When the driver is running, the device will be accessible using the SCSI device (/dev/sda, /dev/sr0, etc), and not through the corresponding /dev/hdx device. Still, the /dev/hdx device will be available, but only for configuration.
All the generic IDE configuration parameters (DMA on/off, 32-bit I/O, unmasking irq's, etc) are available by using the /dev/hdx device, for example to enable DMA:
hdparm -d1 /dev/hdx |
bios_cyl
bios_head
bios_sect
transform
log
bit 0: Enable(1)/Disable(0) transformation for commands not originated from the sg driver.
bit 1: Enable/Disable transformation for commands issued using the sg driver.
echo "log:1" > /proc/ide/hdx/settings |
PPA + IMM. Iomega ZIP drives come in a variety of flavours including parallel port, SCSI, and ATAPI. The parallel port versions (both old and new) are driven by ppa and imm respectively.
The parallel port ZIP drives are actually SCSI devices which tunnel SCSI commands over the parallel port using interfaces called VPI0 (older-style) and VPI2 (newer-style). The ppa driver is the VPI0 host implementation and the imm driver is the VPI2 host implementation.
The way it works is that the HBA is a chip inside the ZIP drive, so that the host adapter and the peripheral are in the same actual case.
PPSCSI. The new, not-yet-integrated, architecture for devices that use SCSI over a parallel port cable is ppscsi. The ppscsi module provides the boiler plate code and makes it easy to write implementations for different interfaces.
Each ppscsi protocol module registers itself with the ppscsi module, passing in a list of entry points for the various things that are common to all protocol drivers.
The structure of the PPSCSI drivers.
The plan is that the ppscsi architecture will absorb both the ppa and imm drivers and protocol modules; only vpi0 has been written so far. See www.torque.net/parport/ppscsi.html.
USB. USB classifies a group of devices as "mass storage" (e.g. disks) and interacts with these using the SCSI command set. The module name is "usb-storage". See www.one-eyed-alien.net/~mdharm/linux-usb.
There is also the usb/microtek driver for controlling X6 USB scanners from Microtek. When configured, the SANE application uses the sg driver to send SCSI commands over USB to control this scanner.
I2O. See kernel source file /usr/src/linux/drivers/i2o/io2_scsi.c.
IEEE 1394. Support for IEEE 1394 devices that use the SBP-2 protocol is now available (lk 2.4.7). See the IEEE 1394 paragraph in this section for more information.
iSCSI. An IETF draft is taking shape for iSCSI. This sends the SCSI command set over a TCP network connection. iSCSI seems to be gaining popularity quickly and there are several implementations for Linux taking shape. One implementation is at sourceforge.net/projects/intel-iscsi/. Use your favourite search engine to find other projects.