1 /* 2 * MEN Chameleon Bus. 3 * 4 * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de) 5 * Author: Johannes Thumshirn <johannes.thumshirn@men.de> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation; version 2 of the License. 10 */ 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/types.h> 15 #include <linux/idr.h> 16 #include <linux/mcb.h> 17 18 static DEFINE_IDA(mcb_ida); 19 20 static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids, 21 struct mcb_device *dev) 22 { 23 if (ids) { 24 while (ids->device) { 25 if (ids->device == dev->id) 26 return ids; 27 ids++; 28 } 29 } 30 31 return NULL; 32 } 33 34 static int mcb_match(struct device *dev, struct device_driver *drv) 35 { 36 struct mcb_driver *mdrv = to_mcb_driver(drv); 37 struct mcb_device *mdev = to_mcb_device(dev); 38 const struct mcb_device_id *found_id; 39 40 found_id = mcb_match_id(mdrv->id_table, mdev); 41 if (found_id) 42 return 1; 43 44 return 0; 45 } 46 47 static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env) 48 { 49 struct mcb_device *mdev = to_mcb_device(dev); 50 int ret; 51 52 ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id); 53 if (ret) 54 return -ENOMEM; 55 56 return 0; 57 } 58 59 static int mcb_probe(struct device *dev) 60 { 61 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 62 struct mcb_device *mdev = to_mcb_device(dev); 63 const struct mcb_device_id *found_id; 64 65 found_id = mcb_match_id(mdrv->id_table, mdev); 66 if (!found_id) 67 return -ENODEV; 68 69 return mdrv->probe(mdev, found_id); 70 } 71 72 static int mcb_remove(struct device *dev) 73 { 74 struct mcb_driver *mdrv = to_mcb_driver(dev->driver); 75 struct mcb_device *mdev = to_mcb_device(dev); 76 77 mdrv->remove(mdev); 78 79 put_device(&mdev->dev); 80 81 return 0; 82 } 83 84 static void mcb_shutdown(struct device *dev) 85 { 86 struct mcb_device *mdev = to_mcb_device(dev); 87 struct mcb_driver *mdrv = mdev->driver; 88 89 if (mdrv && mdrv->shutdown) 90 mdrv->shutdown(mdev); 91 } 92 93 static struct bus_type mcb_bus_type = { 94 .name = "mcb", 95 .match = mcb_match, 96 .uevent = mcb_uevent, 97 .probe = mcb_probe, 98 .remove = mcb_remove, 99 .shutdown = mcb_shutdown, 100 }; 101 102 /** 103 * __mcb_register_driver() - Register a @mcb_driver at the system 104 * @drv: The @mcb_driver 105 * @owner: The @mcb_driver's module 106 * @mod_name: The name of the @mcb_driver's module 107 * 108 * Register a @mcb_driver at the system. Perform some sanity checks, if 109 * the .probe and .remove methods are provided by the driver. 110 */ 111 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, 112 const char *mod_name) 113 { 114 if (!drv->probe || !drv->remove) 115 return -EINVAL; 116 117 drv->driver.owner = owner; 118 drv->driver.bus = &mcb_bus_type; 119 drv->driver.mod_name = mod_name; 120 121 return driver_register(&drv->driver); 122 } 123 EXPORT_SYMBOL_GPL(__mcb_register_driver); 124 125 /** 126 * mcb_unregister_driver() - Unregister a @mcb_driver from the system 127 * @drv: The @mcb_driver 128 * 129 * Unregister a @mcb_driver from the system. 130 */ 131 void mcb_unregister_driver(struct mcb_driver *drv) 132 { 133 driver_unregister(&drv->driver); 134 } 135 EXPORT_SYMBOL_GPL(mcb_unregister_driver); 136 137 static void mcb_release_dev(struct device *dev) 138 { 139 struct mcb_device *mdev = to_mcb_device(dev); 140 141 mcb_bus_put(mdev->bus); 142 kfree(mdev); 143 } 144 145 /** 146 * mcb_device_register() - Register a mcb_device 147 * @bus: The @mcb_bus of the device 148 * @dev: The @mcb_device 149 * 150 * Register a specific @mcb_device at a @mcb_bus and the system itself. 151 */ 152 int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) 153 { 154 int ret; 155 int device_id; 156 157 device_initialize(&dev->dev); 158 dev->dev.bus = &mcb_bus_type; 159 dev->dev.parent = bus->dev.parent; 160 dev->dev.release = mcb_release_dev; 161 162 device_id = dev->id; 163 dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", 164 bus->bus_nr, device_id, dev->inst, dev->group, dev->var); 165 166 ret = device_add(&dev->dev); 167 if (ret < 0) { 168 pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", 169 device_id, bus->bus_nr, ret); 170 goto out; 171 } 172 173 return 0; 174 175 out: 176 177 return ret; 178 } 179 EXPORT_SYMBOL_GPL(mcb_device_register); 180 181 /** 182 * mcb_alloc_bus() - Allocate a new @mcb_bus 183 * 184 * Allocate a new @mcb_bus. 185 */ 186 struct mcb_bus *mcb_alloc_bus(struct device *carrier) 187 { 188 struct mcb_bus *bus; 189 int bus_nr; 190 191 bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); 192 if (!bus) 193 return ERR_PTR(-ENOMEM); 194 195 bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); 196 if (bus_nr < 0) { 197 kfree(bus); 198 return ERR_PTR(bus_nr); 199 } 200 201 INIT_LIST_HEAD(&bus->children); 202 bus->bus_nr = bus_nr; 203 bus->carrier = carrier; 204 return bus; 205 } 206 EXPORT_SYMBOL_GPL(mcb_alloc_bus); 207 208 static int __mcb_devices_unregister(struct device *dev, void *data) 209 { 210 device_unregister(dev); 211 return 0; 212 } 213 214 static void mcb_devices_unregister(struct mcb_bus *bus) 215 { 216 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); 217 } 218 /** 219 * mcb_release_bus() - Free a @mcb_bus 220 * @bus: The @mcb_bus to release 221 * 222 * Release an allocated @mcb_bus from the system. 223 */ 224 void mcb_release_bus(struct mcb_bus *bus) 225 { 226 mcb_devices_unregister(bus); 227 228 ida_simple_remove(&mcb_ida, bus->bus_nr); 229 230 kfree(bus); 231 } 232 EXPORT_SYMBOL_GPL(mcb_release_bus); 233 234 /** 235 * mcb_bus_put() - Increment refcnt 236 * @bus: The @mcb_bus 237 * 238 * Get a @mcb_bus' ref 239 */ 240 struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) 241 { 242 if (bus) 243 get_device(&bus->dev); 244 245 return bus; 246 } 247 EXPORT_SYMBOL_GPL(mcb_bus_get); 248 249 /** 250 * mcb_bus_put() - Decrement refcnt 251 * @bus: The @mcb_bus 252 * 253 * Release a @mcb_bus' ref 254 */ 255 void mcb_bus_put(struct mcb_bus *bus) 256 { 257 if (bus) 258 put_device(&bus->dev); 259 } 260 EXPORT_SYMBOL_GPL(mcb_bus_put); 261 262 /** 263 * mcb_alloc_dev() - Allocate a device 264 * @bus: The @mcb_bus the device is part of 265 * 266 * Allocate a @mcb_device and add bus. 267 */ 268 struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) 269 { 270 struct mcb_device *dev; 271 272 dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); 273 if (!dev) 274 return NULL; 275 276 INIT_LIST_HEAD(&dev->bus_list); 277 dev->bus = bus; 278 279 return dev; 280 } 281 EXPORT_SYMBOL_GPL(mcb_alloc_dev); 282 283 /** 284 * mcb_free_dev() - Free @mcb_device 285 * @dev: The device to free 286 * 287 * Free a @mcb_device 288 */ 289 void mcb_free_dev(struct mcb_device *dev) 290 { 291 kfree(dev); 292 } 293 EXPORT_SYMBOL_GPL(mcb_free_dev); 294 295 static int __mcb_bus_add_devices(struct device *dev, void *data) 296 { 297 struct mcb_device *mdev = to_mcb_device(dev); 298 int retval; 299 300 if (mdev->is_added) 301 return 0; 302 303 retval = device_attach(dev); 304 if (retval < 0) 305 dev_err(dev, "Error adding device (%d)\n", retval); 306 307 mdev->is_added = true; 308 309 return 0; 310 } 311 312 static int __mcb_bus_add_child(struct device *dev, void *data) 313 { 314 struct mcb_device *mdev = to_mcb_device(dev); 315 struct mcb_bus *child; 316 317 BUG_ON(!mdev->is_added); 318 child = mdev->subordinate; 319 320 if (child) 321 mcb_bus_add_devices(child); 322 323 return 0; 324 } 325 326 /** 327 * mcb_bus_add_devices() - Add devices in the bus' internal device list 328 * @bus: The @mcb_bus we add the devices 329 * 330 * Add devices in the bus' internal device list to the system. 331 */ 332 void mcb_bus_add_devices(const struct mcb_bus *bus) 333 { 334 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); 335 bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child); 336 337 } 338 EXPORT_SYMBOL_GPL(mcb_bus_add_devices); 339 340 /** 341 * mcb_request_mem() - Request memory 342 * @dev: The @mcb_device the memory is for 343 * @name: The name for the memory reference. 344 * 345 * Request memory for a @mcb_device. If @name is NULL the driver name will 346 * be used. 347 */ 348 struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) 349 { 350 struct resource *mem; 351 u32 size; 352 353 if (!name) 354 name = dev->dev.driver->name; 355 356 size = resource_size(&dev->mem); 357 358 mem = request_mem_region(dev->mem.start, size, name); 359 if (!mem) 360 return ERR_PTR(-EBUSY); 361 362 return mem; 363 } 364 EXPORT_SYMBOL_GPL(mcb_request_mem); 365 366 /** 367 * mcb_release_mem() - Release memory requested by device 368 * @dev: The @mcb_device that requested the memory 369 * 370 * Release memory that was prior requested via @mcb_request_mem(). 371 */ 372 void mcb_release_mem(struct resource *mem) 373 { 374 u32 size; 375 376 size = resource_size(mem); 377 release_mem_region(mem->start, size); 378 } 379 EXPORT_SYMBOL_GPL(mcb_release_mem); 380 381 static int __mcb_get_irq(struct mcb_device *dev) 382 { 383 struct resource *irq = &dev->irq; 384 385 return irq->start; 386 } 387 388 /** 389 * mcb_get_irq() - Get device's IRQ number 390 * @dev: The @mcb_device the IRQ is for 391 * 392 * Get the IRQ number of a given @mcb_device. 393 */ 394 int mcb_get_irq(struct mcb_device *dev) 395 { 396 struct mcb_bus *bus = dev->bus; 397 398 if (bus->get_irq) 399 return bus->get_irq(dev); 400 401 return __mcb_get_irq(dev); 402 } 403 EXPORT_SYMBOL_GPL(mcb_get_irq); 404 405 static int mcb_init(void) 406 { 407 return bus_register(&mcb_bus_type); 408 } 409 410 static void mcb_exit(void) 411 { 412 bus_unregister(&mcb_bus_type); 413 } 414 415 /* mcb must be initialized after PCI but before the chameleon drivers. 416 * That means we must use some initcall between subsys_initcall and 417 * device_initcall. 418 */ 419 fs_initcall(mcb_init); 420 module_exit(mcb_exit); 421 422 MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); 423 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 424 MODULE_LICENSE("GPL v2"); 425