arch/mips/pci/ops-msc.c

   1 /*
   2  * Copyright (C) 1999, 2000, 2004, 2005  MIPS Technologies, Inc.
   3  *    All rights reserved.
   4  *    Authors: Carsten Langgaard <carstenl@mips.com>
   5  *             Maciej W. Rozycki <macro@mips.com>
   6  * Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org)
   7  *
   8  *  This program is free software; you can distribute it and/or modify it
   9  *  under the terms of the GNU General Public License (Version 2) as
  10  *  published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope it will be useful, but WITHOUT
  13  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  *  for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License along
  18  *  with this program; if not, write to the Free Software Foundation, Inc.,
  19  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  20  *
  21  * MIPS boards specific PCI support.
  22  *
  23  */
  24 #include <linux/types.h>
  25 #include <linux/pci.h>
  26 #include <linux/kernel.h>
  27 #include <linux/init.h>
  28
  29 #include <asm/mips-boards/msc01_pci.h>
  30
  31 #define PCI_ACCESS_READ  0
  32 #define PCI_ACCESS_WRITE 1
  33
  34 /*
  35  *  PCI configuration cycle AD bus definition
  36  */
  37 /* Type 0 */
  38 #define PCI_CFG_TYPE0_REG_SHF           0
  39 #define PCI_CFG_TYPE0_FUNC_SHF          8
  40
  41 /* Type 1 */
  42 #define PCI_CFG_TYPE1_REG_SHF           0
  43 #define PCI_CFG_TYPE1_FUNC_SHF          8
  44 #define PCI_CFG_TYPE1_DEV_SHF           11
  45 #define PCI_CFG_TYPE1_BUS_SHF           16
  46
  47 static int msc_pcibios_config_access(unsigned char access_type,
  48         struct pci_bus *bus, unsigned int devfn, int where, u32 * data)
  49 {
  50         unsigned char busnum = bus->number;
  51         u32 intr;
  52
  53         /* Clear status register bits. */
  54         MSC_WRITE(MSC01_PCI_INTSTAT,
  55                   (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT));
  56
  57         MSC_WRITE(MSC01_PCI_CFGADDR,
  58                   ((busnum << MSC01_PCI_CFGADDR_BNUM_SHF) |
  59                    (PCI_SLOT(devfn) << MSC01_PCI_CFGADDR_DNUM_SHF) |
  60                    (PCI_FUNC(devfn) << MSC01_PCI_CFGADDR_FNUM_SHF) |
  61                    ((where / 4) << MSC01_PCI_CFGADDR_RNUM_SHF)));
  62
  63         /* Perform access */
  64         if (access_type == PCI_ACCESS_WRITE)
  65                 MSC_WRITE(MSC01_PCI_CFGDATA, *data);
  66         else
  67                 MSC_READ(MSC01_PCI_CFGDATA, *data);
  68
  69         /* Detect Master/Target abort */
  70         MSC_READ(MSC01_PCI_INTSTAT, intr);
  71         if (intr & (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT)) {
  72                 /* Error occurred */
  73
  74                 /* Clear bits */
  75                 MSC_WRITE(MSC01_PCI_INTSTAT,
  76                           (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT));
  77
  78                 return -1;
  79         }
  80
  81         return 0;
  82 }
  83
  84
  85 /*
  86  * We can't address 8 and 16 bit words directly.  Instead we have to
  87  * read/write a 32bit word and mask/modify the data we actually want.
  88  */
  89 static int msc_pcibios_read(struct pci_bus *bus, unsigned int devfn,
  90                              int where, int size, u32 * val)
  91 {
  92         u32 data = 0;
  93
  94         if ((size == 2) && (where & 1))
  95                 return PCIBIOS_BAD_REGISTER_NUMBER;
  96         else if ((size == 4) && (where & 3))
  97                 return PCIBIOS_BAD_REGISTER_NUMBER;
  98
  99         if (msc_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
 100                                       &data))
 101                 return -1;
 102
 103         if (size == 1)
 104                 *val = (data >> ((where & 3) << 3)) & 0xff;
 105         else if (size == 2)
 106                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 107         else
 108                 *val = data;
 109
 110         return PCIBIOS_SUCCESSFUL;
 111 }
 112
 113 static int msc_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 114                               int where, int size, u32 val)
 115 {
 116         u32 data = 0;
 117
 118         if ((size == 2) && (where & 1))
 119                 return PCIBIOS_BAD_REGISTER_NUMBER;
 120         else if ((size == 4) && (where & 3))
 121                 return PCIBIOS_BAD_REGISTER_NUMBER;
 122
 123         if (size == 4)
 124                 data = val;
 125         else {
 126                 if (msc_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
 127                                               where, &data))
 128                         return -1;
 129
 130                 if (size == 1)
 131                         data = (data & ~(0xff << ((where & 3) << 3))) |
 132                                 (val << ((where & 3) << 3));
 133                 else if (size == 2)
 134                         data = (data & ~(0xffff << ((where & 3) << 3))) |
 135                                 (val << ((where & 3) << 3));
 136         }
 137
 138         if (msc_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
 139                                        &data))
 140                 return -1;
 141
 142         return PCIBIOS_SUCCESSFUL;
 143 }
 144
 145 struct pci_ops msc_pci_ops = {
 146         .read = msc_pcibios_read,
 147         .write = msc_pcibios_write
 148 };