1.\" $NetBSD: pci.3,v 1.9 2014/07/25 10:21:34 wiz Exp $ 2.\" 3.\" Copyright 2001 Wasabi Systems, Inc. 4.\" All rights reserved. 5.\" 6.\" Written by Jason R. Thorpe for Wasabi Systems, Inc. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed for the NetBSD Project by 19.\" Wasabi Systems, Inc. 20.\" 4. The name of Wasabi Systems, Inc. may not be used to endorse 21.\" or promote products derived from this software without specific prior 22.\" written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 26.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 27.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 28.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34.\" POSSIBILITY OF SUCH DAMAGE. 35.\" 36.Dd July 24, 2014 37.Dt PCI 3 38.Os 39.Sh NAME 40.Nm pci 41.Nd library interface for PCI bus access 42.Sh LIBRARY 43.Lb libpci 44.Sh SYNOPSIS 45.In pci.h 46.Ft int 47.Fn pcibus_conf_read "int pcifd" "u_int bus" "u_int dev" "u_int func" \ 48"u_int reg" "pcireg_t *valp" 49.Ft int 50.Fn pcibus_conf_write "int pcifd" "u_int bus" "u_int dev" "u_int func" \ 51"u_int reg" "pcireg_t val" 52.Ft int 53.Fn pcidev_conf_read "int devfd" "u_int reg" "pcireg_t *valp" 54.Ft int 55.Fn pcidev_conf_write "int devfd" "u_int reg" "pcireg_t val" 56.Ft char * 57.Fn pci_findvendor "pcireg_t id_reg" 58.Ft void 59.Fn pci_devinfo "pcireg_t id_reg" "pcireg_t class_reg" "char *devinfo" "size_t len" 60.Ft void 61.Fn pci_conf_print "int pcifd" "u_int bus" "u_int dev" "u_int func" 62.Ft int 63.Fn pci_drvname "int pcifd" "u_int dev" "u_int func" "char *drvname" "size_t len" 64.Sh DESCRIPTION 65The 66.Nm 67library provides support for accessing the PCI bus by user programs. 68.Pp 69These functions are available in the 70.Nm libpci 71library. 72Programs should be linked with 73.Fl lpci . 74.Sh CONFIGURATION SPACE FUNCTIONS 75The following functions are used to access PCI configuration space: 76.Bl -tag -width 4n 77.It Fn pcibus_conf_read 78Access the PCI configuration register 79.Fa reg 80on the device located at 81.Fa bus , 82.Fa dev , 83.Fa func , 84and place the result in 85.Fa *valp . 86.Fa pcifd 87must be an open file descriptor to a PCI bus within the target PCI domain. 88.It Fn pcibus_conf_write 89Write the value specified by 90.Fa val 91into the PCI configuration register 92.Fa reg 93on the device located at 94.Fa bus , 95.Fa dev , 96.Fa func . 97.Fa pcifd 98must be an open file descriptor to a PCI bus within the target PCI domain. 99.It Fn pcidev_conf_read 100Access the PCI configuration register 101.Fa reg 102on the device associated with the open file descriptor 103.Fa devfd 104and place the result in 105.Fa *valp . 106.It Fn pcidev_conf_write 107Write the value specified by 108.Fa val 109into the PCI configuration register 110.Fa reg 111on the device associated with the open file descriptor 112.Fa devfd . 113.El 114.Sh MISCELLANEOUS FUNCTIONS 115The following miscellaneous functions are available: 116.Bl -tag -width 4n 117.It Fn pci_findvendor 118Return an ASCII description of the PCI vendor in the 119PCI ID register 120.Fa id_reg . 121.It Fn pci_devinfo 122Return an ASCII description of the PCI vendor, PCI product, 123and PCI class specified by the PCI ID register 124.Fa id_reg 125and PCI class ID register 126.Fa class_reg . 127The description is placed into the buffer pointed to by 128.Fa devinfo ; 129the size of that buffer is specified in 130.Fa len . 131.It Fn pci_conf_print 132Print the PCI configuration information for the device located 133at 134.Fa bus , 135.Fa dev , 136.Fa func . 137.Fa pcifd 138must be an open file descriptor to a PCI bus within the target PCI domain. 139.It Fn pci_drvname 140For the PCI bus opened on 141.Fa pcifd , 142return the driver name for 143.Fa dev 144and 145.Fa func 146into 147.Fa drvname 148using 149.Fa len 150as the buffer length. 151.El 152.Sh RETURN VALUES 153The 154.Fn pcibus_conf_read , 155.Fn pcibus_conf_write , 156.Fn pcidev_conf_read , 157.Fn pcidev_conf_write , 158.Fn pci_devinfo , 159and 160.Fn pci_drvname 161functions return 0 on success and \-1 on failure. 162.Pp 163The 164.Fn pci_findvendor 165function returns 166.Dv NULL 167if the PCI vendor description cannot be found. 168.Sh SEE ALSO 169.Xr pci 4 170.Sh HISTORY 171The 172.Fn pcibus_conf_read , 173.Fn pcibus_conf_write , 174.Fn pcidev_conf_read , 175.Fn pcidev_conf_write , 176.Fn pci_findvendor , 177.Fn pci_devinfo , 178and 179.Fn pci_conf_print 180functions first appeared in 181.Nx 1.6 . 182The 183.Fn pci_drvname 184function first appeared in 185.Nx 7.0 . 186