summaryrefslogtreecommitdiff
path: root/arch/x86/pci/sta2x11-fixup.c
blob: 97bbc12dd6b2ca0380f773ca09fec81549aba522 (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
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
// SPDX-License-Identifier: GPL-2.0-only
/*
 * arch/x86/pci/sta2x11-fixup.c
 * glue code for lib/swiotlb.c and DMA translation between STA2x11
 * AMBA memory mapping and the X86 memory mapping
 *
 * ST Microelectronics ConneXt (STA2X11/STA2X10)
 *
 * Copyright (c) 2010-2011 Wind River Systems, Inc.
 */

#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/export.h>
#include <linux/list.h>
#include <linux/dma-direct.h>
#include <asm/iommu.h>

#define STA2X11_SWIOTLB_SIZE (4*1024*1024)
extern int swiotlb_late_init_with_default_size(size_t default_size);

/*
 * We build a list of bus numbers that are under the ConneXt. The
 * main bridge hosts 4 busses, which are the 4 endpoints, in order.
 */
#define STA2X11_NR_EP		4	/* 0..3 included */
#define STA2X11_NR_FUNCS	8	/* 0..7 included */
#define STA2X11_AMBA_SIZE	(512 << 20)

struct sta2x11_ahb_regs { /* saved during suspend */
	u32 base, pexlbase, pexhbase, crw;
};

struct sta2x11_mapping {
	u32 amba_base;
	int is_suspended;
	struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
};

struct sta2x11_instance {
	struct list_head list;
	int bus0;
	struct sta2x11_mapping map[STA2X11_NR_EP];
};

static LIST_HEAD(sta2x11_instance_list);

/* At probe time, record new instances of this bridge (likely one only) */
static void sta2x11_new_instance(struct pci_dev *pdev)
{
	struct sta2x11_instance *instance;

	instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
	if (!instance)
		return;
	/* This has a subordinate bridge, with 4 more-subordinate ones */
	instance->bus0 = pdev->subordinate->number + 1;

	if (list_empty(&sta2x11_instance_list)) {
		int size = STA2X11_SWIOTLB_SIZE;
		/* First instance: register your own swiotlb area */
		dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
		if (swiotlb_late_init_with_default_size(size))
			dev_emerg(&pdev->dev, "init swiotlb failed\n");
	}
	list_add(&instance->list, &sta2x11_instance_list);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);

/*
 * Utility functions used in this file from below
 */
static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
{
	struct sta2x11_instance *instance;
	int ep;

	list_for_each_entry(instance, &sta2x11_instance_list, list) {
		ep = pdev->bus->number - instance->bus0;
		if (ep >= 0 && ep < STA2X11_NR_EP)
			return instance;
	}
	return NULL;
}

static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
{
	struct sta2x11_instance *instance;

	instance = sta2x11_pdev_to_instance(pdev);
	if (!instance)
		return -1;

	return pdev->bus->number - instance->bus0;
}

static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
{
	struct sta2x11_instance *instance;
	int ep;

	instance = sta2x11_pdev_to_instance(pdev);
	if (!instance)
		return NULL;
	ep = sta2x11_pdev_to_ep(pdev);
	return instance->map + ep;
}

/* This is exported, as some devices need to access the MFD registers */
struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
{
	return sta2x11_pdev_to_instance(pdev);
}
EXPORT_SYMBOL(sta2x11_get_instance);


/**
 * p2a - Translate physical address to STA2x11 AMBA address,
 *       used for DMA transfers to STA2x11
 * @p: Physical address
 * @pdev: PCI device (must be hosted within the connext)
 */
static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
{
	struct sta2x11_mapping *map;
	dma_addr_t a;

	map = sta2x11_pdev_to_mapping(pdev);
	a = p + map->amba_base;
	return a;
}

/**
 * a2p - Translate STA2x11 AMBA address to physical address
 *       used for DMA transfers from STA2x11
 * @a: STA2x11 AMBA address
 * @pdev: PCI device (must be hosted within the connext)
 */
static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
{
	struct sta2x11_mapping *map;
	dma_addr_t p;

	map = sta2x11_pdev_to_mapping(pdev);
	p = a - map->amba_base;
	return p;
}

/* At setup time, we use our own ops if the device is a ConneXt one */
static void sta2x11_setup_pdev(struct pci_dev *pdev)
{
	struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);

	if (!instance) /* either a sta2x11 bridge or another ST device */
		return;
	pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
	pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
	pdev->dev.archdata.is_sta2x11 = true;

	/* We must enable all devices as master, for audio DMA to work */
	pci_set_master(pdev);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);

/*
 * The following three functions are exported (used in swiotlb: FIXME)
 */
/**
 * dma_capable - Check if device can manage DMA transfers (FIXME: kill it)
 * @dev: device for a PCI device
 * @addr: DMA address
 * @size: DMA size
 */
bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
	struct sta2x11_mapping *map;

	if (!dev->archdata.is_sta2x11) {
		if (!dev->dma_mask)
			return false;
		return addr + size - 1 <= *dev->dma_mask;
	}

	map = sta2x11_pdev_to_mapping(to_pci_dev(dev));

	if (!map || (addr < map->amba_base))
		return false;
	if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
		return false;
	}

	return true;
}

/**
 * __phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
 * @dev: device for a PCI device
 * @paddr: Physical address
 */
dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
	if (!dev->archdata.is_sta2x11)
		return paddr;
	return p2a(paddr, to_pci_dev(dev));
}

/**
 * dma_to_phys - Return the physical address used for this STA2x11 DMA address
 * @dev: device for a PCI device
 * @daddr: STA2x11 AMBA DMA address
 */
phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
{
	if (!dev->archdata.is_sta2x11)
		return daddr;
	return a2p(daddr, to_pci_dev(dev));
}


/*
 * At boot we must set up the mappings for the pcie-to-amba bridge.
 * It involves device access, and the same happens at suspend/resume time
 */

#define AHB_MAPB		0xCA4
#define AHB_CRW(i)		(AHB_MAPB + 0  + (i) * 0x10)
#define AHB_CRW_SZMASK			0xfffffc00UL
#define AHB_CRW_ENABLE			(1 << 0)
#define AHB_CRW_WTYPE_MEM		(2 << 1)
#define AHB_CRW_ROE			(1UL << 3)	/* Relax Order Ena */
#define AHB_CRW_NSE			(1UL << 4)	/* No Snoop Enable */
#define AHB_BASE(i)		(AHB_MAPB + 4  + (i) * 0x10)
#define AHB_PEXLBASE(i)		(AHB_MAPB + 8  + (i) * 0x10)
#define AHB_PEXHBASE(i)		(AHB_MAPB + 12 + (i) * 0x10)

/* At probe time, enable mapping for each endpoint, using the pdev */
static void sta2x11_map_ep(struct pci_dev *pdev)
{
	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
	int i;

	if (!map)
		return;
	pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);

	/* Configure AHB mapping */
	pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
	pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
	pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
			       AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);

	/* Disable all the other windows */
	for (i = 1; i < STA2X11_NR_FUNCS; i++)
		pci_write_config_dword(pdev, AHB_CRW(i), 0);

	dev_info(&pdev->dev,
		 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
		 sta2x11_pdev_to_ep(pdev),  map->amba_base,
		 map->amba_base + STA2X11_AMBA_SIZE - 1);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);

#ifdef CONFIG_PM /* Some register values must be saved and restored */

static void suspend_mapping(struct pci_dev *pdev)
{
	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
	int i;

	if (!map)
		return;

	if (map->is_suspended)
		return;
	map->is_suspended = 1;

	/* Save all window configs */
	for (i = 0; i < STA2X11_NR_FUNCS; i++) {
		struct sta2x11_ahb_regs *regs = map->regs + i;

		pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
		pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
		pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
		pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
	}
}
DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);

static void resume_mapping(struct pci_dev *pdev)
{
	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
	int i;

	if (!map)
		return;


	if (!map->is_suspended)
		goto out;
	map->is_suspended = 0;

	/* Restore all window configs */
	for (i = 0; i < STA2X11_NR_FUNCS; i++) {
		struct sta2x11_ahb_regs *regs = map->regs + i;

		pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
		pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
		pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
		pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
	}
out:
	pci_set_master(pdev); /* Like at boot, enable master on all devices */
}
DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);

#endif /* CONFIG_PM */