1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr> 4 */ 5 6 #include <linux/module.h> 7 #include <linux/bitops.h> 8 #include <linux/clk.h> 9 #include <linux/device.h> 10 #include <linux/idr.h> 11 #include <linux/list.h> 12 #include <linux/mutex.h> 13 #include <linux/of.h> 14 #include <linux/pm.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/slab.h> 17 #include <linux/sysfs.h> 18 #include <sound/ac97_codec.h> 19 #include <sound/ac97/codec.h> 20 #include <sound/ac97/controller.h> 21 #include <sound/ac97/regs.h> 22 23 #include "ac97_core.h" 24 25 /* 26 * Protects ac97_controllers and each ac97_controller structure. 27 */ 28 static DEFINE_MUTEX(ac97_controllers_mutex); 29 static DEFINE_IDR(ac97_adapter_idr); 30 static LIST_HEAD(ac97_controllers); 31 32 static inline struct ac97_controller* 33 to_ac97_controller(struct device *ac97_adapter) 34 { 35 return container_of(ac97_adapter, struct ac97_controller, adap); 36 } 37 38 static int ac97_unbound_ctrl_write(struct ac97_controller *adrv, int slot, 39 unsigned short reg, unsigned short val) 40 { 41 return -ENODEV; 42 } 43 44 static int ac97_unbound_ctrl_read(struct ac97_controller *adrv, int slot, 45 unsigned short reg) 46 { 47 return -ENODEV; 48 } 49 50 static const struct ac97_controller_ops ac97_unbound_ctrl_ops = { 51 .write = ac97_unbound_ctrl_write, 52 .read = ac97_unbound_ctrl_read, 53 }; 54 55 static struct ac97_controller ac97_unbound_ctrl = { 56 .ops = &ac97_unbound_ctrl_ops, 57 }; 58 59 static struct ac97_codec_device * 60 ac97_codec_find(struct ac97_controller *ac97_ctrl, unsigned int codec_num) 61 { 62 if (codec_num >= AC97_BUS_MAX_CODECS) 63 return ERR_PTR(-EINVAL); 64 65 return ac97_ctrl->codecs[codec_num]; 66 } 67 68 static struct device_node * 69 ac97_of_get_child_device(struct ac97_controller *ac97_ctrl, int idx, 70 unsigned int vendor_id) 71 { 72 struct device_node *node; 73 u32 reg; 74 char compat[] = "ac97,0000,0000"; 75 76 snprintf(compat, sizeof(compat), "ac97,%04x,%04x", 77 vendor_id >> 16, vendor_id & 0xffff); 78 79 for_each_child_of_node(ac97_ctrl->parent->of_node, node) { 80 if ((idx != of_property_read_u32(node, "reg", ®)) || 81 !of_device_is_compatible(node, compat)) 82 continue; 83 return node; 84 } 85 86 return NULL; 87 } 88 89 static void ac97_codec_release(struct device *dev) 90 { 91 struct ac97_codec_device *adev; 92 struct ac97_controller *ac97_ctrl; 93 94 adev = to_ac97_device(dev); 95 ac97_ctrl = adev->ac97_ctrl; 96 ac97_ctrl->codecs[adev->num] = NULL; 97 of_node_put(dev->of_node); 98 kfree(adev); 99 } 100 101 static int ac97_codec_add(struct ac97_controller *ac97_ctrl, int idx, 102 unsigned int vendor_id) 103 { 104 struct ac97_codec_device *codec; 105 int ret; 106 107 codec = kzalloc_obj(*codec); 108 if (!codec) 109 return -ENOMEM; 110 ac97_ctrl->codecs[idx] = codec; 111 codec->vendor_id = vendor_id; 112 codec->dev.release = ac97_codec_release; 113 codec->dev.bus = &ac97_bus_type; 114 codec->dev.parent = &ac97_ctrl->adap; 115 codec->num = idx; 116 codec->ac97_ctrl = ac97_ctrl; 117 118 device_initialize(&codec->dev); 119 dev_set_name(&codec->dev, "%s:%u", dev_name(ac97_ctrl->parent), idx); 120 codec->dev.of_node = ac97_of_get_child_device(ac97_ctrl, idx, 121 vendor_id); 122 123 ret = device_add(&codec->dev); 124 if (ret) { 125 put_device(&codec->dev); 126 return ret; 127 } 128 129 return 0; 130 } 131 132 unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv, 133 unsigned int codec_num) 134 { 135 unsigned short vid1, vid2; 136 int ret; 137 138 ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID1); 139 vid1 = (ret & 0xffff); 140 if (ret < 0) 141 return 0; 142 143 ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID2); 144 vid2 = (ret & 0xffff); 145 if (ret < 0) 146 return 0; 147 148 dev_dbg(&adrv->adap, "%s(codec_num=%u): vendor_id=0x%08x\n", 149 __func__, codec_num, AC97_ID(vid1, vid2)); 150 return AC97_ID(vid1, vid2); 151 } 152 153 static int ac97_bus_scan(struct ac97_controller *ac97_ctrl) 154 { 155 int ret, i; 156 unsigned int vendor_id; 157 158 for (i = 0; i < AC97_BUS_MAX_CODECS; i++) { 159 if (ac97_codec_find(ac97_ctrl, i)) 160 continue; 161 if (!(ac97_ctrl->slots_available & BIT(i))) 162 continue; 163 vendor_id = snd_ac97_bus_scan_one(ac97_ctrl, i); 164 if (!vendor_id) 165 continue; 166 167 ret = ac97_codec_add(ac97_ctrl, i, vendor_id); 168 if (ret < 0) 169 return ret; 170 } 171 return 0; 172 } 173 174 static int ac97_bus_reset(struct ac97_controller *ac97_ctrl) 175 { 176 ac97_ctrl->ops->reset(ac97_ctrl); 177 178 return 0; 179 } 180 181 /** 182 * snd_ac97_codec_driver_register - register an AC97 codec driver 183 * @drv: AC97 driver codec to register 184 * 185 * Register an AC97 codec driver to the ac97 bus driver, aka. the AC97 digital 186 * controller. 187 * 188 * Returns 0 on success or error code 189 */ 190 int snd_ac97_codec_driver_register(struct ac97_codec_driver *drv) 191 { 192 drv->driver.bus = &ac97_bus_type; 193 return driver_register(&drv->driver); 194 } 195 EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_register); 196 197 /** 198 * snd_ac97_codec_driver_unregister - unregister an AC97 codec driver 199 * @drv: AC97 codec driver to unregister 200 * 201 * Unregister a previously registered ac97 codec driver. 202 */ 203 void snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv) 204 { 205 driver_unregister(&drv->driver); 206 } 207 EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_unregister); 208 209 static void ac97_ctrl_codecs_unregister(struct ac97_controller *ac97_ctrl) 210 { 211 int i; 212 213 for (i = 0; i < AC97_BUS_MAX_CODECS; i++) 214 if (ac97_ctrl->codecs[i]) { 215 ac97_ctrl->codecs[i]->ac97_ctrl = &ac97_unbound_ctrl; 216 device_unregister(&ac97_ctrl->codecs[i]->dev); 217 } 218 } 219 220 static ssize_t cold_reset_store(struct device *dev, 221 struct device_attribute *attr, const char *buf, 222 size_t len) 223 { 224 struct ac97_controller *ac97_ctrl; 225 226 guard(mutex)(&ac97_controllers_mutex); 227 ac97_ctrl = to_ac97_controller(dev); 228 ac97_ctrl->ops->reset(ac97_ctrl); 229 return len; 230 } 231 static DEVICE_ATTR_WO(cold_reset); 232 233 static ssize_t warm_reset_store(struct device *dev, 234 struct device_attribute *attr, const char *buf, 235 size_t len) 236 { 237 struct ac97_controller *ac97_ctrl; 238 239 if (!dev) 240 return -ENODEV; 241 242 guard(mutex)(&ac97_controllers_mutex); 243 ac97_ctrl = to_ac97_controller(dev); 244 ac97_ctrl->ops->warm_reset(ac97_ctrl); 245 return len; 246 } 247 static DEVICE_ATTR_WO(warm_reset); 248 249 static struct attribute *ac97_controller_device_attrs[] = { 250 &dev_attr_cold_reset.attr, 251 &dev_attr_warm_reset.attr, 252 NULL 253 }; 254 255 static const struct attribute_group ac97_adapter_attr_group = { 256 .name = "ac97_operations", 257 .attrs = ac97_controller_device_attrs, 258 }; 259 260 static const struct attribute_group *ac97_adapter_groups[] = { 261 &ac97_adapter_attr_group, 262 NULL, 263 }; 264 265 static void ac97_del_adapter(struct ac97_controller *ac97_ctrl) 266 { 267 scoped_guard(mutex, &ac97_controllers_mutex) { 268 ac97_ctrl_codecs_unregister(ac97_ctrl); 269 list_del(&ac97_ctrl->controllers); 270 } 271 272 device_unregister(&ac97_ctrl->adap); 273 } 274 275 static void ac97_adapter_release(struct device *dev) 276 { 277 struct ac97_controller *ac97_ctrl; 278 279 ac97_ctrl = to_ac97_controller(dev); 280 idr_remove(&ac97_adapter_idr, ac97_ctrl->nr); 281 dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n", 282 dev_name(ac97_ctrl->parent)); 283 kfree(ac97_ctrl); 284 } 285 286 static const struct device_type ac97_adapter_type = { 287 .groups = ac97_adapter_groups, 288 .release = ac97_adapter_release, 289 }; 290 291 static int ac97_add_adapter(struct ac97_controller *ac97_ctrl) 292 { 293 int ret; 294 295 guard(mutex)(&ac97_controllers_mutex); 296 ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL); 297 ac97_ctrl->nr = ret; 298 if (ret >= 0) { 299 dev_set_name(&ac97_ctrl->adap, "ac97-%d", ret); 300 ac97_ctrl->adap.type = &ac97_adapter_type; 301 ac97_ctrl->adap.parent = ac97_ctrl->parent; 302 ret = device_register(&ac97_ctrl->adap); 303 if (ret) 304 put_device(&ac97_ctrl->adap); 305 } else 306 kfree(ac97_ctrl); 307 308 if (!ret) { 309 list_add(&ac97_ctrl->controllers, &ac97_controllers); 310 dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n", 311 dev_name(ac97_ctrl->parent)); 312 } 313 return ret; 314 } 315 316 /** 317 * snd_ac97_controller_register - register an ac97 controller 318 * @ops: the ac97 bus operations 319 * @dev: the device providing the ac97 DC function 320 * @slots_available: mask of the ac97 codecs that can be scanned and probed 321 * bit0 => codec 0, bit1 => codec 1 ... bit 3 => codec 3 322 * 323 * Register a digital controller which can control up to 4 ac97 codecs. This is 324 * the controller side of the AC97 AC-link, while the slave side are the codecs. 325 * 326 * Returns a valid controller upon success, negative pointer value upon error 327 */ 328 struct ac97_controller *snd_ac97_controller_register( 329 const struct ac97_controller_ops *ops, struct device *dev, 330 unsigned short slots_available) 331 { 332 struct ac97_controller *ac97_ctrl; 333 int ret; 334 335 ac97_ctrl = kzalloc_obj(*ac97_ctrl); 336 if (!ac97_ctrl) 337 return ERR_PTR(-ENOMEM); 338 339 ac97_ctrl->ops = ops; 340 ac97_ctrl->slots_available = slots_available; 341 ac97_ctrl->parent = dev; 342 ret = ac97_add_adapter(ac97_ctrl); 343 344 if (ret) 345 return ERR_PTR(ret); 346 ac97_bus_reset(ac97_ctrl); 347 ac97_bus_scan(ac97_ctrl); 348 349 return ac97_ctrl; 350 } 351 EXPORT_SYMBOL_GPL(snd_ac97_controller_register); 352 353 /** 354 * snd_ac97_controller_unregister - unregister an ac97 controller 355 * @ac97_ctrl: the device previously provided to ac97_controller_register() 356 * 357 */ 358 void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl) 359 { 360 ac97_del_adapter(ac97_ctrl); 361 } 362 EXPORT_SYMBOL_GPL(snd_ac97_controller_unregister); 363 364 static int ac97_pm_runtime_suspend(struct device *dev) 365 { 366 struct ac97_codec_device *codec = to_ac97_device(dev); 367 int ret = pm_generic_runtime_suspend(dev); 368 369 if (ret == 0 && dev->driver) { 370 if (pm_runtime_is_irq_safe(dev)) 371 clk_disable(codec->clk); 372 else 373 clk_disable_unprepare(codec->clk); 374 } 375 376 return ret; 377 } 378 379 static int ac97_pm_runtime_resume(struct device *dev) 380 { 381 struct ac97_codec_device *codec = to_ac97_device(dev); 382 int ret; 383 384 if (dev->driver) { 385 if (pm_runtime_is_irq_safe(dev)) 386 ret = clk_enable(codec->clk); 387 else 388 ret = clk_prepare_enable(codec->clk); 389 if (ret) 390 return ret; 391 } 392 393 return pm_generic_runtime_resume(dev); 394 } 395 396 static const struct dev_pm_ops ac97_pm = { 397 .suspend = pm_generic_suspend, 398 .resume = pm_generic_resume, 399 .freeze = pm_generic_freeze, 400 .thaw = pm_generic_thaw, 401 .poweroff = pm_generic_poweroff, 402 .restore = pm_generic_restore, 403 RUNTIME_PM_OPS(ac97_pm_runtime_suspend, ac97_pm_runtime_resume, NULL) 404 }; 405 406 static int ac97_get_enable_clk(struct ac97_codec_device *adev) 407 { 408 int ret; 409 410 adev->clk = clk_get(&adev->dev, "ac97_clk"); 411 if (IS_ERR(adev->clk)) 412 return PTR_ERR(adev->clk); 413 414 ret = clk_prepare_enable(adev->clk); 415 if (ret) 416 clk_put(adev->clk); 417 418 return ret; 419 } 420 421 static void ac97_put_disable_clk(struct ac97_codec_device *adev) 422 { 423 clk_disable_unprepare(adev->clk); 424 clk_put(adev->clk); 425 } 426 427 static ssize_t vendor_id_show(struct device *dev, 428 struct device_attribute *attr, char *buf) 429 { 430 struct ac97_codec_device *codec = to_ac97_device(dev); 431 432 return sysfs_emit(buf, "%08x", codec->vendor_id); 433 } 434 static DEVICE_ATTR_RO(vendor_id); 435 436 static struct attribute *ac97_dev_attrs[] = { 437 &dev_attr_vendor_id.attr, 438 NULL, 439 }; 440 ATTRIBUTE_GROUPS(ac97_dev); 441 442 static int ac97_bus_match(struct device *dev, const struct device_driver *drv) 443 { 444 struct ac97_codec_device *adev = to_ac97_device(dev); 445 const struct ac97_codec_driver *adrv = to_ac97_driver(drv); 446 const struct ac97_id *id = adrv->id_table; 447 int i = 0; 448 449 if (adev->vendor_id == 0x0 || adev->vendor_id == 0xffffffff) 450 return false; 451 452 do { 453 if (ac97_ids_match(id[i].id, adev->vendor_id, id[i].mask)) 454 return true; 455 } while (id[i++].id); 456 457 return false; 458 } 459 460 static int ac97_bus_probe(struct device *dev) 461 { 462 struct ac97_codec_device *adev = to_ac97_device(dev); 463 struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver); 464 int ret; 465 466 ret = ac97_get_enable_clk(adev); 467 if (ret) 468 return ret; 469 470 pm_runtime_get_noresume(dev); 471 pm_runtime_set_active(dev); 472 pm_runtime_enable(dev); 473 474 ret = adrv->probe(adev); 475 if (ret == 0) 476 return 0; 477 478 pm_runtime_disable(dev); 479 pm_runtime_set_suspended(dev); 480 pm_runtime_put_noidle(dev); 481 ac97_put_disable_clk(adev); 482 483 return ret; 484 } 485 486 static void ac97_bus_remove(struct device *dev) 487 { 488 struct ac97_codec_device *adev = to_ac97_device(dev); 489 struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver); 490 int ret; 491 492 ret = pm_runtime_resume_and_get(dev); 493 if (ret < 0) 494 return; 495 496 adrv->remove(adev); 497 pm_runtime_put_noidle(dev); 498 ac97_put_disable_clk(adev); 499 500 pm_runtime_disable(dev); 501 } 502 503 const struct bus_type ac97_bus_type = { 504 .name = "ac97bus", 505 .dev_groups = ac97_dev_groups, 506 .match = ac97_bus_match, 507 .pm = pm_ptr(&ac97_pm), 508 .probe = ac97_bus_probe, 509 .remove = ac97_bus_remove, 510 }; 511 512 static int __init ac97_bus_init(void) 513 { 514 return bus_register(&ac97_bus_type); 515 } 516 subsys_initcall(ac97_bus_init); 517 518 static void __exit ac97_bus_exit(void) 519 { 520 bus_unregister(&ac97_bus_type); 521 } 522 module_exit(ac97_bus_exit); 523 524 MODULE_DESCRIPTION("AC97 bus interface"); 525 MODULE_LICENSE("GPL"); 526 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>"); 527