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lpt(4) [freebsd man page]

LPT(4)							   BSD Kernel Interfaces Manual 						    LPT(4)

lpt -- generic printer device driver SYNOPSIS
device ppc device ppbus device lpt DESCRIPTION
The current lpt driver is the port of the original lpt driver to the ppbus(4) system. One purpose of this port was to allow parallel port sharing with other parallel devices. Secondly, inb()/outb() calls have been replaced by ppbus function calls. lpt is now arch-independent thanks to the ppbus interface. See ppbus(4) for more info about the ppbus system. The parallel port bus is allocated by lpt when the printer device is opened and released only when the transfer is completed: either when the device is closed or when the entire buffer is sent in interrupt driven mode. The driver can be configured to be either interrupt-driven, or to poll the printer. Ports that are configured to be interrupt-driven can be switched to polled mode by using the lptcontrol(8) command. Depending on your hardware, extended capabilities may be configured with the lptcontrol(8) command. With an ECP/ISA port, you can take advantage of FIFO and DMA. In order to retrieve printer info from /dev/lpt0, just apply the cat command to the device. If the printer supports IEEE1284 nibble mode and has data to send to the host, you will get it. FILES
/dev/lpt0 first parallel port driver SEE ALSO
ppbus(4), ppc(4), lptcontrol(8) HISTORY
This driver replaces the functionality of the lpa driver, which is now defunct. BUGS
There are lots of them, especially in cheap parallel port implementations. It is only possible to open a lpt port when a printer is connected and on-line, making it impossible to run lptcontrol(8) when there is no printer connected. This driver could still stand a rewrite. BSD
February 14, 1999 BSD

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PPC(4)							   BSD Kernel Interfaces Manual 						    PPC(4)

ppc -- Parallel Port Chipset driver SYNOPSIS
device ppc In /boot/device.hints:"isa" hint.ppc.0.irq="7" For one or more PPBUS busses: device ppbus DESCRIPTION
The ppc driver provides low level support to various parallel port chipsets for the ppbus(4) system. During the probe phase, ppc detects parallel port chipsets and initializes private data according to their operating mode: COMPATIBLE, NIB- BLE, PS/2, EPP, ECP and other mixed modes. If a mode is provided at startup through the flags variable of the boot interface, the operating mode of the chipset is forced according to flags and the hardware supported modes. During the attach phase, ppc allocates a ppbus structure, initializes it and calls the ppbus attach function. Supported flags bits 0-3: chipset forced mode(s) PPB_COMPATIBLE 0x0 /* Centronics compatible mode */ PPB_NIBBLE 0x1 /* reverse 4 bit mode */ PPB_PS2 0x2 /* PS/2 byte mode */ PPB_EPP 0x4 /* EPP mode, 32 bit */ PPB_ECP 0x8 /* ECP mode */ And any mixed values. bit 4: EPP protocol (0 EPP 1.9, 1 EPP 1.7) bit 5: activate IRQ (1 IRQ disabled, 0 IRQ enabled) bit 6: disable chipset specific detection bit 7: disable FIFO detection Supported chipsets Some parallel port chipsets are explicitly supported: detection and initialisation code has been written according to their datasheets. o SMC FDC37C665GT and FDC37C666GT chipsets o Natsemi PC873xx-family (PC87332 and PC87306) o Winbond W83877xx-family (W83877F and W83877AF) o SMC-like chipsets with mixed modes (see ppbus(4)) Adding support to a new chipset You may want to add support for the newest chipset your motherboard was sold with. For the ISA bus, just retrieve the specs of the chipset and write the corresponding ppc_mychipset_detect() function. Then add an entry to the general purpose ppc_detect() function. Your ppc_mychipset_detect() function should ensure that if the mode field of the flags boot variable is not null, then the operating mode is forced to the given mode and no other mode is available and ppb->ppb_avm field contains the available modes of the chipset. SEE ALSO
ppbus(4), ppi(4), device.hints(5) HISTORY
The ppc manual page first appeared in FreeBSD 3.0. AUTHORS
This manual page was written by Nicolas Souchu. BUGS
The chipset detection process may corrupt your chipset configuration. You may disable chipset specific detection by using the above flags. BSD
March 5, 1998 BSD
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