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1/*
2 * Copyright (C) 2006 PA Semi, Inc
3 *
4 * Authors: Kip Walker, PA Semi
5 * Olof Johansson, PA Semi
6 *
7 * Maintained by: Olof Johansson <olof@lixom.net>
8 *
9 * Based on arch/powerpc/platforms/maple/pci.c
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25
26#include <linux/kernel.h>
27#include <linux/pci.h>
28
29#include <asm/pci-bridge.h>
30#include <asm/machdep.h>
31
32#include <asm/ppc-pci.h>
33
34#define PA_PXP_CFA(bus, devfn, off) (((bus) << 20) | ((devfn) << 12) | (off))
35
36static inline int pa_pxp_offset_valid(u8 bus, u8 devfn, int offset)
37{
38 /* Device 0 Function 0 is special: It's config space spans function 1 as
39 * well, so allow larger offset. It's really a two-function device but the
40 * second function does not probe.
41 */
42 if (bus == 0 && devfn == 0)
43 return offset < 8192;
44 else
45 return offset < 4096;
46}
47
48static void volatile __iomem *pa_pxp_cfg_addr(struct pci_controller *hose,
49 u8 bus, u8 devfn, int offset)
50{
51 return hose->cfg_data + PA_PXP_CFA(bus, devfn, offset);
52}
53
54static inline int is_root_port(int busno, int devfn)
55{
56 return ((busno == 0) && (PCI_FUNC(devfn) < 4) &&
57 ((PCI_SLOT(devfn) == 16) || (PCI_SLOT(devfn) == 17)));
58}
59
60static inline int is_5945_reg(int reg)
61{
62 return (((reg >= 0x18) && (reg < 0x34)) ||
63 ((reg >= 0x158) && (reg < 0x178)));
64}
65
66static int workaround_5945(struct pci_bus *bus, unsigned int devfn,
67 int offset, int len, u32 *val)
68{
69 struct pci_controller *hose;
70 void volatile __iomem *addr, *dummy;
71 int byte;
72 u32 tmp;
73
74 if (!is_root_port(bus->number, devfn) || !is_5945_reg(offset))
75 return 0;
76
77 hose = pci_bus_to_host(bus);
78
79 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset & ~0x3);
80 byte = offset & 0x3;
81
82 /* Workaround bug 5945: write 0 to a dummy register before reading,
83 * and write back what we read. We must read/write the full 32-bit
84 * contents so we need to shift and mask by hand.
85 */
86 dummy = pa_pxp_cfg_addr(hose, bus->number, devfn, 0x10);
87 out_le32(dummy, 0);
88 tmp = in_le32(addr);
89 out_le32(addr, tmp);
90
91 switch (len) {
92 case 1:
93 *val = (tmp >> (8*byte)) & 0xff;
94 break;
95 case 2:
96 if (byte == 0)
97 *val = tmp & 0xffff;
98 else
99 *val = (tmp >> 16) & 0xffff;
100 break;
101 default:
102 *val = tmp;
103 break;
104 }
105
106 return 1;
107}
108
109static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
110 int offset, int len, u32 *val)
111{
112 struct pci_controller *hose;
113 void volatile __iomem *addr;
114
115 hose = pci_bus_to_host(bus);
116 if (!hose)
117 return PCIBIOS_DEVICE_NOT_FOUND;
118
119 if (!pa_pxp_offset_valid(bus->number, devfn, offset))
120 return PCIBIOS_BAD_REGISTER_NUMBER;
121
122 if (workaround_5945(bus, devfn, offset, len, val))
123 return PCIBIOS_SUCCESSFUL;
124
125 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
126
127 /*
128 * Note: the caller has already checked that offset is
129 * suitably aligned and that len is 1, 2 or 4.
130 */
131 switch (len) {
132 case 1:
133 *val = in_8(addr);
134 break;
135 case 2:
136 *val = in_le16(addr);
137 break;
138 default:
139 *val = in_le32(addr);
140 break;
141 }
142
143 return PCIBIOS_SUCCESSFUL;
144}
145
146static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
147 int offset, int len, u32 val)
148{
149 struct pci_controller *hose;
150 void volatile __iomem *addr;
151
152 hose = pci_bus_to_host(bus);
153 if (!hose)
154 return PCIBIOS_DEVICE_NOT_FOUND;
155
156 if (!pa_pxp_offset_valid(bus->number, devfn, offset))
157 return PCIBIOS_BAD_REGISTER_NUMBER;
158
159 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
160
161 /*
162 * Note: the caller has already checked that offset is
163 * suitably aligned and that len is 1, 2 or 4.
164 */
165 switch (len) {
166 case 1:
167 out_8(addr, val);
168 break;
169 case 2:
170 out_le16(addr, val);
171 break;
172 default:
173 out_le32(addr, val);
174 break;
175 }
176 return PCIBIOS_SUCCESSFUL;
177}
178
179static struct pci_ops pa_pxp_ops = {
180 .read = pa_pxp_read_config,
181 .write = pa_pxp_write_config,
182};
183
184static void __init setup_pa_pxp(struct pci_controller *hose)
185{
186 hose->ops = &pa_pxp_ops;
187 hose->cfg_data = ioremap(0xe0000000, 0x10000000);
188}
189
190static int __init pas_add_bridge(struct device_node *dev)
191{
192 struct pci_controller *hose;
193
194 pr_debug("Adding PCI host bridge %s\n", dev->full_name);
195
196 hose = pcibios_alloc_controller(dev);
197 if (!hose)
198 return -ENOMEM;
199
200 hose->first_busno = 0;
201 hose->last_busno = 0xff;
202
203 setup_pa_pxp(hose);
204
205 printk(KERN_INFO "Found PA-PXP PCI host bridge.\n");
206
207 /* Interpret the "ranges" property */
208 pci_process_bridge_OF_ranges(hose, dev, 1);
209
210 return 0;
211}
212
213void __init pas_pci_init(void)
214{
215 struct device_node *np, *root;
216
217 root = of_find_node_by_path("/");
218 if (!root) {
219 printk(KERN_CRIT "pas_pci_init: can't find root "
220 "of device tree\n");
221 return;
222 }
223
224 for (np = NULL; (np = of_get_next_child(root, np)) != NULL;)
225 if (np->name && !strcmp(np->name, "pxp") && !pas_add_bridge(np))
226 of_node_get(np);
227
228 of_node_put(root);
229
230 /* Setup the linkage between OF nodes and PHBs */
231 pci_devs_phb_init();
232}
233
234void __iomem *pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset)
235{
236 struct pci_controller *hose;
237
238 hose = pci_bus_to_host(dev->bus);
239
240 return (void __iomem *)pa_pxp_cfg_addr(hose, dev->bus->number, dev->devfn, offset);
241}