xref: /openbmc/linux/arch/mips/pci/ops-lantiq.c (revision 6d99a79c)
1 /*
2  *  This program is free software; you can redistribute it and/or modify it
3  *  under the terms of the GNU General Public License version 2 as published
4  *  by the Free Software Foundation.
5  *
6  *  Copyright (C) 2010 John Crispin <john@phrozen.org>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/mm.h>
14 #include <asm/addrspace.h>
15 #include <linux/vmalloc.h>
16 
17 #include <lantiq_soc.h>
18 
19 #include "pci-lantiq.h"
20 
21 #define LTQ_PCI_CFG_BUSNUM_SHF 16
22 #define LTQ_PCI_CFG_DEVNUM_SHF 11
23 #define LTQ_PCI_CFG_FUNNUM_SHF 8
24 
25 #define PCI_ACCESS_READ	 0
26 #define PCI_ACCESS_WRITE 1
27 
28 static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
29 	unsigned int devfn, unsigned int where, u32 *data)
30 {
31 	unsigned long cfg_base;
32 	unsigned long flags;
33 	u32 temp;
34 
35 	/* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
36 	   SoC itself */
37 	if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
38 		|| ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
39 		return 1;
40 
41 	spin_lock_irqsave(&ebu_lock, flags);
42 
43 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
44 	cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
45 			LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
46 
47 	/* Perform access */
48 	if (access_type == PCI_ACCESS_WRITE) {
49 		ltq_w32(swab32(*data), ((u32 *)cfg_base));
50 	} else {
51 		*data = ltq_r32(((u32 *)(cfg_base)));
52 		*data = swab32(*data);
53 	}
54 	wmb();
55 
56 	/* clean possible Master abort */
57 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
58 	cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
59 	temp = ltq_r32(((u32 *)(cfg_base)));
60 	temp = swab32(temp);
61 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
62 	cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
63 	ltq_w32(temp, ((u32 *)cfg_base));
64 
65 	spin_unlock_irqrestore(&ebu_lock, flags);
66 
67 	if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
68 		return 1;
69 
70 	return 0;
71 }
72 
73 int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
74 	int where, int size, u32 *val)
75 {
76 	u32 data = 0;
77 
78 	if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
79 		return PCIBIOS_DEVICE_NOT_FOUND;
80 
81 	if (size == 1)
82 		*val = (data >> ((where & 3) << 3)) & 0xff;
83 	else if (size == 2)
84 		*val = (data >> ((where & 3) << 3)) & 0xffff;
85 	else
86 		*val = data;
87 
88 	return PCIBIOS_SUCCESSFUL;
89 }
90 
91 int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
92 	int where, int size, u32 val)
93 {
94 	u32 data = 0;
95 
96 	if (size == 4) {
97 		data = val;
98 	} else {
99 		if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
100 				devfn, where, &data))
101 			return PCIBIOS_DEVICE_NOT_FOUND;
102 
103 		if (size == 1)
104 			data = (data & ~(0xff << ((where & 3) << 3))) |
105 				(val << ((where & 3) << 3));
106 		else if (size == 2)
107 			data = (data & ~(0xffff << ((where & 3) << 3))) |
108 				(val << ((where & 3) << 3));
109 	}
110 
111 	if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
112 		return PCIBIOS_DEVICE_NOT_FOUND;
113 
114 	return PCIBIOS_SUCCESSFUL;
115 }
116