summaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/pasemi/pci.c
blob: 55f0160910bf487fa94d36231eb728610e6112bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2006 PA Semi, Inc
 *
 * Authors: Kip Walker, PA Semi
 *	    Olof Johansson, PA Semi
 *
 * Maintained by: Olof Johansson <olof@lixom.net>
 *
 * Based on arch/powerpc/platforms/maple/pci.c
 */


#include <linux/kernel.h>
#include <linux/of_address.h>
#include <linux/pci.h>

#include <asm/pci-bridge.h>
#include <asm/isa-bridge.h>
#include <asm/machdep.h>

#include <asm/ppc-pci.h>

#include "pasemi.h"

#define PA_PXP_CFA(bus, devfn, off) (((bus) << 20) | ((devfn) << 12) | (off))

static inline int pa_pxp_offset_valid(u8 bus, u8 devfn, int offset)
{
	/* Device 0 Function 0 is special: It's config space spans function 1 as
	 * well, so allow larger offset. It's really a two-function device but the
	 * second function does not probe.
	 */
	if (bus == 0 && devfn == 0)
		return offset < 8192;
	else
		return offset < 4096;
}

static void volatile __iomem *pa_pxp_cfg_addr(struct pci_controller *hose,
				       u8 bus, u8 devfn, int offset)
{
	return hose->cfg_data + PA_PXP_CFA(bus, devfn, offset);
}

static inline int is_root_port(int busno, int devfn)
{
	return ((busno == 0) && (PCI_FUNC(devfn) < 4) &&
		 ((PCI_SLOT(devfn) == 16) || (PCI_SLOT(devfn) == 17)));
}

static inline int is_5945_reg(int reg)
{
	return (((reg >= 0x18) && (reg < 0x34)) ||
		((reg >= 0x158) && (reg < 0x178)));
}

static int workaround_5945(struct pci_bus *bus, unsigned int devfn,
			   int offset, int len, u32 *val)
{
	struct pci_controller *hose;
	void volatile __iomem *addr, *dummy;
	int byte;
	u32 tmp;

	if (!is_root_port(bus->number, devfn) || !is_5945_reg(offset))
		return 0;

	hose = pci_bus_to_host(bus);

	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset & ~0x3);
	byte = offset & 0x3;

	/* Workaround bug 5945: write 0 to a dummy register before reading,
	 * and write back what we read. We must read/write the full 32-bit
	 * contents so we need to shift and mask by hand.
	 */
	dummy = pa_pxp_cfg_addr(hose, bus->number, devfn, 0x10);
	out_le32(dummy, 0);
	tmp = in_le32(addr);
	out_le32(addr, tmp);

	switch (len) {
	case 1:
		*val = (tmp >> (8*byte)) & 0xff;
		break;
	case 2:
		if (byte == 0)
			*val = tmp & 0xffff;
		else
			*val = (tmp >> 16) & 0xffff;
		break;
	default:
		*val = tmp;
		break;
	}

	return 1;
}

#ifdef CONFIG_PPC_PASEMI_NEMO
#define PXP_ERR_CFG_REG	0x4
#define PXP_IGNORE_PCIE_ERRORS	0x800
#define SB600_BUS 5

static void sb600_set_flag(int bus)
{
	static void __iomem *iob_mapbase = NULL;
	struct resource res;
	struct device_node *dn;
	int err;

	if (iob_mapbase == NULL) {
		dn = of_find_compatible_node(NULL, "isa", "pasemi,1682m-iob");
		if (!dn) {
			pr_crit("NEMO SB600 missing iob node\n");
			return;
		}

		err = of_address_to_resource(dn, 0, &res);
		of_node_put(dn);

		if (err) {
			pr_crit("NEMO SB600 missing resource\n");
			return;
		}

		pr_info("NEMO SB600 IOB base %08llx\n",res.start);

		iob_mapbase = ioremap(res.start + 0x100, 0x94);
	}

	if (iob_mapbase != NULL) {
		if (bus == SB600_BUS) {
			/*
			 * This is the SB600's bus, tell the PCI-e root port
			 * to allow non-zero devices to enumerate.
			 */
			out_le32(iob_mapbase + PXP_ERR_CFG_REG, in_le32(iob_mapbase + PXP_ERR_CFG_REG) | PXP_IGNORE_PCIE_ERRORS);
		} else {
			/*
			 * Only scan device 0 on other busses
			 */
			out_le32(iob_mapbase + PXP_ERR_CFG_REG, in_le32(iob_mapbase + PXP_ERR_CFG_REG) & ~PXP_IGNORE_PCIE_ERRORS);
		}
	}
}

#else

static void sb600_set_flag(int bus)
{
}
#endif

static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
			      int offset, int len, u32 *val)
{
	struct pci_controller *hose;
	void volatile __iomem *addr;

	hose = pci_bus_to_host(bus);
	if (!hose)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (workaround_5945(bus, devfn, offset, len, val))
		return PCIBIOS_SUCCESSFUL;

	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);

	sb600_set_flag(bus->number);

	/*
	 * Note: the caller has already checked that offset is
	 * suitably aligned and that len is 1, 2 or 4.
	 */
	switch (len) {
	case 1:
		*val = in_8(addr);
		break;
	case 2:
		*val = in_le16(addr);
		break;
	default:
		*val = in_le32(addr);
		break;
	}

	return PCIBIOS_SUCCESSFUL;
}

static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
			       int offset, int len, u32 val)
{
	struct pci_controller *hose;
	void volatile __iomem *addr;

	hose = pci_bus_to_host(bus);
	if (!hose)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);

	sb600_set_flag(bus->number);

	/*
	 * Note: the caller has already checked that offset is
	 * suitably aligned and that len is 1, 2 or 4.
	 */
	switch (len) {
	case 1:
		out_8(addr, val);
		break;
	case 2:
		out_le16(addr, val);
		break;
	default:
		out_le32(addr, val);
		break;
	}
	return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops pa_pxp_ops = {
	.read = pa_pxp_read_config,
	.write = pa_pxp_write_config,
};

static void __init setup_pa_pxp(struct pci_controller *hose)
{
	hose->ops = &pa_pxp_ops;
	hose->cfg_data = ioremap(0xe0000000, 0x10000000);
}

static int __init pas_add_bridge(struct device_node *dev)
{
	struct pci_controller *hose;

	pr_debug("Adding PCI host bridge %pOF\n", dev);

	hose = pcibios_alloc_controller(dev);
	if (!hose)
		return -ENOMEM;

	hose->first_busno = 0;
	hose->last_busno = 0xff;
	hose->controller_ops = pasemi_pci_controller_ops;

	setup_pa_pxp(hose);

	pr_info("Found PA-PXP PCI host bridge.\n");

	/* Interpret the "ranges" property */
	pci_process_bridge_OF_ranges(hose, dev, 1);

	/*
	 * Scan for an isa bridge. This is needed to find the SB600 on the nemo
	 * and does nothing on machines without one.
	 */
	isa_bridge_find_early(hose);

	return 0;
}

void __init pas_pci_init(void)
{
	struct device_node *np, *root;
	int res;

	root = of_find_node_by_path("/");
	if (!root) {
		pr_crit("pas_pci_init: can't find root of device tree\n");
		return;
	}

	pci_set_flags(PCI_SCAN_ALL_PCIE_DEVS);

	np = of_find_compatible_node(root, NULL, "pasemi,rootbus");
	if (np) {
		res = pas_add_bridge(np);
		of_node_put(np);
	}
}

void __iomem *__init pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset)
{
	struct pci_controller *hose;

	hose = pci_bus_to_host(dev->bus);

	return (void __iomem *)pa_pxp_cfg_addr(hose, dev->bus->number, dev->devfn, offset);
}

struct pci_controller_ops pasemi_pci_controller_ops;