xref: /openbmc/linux/arch/powerpc/sysdev/grackle.c (revision b627b4ed)
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, 0);
59 	if (machine_is_compatible("PowerMac1,1"))
60 		ppc_pci_add_flags(PPC_PCI_REASSIGN_ALL_BUS);
61 	if (machine_is_compatible("AAPL,PowerBook1998"))
62 		grackle_set_loop_snoop(hose, 1);
63 #if 0	/* Disabled for now, HW problems ??? */
64 	grackle_set_stg(hose, 1);
65 #endif
66 }
67