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diff --git a/Documentation/admin-guide/blockdev/paride.rst b/Documentation/admin-guide/blockdev/paride.rst new file mode 100644 index 0000000000..e85ad37cc0 --- /dev/null +++ b/Documentation/admin-guide/blockdev/paride.rst @@ -0,0 +1,207 @@ +=================================== +Linux and parallel port IDE devices +=================================== + +PARIDE v1.03 (c) 1997-8 Grant Guenther <grant@torque.net> +PATA_PARPORT (c) 2023 Ondrej Zary + +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, pata_parport is actually structured +in two parts. There is a base pata_parport module which provides an interface +to kernel libata subsystem, registry and some common methods for accessing +the parallel ports. + +The second component 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 pata_parport subsystem +=============================== + +While configuring the Linux kernel, you may choose either to build +the pata_parport drivers into your kernel, or to build them as modules. + +In either case, you will need to select "Parallel port IDE device support" +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 pata_parport +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 Protocol + ================ ============ ======== + MicroSolutions CD-ROM bpck + MicroSolutions PD drive bpck + MicroSolutions hard-drive bpck + MicroSolutions 8000t tape bpck + SyQuest EZ, SparQ epat + Imation Superdisk epat + Maxell Superdisk friq + Avatar Shark epat + FreeCom CD-ROM frpw + Hewlett-Packard 5GB Tape epat + Hewlett-Packard 7200e (CD) epat + Hewlett-Packard 7200e (CD-R) epat + ================ ============ ======== + +All parports and all protocol drivers are probed automatically unless probe=0 +parameter is used. So just "modprobe epat" is enough for a Imation SuperDisk +drive to work. + +Manual device creation:: + + # echo "port protocol mode unit delay" >/sys/bus/pata_parport/new_device + +where: + + ======== ================================================ + port parport name (or "auto" for all parports) + protocol protocol name (or "auto" for all protocols) + mode mode number (protocol-specific) or -1 for probe + unit unit number (for backpack only, see below) + delay I/O delay (see troubleshooting section below) + ======== ================================================ + +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). + +If you omit the parameters from the end, defaults will be used, e.g.: + +Probe all parports with all protocols:: + + # echo auto >/sys/bus/pata_parport/new_device + +Probe parport0 using protocol epat and mode 4 (EPP-16):: + + # echo "parport0 epat 4" >/sys/bus/pata_parport/new_device + +Probe parport0 using all protocols:: + + # echo "parport0 auto" >/sys/bus/pata_parport/new_device + +Probe all parports using protoocol epat:: + + # echo "auto epat" >/sys/bus/pata_parport/new_device + +Deleting devices:: + + # echo pata_parport.0 >/sys/bus/pata_parport/delete_device + + +3. Troubleshooting +================== + +3.1 Use EPP mode if you can +---------------------------- + +The most common problems that people report with the pata_parport drivers +concern the parallel port CMOS settings. At this time, none of the +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 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. + +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 pata_parport 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 pata_parport drivers as modules, and arrange to do the printer reset +before loading the pata_parport drivers. |