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 return mdrv->probe(mdev, found_id); 70 } 71 72 static int mcb_remove(struct device *dev) 73 { 74 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 75 struct mcb_device *mdev = to_mcb_device(dev); 76 77 mdrv->remove(mdev); 78 79 put_device(&mdev->dev); 80 81 return 0; 82 } 83 84 static void mcb_shutdown(struct device *dev) 85 { 86 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 87 struct mcb_device *mdev = to_mcb_device(dev); 88 89 if (mdrv && mdrv->shutdown) 90 mdrv->shutdown(mdev); 91 } 92 93 static ssize_t revision_show(struct device *dev, struct device_attribute *attr, 94 char *buf) 95 { 96 struct mcb_bus *bus = to_mcb_bus(dev); 97 98 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision); 99 } 100 static DEVICE_ATTR_RO(revision); 101 102 static ssize_t model_show(struct device *dev, struct device_attribute *attr, 103 char *buf) 104 { 105 struct mcb_bus *bus = to_mcb_bus(dev); 106 107 return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model); 108 } 109 static DEVICE_ATTR_RO(model); 110 111 static ssize_t minor_show(struct device *dev, struct device_attribute *attr, 112 char *buf) 113 { 114 struct mcb_bus *bus = to_mcb_bus(dev); 115 116 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor); 117 } 118 static DEVICE_ATTR_RO(minor); 119 120 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 121 char *buf) 122 { 123 struct mcb_bus *bus = to_mcb_bus(dev); 124 125 return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name); 126 } 127 static DEVICE_ATTR_RO(name); 128 129 static struct attribute *mcb_bus_attrs[] = { 130 &dev_attr_revision.attr, 131 &dev_attr_model.attr, 132 &dev_attr_minor.attr, 133 &dev_attr_name.attr, 134 NULL, 135 }; 136 137 static const struct attribute_group mcb_carrier_group = { 138 .attrs = mcb_bus_attrs, 139 }; 140 141 static const struct attribute_group *mcb_carrier_groups[] = { 142 &mcb_carrier_group, 143 NULL, 144 }; 145 146 147 static struct bus_type mcb_bus_type = { 148 .name = "mcb", 149 .match = mcb_match, 150 .uevent = mcb_uevent, 151 .probe = mcb_probe, 152 .remove = mcb_remove, 153 .shutdown = mcb_shutdown, 154 }; 155 156 static struct device_type mcb_carrier_device_type = { 157 .name = "mcb-carrier", 158 .groups = mcb_carrier_groups, 159 }; 160 161 /** 162 * __mcb_register_driver() - Register a @mcb_driver at the system 163 * @drv: The @mcb_driver 164 * @owner: The @mcb_driver's module 165 * @mod_name: The name of the @mcb_driver's module 166 * 167 * Register a @mcb_driver at the system. Perform some sanity checks, if 168 * the .probe and .remove methods are provided by the driver. 169 */ 170 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, 171 const char *mod_name) 172 { 173 if (!drv->probe || !drv->remove) 174 return -EINVAL; 175 176 drv->driver.owner = owner; 177 drv->driver.bus = &mcb_bus_type; 178 drv->driver.mod_name = mod_name; 179 180 return driver_register(&drv->driver); 181 } 182 EXPORT_SYMBOL_GPL(__mcb_register_driver); 183 184 /** 185 * mcb_unregister_driver() - Unregister a @mcb_driver from the system 186 * @drv: The @mcb_driver 187 * 188 * Unregister a @mcb_driver from the system. 189 */ 190 void mcb_unregister_driver(struct mcb_driver *drv) 191 { 192 driver_unregister(&drv->driver); 193 } 194 EXPORT_SYMBOL_GPL(mcb_unregister_driver); 195 196 static void mcb_release_dev(struct device *dev) 197 { 198 struct mcb_device *mdev = to_mcb_device(dev); 199 200 mcb_bus_put(mdev->bus); 201 kfree(mdev); 202 } 203 204 /** 205 * mcb_device_register() - Register a mcb_device 206 * @bus: The @mcb_bus of the device 207 * @dev: The @mcb_device 208 * 209 * Register a specific @mcb_device at a @mcb_bus and the system itself. 210 */ 211 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) 212 { 213 int ret; 214 int device_id; 215 216 device_initialize(&dev->dev); 217 mcb_bus_get(bus); 218 dev->dev.bus = &mcb_bus_type; 219 dev->dev.parent = bus->dev.parent; 220 dev->dev.release = mcb_release_dev; 221 222 device_id = dev->id; 223 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 224 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 225 226 ret = device_add(&dev->dev); 227 if (ret < 0) { 228 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 229 device_id, bus->bus_nr, ret); 230 goto out; 231 } 232 233 return 0; 234 235 out: 236 237 return ret; 238 } 239 EXPORT_SYMBOL_GPL(mcb_device_register); 240 241 static void mcb_free_bus(struct device *dev) 242 { 243 struct mcb_bus *bus = to_mcb_bus(dev); 244 245 put_device(bus->carrier); 246 ida_simple_remove(&mcb_ida, bus->bus_nr); 247 kfree(bus); 248 } 249 250 /** 251 * mcb_alloc_bus() - Allocate a new @mcb_bus 252 * 253 * Allocate a new @mcb_bus. 254 */ 255 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 256 { 257 struct mcb_bus *bus; 258 int bus_nr; 259 int rc; 260 261 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 262 if (!bus) 263 return ERR_PTR(-ENOMEM); 264 265 bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); 266 if (bus_nr < 0) { 267 rc = bus_nr; 268 goto err_free; 269 } 270 271 bus->bus_nr = bus_nr; 272 bus->carrier = get_device(carrier); 273 274 device_initialize(&bus->dev); 275 bus->dev.parent = carrier; 276 bus->dev.bus = &mcb_bus_type; 277 bus->dev.type = &mcb_carrier_device_type; 278 bus->dev.release = &mcb_free_bus; 279 280 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 281 rc = device_add(&bus->dev); 282 if (rc) 283 goto err_free; 284 285 return bus; 286 err_free: 287 put_device(carrier); 288 kfree(bus); 289 return ERR_PTR(rc); 290 } 291 EXPORT_SYMBOL_GPL(mcb_alloc_bus); 292 293 static int __mcb_devices_unregister(struct device *dev, void *data) 294 { 295 device_unregister(dev); 296 return 0; 297 } 298 299 static void mcb_devices_unregister(struct mcb_bus *bus) 300 { 301 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 302 } 303 /** 304 * mcb_release_bus() - Free a @mcb_bus 305 * @bus: The @mcb_bus to release 306 * 307 * Release an allocated @mcb_bus from the system. 308 */ 309 void mcb_release_bus(struct mcb_bus *bus) 310 { 311 mcb_devices_unregister(bus); 312 } 313 EXPORT_SYMBOL_GPL(mcb_release_bus); 314 315 /** 316 * mcb_bus_put() - Increment refcnt 317 * @bus: The @mcb_bus 318 * 319 * Get a @mcb_bus' ref 320 */ 321 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 322 { 323 if (bus) 324 get_device(&bus->dev); 325 326 return bus; 327 } 328 EXPORT_SYMBOL_GPL(mcb_bus_get); 329 330 /** 331 * mcb_bus_put() - Decrement refcnt 332 * @bus: The @mcb_bus 333 * 334 * Release a @mcb_bus' ref 335 */ 336 void mcb_bus_put(struct mcb_bus *bus) 337 { 338 if (bus) 339 put_device(&bus->dev); 340 } 341 EXPORT_SYMBOL_GPL(mcb_bus_put); 342 343 /** 344 * mcb_alloc_dev() - Allocate a device 345 * @bus: The @mcb_bus the device is part of 346 * 347 * Allocate a @mcb_device and add bus. 348 */ 349 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 350 { 351 struct mcb_device *dev; 352 353 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 354 if (!dev) 355 return NULL; 356 357 INIT_LIST_HEAD(&dev->bus_list); 358 dev->bus = bus; 359 360 return dev; 361 } 362 EXPORT_SYMBOL_GPL(mcb_alloc_dev); 363 364 /** 365 * mcb_free_dev() - Free @mcb_device 366 * @dev: The device to free 367 * 368 * Free a @mcb_device 369 */ 370 void mcb_free_dev(struct mcb_device *dev) 371 { 372 kfree(dev); 373 } 374 EXPORT_SYMBOL_GPL(mcb_free_dev); 375 376 static int __mcb_bus_add_devices(struct device *dev, void *data) 377 { 378 struct mcb_device *mdev = to_mcb_device(dev); 379 int retval; 380 381 if (mdev->is_added) 382 return 0; 383 384 retval = device_attach(dev); 385 if (retval < 0) 386 dev_err(dev, "Error adding device (%d)\n", retval); 387 388 mdev->is_added = true; 389 390 return 0; 391 } 392 393 static int __mcb_bus_add_child(struct device *dev, void *data) 394 { 395 struct mcb_device *mdev = to_mcb_device(dev); 396 struct mcb_bus *child; 397 398 BUG_ON(!mdev->is_added); 399 child = mdev->subordinate; 400 401 if (child) 402 mcb_bus_add_devices(child); 403 404 return 0; 405 } 406 407 /** 408 * mcb_bus_add_devices() - Add devices in the bus' internal device list 409 * @bus: The @mcb_bus we add the devices 410 * 411 * Add devices in the bus' internal device list to the system. 412 */ 413 void mcb_bus_add_devices(const struct mcb_bus *bus) 414 { 415 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); 416 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child); 417 418 } 419 EXPORT_SYMBOL_GPL(mcb_bus_add_devices); 420 421 /** 422 * mcb_request_mem() - Request memory 423 * @dev: The @mcb_device the memory is for 424 * @name: The name for the memory reference. 425 * 426 * Request memory for a @mcb_device. If @name is NULL the driver name will 427 * be used. 428 */ 429 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 430 { 431 struct resource *mem; 432 u32 size; 433 434 if (!name) 435 name = dev->dev.driver->name; 436 437 size = resource_size(&dev->mem); 438 439 mem = request_mem_region(dev->mem.start, size, name); 440 if (!mem) 441 return ERR_PTR(-EBUSY); 442 443 return mem; 444 } 445 EXPORT_SYMBOL_GPL(mcb_request_mem); 446 447 /** 448 * mcb_release_mem() - Release memory requested by device 449 * @dev: The @mcb_device that requested the memory 450 * 451 * Release memory that was prior requested via @mcb_request_mem(). 452 */ 453 void mcb_release_mem(struct resource *mem) 454 { 455 u32 size; 456 457 size = resource_size(mem); 458 release_mem_region(mem->start, size); 459 } 460 EXPORT_SYMBOL_GPL(mcb_release_mem); 461 462 static int __mcb_get_irq(struct mcb_device *dev) 463 { 464 struct resource *irq = &dev->irq; 465 466 return irq->start; 467 } 468 469 /** 470 * mcb_get_irq() - Get device's IRQ number 471 * @dev: The @mcb_device the IRQ is for 472 * 473 * Get the IRQ number of a given @mcb_device. 474 */ 475 int mcb_get_irq(struct mcb_device *dev) 476 { 477 struct mcb_bus *bus = dev->bus; 478 479 if (bus->get_irq) 480 return bus->get_irq(dev); 481 482 return __mcb_get_irq(dev); 483 } 484 EXPORT_SYMBOL_GPL(mcb_get_irq); 485 486 static int mcb_init(void) 487 { 488 return bus_register(&mcb_bus_type); 489 } 490 491 static void mcb_exit(void) 492 { 493 ida_destroy(&mcb_ida); 494 bus_unregister(&mcb_bus_type); 495 } 496 497 /* mcb must be initialized after PCI but before the chameleon drivers. 498 * That means we must use some initcall between subsys_initcall and 499 * device_initcall. 500 */ 501 fs_initcall(mcb_init); 502 module_exit(mcb_exit); 503 504 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 505 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 506 MODULE_LICENSE("GPL v2"); 507