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diff --git a/Documentation/blockdev/paride.txt b/Documentation/blockdev/paride.txt new file mode 100644 index 0000000..e431267 --- /dev/null +++ b/Documentation/blockdev/paride.txt @@ -0,0 +1,417 @@ + + Linux and parallel port IDE devices + +PARIDE v1.03 (c) 1997-8 Grant Guenther <grant@torque.net> + +1. Introduction + +Owing to the simplicity and near universality of the parallel port interface +to personal computers, many external devices such as portable hard-disk, +CD-ROM, LS-120 and tape drives use the parallel port to connect to their +host computer. While some devices (notably scanners) use ad-hoc methods +to pass commands and data through the parallel port interface, most +external devices are actually identical to an internal model, but with +a parallel-port adapter chip added in. Some of the original parallel port +adapters were little more than mechanisms for multiplexing a SCSI bus. +(The Iomega PPA-3 adapter used in the ZIP drives is an example of this +approach). Most current designs, however, take a different approach. +The adapter chip reproduces a small ISA or IDE bus in the external device +and the communication protocol provides operations for reading and writing +device registers, as well as data block transfer functions. Sometimes, +the device being addressed via the parallel cable is a standard SCSI +controller like an NCR 5380. The "ditto" family of external tape +drives use the ISA replicator to interface a floppy disk controller, +which is then connected to a floppy-tape mechanism. The vast majority +of external parallel port devices, however, are now based on standard +IDE type devices, which require no intermediate controller. If one +were to open up a parallel port CD-ROM drive, for instance, one would +find a standard ATAPI CD-ROM drive, a power supply, and a single adapter +that interconnected a standard PC parallel port cable and a standard +IDE cable. It is usually possible to exchange the CD-ROM device with +any other device using the IDE interface. + +The document describes the support in Linux for parallel port IDE +devices. It does not cover parallel port SCSI devices, "ditto" tape +drives or scanners. Many different devices are supported by the +parallel port IDE subsystem, including: + + MicroSolutions backpack CD-ROM + MicroSolutions backpack PD/CD + MicroSolutions backpack hard-drives + MicroSolutions backpack 8000t tape drive + SyQuest EZ-135, EZ-230 & SparQ drives + Avatar Shark + Imation Superdisk LS-120 + Maxell Superdisk LS-120 + FreeCom Power CD + Hewlett-Packard 5GB and 8GB tape drives + Hewlett-Packard 7100 and 7200 CD-RW drives + +as well as most of the clone and no-name products on the market. + +To support such a wide range of devices, PARIDE, the parallel port IDE +subsystem, is actually structured in three parts. There is a base +paride module which provides a registry and some common methods for +accessing the parallel ports. The second component is a set of +high-level drivers for each of the different types of supported devices: + + pd IDE disk + pcd ATAPI CD-ROM + pf ATAPI disk + pt ATAPI tape + pg ATAPI generic + +(Currently, the pg driver is only used with CD-R drives). + +The high-level drivers function according to the relevant standards. +The third component of PARIDE is a set of low-level protocol drivers +for each of the parallel port IDE adapter chips. Thanks to the interest +and encouragement of Linux users from many parts of the world, +support is available for almost all known adapter protocols: + + aten ATEN EH-100 (HK) + bpck Microsolutions backpack (US) + comm DataStor (old-type) "commuter" adapter (TW) + dstr DataStor EP-2000 (TW) + epat Shuttle EPAT (UK) + epia Shuttle EPIA (UK) + fit2 FIT TD-2000 (US) + fit3 FIT TD-3000 (US) + friq Freecom IQ cable (DE) + frpw Freecom Power (DE) + kbic KingByte KBIC-951A and KBIC-971A (TW) + ktti KT Technology PHd adapter (SG) + on20 OnSpec 90c20 (US) + on26 OnSpec 90c26 (US) + + +2. Using the PARIDE subsystem + +While configuring the Linux kernel, you may choose either to build +the PARIDE drivers into your kernel, or to build them as modules. + +In either case, you will need to select "Parallel port IDE device support" +as well as at least one of the high-level drivers and at least one +of the parallel port communication protocols. If you do not know +what kind of parallel port adapter is used in your drive, you could +begin by checking the file names and any text files on your DOS +installation floppy. Alternatively, you can look at the markings on +the adapter chip itself. That's usually sufficient to identify the +correct device. + +You can actually select all the protocol modules, and allow the PARIDE +subsystem to try them all for you. + +For the "brand-name" products listed above, here are the protocol +and high-level drivers that you would use: + + Manufacturer Model Driver Protocol + + MicroSolutions CD-ROM pcd bpck + MicroSolutions PD drive pf bpck + MicroSolutions hard-drive pd bpck + MicroSolutions 8000t tape pt bpck + SyQuest EZ, SparQ pd epat + Imation Superdisk pf epat + Maxell Superdisk pf friq + Avatar Shark pd epat + FreeCom CD-ROM pcd frpw + Hewlett-Packard 5GB Tape pt epat + Hewlett-Packard 7200e (CD) pcd epat + Hewlett-Packard 7200e (CD-R) pg epat + +2.1 Configuring built-in drivers + +We recommend that you get to know how the drivers work and how to +configure them as loadable modules, before attempting to compile a +kernel with the drivers built-in. + +If you built all of your PARIDE support directly into your kernel, +and you have just a single parallel port IDE device, your kernel should +locate it automatically for you. If you have more than one device, +you may need to give some command line options to your bootloader +(eg: LILO), how to do that is beyond the scope of this document. + +The high-level drivers accept a number of command line parameters, all +of which are documented in the source files in linux/drivers/block/paride. +By default, each driver will automatically try all parallel ports it +can find, and all protocol types that have been installed, until it finds +a parallel port IDE adapter. Once it finds one, the probe stops. So, +if you have more than one device, you will need to tell the drivers +how to identify them. This requires specifying the port address, the +protocol identification number and, for some devices, the drive's +chain ID. While your system is booting, a number of messages are +displayed on the console. Like all such messages, they can be +reviewed with the 'dmesg' command. Among those messages will be +some lines like: + + paride: bpck registered as protocol 0 + paride: epat registered as protocol 1 + +The numbers will always be the same until you build a new kernel with +different protocol selections. You should note these numbers as you +will need them to identify the devices. + +If you happen to be using a MicroSolutions backpack device, you will +also need to know the unit ID number for each drive. This is usually +the last two digits of the drive's serial number (but read MicroSolutions' +documentation about this). + +As an example, let's assume that you have a MicroSolutions PD/CD drive +with unit ID number 36 connected to the parallel port at 0x378, a SyQuest +EZ-135 connected to the chained port on the PD/CD drive and also an +Imation Superdisk connected to port 0x278. You could give the following +options on your boot command: + + pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36 + +In the last option, pf.drive1 configures device /dev/pf1, the 0x378 +is the parallel port base address, the 0 is the protocol registration +number and 36 is the chain ID. + +Please note: while PARIDE will work both with and without the +PARPORT parallel port sharing system that is included by the +"Parallel port support" option, PARPORT must be included and enabled +if you want to use chains of devices on the same parallel port. + +2.2 Loading and configuring PARIDE as modules + +It is much faster and simpler to get to understand the PARIDE drivers +if you use them as loadable kernel modules. + +Note 1: using these drivers with the "kerneld" automatic module loading +system is not recommended for beginners, and is not documented here. + +Note 2: if you build PARPORT support as a loadable module, PARIDE must +also be built as loadable modules, and PARPORT must be loaded before the +PARIDE modules. + +To use PARIDE, you must begin by + + insmod paride + +this loads a base module which provides a registry for the protocols, +among other tasks. + +Then, load as many of the protocol modules as you think you might need. +As you load each module, it will register the protocols that it supports, +and print a log message to your kernel log file and your console. For +example: + + # insmod epat + paride: epat registered as protocol 0 + # insmod kbic + paride: k951 registered as protocol 1 + paride: k971 registered as protocol 2 + +Finally, you can load high-level drivers for each kind of device that +you have connected. By default, each driver will autoprobe for a single +device, but you can support up to four similar devices by giving their +individual co-ordinates when you load the driver. + +For example, if you had two no-name CD-ROM drives both using the +KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc +you could give the following command: + + # insmod pcd drive0=0x378,1 drive1=0x3bc,1 + +For most adapters, giving a port address and protocol number is sufficient, +but check the source files in linux/drivers/block/paride for more +information. (Hopefully someone will write some man pages one day !). + +As another example, here's what happens when PARPORT is installed, and +a SyQuest EZ-135 is attached to port 0x378: + + # insmod paride + paride: version 1.0 installed + # insmod epat + paride: epat registered as protocol 0 + # insmod pd + pd: pd version 1.0, major 45, cluster 64, nice 0 + pda: Sharing parport1 at 0x378 + pda: epat 1.0, Shuttle EPAT chip c3 at 0x378, mode 5 (EPP-32), delay 1 + pda: SyQuest EZ135A, 262144 blocks [128M], (512/16/32), removable media + pda: pda1 + +Note that the last line is the output from the generic partition table +scanner - in this case it reports that it has found a disk with one partition. + +2.3 Using a PARIDE device + +Once the drivers have been loaded, you can access PARIDE devices in the +same way as their traditional counterparts. You will probably need to +create the device "special files". Here is a simple script that you can +cut to a file and execute: + +#!/bin/bash +# +# mkd -- a script to create the device special files for the PARIDE subsystem +# +function mkdev { + mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1 +} +# +function pd { + D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) ) + mkdev pd$D b 45 $[ $1 * 16 ] + for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 + do mkdev pd$D$P b 45 $[ $1 * 16 + $P ] + done +} +# +cd /dev +# +for u in 0 1 2 3 ; do pd $u ; done +for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done +for u in 0 1 2 3 ; do mkdev pf$u b 47 $u ; done +for u in 0 1 2 3 ; do mkdev pt$u c 96 $u ; done +for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done +for u in 0 1 2 3 ; do mkdev pg$u c 97 $u ; done +# +# end of mkd + +With the device files and drivers in place, you can access PARIDE devices +like any other Linux device. For example, to mount a CD-ROM in pcd0, use: + + mount /dev/pcd0 /cdrom + +If you have a fresh Avatar Shark cartridge, and the drive is pda, you +might do something like: + + fdisk /dev/pda -- make a new partition table with + partition 1 of type 83 + + mke2fs /dev/pda1 -- to build the file system + + mkdir /shark -- make a place to mount the disk + + mount /dev/pda1 /shark + +Devices like the Imation superdisk work in the same way, except that +they do not have a partition table. For example to make a 120MB +floppy that you could share with a DOS system: + + mkdosfs /dev/pf0 + mount /dev/pf0 /mnt + + +2.4 The pf driver + +The pf driver is intended for use with parallel port ATAPI disk +devices. The most common devices in this category are PD drives +and LS-120 drives. Traditionally, media for these devices are not +partitioned. Consequently, the pf driver does not support partitioned +media. This may be changed in a future version of the driver. + +2.5 Using the pt driver + +The pt driver for parallel port ATAPI tape drives is a minimal driver. +It does not yet support many of the standard tape ioctl operations. +For best performance, a block size of 32KB should be used. You will +probably want to set the parallel port delay to 0, if you can. + +2.6 Using the pg driver + +The pg driver can be used in conjunction with the cdrecord program +to create CD-ROMs. Please get cdrecord version 1.6.1 or later +from ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ . To record CD-R media +your parallel port should ideally be set to EPP mode, and the "port delay" +should be set to 0. With those settings it is possible to record at 2x +speed without any buffer underruns. If you cannot get the driver to work +in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only. + + +3. Troubleshooting + +3.1 Use EPP mode if you can + +The most common problems that people report with the PARIDE drivers +concern the parallel port CMOS settings. At this time, none of the +PARIDE protocol modules support ECP mode, or any ECP combination modes. +If you are able to do so, please set your parallel port into EPP mode +using your CMOS setup procedure. + +3.2 Check the port delay + +Some parallel ports cannot reliably transfer data at full speed. To +offset the errors, the PARIDE protocol modules introduce a "port +delay" between each access to the i/o ports. Each protocol sets +a default value for this delay. In most cases, the user can override +the default and set it to 0 - resulting in somewhat higher transfer +rates. In some rare cases (especially with older 486 systems) the +default delays are not long enough. if you experience corrupt data +transfers, or unexpected failures, you may wish to increase the +port delay. The delay can be programmed using the "driveN" parameters +to each of the high-level drivers. Please see the notes above, or +read the comments at the beginning of the driver source files in +linux/drivers/block/paride. + +3.3 Some drives need a printer reset + +There appear to be a number of "noname" external drives on the market +that do not always power up correctly. We have noticed this with some +drives based on OnSpec and older Freecom adapters. In these rare cases, +the adapter can often be reinitialised by issuing a "printer reset" on +the parallel port. As the reset operation is potentially disruptive in +multiple device environments, the PARIDE drivers will not do it +automatically. You can however, force a printer reset by doing: + + insmod lp reset=1 + rmmod lp + +If you have one of these marginal cases, you should probably build +your paride drivers as modules, and arrange to do the printer reset +before loading the PARIDE drivers. + +3.4 Use the verbose option and dmesg if you need help + +While a lot of testing has gone into these drivers to make them work +as smoothly as possible, problems will arise. If you do have problems, +please check all the obvious things first: does the drive work in +DOS with the manufacturer's drivers ? If that doesn't yield any useful +clues, then please make sure that only one drive is hooked to your system, +and that either (a) PARPORT is enabled or (b) no other device driver +is using your parallel port (check in /proc/ioports). Then, load the +appropriate drivers (you can load several protocol modules if you want) +as in: + + # insmod paride + # insmod epat + # insmod bpck + # insmod kbic + ... + # insmod pd verbose=1 + +(using the correct driver for the type of device you have, of course). +The verbose=1 parameter will cause the drivers to log a trace of their +activity as they attempt to locate your drive. + +Use 'dmesg' to capture a log of all the PARIDE messages (any messages +beginning with paride:, a protocol module's name or a driver's name) and +include that with your bug report. You can submit a bug report in one +of two ways. Either send it directly to the author of the PARIDE suite, +by e-mail to grant@torque.net, or join the linux-parport mailing list +and post your report there. + +3.5 For more information or help + +You can join the linux-parport mailing list by sending a mail message +to + linux-parport-request@torque.net + +with the single word + + subscribe + +in the body of the mail message (not in the subject line). Please be +sure that your mail program is correctly set up when you do this, as +the list manager is a robot that will subscribe you using the reply +address in your mail headers. REMOVE any anti-spam gimmicks you may +have in your mail headers, when sending mail to the list server. + +You might also find some useful information on the linux-parport +web pages (although they are not always up to date) at + + http://www.torque.net/parport/ + + |
