2 * Copyright (C) 2014 Broadcom Corporation
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
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>
21 #include <linux/string.h>
22 #include <linux/device.h>
23 #include <linux/list.h>
25 #include <linux/bitops.h>
30 #include <asm/signal.h>
34 #include <asm/traps.h>
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)
55 static const int gisb_offsets_bcm7038[] = {
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,
65 static const int gisb_offsets_bcm7400[] = {
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,
75 static const int gisb_offsets_bcm7435[] = {
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,
85 static const int gisb_offsets_bcm7445[] = {
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,
95 struct brcmstb_gisb_arb_device {
97 const int *gisb_offsets;
100 struct list_head next;
102 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
106 static LIST_HEAD(brcmstb_gisb_arb_device_list);
108 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
110 int offset = gdev->gisb_offsets[reg];
112 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
116 if (gdev->big_endian)
117 return ioread32be(gdev->base + offset);
119 return ioread32(gdev->base + offset);
122 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
124 int offset = gdev->gisb_offsets[reg];
129 if (gdev->big_endian)
130 iowrite32be(val, gdev->base + reg);
132 iowrite32(val, gdev->base + reg);
135 static ssize_t gisb_arb_get_timeout(struct device *dev,
136 struct device_attribute *attr,
139 struct platform_device *pdev = to_platform_device(dev);
140 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
143 mutex_lock(&gdev->lock);
144 timeout = gisb_read(gdev, ARB_TIMER);
145 mutex_unlock(&gdev->lock);
147 return sprintf(buf, "%d", timeout);
150 static ssize_t gisb_arb_set_timeout(struct device *dev,
151 struct device_attribute *attr,
152 const char *buf, size_t count)
154 struct platform_device *pdev = to_platform_device(dev);
155 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
158 ret = kstrtoint(buf, 10, &val);
162 if (val == 0 || val >= 0xffffffff)
165 mutex_lock(&gdev->lock);
166 gisb_write(gdev, val, ARB_TIMER);
167 mutex_unlock(&gdev->lock);
173 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
176 u32 mask = gdev->valid_mask & masters;
178 if (hweight_long(mask) != 1)
181 return gdev->master_names[ffs(mask) - 1];
184 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
188 unsigned long arb_addr;
193 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
195 /* Invalid captured address, bail out */
196 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
199 /* Read the address and master */
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;
204 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
206 m_name = brcmstb_gisb_master_to_str(gdev, master);
208 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
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" : "",
218 /* clear the GISB error */
219 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
225 static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
226 struct pt_regs *regs)
229 struct brcmstb_gisb_arb_device *gdev;
231 /* iterate over each GISB arb registered handlers */
232 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
233 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
235 * If it was an imprecise abort, then we need to correct the
236 * return address to be _after_ the instruction.
246 static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
249 struct brcmstb_gisb_arb_device *gdev;
252 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
253 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
255 /* Invalid captured address, bail out */
256 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
261 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
264 return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
268 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
270 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
275 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
277 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
282 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
283 gisb_arb_get_timeout, gisb_arb_set_timeout);
285 static struct attribute *gisb_arb_sysfs_attrs[] = {
286 &dev_attr_gisb_arb_timeout.attr,
290 static struct attribute_group gisb_arb_sysfs_attr_group = {
291 .attrs = gisb_arb_sysfs_attrs,
294 static 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 },
303 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
305 struct device_node *dn = pdev->dev.of_node;
306 struct brcmstb_gisb_arb_device *gdev;
307 const struct of_device_id *of_id;
309 int err, timeout_irq, tea_irq;
310 unsigned int num_masters, j = 0;
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);
317 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
321 mutex_init(&gdev->lock);
322 INIT_LIST_HEAD(&gdev->next);
324 gdev->base = devm_ioremap_resource(&pdev->dev, r);
325 if (IS_ERR(gdev->base))
326 return PTR_ERR(gdev->base);
328 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
330 pr_err("failed to look up compatible string\n");
333 gdev->gisb_offsets = of_id->data;
334 gdev->big_endian = of_device_is_big_endian(dn);
336 err = devm_request_irq(&pdev->dev, timeout_irq,
337 brcmstb_gisb_timeout_handler, 0, pdev->name,
342 err = devm_request_irq(&pdev->dev, tea_irq,
343 brcmstb_gisb_tea_handler, 0, pdev->name,
348 /* If we do not have a valid mask, assume all masters are enabled */
349 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
351 gdev->valid_mask = 0xffffffff;
353 /* Proceed with reading the litteral names if we agree on the
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;
362 for (i = first; i < last; i++) {
363 if (!(gdev->valid_mask & BIT(i)))
366 of_property_read_string_index(dn,
367 "brcm,gisb-arb-master-names", j,
368 &gdev->master_names[i]);
373 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
377 platform_set_drvdata(pdev, gdev);
379 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
382 hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
383 "imprecise external abort");
386 board_be_handler = brcmstb_bus_error_handler;
389 dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
390 gdev->base, timeout_irq, tea_irq);
395 #ifdef CONFIG_PM_SLEEP
396 static int brcmstb_gisb_arb_suspend(struct device *dev)
398 struct platform_device *pdev = to_platform_device(dev);
399 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
401 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
406 /* Make sure we provide the same timeout value that was configured before, and
407 * do this before the GISB timeout interrupt handler has any chance to run.
409 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
411 struct platform_device *pdev = to_platform_device(dev);
412 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
414 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
419 #define brcmstb_gisb_arb_suspend NULL
420 #define brcmstb_gisb_arb_resume_noirq NULL
423 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
424 .suspend = brcmstb_gisb_arb_suspend,
425 .resume_noirq = brcmstb_gisb_arb_resume_noirq,
428 static struct platform_driver brcmstb_gisb_arb_driver = {
430 .name = "brcm-gisb-arb",
431 .of_match_table = brcmstb_gisb_arb_of_match,
432 .pm = &brcmstb_gisb_arb_pm_ops,
436 static int __init brcm_gisb_driver_init(void)
438 return platform_driver_probe(&brcmstb_gisb_arb_driver,
439 brcmstb_gisb_arb_probe);
442 module_init(brcm_gisb_driver_init);