69	and encouragement of Linux users from many parts of the world, 
70	support is available for almost all known adapter protocols:
71	
72	        aten    ATEN EH-100                            (HK)
73	        bpck    Microsolutions backpack                (US)
74	        comm    DataStor (old-type) "commuter" adapter (TW)
75	        dstr    DataStor EP-2000                       (TW)
76	        epat    Shuttle EPAT                           (UK)
77	        epia    Shuttle EPIA                           (UK)
78		fit2    FIT TD-2000			       (US)
79		fit3    FIT TD-3000			       (US)
80		friq    Freecom IQ cable                       (DE)
81	        frpw    Freecom Power                          (DE)
82	        kbic    KingByte KBIC-951A and KBIC-971A       (TW)
83		ktti    KT Technology PHd adapter              (SG)
84	        on20    OnSpec 90c20                           (US)
85	        on26    OnSpec 90c26                           (US)
86	
87	
88	2. Using the PARIDE subsystem
89	
90	While configuring the Linux kernel, you may choose either to build
91	the PARIDE drivers into your kernel, or to build them as modules.
92	
93	In either case, you will need to select "Parallel port IDE device support"
94	as well as at least one of the high-level drivers and at least one
95	of the parallel port communication protocols.  If you do not know
96	what kind of parallel port adapter is used in your drive, you could
97	begin by checking the file names and any text files on your DOS 
98	installation floppy.  Alternatively, you can look at the markings on
99	the adapter chip itself.  That's usually sufficient to identify the
100	correct device.  
101	
102	You can actually select all the protocol modules, and allow the PARIDE
103	subsystem to try them all for you.
104	
105	For the "brand-name" products listed above, here are the protocol
106	and high-level drivers that you would use:
107	
108		Manufacturer		Model		Driver	Protocol
109		
110		MicroSolutions		CD-ROM		pcd	bpck
111		MicroSolutions		PD drive	pf	bpck
112		MicroSolutions		hard-drive	pd	bpck
113		MicroSolutions          8000t tape      pt      bpck
114		SyQuest			EZ, SparQ	pd	epat
115		Imation			Superdisk	pf	epat
116		Maxell                  Superdisk       pf      friq
117		Avatar			Shark		pd	epat
118		FreeCom			CD-ROM		pcd	frpw
119		Hewlett-Packard		5GB Tape	pt	epat
120		Hewlett-Packard		7200e (CD)	pcd	epat
121		Hewlett-Packard		7200e (CD-R)	pg	epat
122	
123	2.1  Configuring built-in drivers
124	
125	We recommend that you get to know how the drivers work and how to
126	configure them as loadable modules, before attempting to compile a
127	kernel with the drivers built-in.
128	
129	If you built all of your PARIDE support directly into your kernel,
130	and you have just a single parallel port IDE device, your kernel should
131	locate it automatically for you.  If you have more than one device,
132	you may need to give some command line options to your bootloader
133	(eg: LILO), how to do that is beyond the scope of this document.
134	
135	The high-level drivers accept a number of command line parameters, all
136	of which are documented in the source files in linux/drivers/block/paride.
137	By default, each driver will automatically try all parallel ports it
138	can find, and all protocol types that have been installed, until it finds
139	a parallel port IDE adapter.  Once it finds one, the probe stops.  So,
140	if you have more than one device, you will need to tell the drivers
141	how to identify them.  This requires specifying the port address, the
142	protocol identification number and, for some devices, the drive's
143	chain ID.  While your system is booting, a number of messages are
144	displayed on the console.  Like all such messages, they can be
145	reviewed with the 'dmesg' command.  Among those messages will be
146	some lines like:
147	
148		paride: bpck registered as protocol 0
149		paride: epat registered as protocol 1
150	
151	The numbers will always be the same until you build a new kernel with
152	different protocol selections.  You should note these numbers as you
153	will need them to identify the devices.
154	
155	If you happen to be using a MicroSolutions backpack device, you will
156	also need to know the unit ID number for each drive.  This is usually
157	the last two digits of the drive's serial number (but read MicroSolutions'
158	documentation about this).
159	
160	As an example, let's assume that you have a MicroSolutions PD/CD drive
161	with unit ID number 36 connected to the parallel port at 0x378, a SyQuest 
162	EZ-135 connected to the chained port on the PD/CD drive and also an 
163	Imation Superdisk connected to port 0x278.  You could give the following 
164	options on your boot command:
165	
166		pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36
167	
168	In the last option, pf.drive1 configures device /dev/pf1, the 0x378
169	is the parallel port base address, the 0 is the protocol registration
170	number and 36 is the chain ID.
171	
172	Please note:  while PARIDE will work both with and without the 
173	PARPORT parallel port sharing system that is included by the
174	"Parallel port support" option, PARPORT must be included and enabled
175	if you want to use chains of devices on the same parallel port.
176	
177	2.2  Loading and configuring PARIDE as modules
178	
179	It is much faster and simpler to get to understand the PARIDE drivers
180	if you use them as loadable kernel modules.   
181	
182	Note 1:  using these drivers with the "kerneld" automatic module loading
183	system is not recommended for beginners, and is not documented here.  
184	
185	Note 2:  if you build PARPORT support as a loadable module, PARIDE must
186	also be built as loadable modules, and PARPORT must be loaded before the
187	PARIDE modules.
188	
189	To use PARIDE, you must begin by 
190	
191		insmod paride
192	
193	this loads a base module which provides a registry for the protocols,
194	among other tasks.
195	
196	Then, load as many of the protocol modules as you think you might need.
197	As you load each module, it will register the protocols that it supports,
198	and print a log message to your kernel log file and your console. For 
199	example:
200	
201		# insmod epat
202		paride: epat registered as protocol 0
203		# insmod kbic
204		paride: k951 registered as protocol 1
205	        paride: k971 registered as protocol 2
206	
207	Finally, you can load high-level drivers for each kind of device that
208	you have connected.  By default, each driver will autoprobe for a single 
209	device, but you can support up to four similar devices by giving their
210	individual co-ordinates when you load the driver.
211	
212	For example, if you had two no-name CD-ROM drives both using the
213	KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc
214	you could give the following command:
215	
216		# insmod pcd drive0=0x378,1 drive1=0x3bc,1
217	
218	For most adapters, giving a port address and protocol number is sufficient,
219	but check the source files in linux/drivers/block/paride for more 
220	information.  (Hopefully someone will write some man pages one day !).
221	
222	As another example, here's what happens when PARPORT is installed, and
223	a SyQuest EZ-135 is attached to port 0x378:
224	
225		# insmod paride
226		paride: version 1.0 installed
227		# insmod epat
228		paride: epat registered as protocol 0
229		# insmod pd
230		pd: pd version 1.0, major 45, cluster 64, nice 0
231		pda: Sharing parport1 at 0x378
232		pda: epat 1.0, Shuttle EPAT chip c3 at 0x378, mode 5 (EPP-32), delay 1
233		pda: SyQuest EZ135A, 262144 blocks [128M], (512/16/32), removable media
234		 pda: pda1
235	
236	Note that the last line is the output from the generic partition table
237	scanner - in this case it reports that it has found a disk with one partition.
238	
239	2.3  Using a PARIDE device
240	
241	Once the drivers have been loaded, you can access PARIDE devices in the
242	same way as their traditional counterparts.  You will probably need to
243	create the device "special files".  Here is a simple script that you can
244	cut to a file and execute:
245	
246	#!/bin/bash
247	#
248	# mkd -- a script to create the device special files for the PARIDE subsystem
249	#
250	function mkdev {
251	  mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1
252	}
253	#
254	function pd {
255	  D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) )
256	  mkdev pd$D b 45 $[ $1 * 16 ]
257	  for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
258	  do mkdev pd$D$P b 45 $[ $1 * 16 + $P ]
259	  done
260	}
261	#
262	cd /dev
263	#
264	for u in 0 1 2 3 ; do pd $u ; done
265	for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done 
266	for u in 0 1 2 3 ; do mkdev pf$u  b 47 $u ; done 
267	for u in 0 1 2 3 ; do mkdev pt$u  c 96 $u ; done 
268	for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done 
269	for u in 0 1 2 3 ; do mkdev pg$u  c 97 $u ; done 
270	#
271	# end of mkd
272	
273	With the device files and drivers in place, you can access PARIDE devices
274	like any other Linux device.   For example, to mount a CD-ROM in pcd0, use:
275	
276		mount /dev/pcd0 /cdrom
277	
278	If you have a fresh Avatar Shark cartridge, and the drive is pda, you
279	might do something like:
280	
281		fdisk /dev/pda		-- make a new partition table with
282					   partition 1 of type 83
283	
284		mke2fs /dev/pda1	-- to build the file system
285	
286		mkdir /shark		-- make a place to mount the disk
287	
288		mount /dev/pda1 /shark
289	
290	Devices like the Imation superdisk work in the same way, except that
291	they do not have a partition table.  For example to make a 120MB
292	floppy that you could share with a DOS system:
293	
294		mkdosfs /dev/pf0
295		mount /dev/pf0 /mnt
296	
297	
298	2.4  The pf driver
299	
300	The pf driver is intended for use with parallel port ATAPI disk
301	devices.  The most common devices in this category are PD drives
302	and LS-120 drives.  Traditionally, media for these devices are not
303	partitioned.  Consequently, the pf driver does not support partitioned
304	media.  This may be changed in a future version of the driver. 
305	
306	2.5  Using the pt driver
307	
308	The pt driver for parallel port ATAPI tape drives is a minimal driver.
309	It does not yet support many of the standard tape ioctl operations. 
310	For best performance, a block size of 32KB should be used.  You will
311	probably want to set the parallel port delay to 0, if you can.
312	
313	2.6  Using the pg driver
314	
315	The pg driver can be used in conjunction with the cdrecord program
316	to create CD-ROMs.  Please get cdrecord version 1.6.1 or later
317	from ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ .  To record CD-R media 
318	your parallel port should ideally be set to EPP mode, and the "port delay" 
319	should be set to 0.  With those settings it is possible to record at 2x 
320	speed without any buffer underruns.  If you cannot get the driver to work
321	in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only.
322	
323	
324	3. Troubleshooting
325	
326	3.1  Use EPP mode if you can
327	
328	The most common problems that people report with the PARIDE drivers
329	concern the parallel port CMOS settings.  At this time, none of the
330	PARIDE protocol modules support ECP mode, or any ECP combination modes.
331	If you are able to do so, please set your parallel port into EPP mode
332	using your CMOS setup procedure.
333	
334	3.2  Check the port delay
335	
336	Some parallel ports cannot reliably transfer data at full speed.  To
337	offset the errors, the PARIDE protocol modules introduce a "port
338	delay" between each access to the i/o ports.  Each protocol sets
339	a default value for this delay.  In most cases, the user can override
340	the default and set it to 0 - resulting in somewhat higher transfer
341	rates.  In some rare cases (especially with older 486 systems) the
342	default delays are not long enough.  if you experience corrupt data
343	transfers, or unexpected failures, you may wish to increase the
344	port delay.   The delay can be programmed using the "driveN" parameters
345	to each of the high-level drivers.  Please see the notes above, or
346	read the comments at the beginning of the driver source files in
347	linux/drivers/block/paride.
348	
349	3.3  Some drives need a printer reset
350	
351	There appear to be a number of "noname" external drives on the market
352	that do not always power up correctly.  We have noticed this with some
353	drives based on OnSpec and older Freecom adapters.  In these rare cases,
354	the adapter can often be reinitialised by issuing a "printer reset" on
355	the parallel port.  As the reset operation is potentially disruptive in 
356	multiple device environments, the PARIDE drivers will not do it 
357	automatically.  You can however, force a printer reset by doing:
358	
359		insmod lp reset=1
360		rmmod lp
361	
362	If you have one of these marginal cases, you should probably build
363	your paride drivers as modules, and arrange to do the printer reset
364	before loading the PARIDE drivers. 
365	
366	3.4  Use the verbose option and dmesg if you need help
367	
368	While a lot of testing has gone into these drivers to make them work
369	as smoothly as possible, problems will arise.  If you do have problems,
370	please check all the obvious things first:  does the drive work in
371	DOS with the manufacturer's drivers ?  If that doesn't yield any useful
372	clues, then please make sure that only one drive is hooked to your system,
373	and that either (a) PARPORT is enabled or (b) no other device driver
374	is using your parallel port (check in /proc/ioports).  Then, load the
375	appropriate drivers (you can load several protocol modules if you want)
376	as in:
377	
378		# insmod paride
379		# insmod epat
380		# insmod bpck
381		# insmod kbic
382		...
383		# insmod pd verbose=1
384	
385	(using the correct driver for the type of device you have, of course).
386	The verbose=1 parameter will cause the drivers to log a trace of their
387	activity as they attempt to locate your drive.
388	
389	Use 'dmesg' to capture a log of all the PARIDE messages (any messages
390	beginning with paride:, a protocol module's name or a driver's name) and
391	include that with your bug report.  You can submit a bug report in one
392	of two ways.  Either send it directly to the author of the PARIDE suite,
393	by e-mail to grant[AT]torque[DOT]net, or join the linux-parport mailing list
394	and post your report there.
395	
396	3.5  For more information or help
397	
398	You can join the linux-parport mailing list by sending a mail message
399	to 
400			linux-parport-request[AT]torque[DOT]net
401	
402	with the single word 
403	
404			subscribe
405	
406	in the body of the mail message (not in the subject line).   Please be
407	sure that your mail program is correctly set up when you do this,  as
408	the list manager is a robot that will subscribe you using the reply
409	address in your mail headers.  REMOVE any anti-spam gimmicks you may
410	have in your mail headers, when sending mail to the list server.
411	
412	You might also find some useful information on the linux-parport
413	web pages (although they are not always up to date) at
414	
415		http://www.torque.net/parport/
416	
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.