linux/drivers/ipack/ipack.c
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   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%hhx\n");
 182
 183static DEVICE_ATTR_RO(id);
 184static DEVICE_ATTR_RO(id_device);
 185static DEVICE_ATTR_RO(id_format);
 186static DEVICE_ATTR_RO(id_vendor);
 187static DEVICE_ATTR_RO(modalias);
 188
 189static 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};
 197ATTRIBUTE_GROUPS(ipack);
 198
 199static 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
 208struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
 209                                            const struct ipack_bus_ops *ops,
 210                                            struct module *owner)
 211{
 212        int bus_nr;
 213        struct ipack_bus_device *bus;
 214
 215        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 216        if (!bus)
 217                return NULL;
 218
 219        bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
 220        if (bus_nr < 0) {
 221                kfree(bus);
 222                return NULL;
 223        }
 224
 225        bus->bus_nr = bus_nr;
 226        bus->parent = parent;
 227        bus->slots = slots;
 228        bus->ops = ops;
 229        bus->owner = owner;
 230        return bus;
 231}
 232EXPORT_SYMBOL_GPL(ipack_bus_register);
 233
 234static int ipack_unregister_bus_member(struct device *dev, void *data)
 235{
 236        struct ipack_device *idev = to_ipack_dev(dev);
 237        struct ipack_bus_device *bus = data;
 238
 239        if (idev->bus == bus)
 240                ipack_device_del(idev);
 241
 242        return 1;
 243}
 244
 245int ipack_bus_unregister(struct ipack_bus_device *bus)
 246{
 247        bus_for_each_dev(&ipack_bus_type, NULL, bus,
 248                ipack_unregister_bus_member);
 249        ida_simple_remove(&ipack_ida, bus->bus_nr);
 250        kfree(bus);
 251        return 0;
 252}
 253EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 254
 255int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 256                          const char *name)
 257{
 258        edrv->driver.owner = owner;
 259        edrv->driver.name = name;
 260        edrv->driver.bus = &ipack_bus_type;
 261        return driver_register(&edrv->driver);
 262}
 263EXPORT_SYMBOL_GPL(ipack_driver_register);
 264
 265void ipack_driver_unregister(struct ipack_driver *edrv)
 266{
 267        driver_unregister(&edrv->driver);
 268}
 269EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 270
 271static u16 ipack_crc_byte(u16 crc, u8 c)
 272{
 273        int i;
 274
 275        crc ^= c << 8;
 276        for (i = 0; i < 8; i++)
 277                crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
 278        return crc;
 279}
 280
 281/*
 282 * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
 283 * opposite bit ordering.
 284 */
 285static u8 ipack_calc_crc1(struct ipack_device *dev)
 286{
 287        u8 c;
 288        u16 crc;
 289        unsigned int i;
 290
 291        crc = 0xffff;
 292        for (i = 0; i < dev->id_avail; i++) {
 293                c = (i != 11) ? dev->id[i] : 0;
 294                crc = ipack_crc_byte(crc, c);
 295        }
 296        crc = ~crc;
 297        return crc & 0xff;
 298}
 299
 300static u16 ipack_calc_crc2(struct ipack_device *dev)
 301{
 302        u8 c;
 303        u16 crc;
 304        unsigned int i;
 305
 306        crc = 0xffff;
 307        for (i = 0; i < dev->id_avail; i++) {
 308                c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
 309                crc = ipack_crc_byte(crc, c);
 310        }
 311        crc = ~crc;
 312        return crc;
 313}
 314
 315static void ipack_parse_id1(struct ipack_device *dev)
 316{
 317        u8 *id = dev->id;
 318        u8 crc;
 319
 320        dev->id_vendor = id[4];
 321        dev->id_device = id[5];
 322        dev->speed_8mhz = 1;
 323        dev->speed_32mhz = (id[7] == 'H');
 324        crc = ipack_calc_crc1(dev);
 325        dev->id_crc_correct = (crc == id[11]);
 326        if (!dev->id_crc_correct) {
 327                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 328                                id[11], crc);
 329        }
 330}
 331
 332static void ipack_parse_id2(struct ipack_device *dev)
 333{
 334        __be16 *id = (__be16 *) dev->id;
 335        u16 flags, crc;
 336
 337        dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
 338                         + be16_to_cpu(id[4]);
 339        dev->id_device = be16_to_cpu(id[5]);
 340        flags = be16_to_cpu(id[10]);
 341        dev->speed_8mhz = !!(flags & 2);
 342        dev->speed_32mhz = !!(flags & 4);
 343        crc = ipack_calc_crc2(dev);
 344        dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
 345        if (!dev->id_crc_correct) {
 346                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 347                                id[11], crc);
 348        }
 349}
 350
 351static int ipack_device_read_id(struct ipack_device *dev)
 352{
 353        u8 __iomem *idmem;
 354        int i;
 355        int ret = 0;
 356
 357        idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
 358                        dev->region[IPACK_ID_SPACE].size);
 359        if (!idmem) {
 360                dev_err(&dev->dev, "error mapping memory\n");
 361                return -ENOMEM;
 362        }
 363
 364        /* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
 365         * we are dealing with a IndustryPack  format 1 device.  If we detect
 366         * "VITA4 " (16 bit big endian formatted) we are dealing with a
 367         * IndustryPack format 2 device */
 368        if ((ioread8(idmem + 1) == 'I') &&
 369                        (ioread8(idmem + 3) == 'P') &&
 370                        (ioread8(idmem + 5) == 'A') &&
 371                        ((ioread8(idmem + 7) == 'C') ||
 372                         (ioread8(idmem + 7) == 'H'))) {
 373                dev->id_format = IPACK_ID_VERSION_1;
 374                dev->id_avail = ioread8(idmem + 0x15);
 375                if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
 376                        dev_warn(&dev->dev, "invalid id size");
 377                        dev->id_avail = 0x0c;
 378                }
 379        } else if ((ioread8(idmem + 0) == 'I') &&
 380                        (ioread8(idmem + 1) == 'V') &&
 381                        (ioread8(idmem + 2) == 'A') &&
 382                        (ioread8(idmem + 3) == 'T') &&
 383                        (ioread8(idmem + 4) == ' ') &&
 384                        (ioread8(idmem + 5) == '4')) {
 385                dev->id_format = IPACK_ID_VERSION_2;
 386                dev->id_avail = ioread16be(idmem + 0x16);
 387                if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
 388                        dev_warn(&dev->dev, "invalid id size");
 389                        dev->id_avail = 0x1a;
 390                }
 391        } else {
 392                dev->id_format = IPACK_ID_VERSION_INVALID;
 393                dev->id_avail = 0;
 394        }
 395
 396        if (!dev->id_avail) {
 397                ret = -ENODEV;
 398                goto out;
 399        }
 400
 401        /* Obtain the amount of memory required to store a copy of the complete
 402         * ID ROM contents */
 403        dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
 404        if (!dev->id) {
 405                ret = -ENOMEM;
 406                goto out;
 407        }
 408        for (i = 0; i < dev->id_avail; i++) {
 409                if (dev->id_format == IPACK_ID_VERSION_1)
 410                        dev->id[i] = ioread8(idmem + (i << 1) + 1);
 411                else
 412                        dev->id[i] = ioread8(idmem + i);
 413        }
 414
 415        /* now we can finally work with the copy */
 416        switch (dev->id_format) {
 417        case IPACK_ID_VERSION_1:
 418                ipack_parse_id1(dev);
 419                break;
 420        case IPACK_ID_VERSION_2:
 421                ipack_parse_id2(dev);
 422                break;
 423        }
 424
 425out:
 426        iounmap(idmem);
 427
 428        return ret;
 429}
 430
 431int ipack_device_init(struct ipack_device *dev)
 432{
 433        int ret;
 434
 435        dev->dev.bus = &ipack_bus_type;
 436        dev->dev.release = ipack_device_release;
 437        dev->dev.parent = dev->bus->parent;
 438        dev_set_name(&dev->dev,
 439                     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
 440        device_initialize(&dev->dev);
 441
 442        if (dev->bus->ops->set_clockrate(dev, 8))
 443                dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
 444        if (dev->bus->ops->reset_timeout(dev))
 445                dev_warn(&dev->dev, "failed to reset potential timeout.");
 446
 447        ret = ipack_device_read_id(dev);
 448        if (ret < 0) {
 449                dev_err(&dev->dev, "error reading device id section.\n");
 450                return ret;
 451        }
 452
 453        /* if the device supports 32 MHz operation, use it. */
 454        if (dev->speed_32mhz) {
 455                ret = dev->bus->ops->set_clockrate(dev, 32);
 456                if (ret < 0)
 457                        dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
 458        }
 459
 460        return 0;
 461}
 462EXPORT_SYMBOL_GPL(ipack_device_init);
 463
 464int ipack_device_add(struct ipack_device *dev)
 465{
 466        return device_add(&dev->dev);
 467}
 468EXPORT_SYMBOL_GPL(ipack_device_add);
 469
 470void ipack_device_del(struct ipack_device *dev)
 471{
 472        device_del(&dev->dev);
 473        ipack_put_device(dev);
 474}
 475EXPORT_SYMBOL_GPL(ipack_device_del);
 476
 477void ipack_get_device(struct ipack_device *dev)
 478{
 479        get_device(&dev->dev);
 480}
 481EXPORT_SYMBOL_GPL(ipack_get_device);
 482
 483void ipack_put_device(struct ipack_device *dev)
 484{
 485        put_device(&dev->dev);
 486}
 487EXPORT_SYMBOL_GPL(ipack_put_device);
 488
 489static int __init ipack_init(void)
 490{
 491        ida_init(&ipack_ida);
 492        return bus_register(&ipack_bus_type);
 493}
 494
 495static void __exit ipack_exit(void)
 496{
 497        bus_unregister(&ipack_bus_type);
 498        ida_destroy(&ipack_ida);
 499}
 500
 501module_init(ipack_init);
 502module_exit(ipack_exit);
 503
 504MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 505MODULE_LICENSE("GPL");
 506MODULE_DESCRIPTION("Industry-pack bus core");
 507