linux/drivers/ipack/ipack.c
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   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
  18static DEFINE_IDA(ipack_ida);
  19
  20static 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
  27static inline const struct ipack_device_id *
  28ipack_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
  39static const struct ipack_device_id *
  40ipack_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
  52static 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
  62static 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        if (!drv->ops->probe)
  68                return -EINVAL;
  69
  70        return drv->ops->probe(dev);
  71}
  72
  73static int ipack_bus_remove(struct device *device)
  74{
  75        struct ipack_device *dev = to_ipack_dev(device);
  76        struct ipack_driver *drv = to_ipack_driver(device->driver);
  77
  78        if (!drv->ops->remove)
  79                return -EINVAL;
  80
  81        drv->ops->remove(dev);
  82        return 0;
  83}
  84
  85static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
  86{
  87        struct ipack_device *idev;
  88
  89        if (!dev)
  90                return -ENODEV;
  91
  92        idev = to_ipack_dev(dev);
  93
  94        if (add_uevent_var(env,
  95                           "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
  96                           idev->id_vendor, idev->id_device))
  97                return -ENOMEM;
  98
  99        return 0;
 100}
 101
 102#define ipack_device_attr(field, format_string)                         \
 103static ssize_t                                                          \
 104field##_show(struct device *dev, struct device_attribute *attr,         \
 105                char *buf)                                              \
 106{                                                                       \
 107        struct ipack_device *idev = to_ipack_dev(dev);                  \
 108        return sprintf(buf, format_string, idev->field);                \
 109}
 110
 111static ssize_t id_show(struct device *dev,
 112                       struct device_attribute *attr, char *buf)
 113{
 114        unsigned int i, c, l, s;
 115        struct ipack_device *idev = to_ipack_dev(dev);
 116
 117
 118        switch (idev->id_format) {
 119        case IPACK_ID_VERSION_1:
 120                l = 0x7; s = 1; break;
 121        case IPACK_ID_VERSION_2:
 122                l = 0xf; s = 2; break;
 123        default:
 124                return -EIO;
 125        }
 126        c = 0;
 127        for (i = 0; i < idev->id_avail; i++) {
 128                if (i > 0) {
 129                        if ((i & l) == 0)
 130                                buf[c++] = '\n';
 131                        else if ((i & s) == 0)
 132                                buf[c++] = ' ';
 133                }
 134                sprintf(&buf[c], "%02x", idev->id[i]);
 135                c += 2;
 136        }
 137        buf[c++] = '\n';
 138        return c;
 139}
 140
 141static ssize_t
 142id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
 143{
 144        struct ipack_device *idev = to_ipack_dev(dev);
 145        switch (idev->id_format) {
 146        case IPACK_ID_VERSION_1:
 147                return sprintf(buf, "0x%02x\n", idev->id_vendor);
 148        case IPACK_ID_VERSION_2:
 149                return sprintf(buf, "0x%06x\n", idev->id_vendor);
 150        default:
 151                return -EIO;
 152        }
 153}
 154
 155static ssize_t
 156id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
 157{
 158        struct ipack_device *idev = to_ipack_dev(dev);
 159        switch (idev->id_format) {
 160        case IPACK_ID_VERSION_1:
 161                return sprintf(buf, "0x%02x\n", idev->id_device);
 162        case IPACK_ID_VERSION_2:
 163                return sprintf(buf, "0x%04x\n", idev->id_device);
 164        default:
 165                return -EIO;
 166        }
 167}
 168
 169static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 170                             char *buf)
 171{
 172        struct ipack_device *idev = to_ipack_dev(dev);
 173
 174        return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
 175                       idev->id_vendor, idev->id_device);
 176}
 177
 178ipack_device_attr(id_format, "0x%hhx\n");
 179
 180static DEVICE_ATTR_RO(id);
 181static DEVICE_ATTR_RO(id_device);
 182static DEVICE_ATTR_RO(id_format);
 183static DEVICE_ATTR_RO(id_vendor);
 184static DEVICE_ATTR_RO(modalias);
 185
 186static struct attribute *ipack_attrs[] = {
 187        &dev_attr_id.attr,
 188        &dev_attr_id_device.attr,
 189        &dev_attr_id_format.attr,
 190        &dev_attr_id_vendor.attr,
 191        &dev_attr_modalias.attr,
 192        NULL,
 193};
 194ATTRIBUTE_GROUPS(ipack);
 195
 196static struct bus_type ipack_bus_type = {
 197        .name      = "ipack",
 198        .probe     = ipack_bus_probe,
 199        .match     = ipack_bus_match,
 200        .remove    = ipack_bus_remove,
 201        .dev_groups = ipack_groups,
 202        .uevent    = ipack_uevent,
 203};
 204
 205struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
 206                                            const struct ipack_bus_ops *ops,
 207                                            struct module *owner)
 208{
 209        int bus_nr;
 210        struct ipack_bus_device *bus;
 211
 212        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 213        if (!bus)
 214                return NULL;
 215
 216        bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
 217        if (bus_nr < 0) {
 218                kfree(bus);
 219                return NULL;
 220        }
 221
 222        bus->bus_nr = bus_nr;
 223        bus->parent = parent;
 224        bus->slots = slots;
 225        bus->ops = ops;
 226        bus->owner = owner;
 227        return bus;
 228}
 229EXPORT_SYMBOL_GPL(ipack_bus_register);
 230
 231static int ipack_unregister_bus_member(struct device *dev, void *data)
 232{
 233        struct ipack_device *idev = to_ipack_dev(dev);
 234        struct ipack_bus_device *bus = data;
 235
 236        if (idev->bus == bus)
 237                ipack_device_del(idev);
 238
 239        return 1;
 240}
 241
 242int ipack_bus_unregister(struct ipack_bus_device *bus)
 243{
 244        bus_for_each_dev(&ipack_bus_type, NULL, bus,
 245                ipack_unregister_bus_member);
 246        ida_simple_remove(&ipack_ida, bus->bus_nr);
 247        kfree(bus);
 248        return 0;
 249}
 250EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 251
 252int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 253                          const char *name)
 254{
 255        edrv->driver.owner = owner;
 256        edrv->driver.name = name;
 257        edrv->driver.bus = &ipack_bus_type;
 258        return driver_register(&edrv->driver);
 259}
 260EXPORT_SYMBOL_GPL(ipack_driver_register);
 261
 262void ipack_driver_unregister(struct ipack_driver *edrv)
 263{
 264        driver_unregister(&edrv->driver);
 265}
 266EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 267
 268static u16 ipack_crc_byte(u16 crc, u8 c)
 269{
 270        int i;
 271
 272        crc ^= c << 8;
 273        for (i = 0; i < 8; i++)
 274                crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
 275        return crc;
 276}
 277
 278/*
 279 * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
 280 * opposite bit ordering.
 281 */
 282static u8 ipack_calc_crc1(struct ipack_device *dev)
 283{
 284        u8 c;
 285        u16 crc;
 286        unsigned int i;
 287
 288        crc = 0xffff;
 289        for (i = 0; i < dev->id_avail; i++) {
 290                c = (i != 11) ? dev->id[i] : 0;
 291                crc = ipack_crc_byte(crc, c);
 292        }
 293        crc = ~crc;
 294        return crc & 0xff;
 295}
 296
 297static u16 ipack_calc_crc2(struct ipack_device *dev)
 298{
 299        u8 c;
 300        u16 crc;
 301        unsigned int i;
 302
 303        crc = 0xffff;
 304        for (i = 0; i < dev->id_avail; i++) {
 305                c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
 306                crc = ipack_crc_byte(crc, c);
 307        }
 308        crc = ~crc;
 309        return crc;
 310}
 311
 312static void ipack_parse_id1(struct ipack_device *dev)
 313{
 314        u8 *id = dev->id;
 315        u8 crc;
 316
 317        dev->id_vendor = id[4];
 318        dev->id_device = id[5];
 319        dev->speed_8mhz = 1;
 320        dev->speed_32mhz = (id[7] == 'H');
 321        crc = ipack_calc_crc1(dev);
 322        dev->id_crc_correct = (crc == id[11]);
 323        if (!dev->id_crc_correct) {
 324                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 325                                id[11], crc);
 326        }
 327}
 328
 329static void ipack_parse_id2(struct ipack_device *dev)
 330{
 331        __be16 *id = (__be16 *) dev->id;
 332        u16 flags, crc;
 333
 334        dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
 335                         + be16_to_cpu(id[4]);
 336        dev->id_device = be16_to_cpu(id[5]);
 337        flags = be16_to_cpu(id[10]);
 338        dev->speed_8mhz = !!(flags & 2);
 339        dev->speed_32mhz = !!(flags & 4);
 340        crc = ipack_calc_crc2(dev);
 341        dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
 342        if (!dev->id_crc_correct) {
 343                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 344                                id[11], crc);
 345        }
 346}
 347
 348static int ipack_device_read_id(struct ipack_device *dev)
 349{
 350        u8 __iomem *idmem;
 351        int i;
 352        int ret = 0;
 353
 354        idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
 355                        dev->region[IPACK_ID_SPACE].size);
 356        if (!idmem) {
 357                dev_err(&dev->dev, "error mapping memory\n");
 358                return -ENOMEM;
 359        }
 360
 361        /* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
 362         * we are dealing with a IndustryPack  format 1 device.  If we detect
 363         * "VITA4 " (16 bit big endian formatted) we are dealing with a
 364         * IndustryPack format 2 device */
 365        if ((ioread8(idmem + 1) == 'I') &&
 366                        (ioread8(idmem + 3) == 'P') &&
 367                        (ioread8(idmem + 5) == 'A') &&
 368                        ((ioread8(idmem + 7) == 'C') ||
 369                         (ioread8(idmem + 7) == 'H'))) {
 370                dev->id_format = IPACK_ID_VERSION_1;
 371                dev->id_avail = ioread8(idmem + 0x15);
 372                if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
 373                        dev_warn(&dev->dev, "invalid id size");
 374                        dev->id_avail = 0x0c;
 375                }
 376        } else if ((ioread8(idmem + 0) == 'I') &&
 377                        (ioread8(idmem + 1) == 'V') &&
 378                        (ioread8(idmem + 2) == 'A') &&
 379                        (ioread8(idmem + 3) == 'T') &&
 380                        (ioread8(idmem + 4) == ' ') &&
 381                        (ioread8(idmem + 5) == '4')) {
 382                dev->id_format = IPACK_ID_VERSION_2;
 383                dev->id_avail = ioread16be(idmem + 0x16);
 384                if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
 385                        dev_warn(&dev->dev, "invalid id size");
 386                        dev->id_avail = 0x1a;
 387                }
 388        } else {
 389                dev->id_format = IPACK_ID_VERSION_INVALID;
 390                dev->id_avail = 0;
 391        }
 392
 393        if (!dev->id_avail) {
 394                ret = -ENODEV;
 395                goto out;
 396        }
 397
 398        /* Obtain the amount of memory required to store a copy of the complete
 399         * ID ROM contents */
 400        dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
 401        if (!dev->id) {
 402                ret = -ENOMEM;
 403                goto out;
 404        }
 405        for (i = 0; i < dev->id_avail; i++) {
 406                if (dev->id_format == IPACK_ID_VERSION_1)
 407                        dev->id[i] = ioread8(idmem + (i << 1) + 1);
 408                else
 409                        dev->id[i] = ioread8(idmem + i);
 410        }
 411
 412        /* now we can finally work with the copy */
 413        switch (dev->id_format) {
 414        case IPACK_ID_VERSION_1:
 415                ipack_parse_id1(dev);
 416                break;
 417        case IPACK_ID_VERSION_2:
 418                ipack_parse_id2(dev);
 419                break;
 420        }
 421
 422out:
 423        iounmap(idmem);
 424
 425        return ret;
 426}
 427
 428int ipack_device_init(struct ipack_device *dev)
 429{
 430        int ret;
 431
 432        dev->dev.bus = &ipack_bus_type;
 433        dev->dev.release = ipack_device_release;
 434        dev->dev.parent = dev->bus->parent;
 435        dev_set_name(&dev->dev,
 436                     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
 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}
 459EXPORT_SYMBOL_GPL(ipack_device_init);
 460
 461int ipack_device_add(struct ipack_device *dev)
 462{
 463        return device_add(&dev->dev);
 464}
 465EXPORT_SYMBOL_GPL(ipack_device_add);
 466
 467void ipack_device_del(struct ipack_device *dev)
 468{
 469        device_del(&dev->dev);
 470        ipack_put_device(dev);
 471}
 472EXPORT_SYMBOL_GPL(ipack_device_del);
 473
 474void ipack_get_device(struct ipack_device *dev)
 475{
 476        get_device(&dev->dev);
 477}
 478EXPORT_SYMBOL_GPL(ipack_get_device);
 479
 480void ipack_put_device(struct ipack_device *dev)
 481{
 482        put_device(&dev->dev);
 483}
 484EXPORT_SYMBOL_GPL(ipack_put_device);
 485
 486static int __init ipack_init(void)
 487{
 488        ida_init(&ipack_ida);
 489        return bus_register(&ipack_bus_type);
 490}
 491
 492static void __exit ipack_exit(void)
 493{
 494        bus_unregister(&ipack_bus_type);
 495        ida_destroy(&ipack_ida);
 496}
 497
 498module_init(ipack_init);
 499module_exit(ipack_exit);
 500
 501MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 502MODULE_LICENSE("GPL");
 503MODULE_DESCRIPTION("Industry-pack bus core");
 504