drivers/bus/brcmstb_gisb.c

   1 /*
   2  * Copyright (C) 2014-2017 Broadcom
   3  *
   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.
   7  *
   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.
  12  */
  13
  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 #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_WRITE       (1 << 1)
  37 #define  ARB_ERR_CAP_STATUS_VALID       (1 << 0)
  38
  39 enum {
  40         ARB_TIMER,
  41         ARB_ERR_CAP_CLR,
  42         ARB_ERR_CAP_HI_ADDR,
  43         ARB_ERR_CAP_ADDR,
  44         ARB_ERR_CAP_STATUS,
  45         ARB_ERR_CAP_MASTER,
  46 };
  47
  48 static const int gisb_offsets_bcm7038[] = {
  49         [ARB_TIMER]             = 0x00c,
  50         [ARB_ERR_CAP_CLR]       = 0x0c4,
  51         [ARB_ERR_CAP_HI_ADDR]   = -1,
  52         [ARB_ERR_CAP_ADDR]      = 0x0c8,
  53         [ARB_ERR_CAP_STATUS]    = 0x0d0,
  54         [ARB_ERR_CAP_MASTER]    = -1,
  55 };
  56
  57 static const int gisb_offsets_bcm7400[] = {
  58         [ARB_TIMER]             = 0x00c,
  59         [ARB_ERR_CAP_CLR]       = 0x0c8,
  60         [ARB_ERR_CAP_HI_ADDR]   = -1,
  61         [ARB_ERR_CAP_ADDR]      = 0x0cc,
  62         [ARB_ERR_CAP_STATUS]    = 0x0d4,
  63         [ARB_ERR_CAP_MASTER]    = 0x0d8,
  64 };
  65
  66 static const int gisb_offsets_bcm7435[] = {
  67         [ARB_TIMER]             = 0x00c,
  68         [ARB_ERR_CAP_CLR]       = 0x168,
  69         [ARB_ERR_CAP_HI_ADDR]   = -1,
  70         [ARB_ERR_CAP_ADDR]      = 0x16c,
  71         [ARB_ERR_CAP_STATUS]    = 0x174,
  72         [ARB_ERR_CAP_MASTER]    = 0x178,
  73 };
  74
  75 static const int gisb_offsets_bcm7445[] = {
  76         [ARB_TIMER]             = 0x008,
  77         [ARB_ERR_CAP_CLR]       = 0x7e4,
  78         [ARB_ERR_CAP_HI_ADDR]   = 0x7e8,
  79         [ARB_ERR_CAP_ADDR]      = 0x7ec,
  80         [ARB_ERR_CAP_STATUS]    = 0x7f4,
  81         [ARB_ERR_CAP_MASTER]    = 0x7f8,
  82 };
  83
  84 struct brcmstb_gisb_arb_device {
  85         void __iomem    *base;
  86         const int       *gisb_offsets;
  87         bool            big_endian;
  88         struct mutex    lock;
  89         struct list_head next;
  90         u32 valid_mask;
  91         const char *master_names[sizeof(u32) * BITS_PER_BYTE];
  92         u32 saved_timeout;
  93 };
  94
  95 static LIST_HEAD(brcmstb_gisb_arb_device_list);
  96
  97 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
  98 {
  99         int offset = gdev->gisb_offsets[reg];
 100
 101         if (offset < 0) {
 102                 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
 103                 if (reg == ARB_ERR_CAP_MASTER)
 104                         return 1;
 105                 else
 106                         return 0;
 107         }
 108
 109         if (gdev->big_endian)
 110                 return ioread32be(gdev->base + offset);
 111         else
 112                 return ioread32(gdev->base + offset);
 113 }
 114
 115 static u64 gisb_read_address(struct brcmstb_gisb_arb_device *gdev)
 116 {
 117         u64 value;
 118
 119         value = gisb_read(gdev, ARB_ERR_CAP_ADDR);
 120         value |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
 121
 122         return value;
 123 }
 124
 125 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
 126 {
 127         int offset = gdev->gisb_offsets[reg];
 128
 129         if (offset == -1)
 130                 return;
 131
 132         if (gdev->big_endian)
 133                 iowrite32be(val, gdev->base + offset);
 134         else
 135                 iowrite32(val, gdev->base + offset);
 136 }
 137
 138 static ssize_t gisb_arb_get_timeout(struct device *dev,
 139                                     struct device_attribute *attr,
 140                                     char *buf)
 141 {
 142         struct platform_device *pdev = to_platform_device(dev);
 143         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 144         u32 timeout;
 145
 146         mutex_lock(&gdev->lock);
 147         timeout = gisb_read(gdev, ARB_TIMER);
 148         mutex_unlock(&gdev->lock);
 149
 150         return sprintf(buf, "%d", timeout);
 151 }
 152
 153 static ssize_t gisb_arb_set_timeout(struct device *dev,
 154                                     struct device_attribute *attr,
 155                                     const char *buf, size_t count)
 156 {
 157         struct platform_device *pdev = to_platform_device(dev);
 158         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 159         int val, ret;
 160
 161         ret = kstrtoint(buf, 10, &val);
 162         if (ret < 0)
 163                 return ret;
 164
 165         if (val == 0 || val >= 0xffffffff)
 166                 return -EINVAL;
 167
 168         mutex_lock(&gdev->lock);
 169         gisb_write(gdev, val, ARB_TIMER);
 170         mutex_unlock(&gdev->lock);
 171
 172         return count;
 173 }
 174
 175 static const char *
 176 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
 177                                                 u32 masters)
 178 {
 179         u32 mask = gdev->valid_mask & masters;
 180
 181         if (hweight_long(mask) != 1)
 182                 return NULL;
 183
 184         return gdev->master_names[ffs(mask) - 1];
 185 }
 186
 187 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
 188                                         const char *reason)
 189 {
 190         u32 cap_status;
 191         u64 arb_addr;
 192         u32 master;
 193         const char *m_name;
 194         char m_fmt[11];
 195
 196         cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
 197
 198         /* Invalid captured address, bail out */
 199         if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
 200                 return 1;
 201
 202         /* Read the address and master */
 203         arb_addr = gisb_read_address(gdev);
 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%llx [%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         /* clear the GISB error */
 219         gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
 220
 221         return 0;
 222 }
 223
 224 #ifdef CONFIG_ARM
 225 static 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         /* 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");
 234         /*
 235          * If it was an imprecise abort, then we need to correct the
 236          * return address to be _after_ the instruction.
 237         */
 238         if (fsr & (1 << 10))
 239                 regs->ARM_pc += 4;
 240
 241         return ret;
 242 }
 243 #endif
 244
 245 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
 246 {
 247         brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
 248
 249         return IRQ_HANDLED;
 250 }
 251
 252 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
 253 {
 254         brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
 255
 256         return IRQ_HANDLED;
 257 }
 258
 259 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
 260                 gisb_arb_get_timeout, gisb_arb_set_timeout);
 261
 262 static struct attribute *gisb_arb_sysfs_attrs[] = {
 263         &dev_attr_gisb_arb_timeout.attr,
 264         NULL,
 265 };
 266
 267 static struct attribute_group gisb_arb_sysfs_attr_group = {
 268         .attrs = gisb_arb_sysfs_attrs,
 269 };
 270
 271 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
 272         { .compatible = "brcm,gisb-arb",         .data = gisb_offsets_bcm7445 },
 273         { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
 274         { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
 275         { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
 276         { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
 277         { },
 278 };
 279
 280 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 281 {
 282         struct device_node *dn = pdev->dev.of_node;
 283         struct brcmstb_gisb_arb_device *gdev;
 284         const struct of_device_id *of_id;
 285         struct resource *r;
 286         int err, timeout_irq, tea_irq;
 287         unsigned int num_masters, j = 0;
 288         int i, first, last;
 289
 290         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 291         timeout_irq = platform_get_irq(pdev, 0);
 292         tea_irq = platform_get_irq(pdev, 1);
 293
 294         gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
 295         if (!gdev)
 296                 return -ENOMEM;
 297
 298         mutex_init(&gdev->lock);
 299         INIT_LIST_HEAD(&gdev->next);
 300
 301         gdev->base = devm_ioremap_resource(&pdev->dev, r);
 302         if (IS_ERR(gdev->base))
 303                 return PTR_ERR(gdev->base);
 304
 305         of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
 306         if (!of_id) {
 307                 pr_err("failed to look up compatible string\n");
 308                 return -EINVAL;
 309         }
 310         gdev->gisb_offsets = of_id->data;
 311         gdev->big_endian = of_device_is_big_endian(dn);
 312
 313         err = devm_request_irq(&pdev->dev, timeout_irq,
 314                                 brcmstb_gisb_timeout_handler, 0, pdev->name,
 315                                 gdev);
 316         if (err < 0)
 317                 return err;
 318
 319         err = devm_request_irq(&pdev->dev, tea_irq,
 320                                 brcmstb_gisb_tea_handler, 0, pdev->name,
 321                                 gdev);
 322         if (err < 0)
 323                 return err;
 324
 325         /* If we do not have a valid mask, assume all masters are enabled */
 326         if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
 327                                 &gdev->valid_mask))
 328                 gdev->valid_mask = 0xffffffff;
 329
 330         /* Proceed with reading the litteral names if we agree on the
 331          * number of masters
 332          */
 333         num_masters = of_property_count_strings(dn,
 334                         "brcm,gisb-arb-master-names");
 335         if (hweight_long(gdev->valid_mask) == num_masters) {
 336                 first = ffs(gdev->valid_mask) - 1;
 337                 last = fls(gdev->valid_mask) - 1;
 338
 339                 for (i = first; i < last; i++) {
 340                         if (!(gdev->valid_mask & BIT(i)))
 341                                 continue;
 342
 343                         of_property_read_string_index(dn,
 344                                         "brcm,gisb-arb-master-names", j,
 345                                         &gdev->master_names[i]);
 346                         j++;
 347                 }
 348         }
 349
 350         err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
 351         if (err)
 352                 return err;
 353
 354         platform_set_drvdata(pdev, gdev);
 355
 356         list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
 357
 358 #ifdef CONFIG_ARM
 359         hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
 360                         "imprecise external abort");
 361 #endif
 362
 363         dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
 364                         gdev->base, timeout_irq, tea_irq);
 365
 366         return 0;
 367 }
 368
 369 #ifdef CONFIG_PM_SLEEP
 370 static int brcmstb_gisb_arb_suspend(struct device *dev)
 371 {
 372         struct platform_device *pdev = to_platform_device(dev);
 373         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 374
 375         gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
 376
 377         return 0;
 378 }
 379
 380 /* Make sure we provide the same timeout value that was configured before, and
 381  * do this before the GISB timeout interrupt handler has any chance to run.
 382  */
 383 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
 384 {
 385         struct platform_device *pdev = to_platform_device(dev);
 386         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 387
 388         gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
 389
 390         return 0;
 391 }
 392 #else
 393 #define brcmstb_gisb_arb_suspend       NULL
 394 #define brcmstb_gisb_arb_resume_noirq  NULL
 395 #endif
 396
 397 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
 398         .suspend        = brcmstb_gisb_arb_suspend,
 399         .resume_noirq   = brcmstb_gisb_arb_resume_noirq,
 400 };
 401
 402 static struct platform_driver brcmstb_gisb_arb_driver = {
 403         .driver = {
 404                 .name   = "brcm-gisb-arb",
 405                 .of_match_table = brcmstb_gisb_arb_of_match,
 406                 .pm     = &brcmstb_gisb_arb_pm_ops,
 407         },
 408 };
 409
 410 static int __init brcm_gisb_driver_init(void)
 411 {
 412         return platform_driver_probe(&brcmstb_gisb_arb_driver,
 413                                      brcmstb_gisb_arb_probe);
 414 }
 415
 416 module_init(brcm_gisb_driver_init);