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 65 found_id = mcb_match_id(mdrv->id_table, mdev); 66 if (!found_id) 67 return -ENODEV; 68 69 get_device(dev); 70 return mdrv->probe(mdev, found_id); 71 } 72 73 static int mcb_remove(struct device *dev) 74 { 75 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 76 struct mcb_device *mdev = to_mcb_device(dev); 77 78 mdrv->remove(mdev); 79 80 put_device(&mdev->dev); 81 82 return 0; 83 } 84 85 static void mcb_shutdown(struct device *dev) 86 { 87 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 88 struct mcb_device *mdev = to_mcb_device(dev); 89 90 if (mdrv && mdrv->shutdown) 91 mdrv->shutdown(mdev); 92 } 93 94 static ssize_t revision_show(struct device *dev, struct device_attribute *attr, 95 char *buf) 96 { 97 struct mcb_bus *bus = to_mcb_bus(dev); 98 99 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision); 100 } 101 static DEVICE_ATTR_RO(revision); 102 103 static ssize_t model_show(struct device *dev, struct device_attribute *attr, 104 char *buf) 105 { 106 struct mcb_bus *bus = to_mcb_bus(dev); 107 108 return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model); 109 } 110 static DEVICE_ATTR_RO(model); 111 112 static ssize_t minor_show(struct device *dev, struct device_attribute *attr, 113 char *buf) 114 { 115 struct mcb_bus *bus = to_mcb_bus(dev); 116 117 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor); 118 } 119 static DEVICE_ATTR_RO(minor); 120 121 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 122 char *buf) 123 { 124 struct mcb_bus *bus = to_mcb_bus(dev); 125 126 return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name); 127 } 128 static DEVICE_ATTR_RO(name); 129 130 static struct attribute *mcb_bus_attrs[] = { 131 &dev_attr_revision.attr, 132 &dev_attr_model.attr, 133 &dev_attr_minor.attr, 134 &dev_attr_name.attr, 135 NULL, 136 }; 137 138 static const struct attribute_group mcb_carrier_group = { 139 .attrs = mcb_bus_attrs, 140 }; 141 142 static const struct attribute_group *mcb_carrier_groups[] = { 143 &mcb_carrier_group, 144 NULL, 145 }; 146 147 148 static struct bus_type mcb_bus_type = { 149 .name = "mcb", 150 .match = mcb_match, 151 .uevent = mcb_uevent, 152 .probe = mcb_probe, 153 .remove = mcb_remove, 154 .shutdown = mcb_shutdown, 155 }; 156 157 static struct device_type mcb_carrier_device_type = { 158 .name = "mcb-carrier", 159 .groups = mcb_carrier_groups, 160 }; 161 162 /** 163 * __mcb_register_driver() - Register a @mcb_driver at the system 164 * @drv: The @mcb_driver 165 * @owner: The @mcb_driver's module 166 * @mod_name: The name of the @mcb_driver's module 167 * 168 * Register a @mcb_driver at the system. Perform some sanity checks, if 169 * the .probe and .remove methods are provided by the driver. 170 */ 171 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, 172 const char *mod_name) 173 { 174 if (!drv->probe || !drv->remove) 175 return -EINVAL; 176 177 drv->driver.owner = owner; 178 drv->driver.bus = &mcb_bus_type; 179 drv->driver.mod_name = mod_name; 180 181 return driver_register(&drv->driver); 182 } 183 EXPORT_SYMBOL_GPL(__mcb_register_driver); 184 185 /** 186 * mcb_unregister_driver() - Unregister a @mcb_driver from the system 187 * @drv: The @mcb_driver 188 * 189 * Unregister a @mcb_driver from the system. 190 */ 191 void mcb_unregister_driver(struct mcb_driver *drv) 192 { 193 driver_unregister(&drv->driver); 194 } 195 EXPORT_SYMBOL_GPL(mcb_unregister_driver); 196 197 static void mcb_release_dev(struct device *dev) 198 { 199 struct mcb_device *mdev = to_mcb_device(dev); 200 201 mcb_bus_put(mdev->bus); 202 kfree(mdev); 203 } 204 205 /** 206 * mcb_device_register() - Register a mcb_device 207 * @bus: The @mcb_bus of the device 208 * @dev: The @mcb_device 209 * 210 * Register a specific @mcb_device at a @mcb_bus and the system itself. 211 */ 212 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) 213 { 214 int ret; 215 int device_id; 216 217 device_initialize(&dev->dev); 218 mcb_bus_get(bus); 219 dev->dev.bus = &mcb_bus_type; 220 dev->dev.parent = bus->dev.parent; 221 dev->dev.release = mcb_release_dev; 222 223 device_id = dev->id; 224 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 225 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 226 227 ret = device_add(&dev->dev); 228 if (ret < 0) { 229 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 230 device_id, bus->bus_nr, ret); 231 goto out; 232 } 233 234 return 0; 235 236 out: 237 238 return ret; 239 } 240 EXPORT_SYMBOL_GPL(mcb_device_register); 241 242 static void mcb_free_bus(struct device *dev) 243 { 244 struct mcb_bus *bus = to_mcb_bus(dev); 245 246 put_device(bus->carrier); 247 ida_simple_remove(&mcb_ida, bus->bus_nr); 248 kfree(bus); 249 } 250 251 /** 252 * mcb_alloc_bus() - Allocate a new @mcb_bus 253 * 254 * Allocate a new @mcb_bus. 255 */ 256 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 257 { 258 struct mcb_bus *bus; 259 int bus_nr; 260 int rc; 261 262 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 263 if (!bus) 264 return ERR_PTR(-ENOMEM); 265 266 bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); 267 if (bus_nr < 0) { 268 rc = bus_nr; 269 goto err_free; 270 } 271 272 bus->bus_nr = bus_nr; 273 bus->carrier = get_device(carrier); 274 275 device_initialize(&bus->dev); 276 bus->dev.parent = carrier; 277 bus->dev.bus = &mcb_bus_type; 278 bus->dev.type = &mcb_carrier_device_type; 279 bus->dev.release = &mcb_free_bus; 280 281 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 282 rc = device_add(&bus->dev); 283 if (rc) 284 goto err_free; 285 286 return bus; 287 err_free: 288 put_device(carrier); 289 kfree(bus); 290 return ERR_PTR(rc); 291 } 292 EXPORT_SYMBOL_GPL(mcb_alloc_bus); 293 294 static int __mcb_devices_unregister(struct device *dev, void *data) 295 { 296 device_unregister(dev); 297 return 0; 298 } 299 300 static void mcb_devices_unregister(struct mcb_bus *bus) 301 { 302 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 303 } 304 /** 305 * mcb_release_bus() - Free a @mcb_bus 306 * @bus: The @mcb_bus to release 307 * 308 * Release an allocated @mcb_bus from the system. 309 */ 310 void mcb_release_bus(struct mcb_bus *bus) 311 { 312 mcb_devices_unregister(bus); 313 } 314 EXPORT_SYMBOL_GPL(mcb_release_bus); 315 316 /** 317 * mcb_bus_put() - Increment refcnt 318 * @bus: The @mcb_bus 319 * 320 * Get a @mcb_bus' ref 321 */ 322 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 323 { 324 if (bus) 325 get_device(&bus->dev); 326 327 return bus; 328 } 329 EXPORT_SYMBOL_GPL(mcb_bus_get); 330 331 /** 332 * mcb_bus_put() - Decrement refcnt 333 * @bus: The @mcb_bus 334 * 335 * Release a @mcb_bus' ref 336 */ 337 void mcb_bus_put(struct mcb_bus *bus) 338 { 339 if (bus) 340 put_device(&bus->dev); 341 } 342 EXPORT_SYMBOL_GPL(mcb_bus_put); 343 344 /** 345 * mcb_alloc_dev() - Allocate a device 346 * @bus: The @mcb_bus the device is part of 347 * 348 * Allocate a @mcb_device and add bus. 349 */ 350 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 351 { 352 struct mcb_device *dev; 353 354 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 355 if (!dev) 356 return NULL; 357 358 INIT_LIST_HEAD(&dev->bus_list); 359 dev->bus = bus; 360 361 return dev; 362 } 363 EXPORT_SYMBOL_GPL(mcb_alloc_dev); 364 365 /** 366 * mcb_free_dev() - Free @mcb_device 367 * @dev: The device to free 368 * 369 * Free a @mcb_device 370 */ 371 void mcb_free_dev(struct mcb_device *dev) 372 { 373 kfree(dev); 374 } 375 EXPORT_SYMBOL_GPL(mcb_free_dev); 376 377 static int __mcb_bus_add_devices(struct device *dev, void *data) 378 { 379 struct mcb_device *mdev = to_mcb_device(dev); 380 int retval; 381 382 if (mdev->is_added) 383 return 0; 384 385 retval = device_attach(dev); 386 if (retval < 0) 387 dev_err(dev, "Error adding device (%d)\n", retval); 388 389 mdev->is_added = true; 390 391 return 0; 392 } 393 394 static int __mcb_bus_add_child(struct device *dev, void *data) 395 { 396 struct mcb_device *mdev = to_mcb_device(dev); 397 struct mcb_bus *child; 398 399 BUG_ON(!mdev->is_added); 400 child = mdev->subordinate; 401 402 if (child) 403 mcb_bus_add_devices(child); 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 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child); 418 419 } 420 EXPORT_SYMBOL_GPL(mcb_bus_add_devices); 421 422 /** 423 * mcb_request_mem() - Request memory 424 * @dev: The @mcb_device the memory is for 425 * @name: The name for the memory reference. 426 * 427 * Request memory for a @mcb_device. If @name is NULL the driver name will 428 * be used. 429 */ 430 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 431 { 432 struct resource *mem; 433 u32 size; 434 435 if (!name) 436 name = dev->dev.driver->name; 437 438 size = resource_size(&dev->mem); 439 440 mem = request_mem_region(dev->mem.start, size, name); 441 if (!mem) 442 return ERR_PTR(-EBUSY); 443 444 return mem; 445 } 446 EXPORT_SYMBOL_GPL(mcb_request_mem); 447 448 /** 449 * mcb_release_mem() - Release memory requested by device 450 * @dev: The @mcb_device that requested the memory 451 * 452 * Release memory that was prior requested via @mcb_request_mem(). 453 */ 454 void mcb_release_mem(struct resource *mem) 455 { 456 u32 size; 457 458 size = resource_size(mem); 459 release_mem_region(mem->start, size); 460 } 461 EXPORT_SYMBOL_GPL(mcb_release_mem); 462 463 static int __mcb_get_irq(struct mcb_device *dev) 464 { 465 struct resource *irq = &dev->irq; 466 467 return irq->start; 468 } 469 470 /** 471 * mcb_get_irq() - Get device's IRQ number 472 * @dev: The @mcb_device the IRQ is for 473 * 474 * Get the IRQ number of a given @mcb_device. 475 */ 476 int mcb_get_irq(struct mcb_device *dev) 477 { 478 struct mcb_bus *bus = dev->bus; 479 480 if (bus->get_irq) 481 return bus->get_irq(dev); 482 483 return __mcb_get_irq(dev); 484 } 485 EXPORT_SYMBOL_GPL(mcb_get_irq); 486 487 static int mcb_init(void) 488 { 489 return bus_register(&mcb_bus_type); 490 } 491 492 static void mcb_exit(void) 493 { 494 ida_destroy(&mcb_ida); 495 bus_unregister(&mcb_bus_type); 496 } 497 498 /* mcb must be initialized after PCI but before the chameleon drivers. 499 * That means we must use some initcall between subsys_initcall and 500 * device_initcall. 501 */ 502 fs_initcall(mcb_init); 503 module_exit(mcb_exit); 504 505 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 506 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 507 MODULE_LICENSE("GPL v2"); 508