xref: /openbmc/linux/arch/mips/pci/ops-lantiq.c (revision 63dc02bd)
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 <blogic@openwrt.org>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/delay.h>
14 #include <linux/mm.h>
15 #include <asm/addrspace.h>
16 #include <linux/vmalloc.h>
17 
18 #include <lantiq_soc.h>
19 
20 #include "pci-lantiq.h"
21 
22 #define LTQ_PCI_CFG_BUSNUM_SHF 16
23 #define LTQ_PCI_CFG_DEVNUM_SHF 11
24 #define LTQ_PCI_CFG_FUNNUM_SHF 8
25 
26 #define PCI_ACCESS_READ  0
27 #define PCI_ACCESS_WRITE 1
28 
29 static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
30 	unsigned int devfn, unsigned int where, u32 *data)
31 {
32 	unsigned long cfg_base;
33 	unsigned long flags;
34 	u32 temp;
35 
36 	/* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
37 	   SoC itself */
38 	if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
39 		|| ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
40 		return 1;
41 
42 	spin_lock_irqsave(&ebu_lock, flags);
43 
44 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
45 	cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
46 			LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
47 
48 	/* Perform access */
49 	if (access_type == PCI_ACCESS_WRITE) {
50 		ltq_w32(swab32(*data), ((u32 *)cfg_base));
51 	} else {
52 		*data = ltq_r32(((u32 *)(cfg_base)));
53 		*data = swab32(*data);
54 	}
55 	wmb();
56 
57 	/* clean possible Master abort */
58 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
59 	cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
60 	temp = ltq_r32(((u32 *)(cfg_base)));
61 	temp = swab32(temp);
62 	cfg_base = (unsigned long) ltq_pci_mapped_cfg;
63 	cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
64 	ltq_w32(temp, ((u32 *)cfg_base));
65 
66 	spin_unlock_irqrestore(&ebu_lock, flags);
67 
68 	if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
69 		return 1;
70 
71 	return 0;
72 }
73 
74 int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
75 	int where, int size, u32 *val)
76 {
77 	u32 data = 0;
78 
79 	if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
80 		return PCIBIOS_DEVICE_NOT_FOUND;
81 
82 	if (size == 1)
83 		*val = (data >> ((where & 3) << 3)) & 0xff;
84 	else if (size == 2)
85 		*val = (data >> ((where & 3) << 3)) & 0xffff;
86 	else
87 		*val = data;
88 
89 	return PCIBIOS_SUCCESSFUL;
90 }
91 
92 int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
93 	int where, int size, u32 val)
94 {
95 	u32 data = 0;
96 
97 	if (size == 4) {
98 		data = val;
99 	} else {
100 		if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
101 				devfn, where, &data))
102 			return PCIBIOS_DEVICE_NOT_FOUND;
103 
104 		if (size == 1)
105 			data = (data & ~(0xff << ((where & 3) << 3))) |
106 				(val << ((where & 3) << 3));
107 		else if (size == 2)
108 			data = (data & ~(0xffff << ((where & 3) << 3))) |
109 				(val << ((where & 3) << 3));
110 	}
111 
112 	if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
113 		return PCIBIOS_DEVICE_NOT_FOUND;
114 
115 	return PCIBIOS_SUCCESSFUL;
116 }
117