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. */
grackle_set_stg(struct pci_controller * bp,int enable)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
grackle_set_loop_snoop(struct pci_controller * bp,int enable)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
setup_grackle(struct pci_controller * hose)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 }
63