drivers/ipack/ipack.c

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