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 #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)
  40
  41 enum {
  42         ARB_TIMER,
  43         ARB_ERR_CAP_CLR,
  44         ARB_ERR_CAP_HI_ADDR,
  45         ARB_ERR_CAP_ADDR,
  46         ARB_ERR_CAP_DATA,
  47         ARB_ERR_CAP_STATUS,
  48         ARB_ERR_CAP_MASTER,
  49 };
  50
  51 static const int gisb_offsets_bcm7038[] = {
  52         [ARB_TIMER]             = 0x00c,
  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,
  59 };
  60
  61 static const int gisb_offsets_bcm7400[] = {
  62         [ARB_TIMER]             = 0x00c,
  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,
  69 };
  70
  71 static const int gisb_offsets_bcm7435[] = {
  72         [ARB_TIMER]             = 0x00c,
  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,
  79 };
  80
  81 static const int gisb_offsets_bcm7445[] = {
  82         [ARB_TIMER]             = 0x008,
  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,
  89 };
  90
  91 struct brcmstb_gisb_arb_device {
  92         void __iomem    *base;
  93         const int       *gisb_offsets;
  94         struct mutex    lock;
  95         struct list_head next;
  96         u32 valid_mask;
  97         const char *master_names[sizeof(u32) * BITS_PER_BYTE];
  98         u32 saved_timeout;
  99 };
 100
 101 static LIST_HEAD(brcmstb_gisb_arb_device_list);
 102
 103 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
 104 {
 105         int offset = gdev->gisb_offsets[reg];
 106
 107         /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
 108         if (offset == -1)
 109                 return 1;
 110
 111         return ioread32(gdev->base + offset);
 112 }
 113
 114 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
 115 {
 116         int offset = gdev->gisb_offsets[reg];
 117
 118         if (offset == -1)
 119                 return;
 120         iowrite32(val, gdev->base + reg);
 121 }
 122
 123 static ssize_t gisb_arb_get_timeout(struct device *dev,
 124                                     struct device_attribute *attr,
 125                                     char *buf)
 126 {
 127         struct platform_device *pdev = to_platform_device(dev);
 128         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 129         u32 timeout;
 130
 131         mutex_lock(&gdev->lock);
 132         timeout = gisb_read(gdev, ARB_TIMER);
 133         mutex_unlock(&gdev->lock);
 134
 135         return sprintf(buf, "%d", timeout);
 136 }
 137
 138 static ssize_t gisb_arb_set_timeout(struct device *dev,
 139                                     struct device_attribute *attr,
 140                                     const char *buf, size_t count)
 141 {
 142         struct platform_device *pdev = to_platform_device(dev);
 143         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 144         int val, ret;
 145
 146         ret = kstrtoint(buf, 10, &val);
 147         if (ret < 0)
 148                 return ret;
 149
 150         if (val == 0 || val >= 0xffffffff)
 151                 return -EINVAL;
 152
 153         mutex_lock(&gdev->lock);
 154         gisb_write(gdev, val, ARB_TIMER);
 155         mutex_unlock(&gdev->lock);
 156
 157         return count;
 158 }
 159
 160 static const char *
 161 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
 162                                                 u32 masters)
 163 {
 164         u32 mask = gdev->valid_mask & masters;
 165
 166         if (hweight_long(mask) != 1)
 167                 return NULL;
 168
 169         return gdev->master_names[ffs(mask) - 1];
 170 }
 171
 172 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
 173                                         const char *reason)
 174 {
 175         u32 cap_status;
 176         unsigned long arb_addr;
 177         u32 master;
 178         const char *m_name;
 179         char m_fmt[11];
 180
 181         cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
 182
 183         /* Invalid captured address, bail out */
 184         if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
 185                 return 1;
 186
 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;
 191 #endif
 192         master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
 193
 194         m_name = brcmstb_gisb_master_to_str(gdev, master);
 195         if (!m_name) {
 196                 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
 197                 m_name = m_fmt;
 198         }
 199
 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" : "",
 204                 m_name);
 205
 206         /* clear the GISB error */
 207         gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
 208
 209         return 0;
 210 }
 211
 212 #ifdef CONFIG_ARM
 213 static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
 214                                      struct pt_regs *regs)
 215 {
 216         int ret = 0;
 217         struct brcmstb_gisb_arb_device *gdev;
 218
 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");
 222         /*
 223          * If it was an imprecise abort, then we need to correct the
 224          * return address to be _after_ the instruction.
 225         */
 226         if (fsr & (1 << 10))
 227                 regs->ARM_pc += 4;
 228
 229         return ret;
 230 }
 231 #endif
 232
 233 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
 234 {
 235         brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
 236
 237         return IRQ_HANDLED;
 238 }
 239
 240 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
 241 {
 242         brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
 243
 244         return IRQ_HANDLED;
 245 }
 246
 247 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
 248                 gisb_arb_get_timeout, gisb_arb_set_timeout);
 249
 250 static struct attribute *gisb_arb_sysfs_attrs[] = {
 251         &dev_attr_gisb_arb_timeout.attr,
 252         NULL,
 253 };
 254
 255 static struct attribute_group gisb_arb_sysfs_attr_group = {
 256         .attrs = gisb_arb_sysfs_attrs,
 257 };
 258
 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 },
 265         { },
 266 };
 267
 268 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 269 {
 270         struct device_node *dn = pdev->dev.of_node;
 271         struct brcmstb_gisb_arb_device *gdev;
 272         const struct of_device_id *of_id;
 273         struct resource *r;
 274         int err, timeout_irq, tea_irq;
 275         unsigned int num_masters, j = 0;
 276         int i, first, last;
 277
 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);
 281
 282         gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
 283         if (!gdev)
 284                 return -ENOMEM;
 285
 286         mutex_init(&gdev->lock);
 287         INIT_LIST_HEAD(&gdev->next);
 288
 289         gdev->base = devm_ioremap_resource(&pdev->dev, r);
 290         if (IS_ERR(gdev->base))
 291                 return PTR_ERR(gdev->base);
 292
 293         of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
 294         if (!of_id) {
 295                 pr_err("failed to look up compatible string\n");
 296                 return -EINVAL;
 297         }
 298         gdev->gisb_offsets = of_id->data;
 299
 300         err = devm_request_irq(&pdev->dev, timeout_irq,
 301                                 brcmstb_gisb_timeout_handler, 0, pdev->name,
 302                                 gdev);
 303         if (err < 0)
 304                 return err;
 305
 306         err = devm_request_irq(&pdev->dev, tea_irq,
 307                                 brcmstb_gisb_tea_handler, 0, pdev->name,
 308                                 gdev);
 309         if (err < 0)
 310                 return err;
 311
 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",
 314                                 &gdev->valid_mask))
 315                 gdev->valid_mask = 0xffffffff;
 316
 317         /* Proceed with reading the litteral names if we agree on the
 318          * number of masters
 319          */
 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;
 325
 326                 for (i = first; i < last; i++) {
 327                         if (!(gdev->valid_mask & BIT(i)))
 328                                 continue;
 329
 330                         of_property_read_string_index(dn,
 331                                         "brcm,gisb-arb-master-names", j,
 332                                         &gdev->master_names[i]);
 333                         j++;
 334                 }
 335         }
 336
 337         err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
 338         if (err)
 339                 return err;
 340
 341         platform_set_drvdata(pdev, gdev);
 342
 343         list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
 344
 345 #ifdef CONFIG_ARM
 346         hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
 347                         "imprecise external abort");
 348 #endif
 349
 350         dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
 351                         gdev->base, timeout_irq, tea_irq);
 352
 353         return 0;
 354 }
 355
 356 #ifdef CONFIG_PM_SLEEP
 357 static int brcmstb_gisb_arb_suspend(struct device *dev)
 358 {
 359         struct platform_device *pdev = to_platform_device(dev);
 360         struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
 361
 362         gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
 363
 364         return 0;
 365 }
 366
 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.
 369  */
 370 static int brcmstb_gisb_arb_resume_noirq(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         gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
 376
 377         return 0;
 378 }
 379 #else
 380 #define brcmstb_gisb_arb_suspend       NULL
 381 #define brcmstb_gisb_arb_resume_noirq  NULL
 382 #endif
 383
 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,
 387 };
 388
 389 static struct platform_driver brcmstb_gisb_arb_driver = {
 390         .driver = {
 391                 .name   = "brcm-gisb-arb",
 392                 .of_match_table = brcmstb_gisb_arb_of_match,
 393                 .pm     = &brcmstb_gisb_arb_pm_ops,
 394         },
 395 };
 396
 397 static int __init brcm_gisb_driver_init(void)
 398 {
 399         return platform_driver_probe(&brcmstb_gisb_arb_driver,
 400                                      brcmstb_gisb_arb_probe);
 401 }
 402
 403 module_init(brcm_gisb_driver_init);