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