drivers/mcb/mcb-core.c

   1 /*
   2  * MEN Chameleon Bus.
   3  *
   4  * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de)
   5  * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
   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 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15 #include <linux/idr.h>
  16 #include <linux/mcb.h>
  17
  18 static DEFINE_IDA(mcb_ida);
  19
  20 static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids,
  21                                                 struct mcb_device *dev)
  22 {
  23         if (ids) {
  24                 while (ids->device) {
  25                         if (ids->device == dev->id)
  26                                 return ids;
  27                         ids++;
  28                 }
  29         }
  30
  31         return NULL;
  32 }
  33
  34 static int mcb_match(struct device *dev, struct device_driver *drv)
  35 {
  36         struct mcb_driver *mdrv = to_mcb_driver(drv);
  37         struct mcb_device *mdev = to_mcb_device(dev);
  38         const struct mcb_device_id *found_id;
  39
  40         found_id = mcb_match_id(mdrv->id_table, mdev);
  41         if (found_id)
  42                 return 1;
  43
  44         return 0;
  45 }
  46
  47 static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env)
  48 {
  49         struct mcb_device *mdev = to_mcb_device(dev);
  50         int ret;
  51
  52         ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id);
  53         if (ret)
  54                 return -ENOMEM;
  55
  56         return 0;
  57 }
  58
  59 static int mcb_probe(struct device *dev)
  60 {
  61         struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
  62         struct mcb_device *mdev = to_mcb_device(dev);
  63         const struct mcb_device_id *found_id;
  64         struct module *carrier_mod;
  65         int ret;
  66
  67         found_id = mcb_match_id(mdrv->id_table, mdev);
  68         if (!found_id)
  69                 return -ENODEV;
  70
  71         carrier_mod = mdev->dev.parent->driver->owner;
  72         if (!try_module_get(carrier_mod))
  73                 return -EINVAL;
  74
  75         get_device(dev);
  76         ret = mdrv->probe(mdev, found_id);
  77         if (ret)
  78                 module_put(carrier_mod);
  79
  80         return ret;
  81 }
  82
  83 static int mcb_remove(struct device *dev)
  84 {
  85         struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
  86         struct mcb_device *mdev = to_mcb_device(dev);
  87         struct module *carrier_mod;
  88
  89         mdrv->remove(mdev);
  90
  91         carrier_mod = mdev->dev.parent->driver->owner;
  92         module_put(carrier_mod);
  93
  94         put_device(&mdev->dev);
  95
  96         return 0;
  97 }
  98
  99 static void mcb_shutdown(struct device *dev)
 100 {
 101         struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
 102         struct mcb_device *mdev = to_mcb_device(dev);
 103
 104         if (mdrv && mdrv->shutdown)
 105                 mdrv->shutdown(mdev);
 106 }
 107
 108 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
 109                          char *buf)
 110 {
 111         struct mcb_bus *bus = to_mcb_bus(dev);
 112
 113         return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision);
 114 }
 115 static DEVICE_ATTR_RO(revision);
 116
 117 static ssize_t model_show(struct device *dev, struct device_attribute *attr,
 118                          char *buf)
 119 {
 120         struct mcb_bus *bus = to_mcb_bus(dev);
 121
 122         return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model);
 123 }
 124 static DEVICE_ATTR_RO(model);
 125
 126 static ssize_t minor_show(struct device *dev, struct device_attribute *attr,
 127                          char *buf)
 128 {
 129         struct mcb_bus *bus = to_mcb_bus(dev);
 130
 131         return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor);
 132 }
 133 static DEVICE_ATTR_RO(minor);
 134
 135 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 136                          char *buf)
 137 {
 138         struct mcb_bus *bus = to_mcb_bus(dev);
 139
 140         return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name);
 141 }
 142 static DEVICE_ATTR_RO(name);
 143
 144 static struct attribute *mcb_bus_attrs[] = {
 145         &dev_attr_revision.attr,
 146         &dev_attr_model.attr,
 147         &dev_attr_minor.attr,
 148         &dev_attr_name.attr,
 149         NULL,
 150 };
 151
 152 static const struct attribute_group mcb_carrier_group = {
 153         .attrs = mcb_bus_attrs,
 154 };
 155
 156 static const struct attribute_group *mcb_carrier_groups[] = {
 157         &mcb_carrier_group,
 158         NULL,
 159 };
 160
 161
 162 static struct bus_type mcb_bus_type = {
 163         .name = "mcb",
 164         .match = mcb_match,
 165         .uevent = mcb_uevent,
 166         .probe = mcb_probe,
 167         .remove = mcb_remove,
 168         .shutdown = mcb_shutdown,
 169 };
 170
 171 static struct device_type mcb_carrier_device_type = {
 172         .name = "mcb-carrier",
 173         .groups = mcb_carrier_groups,
 174 };
 175
 176 /**
 177  * __mcb_register_driver() - Register a @mcb_driver at the system
 178  * @drv: The @mcb_driver
 179  * @owner: The @mcb_driver's module
 180  * @mod_name: The name of the @mcb_driver's module
 181  *
 182  * Register a @mcb_driver at the system. Perform some sanity checks, if
 183  * the .probe and .remove methods are provided by the driver.
 184  */
 185 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
 186                         const char *mod_name)
 187 {
 188         if (!drv->probe || !drv->remove)
 189                 return -EINVAL;
 190
 191         drv->driver.owner = owner;
 192         drv->driver.bus = &mcb_bus_type;
 193         drv->driver.mod_name = mod_name;
 194
 195         return driver_register(&drv->driver);
 196 }
 197 EXPORT_SYMBOL_GPL(__mcb_register_driver);
 198
 199 /**
 200  * mcb_unregister_driver() - Unregister a @mcb_driver from the system
 201  * @drv: The @mcb_driver
 202  *
 203  * Unregister a @mcb_driver from the system.
 204  */
 205 void mcb_unregister_driver(struct mcb_driver *drv)
 206 {
 207         driver_unregister(&drv->driver);
 208 }
 209 EXPORT_SYMBOL_GPL(mcb_unregister_driver);
 210
 211 static void mcb_release_dev(struct device *dev)
 212 {
 213         struct mcb_device *mdev = to_mcb_device(dev);
 214
 215         mcb_bus_put(mdev->bus);
 216         kfree(mdev);
 217 }
 218
 219 /**
 220  * mcb_device_register() - Register a mcb_device
 221  * @bus: The @mcb_bus of the device
 222  * @dev: The @mcb_device
 223  *
 224  * Register a specific @mcb_device at a @mcb_bus and the system itself.
 225  */
 226 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev)
 227 {
 228         int ret;
 229         int device_id;
 230
 231         device_initialize(&dev->dev);
 232         mcb_bus_get(bus);
 233         dev->dev.bus = &mcb_bus_type;
 234         dev->dev.parent = bus->dev.parent;
 235         dev->dev.release = mcb_release_dev;
 236         dev->dma_dev = bus->carrier;
 237
 238         device_id = dev->id;
 239         dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d",
 240                 bus->bus_nr, device_id, dev->inst, dev->group, dev->var);
 241
 242         ret = device_add(&dev->dev);
 243         if (ret < 0) {
 244                 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n",
 245                         device_id, bus->bus_nr, ret);
 246                 goto out;
 247         }
 248
 249         return 0;
 250
 251 out:
 252
 253         return ret;
 254 }
 255 EXPORT_SYMBOL_GPL(mcb_device_register);
 256
 257 static void mcb_free_bus(struct device *dev)
 258 {
 259         struct mcb_bus *bus = to_mcb_bus(dev);
 260
 261         put_device(bus->carrier);
 262         ida_simple_remove(&mcb_ida, bus->bus_nr);
 263         kfree(bus);
 264 }
 265
 266 /**
 267  * mcb_alloc_bus() - Allocate a new @mcb_bus
 268  *
 269  * Allocate a new @mcb_bus.
 270  */
 271 struct mcb_bus *mcb_alloc_bus(struct device *carrier)
 272 {
 273         struct mcb_bus *bus;
 274         int bus_nr;
 275         int rc;
 276
 277         bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL);
 278         if (!bus)
 279                 return ERR_PTR(-ENOMEM);
 280
 281         bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL);
 282         if (bus_nr < 0) {
 283                 rc = bus_nr;
 284                 goto err_free;
 285         }
 286
 287         bus->bus_nr = bus_nr;
 288         bus->carrier = get_device(carrier);
 289
 290         device_initialize(&bus->dev);
 291         bus->dev.parent = carrier;
 292         bus->dev.bus = &mcb_bus_type;
 293         bus->dev.type = &mcb_carrier_device_type;
 294         bus->dev.release = &mcb_free_bus;
 295
 296         dev_set_name(&bus->dev, "mcb:%d", bus_nr);
 297         rc = device_add(&bus->dev);
 298         if (rc)
 299                 goto err_free;
 300
 301         return bus;
 302 err_free:
 303         put_device(carrier);
 304         kfree(bus);
 305         return ERR_PTR(rc);
 306 }
 307 EXPORT_SYMBOL_GPL(mcb_alloc_bus);
 308
 309 static int __mcb_devices_unregister(struct device *dev, void *data)
 310 {
 311         device_unregister(dev);
 312         return 0;
 313 }
 314
 315 static void mcb_devices_unregister(struct mcb_bus *bus)
 316 {
 317         bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister);
 318 }
 319 /**
 320  * mcb_release_bus() - Free a @mcb_bus
 321  * @bus: The @mcb_bus to release
 322  *
 323  * Release an allocated @mcb_bus from the system.
 324  */
 325 void mcb_release_bus(struct mcb_bus *bus)
 326 {
 327         mcb_devices_unregister(bus);
 328 }
 329 EXPORT_SYMBOL_GPL(mcb_release_bus);
 330
 331 /**
 332  * mcb_bus_put() - Increment refcnt
 333  * @bus: The @mcb_bus
 334  *
 335  * Get a @mcb_bus' ref
 336  */
 337 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus)
 338 {
 339         if (bus)
 340                 get_device(&bus->dev);
 341
 342         return bus;
 343 }
 344 EXPORT_SYMBOL_GPL(mcb_bus_get);
 345
 346 /**
 347  * mcb_bus_put() - Decrement refcnt
 348  * @bus: The @mcb_bus
 349  *
 350  * Release a @mcb_bus' ref
 351  */
 352 void mcb_bus_put(struct mcb_bus *bus)
 353 {
 354         if (bus)
 355                 put_device(&bus->dev);
 356 }
 357 EXPORT_SYMBOL_GPL(mcb_bus_put);
 358
 359 /**
 360  * mcb_alloc_dev() - Allocate a device
 361  * @bus: The @mcb_bus the device is part of
 362  *
 363  * Allocate a @mcb_device and add bus.
 364  */
 365 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus)
 366 {
 367         struct mcb_device *dev;
 368
 369         dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL);
 370         if (!dev)
 371                 return NULL;
 372
 373         dev->bus = bus;
 374
 375         return dev;
 376 }
 377 EXPORT_SYMBOL_GPL(mcb_alloc_dev);
 378
 379 /**
 380  * mcb_free_dev() - Free @mcb_device
 381  * @dev: The device to free
 382  *
 383  * Free a @mcb_device
 384  */
 385 void mcb_free_dev(struct mcb_device *dev)
 386 {
 387         kfree(dev);
 388 }
 389 EXPORT_SYMBOL_GPL(mcb_free_dev);
 390
 391 static int __mcb_bus_add_devices(struct device *dev, void *data)
 392 {
 393         struct mcb_device *mdev = to_mcb_device(dev);
 394         int retval;
 395
 396         if (mdev->is_added)
 397                 return 0;
 398
 399         retval = device_attach(dev);
 400         if (retval < 0)
 401                 dev_err(dev, "Error adding device (%d)\n", retval);
 402
 403         mdev->is_added = true;
 404
 405         return 0;
 406 }
 407
 408 /**
 409  * mcb_bus_add_devices() - Add devices in the bus' internal device list
 410  * @bus: The @mcb_bus we add the devices
 411  *
 412  * Add devices in the bus' internal device list to the system.
 413  */
 414 void mcb_bus_add_devices(const struct mcb_bus *bus)
 415 {
 416         bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices);
 417 }
 418 EXPORT_SYMBOL_GPL(mcb_bus_add_devices);
 419
 420 /**
 421  * mcb_request_mem() - Request memory
 422  * @dev: The @mcb_device the memory is for
 423  * @name: The name for the memory reference.
 424  *
 425  * Request memory for a @mcb_device. If @name is NULL the driver name will
 426  * be used.
 427  */
 428 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name)
 429 {
 430         struct resource *mem;
 431         u32 size;
 432
 433         if (!name)
 434                 name = dev->dev.driver->name;
 435
 436         size = resource_size(&dev->mem);
 437
 438         mem = request_mem_region(dev->mem.start, size, name);
 439         if (!mem)
 440                 return ERR_PTR(-EBUSY);
 441
 442         return mem;
 443 }
 444 EXPORT_SYMBOL_GPL(mcb_request_mem);
 445
 446 /**
 447  * mcb_release_mem() - Release memory requested by device
 448  * @dev: The @mcb_device that requested the memory
 449  *
 450  * Release memory that was prior requested via @mcb_request_mem().
 451  */
 452 void mcb_release_mem(struct resource *mem)
 453 {
 454         u32 size;
 455
 456         size = resource_size(mem);
 457         release_mem_region(mem->start, size);
 458 }
 459 EXPORT_SYMBOL_GPL(mcb_release_mem);
 460
 461 static int __mcb_get_irq(struct mcb_device *dev)
 462 {
 463         struct resource *irq = &dev->irq;
 464
 465         return irq->start;
 466 }
 467
 468 /**
 469  * mcb_get_irq() - Get device's IRQ number
 470  * @dev: The @mcb_device the IRQ is for
 471  *
 472  * Get the IRQ number of a given @mcb_device.
 473  */
 474 int mcb_get_irq(struct mcb_device *dev)
 475 {
 476         struct mcb_bus *bus = dev->bus;
 477
 478         if (bus->get_irq)
 479                 return bus->get_irq(dev);
 480
 481         return __mcb_get_irq(dev);
 482 }
 483 EXPORT_SYMBOL_GPL(mcb_get_irq);
 484
 485 static int mcb_init(void)
 486 {
 487         return bus_register(&mcb_bus_type);
 488 }
 489
 490 static void mcb_exit(void)
 491 {
 492         ida_destroy(&mcb_ida);
 493         bus_unregister(&mcb_bus_type);
 494 }
 495
 496 /* mcb must be initialized after PCI but before the chameleon drivers.
 497  * That means we must use some initcall between subsys_initcall and
 498  * device_initcall.
 499  */
 500 fs_initcall(mcb_init);
 501 module_exit(mcb_exit);
 502
 503 MODULE_DESCRIPTION("MEN Chameleon Bus Driver");
 504 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
 505 MODULE_LICENSE("GPL v2");