arch/powerpc/sysdev/grackle.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Functions for setting up and using a MPC106 northbridge
   4  * Extracted from arch/powerpc/platforms/powermac/pci.c.
   5  *
   6  * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
   7  * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/pci.h>
  11 #include <linux/init.h>
  12
  13 #include <asm/io.h>
  14 #include <asm/prom.h>
  15 #include <asm/pci-bridge.h>
  16 #include <asm/grackle.h>
  17
  18 #define GRACKLE_CFA(b, d, o)    (0x80 | ((b) << 8) | ((d) << 16) \
  19                                  | (((o) & ~3) << 24))
  20
  21 #define GRACKLE_PICR1_STG               0x00000040
  22 #define GRACKLE_PICR1_LOOPSNOOP         0x00000010
  23
  24 /* N.B. this is called before bridges is initialized, so we can't
  25    use grackle_pcibios_{read,write}_config_dword. */
  26 static inline void grackle_set_stg(struct pci_controller* bp, int enable)
  27 {
  28         unsigned int val;
  29
  30         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  31         val = in_le32(bp->cfg_data);
  32         val = enable? (val | GRACKLE_PICR1_STG) :
  33                 (val & ~GRACKLE_PICR1_STG);
  34         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  35         out_le32(bp->cfg_data, val);
  36         (void)in_le32(bp->cfg_data);
  37 }
  38
  39 static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable)
  40 {
  41         unsigned int val;
  42
  43         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  44         val = in_le32(bp->cfg_data);
  45         val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) :
  46                 (val & ~GRACKLE_PICR1_LOOPSNOOP);
  47         out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
  48         out_le32(bp->cfg_data, val);
  49         (void)in_le32(bp->cfg_data);
  50 }
  51
  52 void __init setup_grackle(struct pci_controller *hose)
  53 {
  54         setup_indirect_pci(hose, 0xfec00000, 0xfee00000, 0);
  55         if (of_machine_is_compatible("PowerMac1,1"))
  56                 pci_add_flags(PCI_REASSIGN_ALL_BUS);
  57         if (of_machine_is_compatible("AAPL,PowerBook1998"))
  58                 grackle_set_loop_snoop(hose, 1);
  59 #if 0   /* Disabled for now, HW problems ??? */
  60         grackle_set_stg(hose, 1);
  61 #endif
  62 }