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; 236 237 device_id = dev->id; 238 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 239 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 240 241 ret = device_add(&dev->dev); 242 if (ret < 0) { 243 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 244 device_id, bus->bus_nr, ret); 245 goto out; 246 } 247 248 return 0; 249 250 out: 251 252 return ret; 253 } 254 EXPORT_SYMBOL_GPL(mcb_device_register); 255 256 static void mcb_free_bus(struct device *dev) 257 { 258 struct mcb_bus *bus = to_mcb_bus(dev); 259 260 put_device(bus->carrier); 261 ida_simple_remove(&mcb_ida, bus->bus_nr); 262 kfree(bus); 263 } 264 265 /** 266 * mcb_alloc_bus() - Allocate a new @mcb_bus 267 * 268 * Allocate a new @mcb_bus. 269 */ 270 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 271 { 272 struct mcb_bus *bus; 273 int bus_nr; 274 int rc; 275 276 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 277 if (!bus) 278 return ERR_PTR(-ENOMEM); 279 280 bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); 281 if (bus_nr < 0) { 282 rc = bus_nr; 283 goto err_free; 284 } 285 286 bus->bus_nr = bus_nr; 287 bus->carrier = get_device(carrier); 288 289 device_initialize(&bus->dev); 290 bus->dev.parent = carrier; 291 bus->dev.bus = &mcb_bus_type; 292 bus->dev.type = &mcb_carrier_device_type; 293 bus->dev.release = &mcb_free_bus; 294 295 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 296 rc = device_add(&bus->dev); 297 if (rc) 298 goto err_free; 299 300 return bus; 301 err_free: 302 put_device(carrier); 303 kfree(bus); 304 return ERR_PTR(rc); 305 } 306 EXPORT_SYMBOL_GPL(mcb_alloc_bus); 307 308 static int __mcb_devices_unregister(struct device *dev, void *data) 309 { 310 device_unregister(dev); 311 return 0; 312 } 313 314 static void mcb_devices_unregister(struct mcb_bus *bus) 315 { 316 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 317 } 318 /** 319 * mcb_release_bus() - Free a @mcb_bus 320 * @bus: The @mcb_bus to release 321 * 322 * Release an allocated @mcb_bus from the system. 323 */ 324 void mcb_release_bus(struct mcb_bus *bus) 325 { 326 mcb_devices_unregister(bus); 327 } 328 EXPORT_SYMBOL_GPL(mcb_release_bus); 329 330 /** 331 * mcb_bus_put() - Increment refcnt 332 * @bus: The @mcb_bus 333 * 334 * Get a @mcb_bus' ref 335 */ 336 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 337 { 338 if (bus) 339 get_device(&bus->dev); 340 341 return bus; 342 } 343 EXPORT_SYMBOL_GPL(mcb_bus_get); 344 345 /** 346 * mcb_bus_put() - Decrement refcnt 347 * @bus: The @mcb_bus 348 * 349 * Release a @mcb_bus' ref 350 */ 351 void mcb_bus_put(struct mcb_bus *bus) 352 { 353 if (bus) 354 put_device(&bus->dev); 355 } 356 EXPORT_SYMBOL_GPL(mcb_bus_put); 357 358 /** 359 * mcb_alloc_dev() - Allocate a device 360 * @bus: The @mcb_bus the device is part of 361 * 362 * Allocate a @mcb_device and add bus. 363 */ 364 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 365 { 366 struct mcb_device *dev; 367 368 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 369 if (!dev) 370 return NULL; 371 372 INIT_LIST_HEAD(&dev->bus_list); 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 static int __mcb_bus_add_child(struct device *dev, void *data) 409 { 410 struct mcb_device *mdev = to_mcb_device(dev); 411 struct mcb_bus *child; 412 413 BUG_ON(!mdev->is_added); 414 child = mdev->subordinate; 415 416 if (child) 417 mcb_bus_add_devices(child); 418 419 return 0; 420 } 421 422 /** 423 * mcb_bus_add_devices() - Add devices in the bus' internal device list 424 * @bus: The @mcb_bus we add the devices 425 * 426 * Add devices in the bus' internal device list to the system. 427 */ 428 void mcb_bus_add_devices(const struct mcb_bus *bus) 429 { 430 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); 431 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child); 432 433 } 434 EXPORT_SYMBOL_GPL(mcb_bus_add_devices); 435 436 /** 437 * mcb_request_mem() - Request memory 438 * @dev: The @mcb_device the memory is for 439 * @name: The name for the memory reference. 440 * 441 * Request memory for a @mcb_device. If @name is NULL the driver name will 442 * be used. 443 */ 444 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 445 { 446 struct resource *mem; 447 u32 size; 448 449 if (!name) 450 name = dev->dev.driver->name; 451 452 size = resource_size(&dev->mem); 453 454 mem = request_mem_region(dev->mem.start, size, name); 455 if (!mem) 456 return ERR_PTR(-EBUSY); 457 458 return mem; 459 } 460 EXPORT_SYMBOL_GPL(mcb_request_mem); 461 462 /** 463 * mcb_release_mem() - Release memory requested by device 464 * @dev: The @mcb_device that requested the memory 465 * 466 * Release memory that was prior requested via @mcb_request_mem(). 467 */ 468 void mcb_release_mem(struct resource *mem) 469 { 470 u32 size; 471 472 size = resource_size(mem); 473 release_mem_region(mem->start, size); 474 } 475 EXPORT_SYMBOL_GPL(mcb_release_mem); 476 477 static int __mcb_get_irq(struct mcb_device *dev) 478 { 479 struct resource *irq = &dev->irq; 480 481 return irq->start; 482 } 483 484 /** 485 * mcb_get_irq() - Get device's IRQ number 486 * @dev: The @mcb_device the IRQ is for 487 * 488 * Get the IRQ number of a given @mcb_device. 489 */ 490 int mcb_get_irq(struct mcb_device *dev) 491 { 492 struct mcb_bus *bus = dev->bus; 493 494 if (bus->get_irq) 495 return bus->get_irq(dev); 496 497 return __mcb_get_irq(dev); 498 } 499 EXPORT_SYMBOL_GPL(mcb_get_irq); 500 501 static int mcb_init(void) 502 { 503 return bus_register(&mcb_bus_type); 504 } 505 506 static void mcb_exit(void) 507 { 508 ida_destroy(&mcb_ida); 509 bus_unregister(&mcb_bus_type); 510 } 511 512 /* mcb must be initialized after PCI but before the chameleon drivers. 513 * That means we must use some initcall between subsys_initcall and 514 * device_initcall. 515 */ 516 fs_initcall(mcb_init); 517 module_exit(mcb_exit); 518 519 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 520 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 521 MODULE_LICENSE("GPL v2"); 522