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, const struct device_driver *drv) 32 { 33 const 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 const 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 const 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 * @carrier: generic &struct device for the carrier device 267 * 268 * Allocate a new @mcb_bus. 269 */ 270 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 271 { 272 struct mcb_bus *bus; 273 int bus_nr; 274 int rc; 275 276 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 277 if (!bus) 278 return ERR_PTR(-ENOMEM); 279 280 bus_nr = ida_alloc(&mcb_ida, GFP_KERNEL); 281 if (bus_nr < 0) { 282 kfree(bus); 283 return ERR_PTR(bus_nr); 284 } 285 286 bus->bus_nr = bus_nr; 287 bus->carrier = get_device(carrier); 288 289 device_initialize(&bus->dev); 290 bus->dev.parent = carrier; 291 bus->dev.bus = &mcb_bus_type; 292 bus->dev.type = &mcb_carrier_device_type; 293 bus->dev.release = mcb_free_bus; 294 295 dev_set_name(&bus->dev, "mcb:%d", bus_nr); 296 rc = device_add(&bus->dev); 297 if (rc) 298 goto err_put; 299 300 return bus; 301 302 err_put: 303 put_device(&bus->dev); 304 return ERR_PTR(rc); 305 } 306 EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB); 307 308 static int __mcb_devices_unregister(struct device *dev, void *data) 309 { 310 device_unregister(dev); 311 return 0; 312 } 313 314 static void mcb_devices_unregister(struct mcb_bus *bus) 315 { 316 bus_for_each_dev(bus->dev.bus, NULL, NULL, __mcb_devices_unregister); 317 } 318 /** 319 * mcb_release_bus() - Free a @mcb_bus 320 * @bus: The @mcb_bus to release 321 * 322 * Release an allocated @mcb_bus from the system. 323 */ 324 void mcb_release_bus(struct mcb_bus *bus) 325 { 326 mcb_devices_unregister(bus); 327 } 328 EXPORT_SYMBOL_NS_GPL(mcb_release_bus, MCB); 329 330 /** 331 * mcb_bus_get() - Increment refcnt 332 * @bus: The @mcb_bus 333 * 334 * Get a @mcb_bus' ref 335 */ 336 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 337 { 338 if (bus) 339 get_device(&bus->dev); 340 341 return bus; 342 } 343 EXPORT_SYMBOL_NS_GPL(mcb_bus_get, MCB); 344 345 /** 346 * mcb_bus_put() - Decrement refcnt 347 * @bus: The @mcb_bus 348 * 349 * Release a @mcb_bus' ref 350 */ 351 void mcb_bus_put(struct mcb_bus *bus) 352 { 353 if (bus) 354 put_device(&bus->dev); 355 } 356 EXPORT_SYMBOL_NS_GPL(mcb_bus_put, MCB); 357 358 /** 359 * mcb_alloc_dev() - Allocate a device 360 * @bus: The @mcb_bus the device is part of 361 * 362 * Allocate a @mcb_device and add bus. 363 */ 364 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 365 { 366 struct mcb_device *dev; 367 368 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 369 if (!dev) 370 return NULL; 371 372 dev->bus = bus; 373 374 return dev; 375 } 376 EXPORT_SYMBOL_NS_GPL(mcb_alloc_dev, MCB); 377 378 /** 379 * mcb_free_dev() - Free @mcb_device 380 * @dev: The device to free 381 * 382 * Free a @mcb_device 383 */ 384 void mcb_free_dev(struct mcb_device *dev) 385 { 386 kfree(dev); 387 } 388 EXPORT_SYMBOL_NS_GPL(mcb_free_dev, MCB); 389 390 static int __mcb_bus_add_devices(struct device *dev, void *data) 391 { 392 int retval; 393 394 retval = device_attach(dev); 395 if (retval < 0) { 396 dev_err(dev, "Error adding device (%d)\n", retval); 397 return retval; 398 } 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(bus->dev.bus, 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 * @mem: The memory resource to be released 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