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>
29 #include <asm/signal.h>
32 #define ARB_ERR_CAP_CLEAR (1 << 0)
33 #define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
34 #define ARB_ERR_CAP_STATUS_TEA (1 << 11)
35 #define ARB_ERR_CAP_STATUS_BS_SHIFT (1 << 2)
36 #define ARB_ERR_CAP_STATUS_BS_MASK 0x3c
37 #define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
38 #define ARB_ERR_CAP_STATUS_VALID (1 << 0)
50 static const int gisb_offsets_bcm7038[] = {
52 [ARB_ERR_CAP_CLR] = 0x0c4,
53 [ARB_ERR_CAP_HI_ADDR] = -1,
54 [ARB_ERR_CAP_ADDR] = 0x0c8,
55 [ARB_ERR_CAP_DATA] = 0x0cc,
56 [ARB_ERR_CAP_STATUS] = 0x0d0,
57 [ARB_ERR_CAP_MASTER] = -1,
60 static const int gisb_offsets_bcm7400[] = {
62 [ARB_ERR_CAP_CLR] = 0x0c8,
63 [ARB_ERR_CAP_HI_ADDR] = -1,
64 [ARB_ERR_CAP_ADDR] = 0x0cc,
65 [ARB_ERR_CAP_DATA] = 0x0d0,
66 [ARB_ERR_CAP_STATUS] = 0x0d4,
67 [ARB_ERR_CAP_MASTER] = 0x0d8,
70 static const int gisb_offsets_bcm7435[] = {
72 [ARB_ERR_CAP_CLR] = 0x168,
73 [ARB_ERR_CAP_HI_ADDR] = -1,
74 [ARB_ERR_CAP_ADDR] = 0x16c,
75 [ARB_ERR_CAP_DATA] = 0x170,
76 [ARB_ERR_CAP_STATUS] = 0x174,
77 [ARB_ERR_CAP_MASTER] = 0x178,
80 static const int gisb_offsets_bcm7445[] = {
82 [ARB_ERR_CAP_CLR] = 0x7e4,
83 [ARB_ERR_CAP_HI_ADDR] = 0x7e8,
84 [ARB_ERR_CAP_ADDR] = 0x7ec,
85 [ARB_ERR_CAP_DATA] = 0x7f0,
86 [ARB_ERR_CAP_STATUS] = 0x7f4,
87 [ARB_ERR_CAP_MASTER] = 0x7f8,
90 struct brcmstb_gisb_arb_device {
92 const int *gisb_offsets;
94 struct list_head next;
96 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
99 static LIST_HEAD(brcmstb_gisb_arb_device_list);
101 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
103 int offset = gdev->gisb_offsets[reg];
105 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
109 return ioread32(gdev->base + offset);
112 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
114 int offset = gdev->gisb_offsets[reg];
118 iowrite32(val, gdev->base + reg);
121 static ssize_t gisb_arb_get_timeout(struct device *dev,
122 struct device_attribute *attr,
125 struct platform_device *pdev = to_platform_device(dev);
126 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
129 mutex_lock(&gdev->lock);
130 timeout = gisb_read(gdev, ARB_TIMER);
131 mutex_unlock(&gdev->lock);
133 return sprintf(buf, "%d", timeout);
136 static ssize_t gisb_arb_set_timeout(struct device *dev,
137 struct device_attribute *attr,
138 const char *buf, size_t count)
140 struct platform_device *pdev = to_platform_device(dev);
141 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
144 ret = kstrtoint(buf, 10, &val);
148 if (val == 0 || val >= 0xffffffff)
151 mutex_lock(&gdev->lock);
152 gisb_write(gdev, val, ARB_TIMER);
153 mutex_unlock(&gdev->lock);
159 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
162 u32 mask = gdev->valid_mask & masters;
164 if (hweight_long(mask) != 1)
167 return gdev->master_names[ffs(mask) - 1];
170 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
174 unsigned long arb_addr;
179 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
181 /* Invalid captured address, bail out */
182 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
185 /* Read the address and master */
186 arb_addr = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
187 #if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
188 arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
190 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
192 m_name = brcmstb_gisb_master_to_str(gdev, master);
194 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
198 pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
199 __func__, reason, arb_addr,
200 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
201 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
204 /* clear the GISB error */
205 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
211 static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
212 struct pt_regs *regs)
215 struct brcmstb_gisb_arb_device *gdev;
217 /* iterate over each GISB arb registered handlers */
218 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
219 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
221 * If it was an imprecise abort, then we need to correct the
222 * return address to be _after_ the instruction.
230 void __init brcmstb_hook_fault_code(void)
232 hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
233 "imprecise external abort");
237 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
239 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
244 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
246 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
251 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
252 gisb_arb_get_timeout, gisb_arb_set_timeout);
254 static struct attribute *gisb_arb_sysfs_attrs[] = {
255 &dev_attr_gisb_arb_timeout.attr,
259 static struct attribute_group gisb_arb_sysfs_attr_group = {
260 .attrs = gisb_arb_sysfs_attrs,
263 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
264 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
265 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
266 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
267 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
268 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
272 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
274 struct device_node *dn = pdev->dev.of_node;
275 struct brcmstb_gisb_arb_device *gdev;
276 const struct of_device_id *of_id;
278 int err, timeout_irq, tea_irq;
279 unsigned int num_masters, j = 0;
282 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
283 timeout_irq = platform_get_irq(pdev, 0);
284 tea_irq = platform_get_irq(pdev, 1);
286 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
290 mutex_init(&gdev->lock);
291 INIT_LIST_HEAD(&gdev->next);
293 gdev->base = devm_ioremap_resource(&pdev->dev, r);
294 if (IS_ERR(gdev->base))
295 return PTR_ERR(gdev->base);
297 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
299 pr_err("failed to look up compatible string\n");
302 gdev->gisb_offsets = of_id->data;
304 err = devm_request_irq(&pdev->dev, timeout_irq,
305 brcmstb_gisb_timeout_handler, 0, pdev->name,
310 err = devm_request_irq(&pdev->dev, tea_irq,
311 brcmstb_gisb_tea_handler, 0, pdev->name,
316 /* If we do not have a valid mask, assume all masters are enabled */
317 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
319 gdev->valid_mask = 0xffffffff;
321 /* Proceed with reading the litteral names if we agree on the
324 num_masters = of_property_count_strings(dn,
325 "brcm,gisb-arb-master-names");
326 if (hweight_long(gdev->valid_mask) == num_masters) {
327 first = ffs(gdev->valid_mask) - 1;
328 last = fls(gdev->valid_mask) - 1;
330 for (i = first; i < last; i++) {
331 if (!(gdev->valid_mask & BIT(i)))
334 of_property_read_string_index(dn,
335 "brcm,gisb-arb-master-names", j,
336 &gdev->master_names[i]);
341 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
345 platform_set_drvdata(pdev, gdev);
347 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
349 dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
350 gdev->base, timeout_irq, tea_irq);
355 static struct platform_driver brcmstb_gisb_arb_driver = {
357 .name = "brcm-gisb-arb",
358 .owner = THIS_MODULE,
359 .of_match_table = brcmstb_gisb_arb_of_match,
363 static int __init brcm_gisb_driver_init(void)
365 return platform_driver_probe(&brcmstb_gisb_arb_driver,
366 brcmstb_gisb_arb_probe);
369 module_init(brcm_gisb_driver_init);