summaryrefslogtreecommitdiffstats
path: root/arch/mips/pci/pci-ar724x.c
blob: 279585d6eca054b525fc500b553d6e5058348606 (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
/*
 *  Atheros AR724X PCI host controller driver
 *
 *  Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
 *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 */

#include <linux/irq.h>
#include <linux/pci.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include <asm/mach-ath79/pci.h>

#define AR724X_PCI_CFG_BASE	0x14000000
#define AR724X_PCI_CFG_SIZE	0x1000
#define AR724X_PCI_CTRL_BASE	(AR71XX_APB_BASE + 0x000f0000)
#define AR724X_PCI_CTRL_SIZE	0x100

#define AR724X_PCI_MEM_BASE	0x10000000
#define AR724X_PCI_MEM_SIZE	0x04000000

#define AR724X_PCI_REG_RESET		0x18
#define AR724X_PCI_REG_INT_STATUS	0x4c
#define AR724X_PCI_REG_INT_MASK		0x50

#define AR724X_PCI_RESET_LINK_UP	BIT(0)

#define AR724X_PCI_INT_DEV0		BIT(14)

#define AR724X_PCI_IRQ_COUNT		1

#define AR7240_BAR0_WAR_VALUE	0xffff

static DEFINE_SPINLOCK(ar724x_pci_lock);
static void __iomem *ar724x_pci_devcfg_base;
static void __iomem *ar724x_pci_ctrl_base;

static u32 ar724x_pci_bar0_value;
static bool ar724x_pci_bar0_is_cached;
static bool ar724x_pci_link_up;

static inline bool ar724x_pci_check_link(void)
{
	u32 reset;

	reset = __raw_readl(ar724x_pci_ctrl_base + AR724X_PCI_REG_RESET);
	return reset & AR724X_PCI_RESET_LINK_UP;
}

static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
			    int size, uint32_t *value)
{
	unsigned long flags;
	void __iomem *base;
	u32 data;

	if (!ar724x_pci_link_up)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (devfn)
		return PCIBIOS_DEVICE_NOT_FOUND;

	base = ar724x_pci_devcfg_base;

	spin_lock_irqsave(&ar724x_pci_lock, flags);
	data = __raw_readl(base + (where & ~3));

	switch (size) {
	case 1:
		if (where & 1)
			data >>= 8;
		if (where & 2)
			data >>= 16;
		data &= 0xff;
		break;
	case 2:
		if (where & 2)
			data >>= 16;
		data &= 0xffff;
		break;
	case 4:
		break;
	default:
		spin_unlock_irqrestore(&ar724x_pci_lock, flags);

		return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	spin_unlock_irqrestore(&ar724x_pci_lock, flags);

	if (where == PCI_BASE_ADDRESS_0 && size == 4 &&
	    ar724x_pci_bar0_is_cached) {
		/* use the cached value */
		*value = ar724x_pci_bar0_value;
	} else {
		*value = data;
	}

	return PCIBIOS_SUCCESSFUL;
}

static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
			     int size, uint32_t value)
{
	unsigned long flags;
	void __iomem *base;
	u32 data;
	int s;

	if (!ar724x_pci_link_up)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (devfn)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (soc_is_ar7240() && where == PCI_BASE_ADDRESS_0 && size == 4) {
		if (value != 0xffffffff) {
			/*
			 * WAR for a hw issue. If the BAR0 register of the
			 * device is set to the proper base address, the
			 * memory space of the device is not accessible.
			 *
			 * Cache the intended value so it can be read back,
			 * and write a SoC specific constant value to the
			 * BAR0 register in order to make the device memory
			 * accessible.
			 */
			ar724x_pci_bar0_is_cached = true;
			ar724x_pci_bar0_value = value;

			value = AR7240_BAR0_WAR_VALUE;
		} else {
			ar724x_pci_bar0_is_cached = false;
		}
	}

	base = ar724x_pci_devcfg_base;

	spin_lock_irqsave(&ar724x_pci_lock, flags);
	data = __raw_readl(base + (where & ~3));

	switch (size) {
	case 1:
		s = ((where & 3) * 8);
		data &= ~(0xff << s);
		data |= ((value & 0xff) << s);
		break;
	case 2:
		s = ((where & 2) * 8);
		data &= ~(0xffff << s);
		data |= ((value & 0xffff) << s);
		break;
	case 4:
		data = value;
		break;
	default:
		spin_unlock_irqrestore(&ar724x_pci_lock, flags);

		return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	__raw_writel(data, base + (where & ~3));
	/* flush write */
	__raw_readl(base + (where & ~3));
	spin_unlock_irqrestore(&ar724x_pci_lock, flags);

	return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops ar724x_pci_ops = {
	.read	= ar724x_pci_read,
	.write	= ar724x_pci_write,
};

static struct resource ar724x_io_resource = {
	.name	= "PCI IO space",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_IO,
};

static struct resource ar724x_mem_resource = {
	.name	= "PCI memory space",
	.start	= AR724X_PCI_MEM_BASE,
	.end	= AR724X_PCI_MEM_BASE + AR724X_PCI_MEM_SIZE - 1,
	.flags	= IORESOURCE_MEM,
};

static struct pci_controller ar724x_pci_controller = {
	.pci_ops	= &ar724x_pci_ops,
	.io_resource	= &ar724x_io_resource,
	.mem_resource	= &ar724x_mem_resource,
};

static void ar724x_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
{
	void __iomem *base;
	u32 pending;

	base = ar724x_pci_ctrl_base;

	pending = __raw_readl(base + AR724X_PCI_REG_INT_STATUS) &
		  __raw_readl(base + AR724X_PCI_REG_INT_MASK);

	if (pending & AR724X_PCI_INT_DEV0)
		generic_handle_irq(ATH79_PCI_IRQ(0));

	else
		spurious_interrupt();
}

static void ar724x_pci_irq_unmask(struct irq_data *d)
{
	void __iomem *base;
	u32 t;

	base = ar724x_pci_ctrl_base;

	switch (d->irq) {
	case ATH79_PCI_IRQ(0):
		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
		__raw_writel(t | AR724X_PCI_INT_DEV0,
			     base + AR724X_PCI_REG_INT_MASK);
		/* flush write */
		__raw_readl(base + AR724X_PCI_REG_INT_MASK);
	}
}

static void ar724x_pci_irq_mask(struct irq_data *d)
{
	void __iomem *base;
	u32 t;

	base = ar724x_pci_ctrl_base;

	switch (d->irq) {
	case ATH79_PCI_IRQ(0):
		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
		__raw_writel(t & ~AR724X_PCI_INT_DEV0,
			     base + AR724X_PCI_REG_INT_MASK);

		/* flush write */
		__raw_readl(base + AR724X_PCI_REG_INT_MASK);

		t = __raw_readl(base + AR724X_PCI_REG_INT_STATUS);
		__raw_writel(t | AR724X_PCI_INT_DEV0,
			     base + AR724X_PCI_REG_INT_STATUS);

		/* flush write */
		__raw_readl(base + AR724X_PCI_REG_INT_STATUS);
	}
}

static struct irq_chip ar724x_pci_irq_chip = {
	.name		= "AR724X PCI ",
	.irq_mask	= ar724x_pci_irq_mask,
	.irq_unmask	= ar724x_pci_irq_unmask,
	.irq_mask_ack	= ar724x_pci_irq_mask,
};

static void __init ar724x_pci_irq_init(int irq)
{
	void __iomem *base;
	int i;

	base = ar724x_pci_ctrl_base;

	__raw_writel(0, base + AR724X_PCI_REG_INT_MASK);
	__raw_writel(0, base + AR724X_PCI_REG_INT_STATUS);

	BUILD_BUG_ON(ATH79_PCI_IRQ_COUNT < AR724X_PCI_IRQ_COUNT);

	for (i = ATH79_PCI_IRQ_BASE;
	     i < ATH79_PCI_IRQ_BASE + AR724X_PCI_IRQ_COUNT; i++)
		irq_set_chip_and_handler(i, &ar724x_pci_irq_chip,
					 handle_level_irq);

	irq_set_chained_handler(irq, ar724x_pci_irq_handler);
}

int __init ar724x_pcibios_init(int irq)
{
	int ret;

	ret = -ENOMEM;

	ar724x_pci_devcfg_base = ioremap(AR724X_PCI_CFG_BASE,
					 AR724X_PCI_CFG_SIZE);
	if (ar724x_pci_devcfg_base == NULL)
		goto err;

	ar724x_pci_ctrl_base = ioremap(AR724X_PCI_CTRL_BASE,
				       AR724X_PCI_CTRL_SIZE);
	if (ar724x_pci_ctrl_base == NULL)
		goto err_unmap_devcfg;

	ar724x_pci_link_up = ar724x_pci_check_link();
	if (!ar724x_pci_link_up)
		pr_warn("ar724x: PCIe link is down\n");

	ar724x_pci_irq_init(irq);
	register_pci_controller(&ar724x_pci_controller);

	return PCIBIOS_SUCCESSFUL;

err_unmap_devcfg:
	iounmap(ar724x_pci_devcfg_base);
err:
	return ret;
}
OpenPOWER on IntegriCloud