Vision Systems VScom 200E PCIex Manual de usuario descargar pdf (Pagina 42)

5 Linux Driver

VScom PCI cards in Linux do not need a special driver. The driver ’serial’ supplied with your

Distribution is quite capable of controlling the serial ports on VScom cards. Driver ’serial’ is

conﬁgured to detect the old-fashioned ports known as Com1 to Com4 in DOS systems, and support

them. Since the serial ports on VScom PCI cards use the same type of hardware, driver ’serial’ is

well capable to support the new serial ports. After installation of the card the driver ’serial’ just

needs to know about the new hardware.

Since Kernel 2.6 things are no longer as simple as written above. Some programmers invented a

limit to the maximum number of serial ports. This is explained below in 5.3.

5.1 Manual Installation

Usually the command ’setserial’ is used to provide the required information to the driver, thus

adding the port.

setserial ttys4 port 0x100 irq 5 uart 16550A baud_base 921600

Such a command would be good for an ISA card, but with PCI it is not totally as easy as that.

Because PCI is a Plug&Play system, the parameters ’port’ and ’irq’ are unknown in advance; they

are assigned at boot time. Depending on your installation of Linux, you ﬁnd the basic parameters

in /proc/pci or via the lspci command. Given some hardware details about the card, port and irq

for each serial port are calculated easy. These details are seen in table 14.

This is just mentioned here, the better way of installation is automatic.

5.2 Automatic Installation

Depending on your version of the driver ’serial’, some VScom PCI cards are already known. So

the ports are detected, installed and usable. If the card in question is not already known to the

driver (new model or old driver/kernel), the program ’vscardcfg’ is supplied. This program scans

/proc/pci or other information for parameters of VScom PCI cards.

5.2.1 Known Cards

PCI components are detected by BIOS and system routines at boot time. Later they are basically

identiﬁed by the parameters Vendor- and Device-ID, on some hardware also by SubVendor- and

SubDevice-ID. For identiﬁcation of VScom PCI hardware, the Sub-parameters are not required.

Not each speciﬁc hardware model has its unique identiﬁcation, but at least for purposes of driver

conﬁguration diﬀerent identiﬁcation is supplied. So driver and conﬁguration software just has to

look up the identiﬁcation in a table, and then controls the card perfectly.

If the VScom PCI card is known to the driver ’serial’, users do not have to do any extra conﬁgu-

ration. The system detects the card, identiﬁes it and installs additional ports.

July 2011 VScom Industrial Card User Manual 42

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Vision Systems VScom 200E PCIex Manual de usuario Pagina 42