1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MEN Chameleon Bus. 4 * 5 * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de) 6 * Author: Johannes Thumshirn <johannes.thumshirn@men.de> 7 */ 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/slab.h> 11 #include <linux/types.h> 12 #include <linux/idr.h> 13 #include <linux/mcb.h> 14 15 static DEFINE_IDA(mcb_ida); 16 17 static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids, 18 struct mcb_device *dev) 19 { 20 if (ids) { 21 while (ids->device) { 22 if (ids->device == dev->id) 23 return ids; 24 ids++; 25 } 26 } 27 28 return NULL; 29 } 30 31 static int mcb_match(struct device *dev, struct device_driver *drv) 32 { 33 struct mcb_driver *mdrv = to_mcb_driver(drv); 34 struct mcb_device *mdev = to_mcb_device(dev); 35 const struct mcb_device_id *found_id; 36 37 found_id = mcb_match_id(mdrv->id_table, mdev); 38 if (found_id) 39 return 1; 40 41 return 0; 42 } 43 44 static int mcb_uevent(const struct device *dev, struct kobj_uevent_env *env) 45 { 46 const struct mcb_device *mdev = to_mcb_device(dev); 47 int ret; 48 49 ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id); 50 if (ret) 51 return -ENOMEM; 52 53 return 0; 54 } 55 56 static int mcb_probe(struct device *dev) 57 { 58 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 59 struct mcb_device *mdev = to_mcb_device(dev); 60 const struct mcb_device_id *found_id; 61 struct module *carrier_mod; 62 int ret; 63 64 found_id = mcb_match_id(mdrv->id_table, mdev); 65 if (!found_id) 66 return -ENODEV; 67 68 carrier_mod = mdev->dev.parent->driver->owner; 69 if (!try_module_get(carrier_mod)) 70 return -EINVAL; 71 72 get_device(dev); 73 ret = mdrv->probe(mdev, found_id); 74 if (ret) { 75 module_put(carrier_mod); 76 put_device(dev); 77 } 78 79 return ret; 80 } 81 82 static void mcb_remove(struct device *dev) 83 { 84 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 85 struct mcb_device *mdev = to_mcb_device(dev); 86 struct module *carrier_mod; 87 88 mdrv->remove(mdev); 89 90 carrier_mod = mdev->dev.parent->driver->owner; 91 module_put(carrier_mod); 92 93 put_device(&mdev->dev); 94 } 95 96 static void mcb_shutdown(struct device *dev) 97 { 98 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 99 struct mcb_device *mdev = to_mcb_device(dev); 100 101 if (mdrv && mdrv->shutdown) 102 mdrv->shutdown(mdev); 103 } 104 105 static ssize_t revision_show(struct device *dev, struct device_attribute *attr, 106 char *buf) 107 { 108 struct mcb_bus *bus = to_mcb_bus(dev); 109 110 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision); 111 } 112 static DEVICE_ATTR_RO(revision); 113 114 static ssize_t model_show(struct device *dev, struct device_attribute *attr, 115 char *buf) 116 { 117 struct mcb_bus *bus = to_mcb_bus(dev); 118 119 return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model); 120 } 121 static DEVICE_ATTR_RO(model); 122 123 static ssize_t minor_show(struct device *dev, struct device_attribute *attr, 124 char *buf) 125 { 126 struct mcb_bus *bus = to_mcb_bus(dev); 127 128 return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor); 129 } 130 static DEVICE_ATTR_RO(minor); 131 132 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 133 char *buf) 134 { 135 struct mcb_bus *bus = to_mcb_bus(dev); 136 137 return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name); 138 } 139 static DEVICE_ATTR_RO(name); 140 141 static struct attribute *mcb_bus_attrs[] = { 142 &dev_attr_revision.attr, 143 &dev_attr_model.attr, 144 &dev_attr_minor.attr, 145 &dev_attr_name.attr, 146 NULL, 147 }; 148 149 static const struct attribute_group mcb_carrier_group = { 150 .attrs = mcb_bus_attrs, 151 }; 152 153 static const struct attribute_group *mcb_carrier_groups[] = { 154 &mcb_carrier_group, 155 NULL, 156 }; 157 158 159 static struct bus_type mcb_bus_type = { 160 .name = "mcb", 161 .match = mcb_match, 162 .uevent = mcb_uevent, 163 .probe = mcb_probe, 164 .remove = mcb_remove, 165 .shutdown = mcb_shutdown, 166 }; 167 168 static struct device_type mcb_carrier_device_type = { 169 .name = "mcb-carrier", 170 .groups = mcb_carrier_groups, 171 }; 172 173 /** 174 * __mcb_register_driver() - Register a @mcb_driver at the system 175 * @drv: The @mcb_driver 176 * @owner: The @mcb_driver's module 177 * @mod_name: The name of the @mcb_driver's module 178 * 179 * Register a @mcb_driver at the system. Perform some sanity checks, if 180 * the .probe and .remove methods are provided by the driver. 181 */ 182 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, 183 const char *mod_name) 184 { 185 if (!drv->probe || !drv->remove) 186 return -EINVAL; 187 188 drv->driver.owner = owner; 189 drv->driver.bus = &mcb_bus_type; 190 drv->driver.mod_name = mod_name; 191 192 return driver_register(&drv->driver); 193 } 194 EXPORT_SYMBOL_NS_GPL(__mcb_register_driver, MCB); 195 196 /** 197 * mcb_unregister_driver() - Unregister a @mcb_driver from the system 198 * @drv: The @mcb_driver 199 * 200 * Unregister a @mcb_driver from the system. 201 */ 202 void mcb_unregister_driver(struct mcb_driver *drv) 203 { 204 driver_unregister(&drv->driver); 205 } 206 EXPORT_SYMBOL_NS_GPL(mcb_unregister_driver, MCB); 207 208 static void mcb_release_dev(struct device *dev) 209 { 210 struct mcb_device *mdev = to_mcb_device(dev); 211 212 mcb_bus_put(mdev->bus); 213 kfree(mdev); 214 } 215 216 /** 217 * mcb_device_register() - Register a mcb_device 218 * @bus: The @mcb_bus of the device 219 * @dev: The @mcb_device 220 * 221 * Register a specific @mcb_device at a @mcb_bus and the system itself. 222 */ 223 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) 224 { 225 int ret; 226 int device_id; 227 228 device_initialize(&dev->dev); 229 mcb_bus_get(bus); 230 dev->dev.bus = &mcb_bus_type; 231 dev->dev.parent = bus->dev.parent; 232 dev->dev.release = mcb_release_dev; 233 dev->dma_dev = bus->carrier; 234 235 device_id = dev->id; 236 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 237 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 238 239 ret = device_add(&dev->dev); 240 if (ret < 0) { 241 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 242 device_id, bus->bus_nr, ret); 243 goto out; 244 } 245 246 return 0; 247 248 out: 249 250 return ret; 251 } 252 EXPORT_SYMBOL_NS_GPL(mcb_device_register, MCB); 253 254 static void mcb_free_bus(struct device *dev) 255 { 256 struct mcb_bus *bus = to_mcb_bus(dev); 257 258 put_device(bus->carrier); 259 ida_free(&mcb_ida, bus->bus_nr); 260 kfree(bus); 261 } 262 263 /** 264 * mcb_alloc_bus() - Allocate a new @mcb_bus 265 * 266 * Allocate a new @mcb_bus. 267 */ 268 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 269 { 270 struct mcb_bus *bus; 271 int bus_nr; 272 int rc; 273 274 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 275 if (!bus) 276 return ERR_PTR(-ENOMEM); 277 278 bus_nr = ida_alloc(&mcb_ida, GFP_KERNEL); 279 if (bus_nr < 0) { 280 kfree(bus); 281 return ERR_PTR(bus_nr); 282 } 283 284 bus->bus_nr = bus_nr; 285 bus->carrier = get_device(carrier); 286 287 device_initialize(&bus->dev); 288 bus->dev.parent = carrier; 289 bus->dev.bus = &mcb_bus_type; 290 bus->dev.type = &mcb_carrier_device_type; 291 bus->dev.release = &mcb_free_bus; 292 293 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 294 rc = device_add(&bus->dev); 295 if (rc) 296 goto err_put; 297 298 return bus; 299 300 err_put: 301 put_device(&bus->dev); 302 return ERR_PTR(rc); 303 } 304 EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB); 305 306 static int __mcb_devices_unregister(struct device *dev, void *data) 307 { 308 device_unregister(dev); 309 return 0; 310 } 311 312 static void mcb_devices_unregister(struct mcb_bus *bus) 313 { 314 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 315 } 316 /** 317 * mcb_release_bus() - Free a @mcb_bus 318 * @bus: The @mcb_bus to release 319 * 320 * Release an allocated @mcb_bus from the system. 321 */ 322 void mcb_release_bus(struct mcb_bus *bus) 323 { 324 mcb_devices_unregister(bus); 325 } 326 EXPORT_SYMBOL_NS_GPL(mcb_release_bus, MCB); 327 328 /** 329 * mcb_bus_put() - Increment refcnt 330 * @bus: The @mcb_bus 331 * 332 * Get a @mcb_bus' ref 333 */ 334 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 335 { 336 if (bus) 337 get_device(&bus->dev); 338 339 return bus; 340 } 341 EXPORT_SYMBOL_NS_GPL(mcb_bus_get, MCB); 342 343 /** 344 * mcb_bus_put() - Decrement refcnt 345 * @bus: The @mcb_bus 346 * 347 * Release a @mcb_bus' ref 348 */ 349 void mcb_bus_put(struct mcb_bus *bus) 350 { 351 if (bus) 352 put_device(&bus->dev); 353 } 354 EXPORT_SYMBOL_NS_GPL(mcb_bus_put, MCB); 355 356 /** 357 * mcb_alloc_dev() - Allocate a device 358 * @bus: The @mcb_bus the device is part of 359 * 360 * Allocate a @mcb_device and add bus. 361 */ 362 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 363 { 364 struct mcb_device *dev; 365 366 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 367 if (!dev) 368 return NULL; 369 370 dev->bus = bus; 371 372 return dev; 373 } 374 EXPORT_SYMBOL_NS_GPL(mcb_alloc_dev, MCB); 375 376 /** 377 * mcb_free_dev() - Free @mcb_device 378 * @dev: The device to free 379 * 380 * Free a @mcb_device 381 */ 382 void mcb_free_dev(struct mcb_device *dev) 383 { 384 kfree(dev); 385 } 386 EXPORT_SYMBOL_NS_GPL(mcb_free_dev, MCB); 387 388 static int __mcb_bus_add_devices(struct device *dev, void *data) 389 { 390 struct mcb_device *mdev = to_mcb_device(dev); 391 int retval; 392 393 if (mdev->is_added) 394 return 0; 395 396 retval = device_attach(dev); 397 if (retval < 0) 398 dev_err(dev, "Error adding device (%d)\n", retval); 399 400 mdev->is_added = true; 401 402 return 0; 403 } 404 405 /** 406 * mcb_bus_add_devices() - Add devices in the bus' internal device list 407 * @bus: The @mcb_bus we add the devices 408 * 409 * Add devices in the bus' internal device list to the system. 410 */ 411 void mcb_bus_add_devices(const struct mcb_bus *bus) 412 { 413 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); 414 } 415 EXPORT_SYMBOL_NS_GPL(mcb_bus_add_devices, MCB); 416 417 /** 418 * mcb_get_resource() - get a resource for a mcb device 419 * @dev: the mcb device 420 * @type: the type of resource 421 */ 422 struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) 423 { 424 if (type == IORESOURCE_MEM) 425 return &dev->mem; 426 else if (type == IORESOURCE_IRQ) 427 return &dev->irq; 428 else 429 return NULL; 430 } 431 EXPORT_SYMBOL_NS_GPL(mcb_get_resource, MCB); 432 433 /** 434 * mcb_request_mem() - Request memory 435 * @dev: The @mcb_device the memory is for 436 * @name: The name for the memory reference. 437 * 438 * Request memory for a @mcb_device. If @name is NULL the driver name will 439 * be used. 440 */ 441 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 442 { 443 struct resource *mem; 444 u32 size; 445 446 if (!name) 447 name = dev->dev.driver->name; 448 449 size = resource_size(&dev->mem); 450 451 mem = request_mem_region(dev->mem.start, size, name); 452 if (!mem) 453 return ERR_PTR(-EBUSY); 454 455 return mem; 456 } 457 EXPORT_SYMBOL_NS_GPL(mcb_request_mem, MCB); 458 459 /** 460 * mcb_release_mem() - Release memory requested by device 461 * @dev: The @mcb_device that requested the memory 462 * 463 * Release memory that was prior requested via @mcb_request_mem(). 464 */ 465 void mcb_release_mem(struct resource *mem) 466 { 467 u32 size; 468 469 size = resource_size(mem); 470 release_mem_region(mem->start, size); 471 } 472 EXPORT_SYMBOL_NS_GPL(mcb_release_mem, MCB); 473 474 static int __mcb_get_irq(struct mcb_device *dev) 475 { 476 struct resource *irq; 477 478 irq = mcb_get_resource(dev, IORESOURCE_IRQ); 479 480 return irq->start; 481 } 482 483 /** 484 * mcb_get_irq() - Get device's IRQ number 485 * @dev: The @mcb_device the IRQ is for 486 * 487 * Get the IRQ number of a given @mcb_device. 488 */ 489 int mcb_get_irq(struct mcb_device *dev) 490 { 491 struct mcb_bus *bus = dev->bus; 492 493 if (bus->get_irq) 494 return bus->get_irq(dev); 495 496 return __mcb_get_irq(dev); 497 } 498 EXPORT_SYMBOL_NS_GPL(mcb_get_irq, MCB); 499 500 static int mcb_init(void) 501 { 502 return bus_register(&mcb_bus_type); 503 } 504 505 static void mcb_exit(void) 506 { 507 ida_destroy(&mcb_ida); 508 bus_unregister(&mcb_bus_type); 509 } 510 511 /* mcb must be initialized after PCI but before the chameleon drivers. 512 * That means we must use some initcall between subsys_initcall and 513 * device_initcall. 514 */ 515 fs_initcall(mcb_init); 516 module_exit(mcb_exit); 517 518 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 519 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 520 MODULE_LICENSE("GPL v2"); 521