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_get_resource() - get a resource for a mcb device 422 * @dev: the mcb device 423 * @type: the type of resource 424 */ 425 struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) 426 { 427 if (type == IORESOURCE_MEM) 428 return &dev->mem; 429 else if (type == IORESOURCE_IRQ) 430 return &dev->irq; 431 else 432 return NULL; 433 } 434 EXPORT_SYMBOL_GPL(mcb_get_resource); 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; 480 481 irq = mcb_get_resource(dev, IORESOURCE_IRQ); 482 483 return irq->start; 484 } 485 486 /** 487 * mcb_get_irq() - Get device's IRQ number 488 * @dev: The @mcb_device the IRQ is for 489 * 490 * Get the IRQ number of a given @mcb_device. 491 */ 492 int mcb_get_irq(struct mcb_device *dev) 493 { 494 struct mcb_bus *bus = dev->bus; 495 496 if (bus->get_irq) 497 return bus->get_irq(dev); 498 499 return __mcb_get_irq(dev); 500 } 501 EXPORT_SYMBOL_GPL(mcb_get_irq); 502 503 static int mcb_init(void) 504 { 505 return bus_register(&mcb_bus_type); 506 } 507 508 static void mcb_exit(void) 509 { 510 ida_destroy(&mcb_ida); 511 bus_unregister(&mcb_bus_type); 512 } 513 514 /* mcb must be initialized after PCI but before the chameleon drivers. 515 * That means we must use some initcall between subsys_initcall and 516 * device_initcall. 517 */ 518 fs_initcall(mcb_init); 519 module_exit(mcb_exit); 520 521 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 522 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 523 MODULE_LICENSE("GPL v2"); 524