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 if (mdrv->remove) 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 97 static void mcb_shutdown(struct device *dev) 98 { 99 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 100 struct mcb_device *mdev = to_mcb_device(dev); 101 102 if (mdrv && mdrv->shutdown) 103 mdrv->shutdown(mdev); 104 } 105 106 static ssize_t revision_show(struct device *dev, struct device_attribute *attr, 107 char *buf) 108 { 109 struct mcb_bus *bus = to_mcb_bus(dev); 110 111 return sysfs_emit(buf, "%d\n", bus->revision); 112 } 113 static DEVICE_ATTR_RO(revision); 114 115 static ssize_t model_show(struct device *dev, struct device_attribute *attr, 116 char *buf) 117 { 118 struct mcb_bus *bus = to_mcb_bus(dev); 119 120 return sysfs_emit(buf, "%c\n", bus->model); 121 } 122 static DEVICE_ATTR_RO(model); 123 124 static ssize_t minor_show(struct device *dev, struct device_attribute *attr, 125 char *buf) 126 { 127 struct mcb_bus *bus = to_mcb_bus(dev); 128 129 return sysfs_emit(buf, "%d\n", bus->minor); 130 } 131 static DEVICE_ATTR_RO(minor); 132 133 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 134 char *buf) 135 { 136 struct mcb_bus *bus = to_mcb_bus(dev); 137 138 return sysfs_emit(buf, "%s\n", bus->name); 139 } 140 static DEVICE_ATTR_RO(name); 141 142 static struct attribute *mcb_bus_attrs[] = { 143 &dev_attr_revision.attr, 144 &dev_attr_model.attr, 145 &dev_attr_minor.attr, 146 &dev_attr_name.attr, 147 NULL, 148 }; 149 150 static const struct attribute_group mcb_carrier_group = { 151 .attrs = mcb_bus_attrs, 152 }; 153 154 static const struct attribute_group *mcb_carrier_groups[] = { 155 &mcb_carrier_group, 156 NULL, 157 }; 158 159 160 static const struct bus_type mcb_bus_type = { 161 .name = "mcb", 162 .match = mcb_match, 163 .uevent = mcb_uevent, 164 .probe = mcb_probe, 165 .remove = mcb_remove, 166 .shutdown = mcb_shutdown, 167 }; 168 169 static const struct device_type mcb_carrier_device_type = { 170 .name = "mcb-carrier", 171 .groups = mcb_carrier_groups, 172 }; 173 174 /** 175 * __mcb_register_driver() - Register a @mcb_driver at the system 176 * @drv: The @mcb_driver 177 * @owner: The @mcb_driver's module 178 * @mod_name: The name of the @mcb_driver's module 179 * 180 * Register a @mcb_driver at the system. Perform a sanity check, if 181 * .probe method is provided by the driver. 182 */ 183 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, 184 const char *mod_name) 185 { 186 if (!drv->probe) 187 return -EINVAL; 188 189 drv->driver.owner = owner; 190 drv->driver.bus = &mcb_bus_type; 191 drv->driver.mod_name = mod_name; 192 193 return driver_register(&drv->driver); 194 } 195 EXPORT_SYMBOL_NS_GPL(__mcb_register_driver, "MCB"); 196 197 /** 198 * mcb_unregister_driver() - Unregister a @mcb_driver from the system 199 * @drv: The @mcb_driver 200 * 201 * Unregister a @mcb_driver from the system. 202 */ 203 void mcb_unregister_driver(struct mcb_driver *drv) 204 { 205 driver_unregister(&drv->driver); 206 } 207 EXPORT_SYMBOL_NS_GPL(mcb_unregister_driver, "MCB"); 208 209 static void mcb_release_dev(struct device *dev) 210 { 211 struct mcb_device *mdev = to_mcb_device(dev); 212 213 mcb_bus_put(mdev->bus); 214 kfree(mdev); 215 } 216 217 /** 218 * mcb_device_register() - Register a mcb_device 219 * @bus: The @mcb_bus of the device 220 * @dev: The @mcb_device 221 * 222 * Register a specific @mcb_device at a @mcb_bus and the system itself. 223 */ 224 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) 225 { 226 int ret; 227 int device_id; 228 229 device_initialize(&dev->dev); 230 mcb_bus_get(bus); 231 dev->dev.bus = &mcb_bus_type; 232 dev->dev.parent = bus->dev.parent; 233 dev->dev.release = mcb_release_dev; 234 dev->dma_dev = bus->carrier; 235 236 device_id = dev->id; 237 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 238 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 239 240 ret = device_add(&dev->dev); 241 if (ret < 0) { 242 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 243 device_id, bus->bus_nr, ret); 244 goto out; 245 } 246 247 return 0; 248 249 out: 250 put_device(&dev->dev); 251 252 return ret; 253 } 254 EXPORT_SYMBOL_NS_GPL(mcb_device_register, "MCB"); 255 256 static void mcb_free_bus(struct device *dev) 257 { 258 struct mcb_bus *bus = to_mcb_bus(dev); 259 260 put_device(bus->carrier); 261 ida_free(&mcb_ida, bus->bus_nr); 262 kfree(bus); 263 } 264 265 /** 266 * mcb_alloc_bus() - Allocate a new @mcb_bus 267 * @carrier: generic &struct device for the carrier device 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_alloc(&mcb_ida, GFP_KERNEL); 282 if (bus_nr < 0) { 283 kfree(bus); 284 return ERR_PTR(bus_nr); 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_put; 300 301 return bus; 302 303 err_put: 304 put_device(&bus->dev); 305 return ERR_PTR(rc); 306 } 307 EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, "MCB"); 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(bus->dev.bus, 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_NS_GPL(mcb_release_bus, "MCB"); 330 331 /** 332 * mcb_bus_get() - 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_NS_GPL(mcb_bus_get, "MCB"); 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_NS_GPL(mcb_bus_put, "MCB"); 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_NS_GPL(mcb_alloc_dev, "MCB"); 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_NS_GPL(mcb_free_dev, "MCB"); 390 391 static int __mcb_bus_add_devices(struct device *dev, void *data) 392 { 393 int retval; 394 395 retval = device_attach(dev); 396 if (retval < 0) { 397 dev_err(dev, "Error adding device (%d)\n", retval); 398 return retval; 399 } 400 401 return 0; 402 } 403 404 /** 405 * mcb_bus_add_devices() - Add devices in the bus' internal device list 406 * @bus: The @mcb_bus we add the devices 407 * 408 * Add devices in the bus' internal device list to the system. 409 */ 410 void mcb_bus_add_devices(const struct mcb_bus *bus) 411 { 412 bus_for_each_dev(bus->dev.bus, NULL, NULL, __mcb_bus_add_devices); 413 } 414 EXPORT_SYMBOL_NS_GPL(mcb_bus_add_devices, "MCB"); 415 416 /** 417 * mcb_get_resource() - get a resource for a mcb device 418 * @dev: the mcb device 419 * @type: the type of resource 420 */ 421 struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) 422 { 423 if (type == IORESOURCE_MEM) 424 return &dev->mem; 425 else if (type == IORESOURCE_IRQ) 426 return &dev->irq; 427 else 428 return NULL; 429 } 430 EXPORT_SYMBOL_NS_GPL(mcb_get_resource, "MCB"); 431 432 /** 433 * mcb_request_mem() - Request memory 434 * @dev: The @mcb_device the memory is for 435 * @name: The name for the memory reference. 436 * 437 * Request memory for a @mcb_device. If @name is NULL the driver name will 438 * be used. 439 */ 440 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 441 { 442 struct resource *mem; 443 u32 size; 444 445 if (!name) 446 name = dev->dev.driver->name; 447 448 size = resource_size(&dev->mem); 449 450 mem = request_mem_region(dev->mem.start, size, name); 451 if (!mem) 452 return ERR_PTR(-EBUSY); 453 454 return mem; 455 } 456 EXPORT_SYMBOL_NS_GPL(mcb_request_mem, "MCB"); 457 458 /** 459 * mcb_release_mem() - Release memory requested by device 460 * @mem: The memory resource to be released 461 * 462 * Release memory that was prior requested via @mcb_request_mem(). 463 */ 464 void mcb_release_mem(struct resource *mem) 465 { 466 u32 size; 467 468 size = resource_size(mem); 469 release_mem_region(mem->start, size); 470 } 471 EXPORT_SYMBOL_NS_GPL(mcb_release_mem, "MCB"); 472 473 static int __mcb_get_irq(struct mcb_device *dev) 474 { 475 struct resource *irq; 476 477 irq = mcb_get_resource(dev, IORESOURCE_IRQ); 478 479 return irq->start; 480 } 481 482 /** 483 * mcb_get_irq() - Get device's IRQ number 484 * @dev: The @mcb_device the IRQ is for 485 * 486 * Get the IRQ number of a given @mcb_device. 487 */ 488 int mcb_get_irq(struct mcb_device *dev) 489 { 490 struct mcb_bus *bus = dev->bus; 491 492 if (bus->get_irq) 493 return bus->get_irq(dev); 494 495 return __mcb_get_irq(dev); 496 } 497 EXPORT_SYMBOL_NS_GPL(mcb_get_irq, "MCB"); 498 499 static int mcb_init(void) 500 { 501 return bus_register(&mcb_bus_type); 502 } 503 504 static void mcb_exit(void) 505 { 506 ida_destroy(&mcb_ida); 507 bus_unregister(&mcb_bus_type); 508 } 509 510 /* mcb must be initialized after PCI but before the chameleon drivers. 511 * That means we must use some initcall between subsys_initcall and 512 * device_initcall. 513 */ 514 fs_initcall(mcb_init); 515 module_exit(mcb_exit); 516 517 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 518 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 519 MODULE_LICENSE("GPL v2"); 520