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>
33 #define ARB_ERR_CAP_CLEAR (1 << 0)
34 #define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
35 #define ARB_ERR_CAP_STATUS_TEA (1 << 11)
36 #define ARB_ERR_CAP_STATUS_BS_SHIFT (1 << 2)
37 #define ARB_ERR_CAP_STATUS_BS_MASK 0x3c
38 #define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
39 #define ARB_ERR_CAP_STATUS_VALID (1 << 0)
51 static const int gisb_offsets_bcm7038[] = {
53 [ARB_ERR_CAP_CLR] = 0x0c4,
54 [ARB_ERR_CAP_HI_ADDR] = -1,
55 [ARB_ERR_CAP_ADDR] = 0x0c8,
56 [ARB_ERR_CAP_DATA] = 0x0cc,
57 [ARB_ERR_CAP_STATUS] = 0x0d0,
58 [ARB_ERR_CAP_MASTER] = -1,
61 static const int gisb_offsets_bcm7400[] = {
63 [ARB_ERR_CAP_CLR] = 0x0c8,
64 [ARB_ERR_CAP_HI_ADDR] = -1,
65 [ARB_ERR_CAP_ADDR] = 0x0cc,
66 [ARB_ERR_CAP_DATA] = 0x0d0,
67 [ARB_ERR_CAP_STATUS] = 0x0d4,
68 [ARB_ERR_CAP_MASTER] = 0x0d8,
71 static const int gisb_offsets_bcm7435[] = {
73 [ARB_ERR_CAP_CLR] = 0x168,
74 [ARB_ERR_CAP_HI_ADDR] = -1,
75 [ARB_ERR_CAP_ADDR] = 0x16c,
76 [ARB_ERR_CAP_DATA] = 0x170,
77 [ARB_ERR_CAP_STATUS] = 0x174,
78 [ARB_ERR_CAP_MASTER] = 0x178,
81 static const int gisb_offsets_bcm7445[] = {
83 [ARB_ERR_CAP_CLR] = 0x7e4,
84 [ARB_ERR_CAP_HI_ADDR] = 0x7e8,
85 [ARB_ERR_CAP_ADDR] = 0x7ec,
86 [ARB_ERR_CAP_DATA] = 0x7f0,
87 [ARB_ERR_CAP_STATUS] = 0x7f4,
88 [ARB_ERR_CAP_MASTER] = 0x7f8,
91 struct brcmstb_gisb_arb_device {
93 const int *gisb_offsets;
95 struct list_head next;
97 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
101 static LIST_HEAD(brcmstb_gisb_arb_device_list);
103 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
105 int offset = gdev->gisb_offsets[reg];
107 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
111 return ioread32(gdev->base + offset);
114 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
116 int offset = gdev->gisb_offsets[reg];
120 iowrite32(val, gdev->base + reg);
123 static ssize_t gisb_arb_get_timeout(struct device *dev,
124 struct device_attribute *attr,
127 struct platform_device *pdev = to_platform_device(dev);
128 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
131 mutex_lock(&gdev->lock);
132 timeout = gisb_read(gdev, ARB_TIMER);
133 mutex_unlock(&gdev->lock);
135 return sprintf(buf, "%d", timeout);
138 static ssize_t gisb_arb_set_timeout(struct device *dev,
139 struct device_attribute *attr,
140 const char *buf, size_t count)
142 struct platform_device *pdev = to_platform_device(dev);
143 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
146 ret = kstrtoint(buf, 10, &val);
150 if (val == 0 || val >= 0xffffffff)
153 mutex_lock(&gdev->lock);
154 gisb_write(gdev, val, ARB_TIMER);
155 mutex_unlock(&gdev->lock);
161 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
164 u32 mask = gdev->valid_mask & masters;
166 if (hweight_long(mask) != 1)
169 return gdev->master_names[ffs(mask) - 1];
172 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
176 unsigned long arb_addr;
181 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
183 /* Invalid captured address, bail out */
184 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
187 /* Read the address and master */
188 arb_addr = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
189 #if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
190 arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
192 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
194 m_name = brcmstb_gisb_master_to_str(gdev, master);
196 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
200 pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
201 __func__, reason, arb_addr,
202 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
203 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
206 /* clear the GISB error */
207 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
213 static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
214 struct pt_regs *regs)
217 struct brcmstb_gisb_arb_device *gdev;
219 /* iterate over each GISB arb registered handlers */
220 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
221 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
223 * If it was an imprecise abort, then we need to correct the
224 * return address to be _after_ the instruction.
233 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
235 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
240 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
242 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
247 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
248 gisb_arb_get_timeout, gisb_arb_set_timeout);
250 static struct attribute *gisb_arb_sysfs_attrs[] = {
251 &dev_attr_gisb_arb_timeout.attr,
255 static struct attribute_group gisb_arb_sysfs_attr_group = {
256 .attrs = gisb_arb_sysfs_attrs,
259 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
260 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
261 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
262 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
263 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
264 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
268 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
270 struct device_node *dn = pdev->dev.of_node;
271 struct brcmstb_gisb_arb_device *gdev;
272 const struct of_device_id *of_id;
274 int err, timeout_irq, tea_irq;
275 unsigned int num_masters, j = 0;
278 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
279 timeout_irq = platform_get_irq(pdev, 0);
280 tea_irq = platform_get_irq(pdev, 1);
282 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
286 mutex_init(&gdev->lock);
287 INIT_LIST_HEAD(&gdev->next);
289 gdev->base = devm_ioremap_resource(&pdev->dev, r);
290 if (IS_ERR(gdev->base))
291 return PTR_ERR(gdev->base);
293 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
295 pr_err("failed to look up compatible string\n");
298 gdev->gisb_offsets = of_id->data;
300 err = devm_request_irq(&pdev->dev, timeout_irq,
301 brcmstb_gisb_timeout_handler, 0, pdev->name,
306 err = devm_request_irq(&pdev->dev, tea_irq,
307 brcmstb_gisb_tea_handler, 0, pdev->name,
312 /* If we do not have a valid mask, assume all masters are enabled */
313 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
315 gdev->valid_mask = 0xffffffff;
317 /* Proceed with reading the litteral names if we agree on the
320 num_masters = of_property_count_strings(dn,
321 "brcm,gisb-arb-master-names");
322 if (hweight_long(gdev->valid_mask) == num_masters) {
323 first = ffs(gdev->valid_mask) - 1;
324 last = fls(gdev->valid_mask) - 1;
326 for (i = first; i < last; i++) {
327 if (!(gdev->valid_mask & BIT(i)))
330 of_property_read_string_index(dn,
331 "brcm,gisb-arb-master-names", j,
332 &gdev->master_names[i]);
337 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
341 platform_set_drvdata(pdev, gdev);
343 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
346 hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
347 "imprecise external abort");
350 dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
351 gdev->base, timeout_irq, tea_irq);
356 #ifdef CONFIG_PM_SLEEP
357 static int brcmstb_gisb_arb_suspend(struct device *dev)
359 struct platform_device *pdev = to_platform_device(dev);
360 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
362 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
367 /* Make sure we provide the same timeout value that was configured before, and
368 * do this before the GISB timeout interrupt handler has any chance to run.
370 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
372 struct platform_device *pdev = to_platform_device(dev);
373 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
375 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
380 #define brcmstb_gisb_arb_suspend NULL
381 #define brcmstb_gisb_arb_resume_noirq NULL
384 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
385 .suspend = brcmstb_gisb_arb_suspend,
386 .resume_noirq = brcmstb_gisb_arb_resume_noirq,
389 static struct platform_driver brcmstb_gisb_arb_driver = {
391 .name = "brcm-gisb-arb",
392 .of_match_table = brcmstb_gisb_arb_of_match,
393 .pm = &brcmstb_gisb_arb_pm_ops,
397 static int __init brcm_gisb_driver_init(void)
399 return platform_driver_probe(&brcmstb_gisb_arb_driver,
400 brcmstb_gisb_arb_probe);
403 module_init(brcm_gisb_driver_init);