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 put_device(&dev->dev); 250 251 return ret; 252 } 253 EXPORT_SYMBOL_NS_GPL(mcb_device_register, MCB); 254 255 static void mcb_free_bus(struct device *dev) 256 { 257 struct mcb_bus *bus = to_mcb_bus(dev); 258 259 put_device(bus->carrier); 260 ida_free(&mcb_ida, bus->bus_nr); 261 kfree(bus); 262 } 263 264 /** 265 * mcb_alloc_bus() - Allocate a new @mcb_bus 266 * 267 * Allocate a new @mcb_bus. 268 */ 269 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 270 { 271 struct mcb_bus *bus; 272 int bus_nr; 273 int rc; 274 275 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 276 if (!bus) 277 return ERR_PTR(-ENOMEM); 278 279 bus_nr = ida_alloc(&mcb_ida, GFP_KERNEL); 280 if (bus_nr < 0) { 281 kfree(bus); 282 return ERR_PTR(bus_nr); 283 } 284 285 bus->bus_nr = bus_nr; 286 bus->carrier = get_device(carrier); 287 288 device_initialize(&bus->dev); 289 bus->dev.parent = carrier; 290 bus->dev.bus = &mcb_bus_type; 291 bus->dev.type = &mcb_carrier_device_type; 292 bus->dev.release = &mcb_free_bus; 293 294 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 295 rc = device_add(&bus->dev); 296 if (rc) 297 goto err_put; 298 299 return bus; 300 301 err_put: 302 put_device(&bus->dev); 303 return ERR_PTR(rc); 304 } 305 EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB); 306 307 static int __mcb_devices_unregister(struct device *dev, void *data) 308 { 309 device_unregister(dev); 310 return 0; 311 } 312 313 static void mcb_devices_unregister(struct mcb_bus *bus) 314 { 315 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 316 } 317 /** 318 * mcb_release_bus() - Free a @mcb_bus 319 * @bus: The @mcb_bus to release 320 * 321 * Release an allocated @mcb_bus from the system. 322 */ 323 void mcb_release_bus(struct mcb_bus *bus) 324 { 325 mcb_devices_unregister(bus); 326 } 327 EXPORT_SYMBOL_NS_GPL(mcb_release_bus, MCB); 328 329 /** 330 * mcb_bus_put() - Increment refcnt 331 * @bus: The @mcb_bus 332 * 333 * Get a @mcb_bus' ref 334 */ 335 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 336 { 337 if (bus) 338 get_device(&bus->dev); 339 340 return bus; 341 } 342 EXPORT_SYMBOL_NS_GPL(mcb_bus_get, MCB); 343 344 /** 345 * mcb_bus_put() - Decrement refcnt 346 * @bus: The @mcb_bus 347 * 348 * Release a @mcb_bus' ref 349 */ 350 void mcb_bus_put(struct mcb_bus *bus) 351 { 352 if (bus) 353 put_device(&bus->dev); 354 } 355 EXPORT_SYMBOL_NS_GPL(mcb_bus_put, MCB); 356 357 /** 358 * mcb_alloc_dev() - Allocate a device 359 * @bus: The @mcb_bus the device is part of 360 * 361 * Allocate a @mcb_device and add bus. 362 */ 363 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 364 { 365 struct mcb_device *dev; 366 367 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 368 if (!dev) 369 return NULL; 370 371 dev->bus = bus; 372 373 return dev; 374 } 375 EXPORT_SYMBOL_NS_GPL(mcb_alloc_dev, MCB); 376 377 /** 378 * mcb_free_dev() - Free @mcb_device 379 * @dev: The device to free 380 * 381 * Free a @mcb_device 382 */ 383 void mcb_free_dev(struct mcb_device *dev) 384 { 385 kfree(dev); 386 } 387 EXPORT_SYMBOL_NS_GPL(mcb_free_dev, MCB); 388 389 static int __mcb_bus_add_devices(struct device *dev, void *data) 390 { 391 int retval; 392 393 retval = device_attach(dev); 394 if (retval < 0) { 395 dev_err(dev, "Error adding device (%d)\n", retval); 396 return retval; 397 } 398 399 return 0; 400 } 401 402 /** 403 * mcb_bus_add_devices() - Add devices in the bus' internal device list 404 * @bus: The @mcb_bus we add the devices 405 * 406 * Add devices in the bus' internal device list to the system. 407 */ 408 void mcb_bus_add_devices(const struct mcb_bus *bus) 409 { 410 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); 411 } 412 EXPORT_SYMBOL_NS_GPL(mcb_bus_add_devices, MCB); 413 414 /** 415 * mcb_get_resource() - get a resource for a mcb device 416 * @dev: the mcb device 417 * @type: the type of resource 418 */ 419 struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) 420 { 421 if (type == IORESOURCE_MEM) 422 return &dev->mem; 423 else if (type == IORESOURCE_IRQ) 424 return &dev->irq; 425 else 426 return NULL; 427 } 428 EXPORT_SYMBOL_NS_GPL(mcb_get_resource, MCB); 429 430 /** 431 * mcb_request_mem() - Request memory 432 * @dev: The @mcb_device the memory is for 433 * @name: The name for the memory reference. 434 * 435 * Request memory for a @mcb_device. If @name is NULL the driver name will 436 * be used. 437 */ 438 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 439 { 440 struct resource *mem; 441 u32 size; 442 443 if (!name) 444 name = dev->dev.driver->name; 445 446 size = resource_size(&dev->mem); 447 448 mem = request_mem_region(dev->mem.start, size, name); 449 if (!mem) 450 return ERR_PTR(-EBUSY); 451 452 return mem; 453 } 454 EXPORT_SYMBOL_NS_GPL(mcb_request_mem, MCB); 455 456 /** 457 * mcb_release_mem() - Release memory requested by device 458 * @dev: The @mcb_device that requested the memory 459 * 460 * Release memory that was prior requested via @mcb_request_mem(). 461 */ 462 void mcb_release_mem(struct resource *mem) 463 { 464 u32 size; 465 466 size = resource_size(mem); 467 release_mem_region(mem->start, size); 468 } 469 EXPORT_SYMBOL_NS_GPL(mcb_release_mem, MCB); 470 471 static int __mcb_get_irq(struct mcb_device *dev) 472 { 473 struct resource *irq; 474 475 irq = mcb_get_resource(dev, IORESOURCE_IRQ); 476 477 return irq->start; 478 } 479 480 /** 481 * mcb_get_irq() - Get device's IRQ number 482 * @dev: The @mcb_device the IRQ is for 483 * 484 * Get the IRQ number of a given @mcb_device. 485 */ 486 int mcb_get_irq(struct mcb_device *dev) 487 { 488 struct mcb_bus *bus = dev->bus; 489 490 if (bus->get_irq) 491 return bus->get_irq(dev); 492 493 return __mcb_get_irq(dev); 494 } 495 EXPORT_SYMBOL_NS_GPL(mcb_get_irq, MCB); 496 497 static int mcb_init(void) 498 { 499 return bus_register(&mcb_bus_type); 500 } 501 502 static void mcb_exit(void) 503 { 504 ida_destroy(&mcb_ida); 505 bus_unregister(&mcb_bus_type); 506 } 507 508 /* mcb must be initialized after PCI but before the chameleon drivers. 509 * That means we must use some initcall between subsys_initcall and 510 * device_initcall. 511 */ 512 fs_initcall(mcb_init); 513 module_exit(mcb_exit); 514 515 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 516 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 517 MODULE_LICENSE("GPL v2"); 518