aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/bus/brcmstb_gisb.c
blob: f2cd6a2d40b4e5fa1c40b7d1da99d204fafb080d (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
/*
 * Copyright (C) 2014 Broadcom Corporation
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/io.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/bitops.h>

#include <asm/bug.h>
#include <asm/signal.h>

#define ARB_TIMER			0x008
#define ARB_ERR_CAP_CLR			0x7e4
#define  ARB_ERR_CAP_CLEAR		(1 << 0)
#define ARB_ERR_CAP_HI_ADDR		0x7e8
#define ARB_ERR_CAP_ADDR		0x7ec
#define ARB_ERR_CAP_DATA		0x7f0
#define ARB_ERR_CAP_STATUS		0x7f4
#define  ARB_ERR_CAP_STATUS_TIMEOUT	(1 << 12)
#define  ARB_ERR_CAP_STATUS_TEA		(1 << 11)
#define  ARB_ERR_CAP_STATUS_BS_SHIFT	(1 << 2)
#define  ARB_ERR_CAP_STATUS_BS_MASK	0x3c
#define  ARB_ERR_CAP_STATUS_WRITE	(1 << 1)
#define  ARB_ERR_CAP_STATUS_VALID	(1 << 0)
#define ARB_ERR_CAP_MASTER		0x7f8

struct brcmstb_gisb_arb_device {
	void __iomem	*base;
	struct mutex	lock;
	struct list_head next;
	u32 valid_mask;
	const char *master_names[sizeof(u32) * BITS_PER_BYTE];
};

static LIST_HEAD(brcmstb_gisb_arb_device_list);

static ssize_t gisb_arb_get_timeout(struct device *dev,
				    struct device_attribute *attr,
				    char *buf)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
	u32 timeout;

	mutex_lock(&gdev->lock);
	timeout = ioread32(gdev->base + ARB_TIMER);
	mutex_unlock(&gdev->lock);

	return sprintf(buf, "%d", timeout);
}

static ssize_t gisb_arb_set_timeout(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf, size_t count)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
	int val, ret;

	ret = kstrtoint(buf, 10, &val);
	if (ret < 0)
		return ret;

	if (val == 0 || val >= 0xffffffff)
		return -EINVAL;

	mutex_lock(&gdev->lock);
	iowrite32(val, gdev->base + ARB_TIMER);
	mutex_unlock(&gdev->lock);

	return count;
}

static const char *
brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
						u32 masters)
{
	u32 mask = gdev->valid_mask & masters;

	if (hweight_long(mask) != 1)
		return NULL;

	return gdev->master_names[ffs(mask) - 1];
}

static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
					const char *reason)
{
	u32 cap_status;
	unsigned long arb_addr;
	u32 master;
	const char *m_name;
	char m_fmt[11];

	cap_status = ioread32(gdev->base + ARB_ERR_CAP_STATUS);

	/* Invalid captured address, bail out */
	if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
		return 1;

	/* Read the address and master */
	arb_addr = ioread32(gdev->base + ARB_ERR_CAP_ADDR) & 0xffffffff;
#if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
	arb_addr |= (u64)ioread32(gdev->base + ARB_ERR_CAP_HI_ADDR) << 32;
#endif
	master = ioread32(gdev->base + ARB_ERR_CAP_MASTER);

	m_name = brcmstb_gisb_master_to_str(gdev, master);
	if (!m_name) {
		snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
		m_name = m_fmt;
	}

	pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
		__func__, reason, arb_addr,
		cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
		cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
		m_name);

	/* clear the GISB error */
	iowrite32(ARB_ERR_CAP_CLEAR, gdev->base + ARB_ERR_CAP_CLR);

	return 0;
}

static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
				     struct pt_regs *regs)
{
	int ret = 0;
	struct brcmstb_gisb_arb_device *gdev;

	/* iterate over each GISB arb registered handlers */
	list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
		ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
	/*
	 * If it was an imprecise abort, then we need to correct the
	 * return address to be _after_ the instruction.
	*/
	if (fsr & (1 << 10))
		regs->ARM_pc += 4;

	return ret;
}

void __init brcmstb_hook_fault_code(void)
{
	hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
			"imprecise external abort");
}

static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
{
	brcmstb_gisb_arb_decode_addr(dev_id, "timeout");

	return IRQ_HANDLED;
}

static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
{
	brcmstb_gisb_arb_decode_addr(dev_id, "target abort");

	return IRQ_HANDLED;
}

static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
		gisb_arb_get_timeout, gisb_arb_set_timeout);

static struct attribute *gisb_arb_sysfs_attrs[] = {
	&dev_attr_gisb_arb_timeout.attr,
	NULL,
};

static struct attribute_group gisb_arb_sysfs_attr_group = {
	.attrs = gisb_arb_sysfs_attrs,
};

static int brcmstb_gisb_arb_probe(struct platform_device *pdev)
{
	struct device_node *dn = pdev->dev.of_node;
	struct brcmstb_gisb_arb_device *gdev;
	struct resource *r;
	int err, timeout_irq, tea_irq;
	unsigned int num_masters, j = 0;
	int i, first, last;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	timeout_irq = platform_get_irq(pdev, 0);
	tea_irq = platform_get_irq(pdev, 1);

	gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
	if (!gdev)
		return -ENOMEM;

	mutex_init(&gdev->lock);
	INIT_LIST_HEAD(&gdev->next);

	gdev->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(gdev->base))
		return PTR_ERR(gdev->base);

	err = devm_request_irq(&pdev->dev, timeout_irq,
				brcmstb_gisb_timeout_handler, 0, pdev->name,
				gdev);
	if (err < 0)
		return err;

	err = devm_request_irq(&pdev->dev, tea_irq,
				brcmstb_gisb_tea_handler, 0, pdev->name,
				gdev);
	if (err < 0)
		return err;

	/* If we do not have a valid mask, assume all masters are enabled */
	if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
				&gdev->valid_mask))
		gdev->valid_mask = 0xffffffff;

	/* Proceed with reading the litteral names if we agree on the
	 * number of masters
	 */
	num_masters = of_property_count_strings(dn,
			"brcm,gisb-arb-master-names");
	if (hweight_long(gdev->valid_mask) == num_masters) {
		first = ffs(gdev->valid_mask) - 1;
		last = fls(gdev->valid_mask) - 1;

		for (i = first; i < last; i++) {
			if (!(gdev->valid_mask & BIT(i)))
				continue;

			of_property_read_string_index(dn,
					"brcm,gisb-arb-master-names", j,
					&gdev->master_names[i]);
			j++;
		}
	}

	err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
	if (err)
		return err;

	platform_set_drvdata(pdev, gdev);

	list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);

	dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
			gdev->base, timeout_irq, tea_irq);

	return 0;
}

static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
	{ .compatible = "brcm,gisb-arb" },
	{ },
};

static struct platform_driver brcmstb_gisb_arb_driver = {
	.probe	= brcmstb_gisb_arb_probe,
	.driver = {
		.name	= "brcm-gisb-arb",
		.owner	= THIS_MODULE,
		.of_match_table = brcmstb_gisb_arb_of_match,
	},
};

static int __init brcm_gisb_driver_init(void)
{
	return platform_driver_register(&brcmstb_gisb_arb_driver);
}

module_init(brcm_gisb_driver_init);

Privacy Policy