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14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/interrupt.h>
19#include <linux/sysfs.h>
20#include <linux/io.h>
21#include <linux/string.h>
22#include <linux/device.h>
23#include <linux/list.h>
24#include <linux/of.h>
25#include <linux/bitops.h>
26#include <linux/pm.h>
27
28#ifdef CONFIG_ARM
29#include <asm/bug.h>
30#include <asm/signal.h>
31#endif
32
33#ifdef CONFIG_MIPS
34#include <asm/traps.h>
35#endif
36
37#define ARB_ERR_CAP_CLEAR (1 << 0)
38#define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
39#define ARB_ERR_CAP_STATUS_TEA (1 << 11)
40#define ARB_ERR_CAP_STATUS_BS_SHIFT (1 << 2)
41#define ARB_ERR_CAP_STATUS_BS_MASK 0x3c
42#define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
43#define ARB_ERR_CAP_STATUS_VALID (1 << 0)
44
45enum {
46 ARB_TIMER,
47 ARB_ERR_CAP_CLR,
48 ARB_ERR_CAP_HI_ADDR,
49 ARB_ERR_CAP_ADDR,
50 ARB_ERR_CAP_DATA,
51 ARB_ERR_CAP_STATUS,
52 ARB_ERR_CAP_MASTER,
53};
54
55static const int gisb_offsets_bcm7038[] = {
56 [ARB_TIMER] = 0x00c,
57 [ARB_ERR_CAP_CLR] = 0x0c4,
58 [ARB_ERR_CAP_HI_ADDR] = -1,
59 [ARB_ERR_CAP_ADDR] = 0x0c8,
60 [ARB_ERR_CAP_DATA] = 0x0cc,
61 [ARB_ERR_CAP_STATUS] = 0x0d0,
62 [ARB_ERR_CAP_MASTER] = -1,
63};
64
65static const int gisb_offsets_bcm7400[] = {
66 [ARB_TIMER] = 0x00c,
67 [ARB_ERR_CAP_CLR] = 0x0c8,
68 [ARB_ERR_CAP_HI_ADDR] = -1,
69 [ARB_ERR_CAP_ADDR] = 0x0cc,
70 [ARB_ERR_CAP_DATA] = 0x0d0,
71 [ARB_ERR_CAP_STATUS] = 0x0d4,
72 [ARB_ERR_CAP_MASTER] = 0x0d8,
73};
74
75static const int gisb_offsets_bcm7435[] = {
76 [ARB_TIMER] = 0x00c,
77 [ARB_ERR_CAP_CLR] = 0x168,
78 [ARB_ERR_CAP_HI_ADDR] = -1,
79 [ARB_ERR_CAP_ADDR] = 0x16c,
80 [ARB_ERR_CAP_DATA] = 0x170,
81 [ARB_ERR_CAP_STATUS] = 0x174,
82 [ARB_ERR_CAP_MASTER] = 0x178,
83};
84
85static const int gisb_offsets_bcm7445[] = {
86 [ARB_TIMER] = 0x008,
87 [ARB_ERR_CAP_CLR] = 0x7e4,
88 [ARB_ERR_CAP_HI_ADDR] = 0x7e8,
89 [ARB_ERR_CAP_ADDR] = 0x7ec,
90 [ARB_ERR_CAP_DATA] = 0x7f0,
91 [ARB_ERR_CAP_STATUS] = 0x7f4,
92 [ARB_ERR_CAP_MASTER] = 0x7f8,
93};
94
95struct brcmstb_gisb_arb_device {
96 void __iomem *base;
97 const int *gisb_offsets;
98 bool big_endian;
99 struct mutex lock;
100 struct list_head next;
101 u32 valid_mask;
102 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
103 u32 saved_timeout;
104};
105
106static LIST_HEAD(brcmstb_gisb_arb_device_list);
107
108static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
109{
110 int offset = gdev->gisb_offsets[reg];
111
112
113 if (offset == -1)
114 return 1;
115
116 if (gdev->big_endian)
117 return ioread32be(gdev->base + offset);
118 else
119 return ioread32(gdev->base + offset);
120}
121
122static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
123{
124 int offset = gdev->gisb_offsets[reg];
125
126 if (offset == -1)
127 return;
128
129 if (gdev->big_endian)
130 iowrite32be(val, gdev->base + reg);
131 else
132 iowrite32(val, gdev->base + reg);
133}
134
135static ssize_t gisb_arb_get_timeout(struct device *dev,
136 struct device_attribute *attr,
137 char *buf)
138{
139 struct platform_device *pdev = to_platform_device(dev);
140 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
141 u32 timeout;
142
143 mutex_lock(&gdev->lock);
144 timeout = gisb_read(gdev, ARB_TIMER);
145 mutex_unlock(&gdev->lock);
146
147 return sprintf(buf, "%d", timeout);
148}
149
150static ssize_t gisb_arb_set_timeout(struct device *dev,
151 struct device_attribute *attr,
152 const char *buf, size_t count)
153{
154 struct platform_device *pdev = to_platform_device(dev);
155 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
156 int val, ret;
157
158 ret = kstrtoint(buf, 10, &val);
159 if (ret < 0)
160 return ret;
161
162 if (val == 0 || val >= 0xffffffff)
163 return -EINVAL;
164
165 mutex_lock(&gdev->lock);
166 gisb_write(gdev, val, ARB_TIMER);
167 mutex_unlock(&gdev->lock);
168
169 return count;
170}
171
172static const char *
173brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
174 u32 masters)
175{
176 u32 mask = gdev->valid_mask & masters;
177
178 if (hweight_long(mask) != 1)
179 return NULL;
180
181 return gdev->master_names[ffs(mask) - 1];
182}
183
184static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
185 const char *reason)
186{
187 u32 cap_status;
188 unsigned long arb_addr;
189 u32 master;
190 const char *m_name;
191 char m_fmt[11];
192
193 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
194
195
196 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
197 return 1;
198
199
200 arb_addr = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
201#if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
202 arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
203#endif
204 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
205
206 m_name = brcmstb_gisb_master_to_str(gdev, master);
207 if (!m_name) {
208 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
209 m_name = m_fmt;
210 }
211
212 pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
213 __func__, reason, arb_addr,
214 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
215 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
216 m_name);
217
218
219 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
220
221 return 0;
222}
223
224#ifdef CONFIG_ARM
225static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
226 struct pt_regs *regs)
227{
228 int ret = 0;
229 struct brcmstb_gisb_arb_device *gdev;
230
231
232 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
233 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
234
235
236
237
238 if (fsr & (1 << 10))
239 regs->ARM_pc += 4;
240
241 return ret;
242}
243#endif
244
245#ifdef CONFIG_MIPS
246static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
247{
248 int ret = 0;
249 struct brcmstb_gisb_arb_device *gdev;
250 u32 cap_status;
251
252 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
253 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
254
255
256 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
257 is_fixup = 1;
258 goto out;
259 }
260
261 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
262 }
263out:
264 return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
265}
266#endif
267
268static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
269{
270 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
271
272 return IRQ_HANDLED;
273}
274
275static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
276{
277 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
278
279 return IRQ_HANDLED;
280}
281
282static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
283 gisb_arb_get_timeout, gisb_arb_set_timeout);
284
285static struct attribute *gisb_arb_sysfs_attrs[] = {
286 &dev_attr_gisb_arb_timeout.attr,
287 NULL,
288};
289
290static struct attribute_group gisb_arb_sysfs_attr_group = {
291 .attrs = gisb_arb_sysfs_attrs,
292};
293
294static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
295 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
296 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
297 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
298 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
299 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
300 { },
301};
302
303static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
304{
305 struct device_node *dn = pdev->dev.of_node;
306 struct brcmstb_gisb_arb_device *gdev;
307 const struct of_device_id *of_id;
308 struct resource *r;
309 int err, timeout_irq, tea_irq;
310 unsigned int num_masters, j = 0;
311 int i, first, last;
312
313 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
314 timeout_irq = platform_get_irq(pdev, 0);
315 tea_irq = platform_get_irq(pdev, 1);
316
317 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
318 if (!gdev)
319 return -ENOMEM;
320
321 mutex_init(&gdev->lock);
322 INIT_LIST_HEAD(&gdev->next);
323
324 gdev->base = devm_ioremap_resource(&pdev->dev, r);
325 if (IS_ERR(gdev->base))
326 return PTR_ERR(gdev->base);
327
328 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
329 if (!of_id) {
330 pr_err("failed to look up compatible string\n");
331 return -EINVAL;
332 }
333 gdev->gisb_offsets = of_id->data;
334 gdev->big_endian = of_device_is_big_endian(dn);
335
336 err = devm_request_irq(&pdev->dev, timeout_irq,
337 brcmstb_gisb_timeout_handler, 0, pdev->name,
338 gdev);
339 if (err < 0)
340 return err;
341
342 err = devm_request_irq(&pdev->dev, tea_irq,
343 brcmstb_gisb_tea_handler, 0, pdev->name,
344 gdev);
345 if (err < 0)
346 return err;
347
348
349 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
350 &gdev->valid_mask))
351 gdev->valid_mask = 0xffffffff;
352
353
354
355
356 num_masters = of_property_count_strings(dn,
357 "brcm,gisb-arb-master-names");
358 if (hweight_long(gdev->valid_mask) == num_masters) {
359 first = ffs(gdev->valid_mask) - 1;
360 last = fls(gdev->valid_mask) - 1;
361
362 for (i = first; i < last; i++) {
363 if (!(gdev->valid_mask & BIT(i)))
364 continue;
365
366 of_property_read_string_index(dn,
367 "brcm,gisb-arb-master-names", j,
368 &gdev->master_names[i]);
369 j++;
370 }
371 }
372
373 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
374 if (err)
375 return err;
376
377 platform_set_drvdata(pdev, gdev);
378
379 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
380
381#ifdef CONFIG_ARM
382 hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
383 "imprecise external abort");
384#endif
385#ifdef CONFIG_MIPS
386 board_be_handler = brcmstb_bus_error_handler;
387#endif
388
389 dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
390 gdev->base, timeout_irq, tea_irq);
391
392 return 0;
393}
394
395#ifdef CONFIG_PM_SLEEP
396static int brcmstb_gisb_arb_suspend(struct device *dev)
397{
398 struct platform_device *pdev = to_platform_device(dev);
399 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
400
401 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
402
403 return 0;
404}
405
406
407
408
409static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
410{
411 struct platform_device *pdev = to_platform_device(dev);
412 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
413
414 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
415
416 return 0;
417}
418#else
419#define brcmstb_gisb_arb_suspend NULL
420#define brcmstb_gisb_arb_resume_noirq NULL
421#endif
422
423static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
424 .suspend = brcmstb_gisb_arb_suspend,
425 .resume_noirq = brcmstb_gisb_arb_resume_noirq,
426};
427
428static struct platform_driver brcmstb_gisb_arb_driver = {
429 .driver = {
430 .name = "brcm-gisb-arb",
431 .of_match_table = brcmstb_gisb_arb_of_match,
432 .pm = &brcmstb_gisb_arb_pm_ops,
433 },
434};
435
436static int __init brcm_gisb_driver_init(void)
437{
438 return platform_driver_probe(&brcmstb_gisb_arb_driver,
439 brcmstb_gisb_arb_probe);
440}
441
442module_init(brcm_gisb_driver_init);
443
