drivers/ipack/ipack.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Industry-pack bus support functions.
   4  *
   5  * Copyright (C) 2011-2012 CERN (www.cern.ch)
   6  * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/slab.h>
  11 #include <linux/idr.h>
  12 #include <linux/io.h>
  13 #include <linux/ipack.h>
  14
  15 #define to_ipack_dev(device) container_of(device, struct ipack_device, dev)
  16 #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver)
  17
  18 static DEFINE_IDA(ipack_ida);
  19
  20 static void ipack_device_release(struct device *dev)
  21 {
  22         struct ipack_device *device = to_ipack_dev(dev);
  23         kfree(device->id);
  24         device->release(device);
  25 }
  26
  27 static inline const struct ipack_device_id *
  28 ipack_match_one_device(const struct ipack_device_id *id,
  29                        const struct ipack_device *device)
  30 {
  31         if ((id->format == IPACK_ANY_FORMAT ||
  32                                 id->format == device->id_format) &&
  33             (id->vendor == IPACK_ANY_ID || id->vendor == device->id_vendor) &&
  34             (id->device == IPACK_ANY_ID || id->device == device->id_device))
  35                 return id;
  36         return NULL;
  37 }
  38
  39 static const struct ipack_device_id *
  40 ipack_match_id(const struct ipack_device_id *ids, struct ipack_device *idev)
  41 {
  42         if (ids) {
  43                 while (ids->vendor || ids->device) {
  44                         if (ipack_match_one_device(ids, idev))
  45                                 return ids;
  46                         ids++;
  47                 }
  48         }
  49         return NULL;
  50 }
  51
  52 static int ipack_bus_match(struct device *dev, struct device_driver *drv)
  53 {
  54         struct ipack_device *idev = to_ipack_dev(dev);
  55         struct ipack_driver *idrv = to_ipack_driver(drv);
  56         const struct ipack_device_id *found_id;
  57
  58         found_id = ipack_match_id(idrv->id_table, idev);
  59         return found_id ? 1 : 0;
  60 }
  61
  62 static int ipack_bus_probe(struct device *device)
  63 {
  64         struct ipack_device *dev = to_ipack_dev(device);
  65         struct ipack_driver *drv = to_ipack_driver(device->driver);
  66
  67         return drv->ops->probe(dev);
  68 }
  69
  70 static int ipack_bus_remove(struct device *device)
  71 {
  72         struct ipack_device *dev = to_ipack_dev(device);
  73         struct ipack_driver *drv = to_ipack_driver(device->driver);
  74
  75         if (drv->ops->remove)
  76                 drv->ops->remove(dev);
  77
  78         return 0;
  79 }
  80
  81 static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
  82 {
  83         struct ipack_device *idev;
  84
  85         if (!dev)
  86                 return -ENODEV;
  87
  88         idev = to_ipack_dev(dev);
  89
  90         if (add_uevent_var(env,
  91                            "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
  92                            idev->id_vendor, idev->id_device))
  93                 return -ENOMEM;
  94
  95         return 0;
  96 }
  97
  98 #define ipack_device_attr(field, format_string)                         \
  99 static ssize_t                                                          \
 100 field##_show(struct device *dev, struct device_attribute *attr,         \
 101                 char *buf)                                              \
 102 {                                                                       \
 103         struct ipack_device *idev = to_ipack_dev(dev);                  \
 104         return sprintf(buf, format_string, idev->field);                \
 105 }
 106
 107 static ssize_t id_show(struct device *dev,
 108                        struct device_attribute *attr, char *buf)
 109 {
 110         unsigned int i, c, l, s;
 111         struct ipack_device *idev = to_ipack_dev(dev);
 112
 113
 114         switch (idev->id_format) {
 115         case IPACK_ID_VERSION_1:
 116                 l = 0x7; s = 1; break;
 117         case IPACK_ID_VERSION_2:
 118                 l = 0xf; s = 2; break;
 119         default:
 120                 return -EIO;
 121         }
 122         c = 0;
 123         for (i = 0; i < idev->id_avail; i++) {
 124                 if (i > 0) {
 125                         if ((i & l) == 0)
 126                                 buf[c++] = '\n';
 127                         else if ((i & s) == 0)
 128                                 buf[c++] = ' ';
 129                 }
 130                 sprintf(&buf[c], "%02x", idev->id[i]);
 131                 c += 2;
 132         }
 133         buf[c++] = '\n';
 134         return c;
 135 }
 136
 137 static ssize_t
 138 id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
 139 {
 140         struct ipack_device *idev = to_ipack_dev(dev);
 141         switch (idev->id_format) {
 142         case IPACK_ID_VERSION_1:
 143                 return sprintf(buf, "0x%02x\n", idev->id_vendor);
 144         case IPACK_ID_VERSION_2:
 145                 return sprintf(buf, "0x%06x\n", idev->id_vendor);
 146         default:
 147                 return -EIO;
 148         }
 149 }
 150
 151 static ssize_t
 152 id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
 153 {
 154         struct ipack_device *idev = to_ipack_dev(dev);
 155         switch (idev->id_format) {
 156         case IPACK_ID_VERSION_1:
 157                 return sprintf(buf, "0x%02x\n", idev->id_device);
 158         case IPACK_ID_VERSION_2:
 159                 return sprintf(buf, "0x%04x\n", idev->id_device);
 160         default:
 161                 return -EIO;
 162         }
 163 }
 164
 165 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 166                              char *buf)
 167 {
 168         struct ipack_device *idev = to_ipack_dev(dev);
 169
 170         return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
 171                        idev->id_vendor, idev->id_device);
 172 }
 173
 174 ipack_device_attr(id_format, "0x%hhx\n");
 175
 176 static DEVICE_ATTR_RO(id);
 177 static DEVICE_ATTR_RO(id_device);
 178 static DEVICE_ATTR_RO(id_format);
 179 static DEVICE_ATTR_RO(id_vendor);
 180 static DEVICE_ATTR_RO(modalias);
 181
 182 static struct attribute *ipack_attrs[] = {
 183         &dev_attr_id.attr,
 184         &dev_attr_id_device.attr,
 185         &dev_attr_id_format.attr,
 186         &dev_attr_id_vendor.attr,
 187         &dev_attr_modalias.attr,
 188         NULL,
 189 };
 190 ATTRIBUTE_GROUPS(ipack);
 191
 192 static struct bus_type ipack_bus_type = {
 193         .name      = "ipack",
 194         .probe     = ipack_bus_probe,
 195         .match     = ipack_bus_match,
 196         .remove    = ipack_bus_remove,
 197         .dev_groups = ipack_groups,
 198         .uevent    = ipack_uevent,
 199 };
 200
 201 struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
 202                                             const struct ipack_bus_ops *ops,
 203                                             struct module *owner)
 204 {
 205         int bus_nr;
 206         struct ipack_bus_device *bus;
 207
 208         bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 209         if (!bus)
 210                 return NULL;
 211
 212         bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
 213         if (bus_nr < 0) {
 214                 kfree(bus);
 215                 return NULL;
 216         }
 217
 218         bus->bus_nr = bus_nr;
 219         bus->parent = parent;
 220         bus->slots = slots;
 221         bus->ops = ops;
 222         bus->owner = owner;
 223         return bus;
 224 }
 225 EXPORT_SYMBOL_GPL(ipack_bus_register);
 226
 227 static int ipack_unregister_bus_member(struct device *dev, void *data)
 228 {
 229         struct ipack_device *idev = to_ipack_dev(dev);
 230         struct ipack_bus_device *bus = data;
 231
 232         if (idev->bus == bus)
 233                 ipack_device_del(idev);
 234
 235         return 1;
 236 }
 237
 238 int ipack_bus_unregister(struct ipack_bus_device *bus)
 239 {
 240         bus_for_each_dev(&ipack_bus_type, NULL, bus,
 241                 ipack_unregister_bus_member);
 242         ida_simple_remove(&ipack_ida, bus->bus_nr);
 243         kfree(bus);
 244         return 0;
 245 }
 246 EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 247
 248 int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 249                           const char *name)
 250 {
 251         if (!edrv->ops->probe)
 252                 return -EINVAL;
 253
 254         edrv->driver.owner = owner;
 255         edrv->driver.name = name;
 256         edrv->driver.bus = &ipack_bus_type;
 257         return driver_register(&edrv->driver);
 258 }
 259 EXPORT_SYMBOL_GPL(ipack_driver_register);
 260
 261 void ipack_driver_unregister(struct ipack_driver *edrv)
 262 {
 263         driver_unregister(&edrv->driver);
 264 }
 265 EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 266
 267 static u16 ipack_crc_byte(u16 crc, u8 c)
 268 {
 269         int i;
 270
 271         crc ^= c << 8;
 272         for (i = 0; i < 8; i++)
 273                 crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
 274         return crc;
 275 }
 276
 277 /*
 278  * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
 279  * opposite bit ordering.
 280  */
 281 static u8 ipack_calc_crc1(struct ipack_device *dev)
 282 {
 283         u8 c;
 284         u16 crc;
 285         unsigned int i;
 286
 287         crc = 0xffff;
 288         for (i = 0; i < dev->id_avail; i++) {
 289                 c = (i != 11) ? dev->id[i] : 0;
 290                 crc = ipack_crc_byte(crc, c);
 291         }
 292         crc = ~crc;
 293         return crc & 0xff;
 294 }
 295
 296 static u16 ipack_calc_crc2(struct ipack_device *dev)
 297 {
 298         u8 c;
 299         u16 crc;
 300         unsigned int i;
 301
 302         crc = 0xffff;
 303         for (i = 0; i < dev->id_avail; i++) {
 304                 c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
 305                 crc = ipack_crc_byte(crc, c);
 306         }
 307         crc = ~crc;
 308         return crc;
 309 }
 310
 311 static void ipack_parse_id1(struct ipack_device *dev)
 312 {
 313         u8 *id = dev->id;
 314         u8 crc;
 315
 316         dev->id_vendor = id[4];
 317         dev->id_device = id[5];
 318         dev->speed_8mhz = 1;
 319         dev->speed_32mhz = (id[7] == 'H');
 320         crc = ipack_calc_crc1(dev);
 321         dev->id_crc_correct = (crc == id[11]);
 322         if (!dev->id_crc_correct) {
 323                 dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 324                                 id[11], crc);
 325         }
 326 }
 327
 328 static void ipack_parse_id2(struct ipack_device *dev)
 329 {
 330         __be16 *id = (__be16 *) dev->id;
 331         u16 flags, crc;
 332
 333         dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
 334                          + be16_to_cpu(id[4]);
 335         dev->id_device = be16_to_cpu(id[5]);
 336         flags = be16_to_cpu(id[10]);
 337         dev->speed_8mhz = !!(flags & 2);
 338         dev->speed_32mhz = !!(flags & 4);
 339         crc = ipack_calc_crc2(dev);
 340         dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
 341         if (!dev->id_crc_correct) {
 342                 dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 343                                 id[11], crc);
 344         }
 345 }
 346
 347 static int ipack_device_read_id(struct ipack_device *dev)
 348 {
 349         u8 __iomem *idmem;
 350         int i;
 351         int ret = 0;
 352
 353         idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
 354                         dev->region[IPACK_ID_SPACE].size);
 355         if (!idmem) {
 356                 dev_err(&dev->dev, "error mapping memory\n");
 357                 return -ENOMEM;
 358         }
 359
 360         /* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
 361          * we are dealing with a IndustryPack  format 1 device.  If we detect
 362          * "VITA4 " (16 bit big endian formatted) we are dealing with a
 363          * IndustryPack format 2 device */
 364         if ((ioread8(idmem + 1) == 'I') &&
 365                         (ioread8(idmem + 3) == 'P') &&
 366                         (ioread8(idmem + 5) == 'A') &&
 367                         ((ioread8(idmem + 7) == 'C') ||
 368                          (ioread8(idmem + 7) == 'H'))) {
 369                 dev->id_format = IPACK_ID_VERSION_1;
 370                 dev->id_avail = ioread8(idmem + 0x15);
 371                 if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
 372                         dev_warn(&dev->dev, "invalid id size");
 373                         dev->id_avail = 0x0c;
 374                 }
 375         } else if ((ioread8(idmem + 0) == 'I') &&
 376                         (ioread8(idmem + 1) == 'V') &&
 377                         (ioread8(idmem + 2) == 'A') &&
 378                         (ioread8(idmem + 3) == 'T') &&
 379                         (ioread8(idmem + 4) == ' ') &&
 380                         (ioread8(idmem + 5) == '4')) {
 381                 dev->id_format = IPACK_ID_VERSION_2;
 382                 dev->id_avail = ioread16be(idmem + 0x16);
 383                 if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
 384                         dev_warn(&dev->dev, "invalid id size");
 385                         dev->id_avail = 0x1a;
 386                 }
 387         } else {
 388                 dev->id_format = IPACK_ID_VERSION_INVALID;
 389                 dev->id_avail = 0;
 390         }
 391
 392         if (!dev->id_avail) {
 393                 ret = -ENODEV;
 394                 goto out;
 395         }
 396
 397         /* Obtain the amount of memory required to store a copy of the complete
 398          * ID ROM contents */
 399         dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
 400         if (!dev->id) {
 401                 ret = -ENOMEM;
 402                 goto out;
 403         }
 404         for (i = 0; i < dev->id_avail; i++) {
 405                 if (dev->id_format == IPACK_ID_VERSION_1)
 406                         dev->id[i] = ioread8(idmem + (i << 1) + 1);
 407                 else
 408                         dev->id[i] = ioread8(idmem + i);
 409         }
 410
 411         /* now we can finally work with the copy */
 412         switch (dev->id_format) {
 413         case IPACK_ID_VERSION_1:
 414                 ipack_parse_id1(dev);
 415                 break;
 416         case IPACK_ID_VERSION_2:
 417                 ipack_parse_id2(dev);
 418                 break;
 419         }
 420
 421 out:
 422         iounmap(idmem);
 423
 424         return ret;
 425 }
 426
 427 int ipack_device_init(struct ipack_device *dev)
 428 {
 429         int ret;
 430
 431         dev->dev.bus = &ipack_bus_type;
 432         dev->dev.release = ipack_device_release;
 433         dev->dev.parent = dev->bus->parent;
 434         dev_set_name(&dev->dev,
 435                      "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
 436         device_initialize(&dev->dev);
 437
 438         if (dev->bus->ops->set_clockrate(dev, 8))
 439                 dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
 440         if (dev->bus->ops->reset_timeout(dev))
 441                 dev_warn(&dev->dev, "failed to reset potential timeout.");
 442
 443         ret = ipack_device_read_id(dev);
 444         if (ret < 0) {
 445                 dev_err(&dev->dev, "error reading device id section.\n");
 446                 return ret;
 447         }
 448
 449         /* if the device supports 32 MHz operation, use it. */
 450         if (dev->speed_32mhz) {
 451                 ret = dev->bus->ops->set_clockrate(dev, 32);
 452                 if (ret < 0)
 453                         dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
 454         }
 455
 456         return 0;
 457 }
 458 EXPORT_SYMBOL_GPL(ipack_device_init);
 459
 460 int ipack_device_add(struct ipack_device *dev)
 461 {
 462         return device_add(&dev->dev);
 463 }
 464 EXPORT_SYMBOL_GPL(ipack_device_add);
 465
 466 void ipack_device_del(struct ipack_device *dev)
 467 {
 468         device_del(&dev->dev);
 469         ipack_put_device(dev);
 470 }
 471 EXPORT_SYMBOL_GPL(ipack_device_del);
 472
 473 void ipack_get_device(struct ipack_device *dev)
 474 {
 475         get_device(&dev->dev);
 476 }
 477 EXPORT_SYMBOL_GPL(ipack_get_device);
 478
 479 void ipack_put_device(struct ipack_device *dev)
 480 {
 481         put_device(&dev->dev);
 482 }
 483 EXPORT_SYMBOL_GPL(ipack_put_device);
 484
 485 static int __init ipack_init(void)
 486 {
 487         ida_init(&ipack_ida);
 488         return bus_register(&ipack_bus_type);
 489 }
 490
 491 static void __exit ipack_exit(void)
 492 {
 493         bus_unregister(&ipack_bus_type);
 494         ida_destroy(&ipack_ida);
 495 }
 496
 497 module_init(ipack_init);
 498 module_exit(ipack_exit);
 499
 500 MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 501 MODULE_LICENSE("GPL");
 502 MODULE_DESCRIPTION("Industry-pack bus core");