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        return drv->ops->probe(dev);
  68}
  69
  70static int ipack_bus_remove(struct device *device)
  71{
  72        struct ipack_device *dev = to_ipack_dev(device);
  73        struct ipack_driver *drv = to_ipack_driver(device->driver);
  74
  75        if (drv->ops->remove)
  76                drv->ops->remove(dev);
  77
  78        return 0;
  79}
  80
  81static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
  82{
  83        struct ipack_device *idev;
  84
  85        if (!dev)
  86                return -ENODEV;
  87
  88        idev = to_ipack_dev(dev);
  89
  90        if (add_uevent_var(env,
  91                           "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
  92                           idev->id_vendor, idev->id_device))
  93                return -ENOMEM;
  94
  95        return 0;
  96}
  97
  98#define ipack_device_attr(field, format_string)                         \
  99static ssize_t                                                          \
 100field##_show(struct device *dev, struct device_attribute *attr,         \
 101                char *buf)                                              \
 102{                                                                       \
 103        struct ipack_device *idev = to_ipack_dev(dev);                  \
 104        return sprintf(buf, format_string, idev->field);                \
 105}
 106
 107static ssize_t id_show(struct device *dev,
 108                       struct device_attribute *attr, char *buf)
 109{
 110        unsigned int i, c, l, s;
 111        struct ipack_device *idev = to_ipack_dev(dev);
 112
 113
 114        switch (idev->id_format) {
 115        case IPACK_ID_VERSION_1:
 116                l = 0x7; s = 1; break;
 117        case IPACK_ID_VERSION_2:
 118                l = 0xf; s = 2; break;
 119        default:
 120                return -EIO;
 121        }
 122        c = 0;
 123        for (i = 0; i < idev->id_avail; i++) {
 124                if (i > 0) {
 125                        if ((i & l) == 0)
 126                                buf[c++] = '\n';
 127                        else if ((i & s) == 0)
 128                                buf[c++] = ' ';
 129                }
 130                sprintf(&buf[c], "%02x", idev->id[i]);
 131                c += 2;
 132        }
 133        buf[c++] = '\n';
 134        return c;
 135}
 136
 137static ssize_t
 138id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
 139{
 140        struct ipack_device *idev = to_ipack_dev(dev);
 141        switch (idev->id_format) {
 142        case IPACK_ID_VERSION_1:
 143                return sprintf(buf, "0x%02x\n", idev->id_vendor);
 144        case IPACK_ID_VERSION_2:
 145                return sprintf(buf, "0x%06x\n", idev->id_vendor);
 146        default:
 147                return -EIO;
 148        }
 149}
 150
 151static ssize_t
 152id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
 153{
 154        struct ipack_device *idev = to_ipack_dev(dev);
 155        switch (idev->id_format) {
 156        case IPACK_ID_VERSION_1:
 157                return sprintf(buf, "0x%02x\n", idev->id_device);
 158        case IPACK_ID_VERSION_2:
 159                return sprintf(buf, "0x%04x\n", idev->id_device);
 160        default:
 161                return -EIO;
 162        }
 163}
 164
 165static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 166                             char *buf)
 167{
 168        struct ipack_device *idev = to_ipack_dev(dev);
 169
 170        return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
 171                       idev->id_vendor, idev->id_device);
 172}
 173
 174ipack_device_attr(id_format, "0x%hhx\n");
 175
 176static DEVICE_ATTR_RO(id);
 177static DEVICE_ATTR_RO(id_device);
 178static DEVICE_ATTR_RO(id_format);
 179static DEVICE_ATTR_RO(id_vendor);
 180static DEVICE_ATTR_RO(modalias);
 181
 182static struct attribute *ipack_attrs[] = {
 183        &dev_attr_id.attr,
 184        &dev_attr_id_device.attr,
 185        &dev_attr_id_format.attr,
 186        &dev_attr_id_vendor.attr,
 187        &dev_attr_modalias.attr,
 188        NULL,
 189};
 190ATTRIBUTE_GROUPS(ipack);
 191
 192static struct bus_type ipack_bus_type = {
 193        .name      = "ipack",
 194        .probe     = ipack_bus_probe,
 195        .match     = ipack_bus_match,
 196        .remove    = ipack_bus_remove,
 197        .dev_groups = ipack_groups,
 198        .uevent    = ipack_uevent,
 199};
 200
 201struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
 202                                            const struct ipack_bus_ops *ops,
 203                                            struct module *owner)
 204{
 205        int bus_nr;
 206        struct ipack_bus_device *bus;
 207
 208        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 209        if (!bus)
 210                return NULL;
 211
 212        bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
 213        if (bus_nr < 0) {
 214                kfree(bus);
 215                return NULL;
 216        }
 217
 218        bus->bus_nr = bus_nr;
 219        bus->parent = parent;
 220        bus->slots = slots;
 221        bus->ops = ops;
 222        bus->owner = owner;
 223        return bus;
 224}
 225EXPORT_SYMBOL_GPL(ipack_bus_register);
 226
 227static int ipack_unregister_bus_member(struct device *dev, void *data)
 228{
 229        struct ipack_device *idev = to_ipack_dev(dev);
 230        struct ipack_bus_device *bus = data;
 231
 232        if (idev->bus == bus)
 233                ipack_device_del(idev);
 234
 235        return 1;
 236}
 237
 238int ipack_bus_unregister(struct ipack_bus_device *bus)
 239{
 240        bus_for_each_dev(&ipack_bus_type, NULL, bus,
 241                ipack_unregister_bus_member);
 242        ida_simple_remove(&ipack_ida, bus->bus_nr);
 243        kfree(bus);
 244        return 0;
 245}
 246EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 247
 248int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 249                          const char *name)
 250{
 251        if (!edrv->ops->probe)
 252                return -EINVAL;
 253
 254        edrv->driver.owner = owner;
 255        edrv->driver.name = name;
 256        edrv->driver.bus = &ipack_bus_type;
 257        return driver_register(&edrv->driver);
 258}
 259EXPORT_SYMBOL_GPL(ipack_driver_register);
 260
 261void ipack_driver_unregister(struct ipack_driver *edrv)
 262{
 263        driver_unregister(&edrv->driver);
 264}
 265EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 266
 267static u16 ipack_crc_byte(u16 crc, u8 c)
 268{
 269        int i;
 270
 271        crc ^= c << 8;
 272        for (i = 0; i < 8; i++)
 273                crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
 274        return crc;
 275}
 276
 277/*
 278 * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
 279 * opposite bit ordering.
 280 */
 281static u8 ipack_calc_crc1(struct ipack_device *dev)
 282{
 283        u8 c;
 284        u16 crc;
 285        unsigned int i;
 286
 287        crc = 0xffff;
 288        for (i = 0; i < dev->id_avail; i++) {
 289                c = (i != 11) ? dev->id[i] : 0;
 290                crc = ipack_crc_byte(crc, c);
 291        }
 292        crc = ~crc;
 293        return crc & 0xff;
 294}
 295
 296static u16 ipack_calc_crc2(struct ipack_device *dev)
 297{
 298        u8 c;
 299        u16 crc;
 300        unsigned int i;
 301
 302        crc = 0xffff;
 303        for (i = 0; i < dev->id_avail; i++) {
 304                c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
 305                crc = ipack_crc_byte(crc, c);
 306        }
 307        crc = ~crc;
 308        return crc;
 309}
 310
 311static void ipack_parse_id1(struct ipack_device *dev)
 312{
 313        u8 *id = dev->id;
 314        u8 crc;
 315
 316        dev->id_vendor = id[4];
 317        dev->id_device = id[5];
 318        dev->speed_8mhz = 1;
 319        dev->speed_32mhz = (id[7] == 'H');
 320        crc = ipack_calc_crc1(dev);
 321        dev->id_crc_correct = (crc == id[11]);
 322        if (!dev->id_crc_correct) {
 323                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 324                                id[11], crc);
 325        }
 326}
 327
 328static void ipack_parse_id2(struct ipack_device *dev)
 329{
 330        __be16 *id = (__be16 *) dev->id;
 331        u16 flags, crc;
 332
 333        dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
 334                         + be16_to_cpu(id[4]);
 335        dev->id_device = be16_to_cpu(id[5]);
 336        flags = be16_to_cpu(id[10]);
 337        dev->speed_8mhz = !!(flags & 2);
 338        dev->speed_32mhz = !!(flags & 4);
 339        crc = ipack_calc_crc2(dev);
 340        dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
 341        if (!dev->id_crc_correct) {
 342                dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 343                                id[11], crc);
 344        }
 345}
 346
 347static int ipack_device_read_id(struct ipack_device *dev)
 348{
 349        u8 __iomem *idmem;
 350        int i;
 351        int ret = 0;
 352
 353        idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
 354                        dev->region[IPACK_ID_SPACE].size);
 355        if (!idmem) {
 356                dev_err(&dev->dev, "error mapping memory\n");
 357                return -ENOMEM;
 358        }
 359
 360        /* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
 361         * we are dealing with a IndustryPack  format 1 device.  If we detect
 362         * "VITA4 " (16 bit big endian formatted) we are dealing with a
 363         * IndustryPack format 2 device */
 364        if ((ioread8(idmem + 1) == 'I') &&
 365                        (ioread8(idmem + 3) == 'P') &&
 366                        (ioread8(idmem + 5) == 'A') &&
 367                        ((ioread8(idmem + 7) == 'C') ||
 368                         (ioread8(idmem + 7) == 'H'))) {
 369                dev->id_format = IPACK_ID_VERSION_1;
 370                dev->id_avail = ioread8(idmem + 0x15);
 371                if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
 372                        dev_warn(&dev->dev, "invalid id size");
 373                        dev->id_avail = 0x0c;
 374                }
 375        } else if ((ioread8(idmem + 0) == 'I') &&
 376                        (ioread8(idmem + 1) == 'V') &&
 377                        (ioread8(idmem + 2) == 'A') &&
 378                        (ioread8(idmem + 3) == 'T') &&
 379                        (ioread8(idmem + 4) == ' ') &&
 380                        (ioread8(idmem + 5) == '4')) {
 381                dev->id_format = IPACK_ID_VERSION_2;
 382                dev->id_avail = ioread16be(idmem + 0x16);
 383                if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
 384                        dev_warn(&dev->dev, "invalid id size");
 385                        dev->id_avail = 0x1a;
 386                }
 387        } else {
 388                dev->id_format = IPACK_ID_VERSION_INVALID;
 389                dev->id_avail = 0;
 390        }
 391
 392        if (!dev->id_avail) {
 393                ret = -ENODEV;
 394                goto out;
 395        }
 396
 397        /* Obtain the amount of memory required to store a copy of the complete
 398         * ID ROM contents */
 399        dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
 400        if (!dev->id) {
 401                ret = -ENOMEM;
 402                goto out;
 403        }
 404        for (i = 0; i < dev->id_avail; i++) {
 405                if (dev->id_format == IPACK_ID_VERSION_1)
 406                        dev->id[i] = ioread8(idmem + (i << 1) + 1);
 407                else
 408                        dev->id[i] = ioread8(idmem + i);
 409        }
 410
 411        /* now we can finally work with the copy */
 412        switch (dev->id_format) {
 413        case IPACK_ID_VERSION_1:
 414                ipack_parse_id1(dev);
 415                break;
 416        case IPACK_ID_VERSION_2:
 417                ipack_parse_id2(dev);
 418                break;
 419        }
 420
 421out:
 422        iounmap(idmem);
 423
 424        return ret;
 425}
 426
 427int ipack_device_init(struct ipack_device *dev)
 428{
 429        int ret;
 430
 431        dev->dev.bus = &ipack_bus_type;
 432        dev->dev.release = ipack_device_release;
 433        dev->dev.parent = dev->bus->parent;
 434        dev_set_name(&dev->dev,
 435                     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
 436        device_initialize(&dev->dev);
 437
 438        if (dev->bus->ops->set_clockrate(dev, 8))
 439                dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
 440        if (dev->bus->ops->reset_timeout(dev))
 441                dev_warn(&dev->dev, "failed to reset potential timeout.");
 442
 443        ret = ipack_device_read_id(dev);
 444        if (ret < 0) {
 445                dev_err(&dev->dev, "error reading device id section.\n");
 446                return ret;
 447        }
 448
 449        /* if the device supports 32 MHz operation, use it. */
 450        if (dev->speed_32mhz) {
 451                ret = dev->bus->ops->set_clockrate(dev, 32);
 452                if (ret < 0)
 453                        dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
 454        }
 455
 456        return 0;
 457}
 458EXPORT_SYMBOL_GPL(ipack_device_init);
 459
 460int ipack_device_add(struct ipack_device *dev)
 461{
 462        return device_add(&dev->dev);
 463}
 464EXPORT_SYMBOL_GPL(ipack_device_add);
 465
 466void ipack_device_del(struct ipack_device *dev)
 467{
 468        device_del(&dev->dev);
 469        ipack_put_device(dev);
 470}
 471EXPORT_SYMBOL_GPL(ipack_device_del);
 472
 473void ipack_get_device(struct ipack_device *dev)
 474{
 475        get_device(&dev->dev);
 476}
 477EXPORT_SYMBOL_GPL(ipack_get_device);
 478
 479void ipack_put_device(struct ipack_device *dev)
 480{
 481        put_device(&dev->dev);
 482}
 483EXPORT_SYMBOL_GPL(ipack_put_device);
 484
 485static int __init ipack_init(void)
 486{
 487        ida_init(&ipack_ida);
 488        return bus_register(&ipack_bus_type);
 489}
 490
 491static void __exit ipack_exit(void)
 492{
 493        bus_unregister(&ipack_bus_type);
 494        ida_destroy(&ipack_ida);
 495}
 496
 497module_init(ipack_init);
 498module_exit(ipack_exit);
 499
 500MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 501MODULE_LICENSE("GPL");
 502MODULE_DESCRIPTION("Industry-pack bus core");
 503