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