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