target/linux/rb532/files/arch/mips/pci/ops-rc32434.c

   1 /**************************************************************************
   2  *
   3  *  BRIEF MODULE DESCRIPTION
   4  *     pci_ops for IDT EB434 board
   5  *
   6  *  Copyright 2004 IDT Inc. (rischelp@idt.com)
   7  *  Copyright 2006 Felix Fietkau <nbd@openwrt.org>
   8  *
   9  *  This program is free software; you can redistribute  it and/or modify it
  10  *  under  the terms of  the GNU General  Public License as published by the
  11  *  Free Software Foundation;  either version 2 of the  License, or (at your
  12  *  option) any later version.
  13  *
  14  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  15  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  16  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  17  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  18  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  20  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  21  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  22  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  *
  25  *  You should have received a copy of the  GNU General Public License along
  26  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  27  *  675 Mass Ave, Cambridge, MA 02139, USA.
  28  *
  29  *
  30  **************************************************************************
  31  * May 2004 rkt, neb
  32  *
  33  * Initial Release
  34  *
  35  *
  36  *
  37  **************************************************************************
  38  */
  39
  40 #include <linux/autoconf.h>
  41 #include <linux/init.h>
  42 #include <linux/pci.h>
  43 #include <linux/types.h>
  44 #include <linux/delay.h>
  45
  46 #include <asm/cpu.h>
  47 #include <asm/io.h>
  48
  49 #include <asm/rc32434/rc32434.h>
  50 #include <asm/rc32434/pci.h>
  51
  52 #define PCI_ACCESS_READ  0
  53 #define PCI_ACCESS_WRITE 1
  54
  55
  56 #define PCI_CFG_SET(bus,slot,func,off) \
  57         (rc32434_pci->pcicfga = (0x80000000 | \
  58                                 ((bus) << 16) | ((slot)<<11) | \
  59                                 ((func)<<8) | (off)))
  60
  61 static inline int config_access(unsigned char access_type, struct pci_bus *bus,
  62                          unsigned int devfn, unsigned char where,
  63                          u32 * data)
  64 {
  65         unsigned int slot = PCI_SLOT(devfn);
  66         u8 func = PCI_FUNC(devfn);
  67
  68         /* Setup address */
  69         PCI_CFG_SET(bus->number, slot, func, where);
  70         rc32434_sync();
  71
  72         if (access_type == PCI_ACCESS_WRITE)
  73                 rc32434_pci->pcicfgd = *data;
  74         else
  75                 *data = rc32434_pci->pcicfgd;
  76
  77         rc32434_sync();
  78
  79         return 0;
  80 }
  81
  82
  83 /*
  84  * We can't address 8 and 16 bit words directly.  Instead we have to
  85  * read/write a 32bit word and mask/modify the data we actually want.
  86  */
  87 static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
  88                             int where, u8 * val)
  89 {
  90         u32 data;
  91         int ret;
  92
  93         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
  94         *val = (data >> ((where & 3) << 3)) & 0xff;
  95         return ret;
  96 }
  97
  98 static int read_config_word(struct pci_bus *bus, unsigned int devfn,
  99                             int where, u16 * val)
 100 {
 101         u32 data;
 102         int ret;
 103
 104         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
 105         *val = (data >> ((where & 3) << 3)) & 0xffff;
 106         return ret;
 107 }
 108
 109 static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
 110                              int where, u32 * val)
 111 {
 112         int ret;
 113         int delay = 1;
 114
 115         if (bus->number == 0 && PCI_SLOT(devfn) > 21)
 116                 return 0;
 117
 118 retry:
 119         ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
 120
 121         /* PCI scan: check for invalid values, device may not have
 122          * finished initializing */
 123
 124         if (where == PCI_VENDOR_ID) {
 125                 if (ret == 0xffffffff || ret == 0x00000000 ||
 126                         ret == 0x0000ffff || ret == 0xffff0000) {
 127
 128                         if (delay > 4)
 129                                 return 0;
 130
 131                         delay *= 2;
 132                         msleep(delay);
 133                         goto retry;
 134                 }
 135         }
 136
 137         return ret;
 138 }
 139
 140 static int
 141 write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
 142                   u8 val)
 143 {
 144         u32 data = 0;
 145
 146         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 147                 return -1;
 148
 149         data = (data & ~(0xff << ((where & 3) << 3))) |
 150                 (val << ((where & 3) << 3));
 151
 152         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 153                 return -1;
 154
 155         return PCIBIOS_SUCCESSFUL;
 156 }
 157
 158
 159 static int
 160 write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
 161                   u16 val)
 162 {
 163         u32 data = 0;
 164
 165         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 166                 return -1;
 167
 168         data = (data & ~(0xffff << ((where & 3) << 3))) |
 169                 (val << ((where & 3) << 3));
 170
 171         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 172                 return -1;
 173
 174
 175         return PCIBIOS_SUCCESSFUL;
 176 }
 177
 178
 179 static int
 180 write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
 181                    u32 val)
 182 {
 183         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
 184                 return -1;
 185
 186         return PCIBIOS_SUCCESSFUL;
 187 }
 188
 189 static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
 190                            int where, int size, u32 * val)
 191 {
 192         switch (size) {
 193         case 1:
 194                 return read_config_byte(bus, devfn, where, (u8 *) val);
 195         case 2:
 196                 return read_config_word(bus, devfn, where, (u16 *) val);
 197         default:
 198                 return read_config_dword(bus, devfn, where, val);
 199         }
 200 }
 201
 202 static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
 203                             int where, int size, u32 val)
 204 {
 205         switch (size) {
 206         case 1:
 207                 return write_config_byte(bus, devfn, where, (u8) val);
 208         case 2:
 209                 return write_config_word(bus, devfn, where, (u16) val);
 210         default:
 211                 return write_config_dword(bus, devfn, where, val);
 212         }
 213 }
 214
 215 struct pci_ops rc32434_pci_ops = {
 216         .read =  pci_config_read,
 217         .write = pci_config_write,
 218 };