disabled/gpxe/wrap/pci.c

   1 /*
   2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * Based in part on pci.c from Etherboot 5.4, by Ken Yap and David
   5  * Munro, in turn based on the Linux kernel's PCI implementation.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 FILE_LICENCE ( GPL2_OR_LATER );
  23
  24 #include <stdint.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <gpxe/tables.h>
  30 #include <gpxe/device.h>
  31 #include <gpxe/pci.h>
  32
  33 /**
  34  * Enable PCI device
  35  *
  36  * @v pci               PCI device
  37  *
  38  * Set device to be a busmaster in case BIOS neglected to do so.  Also
  39  * adjust PCI latency timer to a reasonable value, 32.
  40  */
  41 void adjust_pci_device ( struct pci_device *pci ) {
  42         unsigned short new_command, pci_command;
  43         unsigned char pci_latency;
  44
  45         pci_read_config_word ( pci, PCI_COMMAND, &pci_command );
  46         new_command = ( pci_command | PCI_COMMAND_MASTER |
  47                         PCI_COMMAND_MEM | PCI_COMMAND_IO );
  48         if ( pci_command != new_command ) {
  49                 pci_write_config_word ( pci, PCI_COMMAND, new_command );
  50         }
  51
  52         pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency);
  53         if ( pci_latency < 32 ) {
  54                 pci_write_config_byte ( pci, PCI_LATENCY_TIMER, 32);
  55         }
  56 }