1.\" Copyright (c) 1998, 1999, Nicolas Souchu 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd March 5, 1998 28.Dt PPC 4 29.Os FreeBSD 30.Sh NAME 31.Nm ppc 32.Nd 33Parallel port chipset driver 34.Sh SYNOPSIS 35.Cd "controller ppc0 at isa? port? flags 0xXX tty irq 7" 36.Pp 37For one or more PPBUS busses: 38.Cd "controller ppbus at ppc0" 39.Sh DESCRIPTION 40The 41.Em ppc 42driver provides low level support to various parallel port chipsets for the 43.Xr ppbus 4 44system. 45.Pp 46During the probe phasis, ppc detects parallel port chipsets and initialize 47private data according to their operating mode: COMPATIBLE, 48NIBBLE, PS/2, EPP, ECP and other mixed modes. If a mode is provided at startup 49throw the flags variable of the boot interface, the operating mode of the 50chipset is forced according to 'flags' and its available modes. 51.Pp 52During attach phasis, ppc allocates a ppbus structure, initializes it and 53calls ppbus attach function. 54.Ss Supported flags 55.Bl -item -offset indent 56.It 57bits 0-3: chipset forced mode(s) 58.Bd -literal 59PPB_COMPATIBLE 0x0 /* Centronics compatible mode */ 60PPB_NIBBLE 0x1 /* reverse 4 bit mode */ 61PPB_PS2 0x2 /* PS/2 byte mode */ 62PPB_EPP 0x4 /* EPP mode, 32 bit */ 63PPB_ECP 0x8 /* ECP mode */ 64.Ed 65.Pp 66And any mixed values. 67.It 68bit 4: EPP protocol (0 EPP 1.9, 1 EPP 1.7) 69.It 70bit 5: activate IRQ (1 IRQ disabled, 0 IRQ enabled) 71.It 72bit 6: disable chipset specific detection 73.It 74bit 7: disable FIFO detection 75.El 76.Ss Supported chipsets 77Some parallel port chipsets are explicitly supported by ppc: detection and 78initialisation code has been written according to specs datasheets. 79.Bl -bullet -offset indent 80.It 81SMC FDC37C665GT and FDC37C666GT chipsets 82.It 83Natsemi PC873xx-family (PC87332 and PC87306) 84.It 85Winbond W83877xx-family (W83877F and W83877AF) 86.It 87SMC-like chipsets with mixed modes (see 88.Xr ppbus 4 ) 89.El 90.Ss Adding support to a new chipset 91You may want to add support for the newest chipset your last motherboard was 92sold with? For the ISA bus, just retrieve the specs of the chipset and 93write the corresponding 94.Fn ppc_mychipset_detect "" 95function. 96Then add an entry to the general purpose 97.Fn ppc_detect "" 98function. 99.Pp 100Your 101.Fn ppc_mychipset_detect "" 102function should ensure that: if the mode field of the 103.Va flags 104boot variable is not null, then the operating 105mode is forced to the given mode and no other mode is available and 106ppb->ppb_avm field contains the available modes of the chipset 107.Sh SEE ALSO 108.Xr ppbus 4 109.Sh BUGS 110The chipset detection process may corrupt your chipset configuration. You may 111disable chipset specific detection by using the above flags. 112.Sh HISTORY 113The 114.Nm 115manual page first appeared in 116.Fx 3.0 . 117.Sh AUTHORS 118This manual page was written by 119.An Nicolas Souchu . 120