drivers/bus/brcmstb_gisb.c

   1 /*
   2  * Copyright (C) 2014 Broadcom Corporation
   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 #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
  45 enum {
  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
  55 static 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
  65 static 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
  75 static 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
  85 static 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
  95 struct 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
 106 static LIST_HEAD(brcmstb_gisb_arb_device_list);
 107
 108 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
 109 {
 110         int offset = gdev->gisb_offsets[reg];
 111
 112         /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
 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
 122 static 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
 135 static 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
 150 static 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
 172 static const char *
 173 brcmstb_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
 184 static 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         /* Invalid captured address, bail out */
 196         if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
 197                 return 1;
 198
 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;
 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         /* 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 #ifdef CONFIG_MIPS
 246 static 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                 /* Invalid captured address, bail out */
 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         }
 263 out:
 264         return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
 265 }
 266 #endif
 267
 268 static 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
 275 static 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
 282 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
 283                 gisb_arb_get_timeout, gisb_arb_set_timeout);
 284
 285 static struct attribute *gisb_arb_sysfs_attrs[] = {
 286         &dev_attr_gisb_arb_timeout.attr,
 287         NULL,
 288 };
 289
 290 static struct attribute_group gisb_arb_sysfs_attr_group = {
 291         .attrs = gisb_arb_sysfs_attrs,
 292 };
 293
 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 },
 300         { },
 301 };
 302
 303 static 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         /* 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",
 350                                 &gdev->valid_mask))
 351                 gdev->valid_mask = 0xffffffff;
 352
 353         /* Proceed with reading the litteral names if we agree on the
 354          * number of masters
 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
 396 static 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 /* 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.
 408  */
 409 static 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
 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,
 426 };
 427
 428 static 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
 436 static int __init brcm_gisb_driver_init(void)
 437 {
 438         return platform_driver_probe(&brcmstb_gisb_arb_driver,
 439                                      brcmstb_gisb_arb_probe);
 440 }
 441
 442 module_init(brcm_gisb_driver_init);