1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2010 John Crispin <john@phrozen.org>
5 */
6
7 #include <linux/types.h>
8 #include <linux/pci.h>
9 #include <linux/kernel.h>
10 #include <linux/delay.h>
11 #include <linux/mm.h>
12 #include <asm/addrspace.h>
13 #include <linux/vmalloc.h>
14
15 #include <lantiq_soc.h>
16
17 #include "pci-lantiq.h"
18
19 #define LTQ_PCI_CFG_BUSNUM_SHF 16
20 #define LTQ_PCI_CFG_DEVNUM_SHF 11
21 #define LTQ_PCI_CFG_FUNNUM_SHF 8
22
23 #define PCI_ACCESS_READ 0
24 #define PCI_ACCESS_WRITE 1
25
26 static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
27 unsigned int devfn, unsigned int where, u32 *data)
28 {
29 unsigned long cfg_base;
30 unsigned long flags;
31 u32 temp;
32
33 /* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
34 SoC itself */
35 if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
36 || ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
37 return 1;
38
39 spin_lock_irqsave(&ebu_lock, flags);
40
41 cfg_base = (unsigned long) ltq_pci_mapped_cfg;
42 cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
43 LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
44
45 /* Perform access */
46 if (access_type == PCI_ACCESS_WRITE) {
47 ltq_w32(swab32(*data), ((u32 *)cfg_base));
48 } else {
49 *data = ltq_r32(((u32 *)(cfg_base)));
50 *data = swab32(*data);
51 }
52 wmb();
53
54 /* clean possible Master abort */
55 cfg_base = (unsigned long) ltq_pci_mapped_cfg;
56 cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
57 temp = ltq_r32(((u32 *)(cfg_base)));
58 temp = swab32(temp);
59 cfg_base = (unsigned long) ltq_pci_mapped_cfg;
60 cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
61 ltq_w32(temp, ((u32 *)cfg_base));
62
63 spin_unlock_irqrestore(&ebu_lock, flags);
64
65 if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
66 return 1;
67
68 return 0;
69 }
70
71 int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
72 int where, int size, u32 *val)
73 {
74 u32 data = 0;
75
76 if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
77 return PCIBIOS_DEVICE_NOT_FOUND;
78
79 if (size == 1)
80 *val = (data >> ((where & 3) << 3)) & 0xff;
81 else if (size == 2)
82 *val = (data >> ((where & 3) << 3)) & 0xffff;
83 else
84 *val = data;
85
86 return PCIBIOS_SUCCESSFUL;
87 }
88
89 int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
90 int where, int size, u32 val)
91 {
92 u32 data = 0;
93
94 if (size == 4) {
95 data = val;
96 } else {
97 if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
98 devfn, where, &data))
99 return PCIBIOS_DEVICE_NOT_FOUND;
100
101 if (size == 1)
102 data = (data & ~(0xff << ((where & 3) << 3))) |
103 (val << ((where & 3) << 3));
104 else if (size == 2)
105 data = (data & ~(0xffff << ((where & 3) << 3))) |
106 (val << ((where & 3) << 3));
107 }
108
109 if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
110 return PCIBIOS_DEVICE_NOT_FOUND;
111
112 return PCIBIOS_SUCCESSFUL;
113 }
114
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