arch/powerpc/sysdev/grackle.c

   1 /*
   2  * Functions for setting up and using a MPC106 northbridge
   3  * Extracted from arch/powerpc/platforms/powermac/pci.c.
   4  *
   5  * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
   6  * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  */
  13 #include <linux/kernel.h>
  14 #include <linux/pci.h>
  15 #include <linux/init.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/prom.h>
  19 #include <asm/pci-bridge.h>
  20 #include <asm/grackle.h>
  21
  22 #define GRACKLE_CFA(b, d, o)    (0x80 | ((b) << 8) | ((d) << 16) \
  23                                  | (((o) & ~3) << 24))
  24
  25 #define GRACKLE_PICR1_STG               0x00000040
  26 #define GRACKLE_PICR1_LOOPSNOOP         0x00000010
  27
  28 /* N.B. this is called before bridges is initialized, so we can't
  29    use grackle_pcibios_{read,write}_config_dword. */
  30 static inline void grackle_set_stg(struct pci_controller* bp, int enable)
  31 {
  32         unsigned int val;
  33
  34         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  35         val = in_le32(bp->cfg_data);
  36         val = enable? (val | GRACKLE_PICR1_STG) :
  37                 (val & ~GRACKLE_PICR1_STG);
  38         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  39         out_le32(bp->cfg_data, val);
  40         (void)in_le32(bp->cfg_data);
  41 }
  42
  43 static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable)
  44 {
  45         unsigned int val;
  46
  47         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  48         val = in_le32(bp->cfg_data);
  49         val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) :
  50                 (val & ~GRACKLE_PICR1_LOOPSNOOP);
  51         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  52         out_le32(bp->cfg_data, val);
  53         (void)in_le32(bp->cfg_data);
  54 }
  55
  56 void __init setup_grackle(struct pci_controller *hose)
  57 {
  58         setup_indirect_pci(hose, 0xfec00000, 0xfee00000);
  59         if (machine_is_compatible("AAPL,PowerBook1998"))
  60                 grackle_set_loop_snoop(hose, 1);
  61 #if 0   /* Disabled for now, HW problems ??? */
  62         grackle_set_stg(hose, 1);
  63 #endif
  64 }