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Based on kernel version 3.13. Page generated on 2014-01-20 22:04 EST.

1	
2	      specialix.txt  -- specialix IO8+ multiport serial driver readme.
3	
4	
5	
6	      Copyright (C) 1997  Roger Wolff (R.E.Wolff@BitWizard.nl)
7	
8	      Specialix pays for the development and support of this driver.
9	      Please DO contact io8-linux@specialix.co.uk if you require
10	      support.
11	
12	      This driver was developed in the BitWizard linux device
13	      driver service. If you require a linux device driver for your
14	      product, please contact devices@BitWizard.nl for a quote.
15	
16	      This code is firmly based on the riscom/8 serial driver,
17	      written by Dmitry Gorodchanin. The specialix IO8+ card
18	      programming information was obtained from the CL-CD1865 Data
19	      Book, and Specialix document number 6200059: IO8+ Hardware
20	      Functional Specification, augmented by document number 6200088:
21	      Merak Hardware Functional Specification. (IO8+/PCI is also 
22	      called Merak)
23	
24	
25	      This program is free software; you can redistribute it and/or
26	      modify it under the terms of the GNU General Public License as
27	      published by the Free Software Foundation; either version 2 of
28	      the License, or (at your option) any later version.
29	
30	      This program is distributed in the hope that it will be
31	      useful, but WITHOUT ANY WARRANTY; without even the implied
32	      warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
33	      PURPOSE.  See the GNU General Public License for more details.
34	
35	      You should have received a copy of the GNU General Public
36	      License along with this program; if not, write to the Free
37	      Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
38	      USA.
39	
40	
41	Intro
42	=====
43	
44	 
45	This file contains some random information, that I like to have online
46	instead of in a manual that can get lost. Ever misplace your Linux
47	kernel sources?  And the manual of one of the boards in your computer?
48	
49	
50	Addresses and interrupts
51	========================
52	
53	Address dip switch settings:
54	The dip switch sets bits 2-9 of the IO address. 
55	
56	       9 8 7 6 5 4 3 2 
57	     +-----------------+
58	   0 | X   X X X X X X |
59	     |                 |    =   IoBase = 0x100 
60	   1 |   X             |
61	     +-----------------+          ------ RS232 connectors ---->
62	         
63	         |    |    |
64	       edge connector
65	         |    |    |
66	         V    V    V
67	
68	Base address 0x100 caused a conflict in one of my computers once.  I
69	haven't the foggiest why. My Specialix card is now at 0x180.  My
70	other computer runs just fine with the Specialix card at 0x100....
71	The card occupies 4 addresses, but actually only two are really used.
72	
73	The PCI version doesn't have any dip switches. The BIOS assigns
74	an IO address. 
75	
76	The driver now still autoprobes at 0x100, 0x180, 0x250 and 0x260.  If
77	that causes trouble for you, please report that. I'll remove
78	autoprobing then.
79	
80	The driver will tell the card what IRQ to use, so you don't have to
81	change any jumpers to change the IRQ. Just use a command line
82	argument (irq=xx) to the insmod program to set the interrupt.
83	
84	The BIOS assigns the IRQ on the PCI version. You have no say in what
85	IRQ to use in that case. 
86	
87	If your specialix cards are not at the default locations, you can use
88	the kernel command line argument "specialix=io0,irq0,io1,irq1...".
89	Here "io0" is the io address for the first card, and "irq0" is the
90	irq line that the first card should use. And so on. 
91	
92	Examples. 
93	
94	You use the driver as a module and have three cards at 0x100, 0x250
95	and 0x180. And some way or another you want them detected in that
96	order. Moreover irq 12 is taken (e.g. by your PS/2 mouse).
97	
98	  insmod specialix.o iobase=0x100,0x250,0x180 irq=9,11,15
99	
100	The same three cards, but now in the kernel would require you to
101	add 
102	
103	   specialix=0x100,9,0x250,11,0x180,15
104	
105	to the command line. This would become 
106	
107	   append="specialix=0x100,9,0x250,11,0x180,15" 
108	
109	in your /etc/lilo.conf file if you use lilo. 
110	
111	The Specialix driver is slightly odd: It allows you to have the second
112	or third card detected without having a first card. This has
113	advantages and disadvantages. A slot that isn't filled by an ISA card,
114	might be filled if a PCI card is detected. Thus if you have an ISA
115	card at 0x250 and a PCI card, you would get:
116	
117	sx0: specialix IO8+ Board at 0x100 not found.
118	sx1: specialix IO8+ Board at 0x180 not found.
119	sx2: specialix IO8+ board detected at 0x250, IRQ 12, CD1865 Rev. B.
120	sx3: specialix IO8+ Board at 0x260 not found.
121	sx0: specialix IO8+ board detected at 0xd800, IRQ 9, CD1865 Rev. B.
122	
123	This would happen if you don't give any probe hints to the driver. 
124	If you would specify:
125	
126	   specialix=0x250,11
127	
128	you'd get the following messages:
129	
130	sx0: specialix IO8+ board detected at 0x250, IRQ 11, CD1865 Rev. B.
131	sx1: specialix IO8+ board detected at 0xd800, IRQ 9, CD1865 Rev. B.
132	
133	ISA probing is aborted after the IO address you gave is exhausted, and
134	the PCI card is now detected as the second card. The ISA card is now
135	also forced to IRQ11....
136	
137	
138	Baud rates
139	==========
140	
141	The rev 1.2 and below boards use a CL-CD1864. These chips can only 
142	do 64kbit. The rev 1.3 and newer boards use a CL-CD1865. These chips
143	are officially capable of 115k2.
144	
145	The Specialix card uses a 25MHz crystal (in times two mode, which in
146	fact is a divided by two mode). This is not enough to reach the rated
147	115k2 on all ports at the same time. With this clock rate you can only
148	do 37% of this rate. This means that at 115k2 on all ports you are
149	going to lose characters (The chip cannot handle that many incoming
150	bits at this clock rate.) (Yes, you read that correctly: there is a
151	limit to the number of -=bits=- per second that the chip can handle.)
152	
153	If you near the "limit" you will first start to see a graceful
154	degradation in that the chip cannot keep the transmitter busy at all
155	times. However with a central clock this slow, you can also get it to
156	miss incoming characters. The driver will print a warning message when
157	you are outside the official specs. The messages usually show up in
158	the file /var/log/messages .
159	
160	The specialix card cannot reliably do 115k2. If you use it, you have
161	to do "extensive testing" (*) to verify if it actually works.
162	
163	When "mgetty" communicates with my modem at 115k2 it reports:
164	got: +++[0d]ATQ0V1H0[0d][0d][8a]O[cb][0d][8a]
165	                            ^^^^ ^^^^    ^^^^ 
166	
167	The three characters that have the "^^^" under them have suffered a
168	bit error in the highest bit. In conclusion: I've tested it, and found
169	that it simply DOESN'T work for me. I also suspect that this is also
170	caused by the baud rate being just a little bit out of tune. 
171	
172	I upgraded the crystal to 66Mhz on one of my Specialix cards. Works
173	great! Contact me for details. (Voids warranty, requires a steady hand
174	and more such restrictions....)
175	
176	
177	(*) Cirrus logic CD1864 databook, page 40.
178	
179	
180	Cables for the Specialix IO8+
181	=============================
182	
183	The pinout of the connectors on the IO8+ is:
184	
185	     pin    short    direction    long name
186	            name
187	    Pin 1   DCD      input        Data Carrier Detect
188	    Pin 2   RXD      input        Receive
189	    Pin 3   DTR/RTS  output       Data Terminal Ready/Ready To Send
190	    Pin 4   GND      -            Ground
191	    Pin 5   TXD      output       Transmit
192	    Pin 6   CTS      input        Clear To Send
193	        
194	    
195	             -- 6  5  4  3  2  1 --
196	             |                    |
197	             |                    |
198	             |                    |
199	             |                    |
200	             +-----          -----+
201	                  |__________|
202	                      clip
203	    
204	    Front view of an RJ12 connector. Cable moves "into" the paper.
205	    (the plug is ready to plug into your mouth this way...)
206	
207	    
208	    NULL cable. I don't know who is going to use these except for
209	    testing purposes, but I tested the cards with this cable. (It 
210	    took quite a while to figure out, so I'm not going to delete
211	    it. So there! :-)
212	    
213	    
214	    This end goes               This end needs
215	    straight into the           some twists in
216	    RJ12 plug.                  the wiring.
217	       IO8+ RJ12                   IO8+ RJ12
218	        1  DCD       white          -
219	        -             -             1 DCD
220	        2  RXD       black          5 TXD
221	        3  DTR/RTS   red            6 CTS
222	        4  GND       green          4 GND
223	        5  TXD       yellow         2 RXD
224	        6  CTS       blue           3 DTR/RTS
225	    
226	
227	    Same NULL cable, but now sorted on the second column.
228	 
229	        1  DCD       white          -
230	        -             -             1 DCD
231	        5  TXD       yellow         2 RXD
232	        6  CTS       blue           3 DTR/RTS
233	        4  GND       green          4 GND
234	        2  RXD       black          5 TXD
235	        3  DTR/RTS   red            6 CTS
236	    
237	    
238	    
239	    This is a modem cable usable for hardware handshaking:
240	        RJ12                        DB25           DB9
241	        1   DCD      white          8 DCD          1 DCD
242	        2   RXD      black          3 RXD          2 RXD
243	        3   DTR/RTS  red            4 RTS          7 RTS
244	        4   GND      green          7 GND          5 GND
245	        5   TXD      yellow         2 TXD          3 TXD
246	        6   CTS      blue           5 CTS          8 CTS
247	                            +----   6 DSR          6 DSR
248	                            +----  20 DTR          4 DTR
249	
250	    This is a modem cable usable for software handshaking:
251	    It allows you to reset the modem using the DTR ioctls.
252	    I (REW) have never tested this, "but xxxxxxxxxxxxx
253	    says that it works." If you test this, please
254	    tell me and I'll fill in your name on the xxx's.
255	
256	        RJ12                        DB25           DB9
257	        1   DCD      white          8 DCD          1 DCD
258	        2   RXD      black          3 RXD          2 RXD
259	        3   DTR/RTS  red           20 DTR          4 DTR
260	        4   GND      green          7 GND          5 GND
261	        5   TXD      yellow         2 TXD          3 TXD
262	        6   CTS      blue           5 CTS          8 CTS
263	                            +----   6 DSR          6 DSR
264	                            +----   4 RTS          7 RTS
265	
266	   I bought a 6 wire flat cable. It was colored as indicated.
267	   Check that yours is the same before you trust me on this.
268	   
269	 
270	Hardware handshaking issues.
271	============================
272	
273	The driver can be told to operate in two different ways. The default
274	behaviour is specialix.sx_rtscts = 0 where the pin behaves as DTR when
275	hardware handshaking is off. It behaves as the RTS hardware
276	handshaking signal when hardware handshaking is selected.
277	
278	When you use this, you have to use the appropriate cable. The
279	cable will either be compatible with hardware handshaking or with
280	software handshaking. So switching on the fly is not really an
281	option.
282	
283	I actually prefer to use the "specialix.sx_rtscts=1" option.
284	This makes the DTR/RTS pin always an RTS pin, and ioctls to
285	change DTR are always ignored. I have a cable that is configured
286	for this. 
287	
288	
289	Ports and devices
290	=================
291	
292	Port 0 is the one furthest from the card-edge connector.
293	
294	Devices:
295	
296	You should make the devices as follows:
297	
298	bash
299	cd /dev
300	for i in  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 \
301	         16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
302	do
303	  echo -n "$i "
304	  mknod /dev/ttyW$i c 75 $i
305	  mknod /dev/cuw$i c 76 $i
306	done
307	echo ""
308	
309	If your system doesn't come with these devices preinstalled, bug your
310	linux-vendor about this. They have had ample time to get this
311	implemented by now.
312	
313	You cannot have more than 4 boards in one computer. The card only
314	supports 4 different interrupts. If you really want this, contact me
315	about this and I'll give you a few tips (requires soldering iron)....
316	
317	If you have enough PCI slots, you can probably use more than 4 PCI
318	versions of the card though.... 
319	
320	The PCI version of the card cannot adhere to the mechanical part of
321	the PCI spec because the 8 serial connectors are simply too large. If
322	it doesn't fit in your computer, bring back the card.
323	
324	
325	------------------------------------------------------------------------
326	
327	
328	  Fixed bugs and restrictions:
329	       - During initialization, interrupts are blindly turned on.
330	            Having a shadow variable would cause an extra memory
331	            access on every IO instruction. 
332	       - The interrupt (on the card) should be disabled when we
333	         don't allocate the Linux end of the interrupt. This allows 
334	         a different driver/card to use it while all ports are not in
335	         use..... (a la standard serial port)
336	       == An extra _off variant of the sx_in and sx_out macros are
337	          now available. They don't set the interrupt enable bit.
338	          These are used during initialization. Normal operation uses
339	          the old variant which enables the interrupt line.
340	       - RTS/DTR issue needs to be implemented according to 
341	         specialix' spec.
342	            I kind of like the "determinism" of the current 
343	            implementation. Compile time flag?
344	       == Ok. Compile time flag! Default is how Specialix likes it.
345	       == Now a config time flag! Gets saved in your config file. Neat!
346	       - Can you set the IO address from the lilo command line?
347	            If you need this, bug me about it, I'll make it. 
348	       == Hah! No bugging needed. Fixed! :-)
349	       - Cirrus logic hasn't gotten back to me yet why the CD1865 can
350	            and the CD1864 can't do 115k2. I suspect that this is
351	            because the CD1864 is not rated for 33MHz operation.
352	            Therefore the CD1864 versions of the card can't do 115k2 on 
353	            all ports just like the CD1865 versions. The driver does
354	            not block 115k2 on CD1864 cards. 
355	        == I called the Cirrus Logic representative here in Holland.
356	           The CD1864 databook is identical to the CD1865 databook, 
357	           except for an extra warning at the end. Similar Bit errors
358	           have been observed in testing at 115k2 on both an 1865 and
359	           a 1864 chip. I see no reason why I would prohibit 115k2 on
360	           1864 chips and not do it on 1865 chips. Actually there is
361	           reason to prohibit it on BOTH chips. I print a warning.
362	           If you use 115k2, you're on your own. 
363	       - A spiky CD may send spurious HUPs. Also in CLOCAL???
364	         -- A fix for this turned out to be counter productive. 
365	            Different fix? Current behaviour is acceptable?
366	         -- Maybe the current implementation is correct. If anybody
367	            gets bitten by this, please report, and it will get fixed.
368	
369	         -- Testing revealed that when in CLOCAL, the problem doesn't
370	            occur. As warned for in the CD1865 manual, the chip may
371	            send modem intr's on a spike. We could filter those out,
372	            but that would be a cludge anyway (You'd still risk getting
373	            a spurious HUP when two spikes occur.).....
374	 
375	
376	
377	  Bugs & restrictions:
378	       - This is a difficult card to autoprobe.
379	            You have to WRITE to the address register to even 
380	            read-probe a CD186x register. Disable autodetection?
381	         -- Specialix: any suggestions?
382	
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