arch/mips/pci/ops-rc32434.c

   1 /*
   2  *  BRIEF MODULE DESCRIPTION
   3  *     pci_ops for IDT EB434 board
   4  *
   5  *  Copyright 2004 IDT Inc. (rischelp@idt.com)
   6  *  Copyright 2006 Felix Fietkau <nbd@openwrt.org>
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  *
  13  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  14  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  15  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  16  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  17  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  19  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  20  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  21  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  *
  24  *  You should have received a copy of the  GNU General Public License along
  25  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  26  *  675 Mass Ave, Cambridge, MA 02139, USA.
  27  */
  28 #include <linux/delay.h>
  29 #include <linux/init.h>
  30 #include <linux/io.h>
  31 #include <linux/pci.h>
  32 #include <linux/types.h>
  33
  34 #include <asm/cpu.h>
  35 #include <asm/mach-rc32434/rc32434.h>
  36 #include <asm/mach-rc32434/pci.h>
  37
  38 #define PCI_ACCESS_READ  0
  39 #define PCI_ACCESS_WRITE 1
  40
  41
  42 #define PCI_CFG_SET(bus, slot, func, off) \
  43         (rc32434_pci->pcicfga = (0x80000000 | \
  44                                 ((bus) << 16) | ((slot)<<11) | \
  45                                 ((func)<<8) | (off)))
  46
  47 static inline int config_access(unsigned char access_type,
  48                                 struct pci_bus *bus, unsigned int devfn,
  49                                 unsigned char where, u32 *data)
  50 {
  51         unsigned int slot = PCI_SLOT(devfn);
  52         u8 func = PCI_FUNC(devfn);
  53
  54         /* Setup address */
  55         PCI_CFG_SET(bus->number, slot, func, where);
  56         rc32434_sync();
  57
  58         if (access_type == PCI_ACCESS_WRITE)
  59                 rc32434_pci->pcicfgd = *data;
  60         else
  61                 *data = rc32434_pci->pcicfgd;
  62
  63         rc32434_sync();
  64
  65         return 0;
  66 }
  67
  68
  69 /*
  70  * We can't address 8 and 16 bit words directly.  Instead we have to
  71  * read/write a 32bit word and mask/modify the data we actually want.
  72  */
  73 static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
  74                             int where, u8 *val)
  75 {
  76         u32 data;
  77         int ret;
  78
  79         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
  80         *val = (data >> ((where & 3) << 3)) & 0xff;
  81         return ret;
  82 }
  83
  84 static int read_config_word(struct pci_bus *bus, unsigned int devfn,
  85                             int where, u16 *val)
  86 {
  87         u32 data;
  88         int ret;
  89
  90         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
  91         *val = (data >> ((where & 3) << 3)) & 0xffff;
  92         return ret;
  93 }
  94
  95 static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
  96                              int where, u32 *val)
  97 {
  98         int ret;
  99         int delay = 1;
 100
 101         /*
 102          * Don't scan too far, else there will be errors with plugged in
 103          * daughterboard (rb564).
 104          */
 105         if (bus->number == 0 && PCI_SLOT(devfn) > 21)
 106                 return 0;
 107
 108 retry:
 109         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
 110
 111         /*
 112          * Certain devices react delayed at device scan time, this
 113          * gives them time to settle
 114          */
 115         if (where == PCI_VENDOR_ID) {
 116                 if (ret == 0xffffffff || ret == 0x00000000 ||
 117                     ret == 0x0000ffff || ret == 0xffff0000) {
 118                         if (delay > 4)
 119                                 return 0;
 120                         delay *= 2;
 121                         msleep(delay);
 122                         goto retry;
 123                 }
 124         }
 125
 126         return ret;
 127 }
 128
 129 static int
 130 write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
 131                   u8 val)
 132 {
 133         u32 data = 0;
 134
 135         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 136                 return -1;
 137
 138         data = (data & ~(0xff << ((where & 3) << 3))) |
 139             (val << ((where & 3) << 3));
 140
 141         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 142                 return -1;
 143
 144         return PCIBIOS_SUCCESSFUL;
 145 }
 146
 147
 148 static int
 149 write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
 150                   u16 val)
 151 {
 152         u32 data = 0;
 153
 154         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 155                 return -1;
 156
 157         data = (data & ~(0xffff << ((where & 3) << 3))) |
 158             (val << ((where & 3) << 3));
 159
 160         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 161                 return -1;
 162
 163
 164         return PCIBIOS_SUCCESSFUL;
 165 }
 166
 167
 168 static int
 169 write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
 170                    u32 val)
 171 {
 172         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
 173                 return -1;
 174
 175         return PCIBIOS_SUCCESSFUL;
 176 }
 177
 178 static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
 179                            int where, int size, u32 *val)
 180 {
 181         switch (size) {
 182         case 1:
 183                 return read_config_byte(bus, devfn, where, (u8 *) val);
 184         case 2:
 185                 return read_config_word(bus, devfn, where, (u16 *) val);
 186         default:
 187                 return read_config_dword(bus, devfn, where, val);
 188         }
 189 }
 190
 191 static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
 192                             int where, int size, u32 val)
 193 {
 194         switch (size) {
 195         case 1:
 196                 return write_config_byte(bus, devfn, where, (u8) val);
 197         case 2:
 198                 return write_config_word(bus, devfn, where, (u16) val);
 199         default:
 200                 return write_config_dword(bus, devfn, where, val);
 201         }
 202 }
 203
 204 struct pci_ops rc32434_pci_ops = {
 205         .read = pci_config_read,
 206         .write = pci_config_write,
 207 };