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diff --git a/Documentation/specialix.txt b/Documentation/specialix.txt new file mode 100644 index 0000000..4a4b428 --- /dev/null +++ b/Documentation/specialix.txt @@ -0,0 +1,385 @@ + + specialix.txt -- specialix IO8+ multiport serial driver readme. + + + + Copyright (C) 1997 Roger Wolff (R.E.Wolff@BitWizard.nl) + + Specialix pays for the development and support of this driver. + Please DO contact io8-linux@specialix.co.uk if you require + support. + + This driver was developed in the BitWizard linux device + driver service. If you require a linux device driver for your + product, please contact devices@BitWizard.nl for a quote. + + This code is firmly based on the riscom/8 serial driver, + written by Dmitry Gorodchanin. The specialix IO8+ card + programming information was obtained from the CL-CD1865 Data + Book, and Specialix document number 6200059: IO8+ Hardware + Functional Specification, augmented by document number 6200088: + Merak Hardware Functional Specification. (IO8+/PCI is also + called Merak) + + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of + the License, or (at your option) any later version. + + This program is distributed in the hope that it will be + useful, but WITHOUT ANY WARRANTY; without even the implied + warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR + PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public + License along with this program; if not, write to the Free + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, + USA. + + +Intro +===== + + +This file contains some random information, that I like to have online +instead of in a manual that can get lost. Ever misplace your Linux +kernel sources? And the manual of one of the boards in your computer? + + +Addresses and interrupts +======================== + +Address dip switch settings: +The dip switch sets bits 2-9 of the IO address. + + 9 8 7 6 5 4 3 2 + +-----------------+ + 0 | X X X X X X X | + | | = IoBase = 0x100 + 1 | X | + +-----------------+ ------ RS232 connectors ----> + + | | | + edge connector + | | | + V V V + +Base address 0x100 caused a conflict in one of my computers once. I +haven't the foggiest why. My Specialix card is now at 0x180. My +other computer runs just fine with the Specialix card at 0x100.... +The card occupies 4 addresses, but actually only two are really used. + +The PCI version doesn't have any dip switches. The BIOS assigns +an IO address. + +The driver now still autoprobes at 0x100, 0x180, 0x250 and 0x260. If +that causes trouble for you, please report that. I'll remove +autoprobing then. + +The driver will tell the card what IRQ to use, so you don't have to +change any jumpers to change the IRQ. Just use a command line +argument (irq=xx) to the insmod program to set the interrupt. + +The BIOS assigns the IRQ on the PCI version. You have no say in what +IRQ to use in that case. + +If your specialix cards are not at the default locations, you can use +the kernel command line argument "specialix=io0,irq0,io1,irq1...". +Here "io0" is the io address for the first card, and "irq0" is the +irq line that the first card should use. And so on. + +Examples. + +You use the driver as a module and have three cards at 0x100, 0x250 +and 0x180. And some way or another you want them detected in that +order. Moreover irq 12 is taken (e.g. by your PS/2 mouse). + + insmod specialix.o iobase=0x100,0x250,0x180 irq=9,11,15 + +The same three cards, but now in the kernel would require you to +add + + specialix=0x100,9,0x250,11,0x180,15 + +to the command line. This would become + + append="specialix=0x100,9,0x250,11,0x180,15" + +in your /etc/lilo.conf file if you use lilo. + +The Specialix driver is slightly odd: It allows you to have the second +or third card detected without having a first card. This has +advantages and disadvantages. A slot that isn't filled by an ISA card, +might be filled if a PCI card is detected. Thus if you have an ISA +card at 0x250 and a PCI card, you would get: + +sx0: specialix IO8+ Board at 0x100 not found. +sx1: specialix IO8+ Board at 0x180 not found. +sx2: specialix IO8+ board detected at 0x250, IRQ 12, CD1865 Rev. B. +sx3: specialix IO8+ Board at 0x260 not found. +sx0: specialix IO8+ board detected at 0xd800, IRQ 9, CD1865 Rev. B. + +This would happen if you don't give any probe hints to the driver. +If you would specify: + + specialix=0x250,11 + +you'd get the following messages: + +sx0: specialix IO8+ board detected at 0x250, IRQ 11, CD1865 Rev. B. +sx1: specialix IO8+ board detected at 0xd800, IRQ 9, CD1865 Rev. B. + +ISA probing is aborted after the IO address you gave is exhausted, and +the PCI card is now detected as the second card. The ISA card is now +also forced to IRQ11.... + + +Baud rates +========== + +The rev 1.2 and below boards use a CL-CD1864. These chips can only +do 64kbit. The rev 1.3 and newer boards use a CL-CD1865. These chips +are officially capable of 115k2. + +The Specialix card uses a 25MHz crystal (in times two mode, which in +fact is a divided by two mode). This is not enough to reach the rated +115k2 on all ports at the same time. With this clock rate you can only +do 37% of this rate. This means that at 115k2 on all ports you are +going to lose characters (The chip cannot handle that many incoming +bits at this clock rate.) (Yes, you read that correctly: there is a +limit to the number of -=bits=- per second that the chip can handle.) + +If you near the "limit" you will first start to see a graceful +degradation in that the chip cannot keep the transmitter busy at all +times. However with a central clock this slow, you can also get it to +miss incoming characters. The driver will print a warning message when +you are outside the official specs. The messages usually show up in +the file /var/log/messages . + +The specialix card cannot reliably do 115k2. If you use it, you have +to do "extensive testing" (*) to verify if it actually works. + +When "mgetty" communicates with my modem at 115k2 it reports: +got: +++[0d]ATQ0V1H0[0d][0d][8a]O[cb][0d][8a] + ^^^^ ^^^^ ^^^^ + +The three characters that have the "^^^" under them have suffered a +bit error in the highest bit. In conclusion: I've tested it, and found +that it simply DOESN'T work for me. I also suspect that this is also +caused by the baud rate being just a little bit out of tune. + +I upgraded the crystal to 66Mhz on one of my Specialix cards. Works +great! Contact me for details. (Voids warranty, requires a steady hand +and more such restrictions....) + + +(*) Cirrus logic CD1864 databook, page 40. + + +Cables for the Specialix IO8+ +============================= + +The pinout of the connectors on the IO8+ is: + + pin short direction long name + name + Pin 1 DCD input Data Carrier Detect + Pin 2 RXD input Receive + Pin 3 DTR/RTS output Data Terminal Ready/Ready To Send + Pin 4 GND - Ground + Pin 5 TXD output Transmit + Pin 6 CTS input Clear To Send + + + -- 6 5 4 3 2 1 -- + | | + | | + | | + | | + +----- -----+ + |__________| + clip + + Front view of an RJ12 connector. Cable moves "into" the paper. + (the plug is ready to plug into your mouth this way...) + + + NULL cable. I don't know who is going to use these except for + testing purposes, but I tested the cards with this cable. (It + took quite a while to figure out, so I'm not going to delete + it. So there! :-) + + + This end goes This end needs + straight into the some twists in + RJ12 plug. the wiring. + IO8+ RJ12 IO8+ RJ12 + 1 DCD white - + - - 1 DCD + 2 RXD black 5 TXD + 3 DTR/RTS red 6 CTS + 4 GND green 4 GND + 5 TXD yellow 2 RXD + 6 CTS blue 3 DTR/RTS + + + Same NULL cable, but now sorted on the second column. + + 1 DCD white - + - - 1 DCD + 5 TXD yellow 2 RXD + 6 CTS blue 3 DTR/RTS + 4 GND green 4 GND + 2 RXD black 5 TXD + 3 DTR/RTS red 6 CTS + + + + This is a modem cable usable for hardware handshaking: + RJ12 DB25 DB9 + 1 DCD white 8 DCD 1 DCD + 2 RXD black 3 RXD 2 RXD + 3 DTR/RTS red 4 RTS 7 RTS + 4 GND green 7 GND 5 GND + 5 TXD yellow 2 TXD 3 TXD + 6 CTS blue 5 CTS 8 CTS + +---- 6 DSR 6 DSR + +---- 20 DTR 4 DTR + + This is a modem cable usable for software handshaking: + It allows you to reset the modem using the DTR ioctls. + I (REW) have never tested this, "but xxxxxxxxxxxxx + says that it works." If you test this, please + tell me and I'll fill in your name on the xxx's. + + RJ12 DB25 DB9 + 1 DCD white 8 DCD 1 DCD + 2 RXD black 3 RXD 2 RXD + 3 DTR/RTS red 20 DTR 4 DTR + 4 GND green 7 GND 5 GND + 5 TXD yellow 2 TXD 3 TXD + 6 CTS blue 5 CTS 8 CTS + +---- 6 DSR 6 DSR + +---- 4 RTS 7 RTS + + I bought a 6 wire flat cable. It was colored as indicated. + Check that yours is the same before you trust me on this. + + +Hardware handshaking issues. +============================ + +The driver can be compiled in two different ways. The default +("Specialix DTR/RTS pin is RTS" is off) the pin behaves as DTR when +hardware handshaking is off. It behaves as the RTS hardware +handshaking signal when hardware handshaking is selected. + +When you use this, you have to use the appropriate cable. The +cable will either be compatible with hardware handshaking or with +software handshaking. So switching on the fly is not really an +option. + +I actually prefer to use the "Specialix DTR/RTS pin is RTS" option. +This makes the DTR/RTS pin always an RTS pin, and ioctls to +change DTR are always ignored. I have a cable that is configured +for this. + + +Ports and devices +================= + +Port 0 is the one furthest from the card-edge connector. + +Devices: + +You should make the devices as follows: + +bash +cd /dev +for i in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 \ + 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 +do + echo -n "$i " + mknod /dev/ttyW$i c 75 $i + mknod /dev/cuw$i c 76 $i +done +echo "" + +If your system doesn't come with these devices preinstalled, bug your +linux-vendor about this. They have had ample time to get this +implemented by now. + +You cannot have more than 4 boards in one computer. The card only +supports 4 different interrupts. If you really want this, contact me +about this and I'll give you a few tips (requires soldering iron).... + +If you have enough PCI slots, you can probably use more than 4 PCI +versions of the card though.... + +The PCI version of the card cannot adhere to the mechanical part of +the PCI spec because the 8 serial connectors are simply too large. If +it doesn't fit in your computer, bring back the card. + + +------------------------------------------------------------------------ + + + Fixed bugs and restrictions: + - During initialization, interrupts are blindly turned on. + Having a shadow variable would cause an extra memory + access on every IO instruction. + - The interrupt (on the card) should be disabled when we + don't allocate the Linux end of the interrupt. This allows + a different driver/card to use it while all ports are not in + use..... (a la standard serial port) + == An extra _off variant of the sx_in and sx_out macros are + now available. They don't set the interrupt enable bit. + These are used during initialization. Normal operation uses + the old variant which enables the interrupt line. + - RTS/DTR issue needs to be implemented according to + specialix' spec. + I kind of like the "determinism" of the current + implementation. Compile time flag? + == Ok. Compile time flag! Default is how Specialix likes it. + == Now a config time flag! Gets saved in your config file. Neat! + - Can you set the IO address from the lilo command line? + If you need this, bug me about it, I'll make it. + == Hah! No bugging needed. Fixed! :-) + - Cirrus logic hasn't gotten back to me yet why the CD1865 can + and the CD1864 can't do 115k2. I suspect that this is + because the CD1864 is not rated for 33MHz operation. + Therefore the CD1864 versions of the card can't do 115k2 on + all ports just like the CD1865 versions. The driver does + not block 115k2 on CD1864 cards. + == I called the Cirrus Logic representative here in Holland. + The CD1864 databook is identical to the CD1865 databook, + except for an extra warning at the end. Similar Bit errors + have been observed in testing at 115k2 on both an 1865 and + a 1864 chip. I see no reason why I would prohibit 115k2 on + 1864 chips and not do it on 1865 chips. Actually there is + reason to prohibit it on BOTH chips. I print a warning. + If you use 115k2, you're on your own. + - A spiky CD may send spurious HUPs. Also in CLOCAL??? + -- A fix for this turned out to be counter productive. + Different fix? Current behaviour is acceptable? + -- Maybe the current implementation is correct. If anybody + gets bitten by this, please report, and it will get fixed. + + -- Testing revealed that when in CLOCAL, the problem doesn't + occur. As warned for in the CD1865 manual, the chip may + send modem intr's on a spike. We could filter those out, + but that would be a cludge anyway (You'd still risk getting + a spurious HUP when two spikes occur.)..... + + + + Bugs & restrictions: + - This is a difficult card to autoprobe. + You have to WRITE to the address register to even + read-probe a CD186x register. Disable autodetection? + -- Specialix: any suggestions? + - Arbitrary baud rates are not implemented yet. + If you need this, bug me about it. + + |
