linux/drivers/ipack/ipack.c
<<
>>
Prefs
   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
  21static DEFINE_IDA(ipack_ida);
  22
  23static 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
  30static inline const struct ipack_device_id *
  31ipack_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
  42static const struct ipack_device_id *
  43ipack_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
  55static 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
  65static 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
  76static 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
  88static 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)                         \
 106static ssize_t                                                          \
 107field##_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
 114static 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
 144static ssize_t
 145id_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
 158static ssize_t
 159id_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
 172static 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
 181ipack_device_attr(id_format, "0x%hhu\n");
 182
 183static 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
 191static 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
 200struct 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}
 222EXPORT_SYMBOL_GPL(ipack_bus_register);
 223
 224static 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
 235int 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}
 243EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 244
 245int 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}
 253EXPORT_SYMBOL_GPL(ipack_driver_register);
 254
 255void ipack_driver_unregister(struct ipack_driver *edrv)
 256{
 257        driver_unregister(&edrv->driver);
 258}
 259EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 260
 261static 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 */
 275static 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
 290static 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
 305static 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
 322static 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
 341static 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
 416out:
 417        iounmap(idmem);
 418
 419        return ret;
 420}
 421
 422int 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}
 453EXPORT_SYMBOL_GPL(ipack_device_init);
 454
 455int ipack_device_add(struct ipack_device *dev)
 456{
 457        return device_add(&dev->dev);
 458}
 459EXPORT_SYMBOL_GPL(ipack_device_add);
 460
 461void ipack_device_del(struct ipack_device *dev)
 462{
 463        device_del(&dev->dev);
 464        ipack_put_device(dev);
 465}
 466EXPORT_SYMBOL_GPL(ipack_device_del);
 467
 468void ipack_get_device(struct ipack_device *dev)
 469{
 470        get_device(&dev->dev);
 471}
 472EXPORT_SYMBOL_GPL(ipack_get_device);
 473
 474void ipack_put_device(struct ipack_device *dev)
 475{
 476        put_device(&dev->dev);
 477}
 478EXPORT_SYMBOL_GPL(ipack_put_device);
 479
 480static int __init ipack_init(void)
 481{
 482        ida_init(&ipack_ida);
 483        return bus_register(&ipack_bus_type);
 484}
 485
 486static void __exit ipack_exit(void)
 487{
 488        bus_unregister(&ipack_bus_type);
 489        ida_destroy(&ipack_ida);
 490}
 491
 492module_init(ipack_init);
 493module_exit(ipack_exit);
 494
 495MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 496MODULE_LICENSE("GPL");
 497MODULE_DESCRIPTION("Industry-pack bus core");
 498
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.