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