drivers/slimbus/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2011-2017, The Linux Foundation
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/errno.h>
   8 #include <linux/slab.h>
   9 #include <linux/init.h>
  10 #include <linux/idr.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13 #include <linux/pm_runtime.h>
  14 #include <linux/slimbus.h>
  15 #include "slimbus.h"
  16
  17 static DEFINE_IDA(ctrl_ida);
  18
  19 static const struct slim_device_id *slim_match(const struct slim_device_id *id,
  20                                                const struct slim_device *sbdev)
  21 {
  22         while (id->manf_id != 0 || id->prod_code != 0) {
  23                 if (id->manf_id == sbdev->e_addr.manf_id &&
  24                     id->prod_code == sbdev->e_addr.prod_code)
  25                         return id;
  26                 id++;
  27         }
  28         return NULL;
  29 }
  30
  31 static int slim_device_match(struct device *dev, struct device_driver *drv)
  32 {
  33         struct slim_device *sbdev = to_slim_device(dev);
  34         struct slim_driver *sbdrv = to_slim_driver(drv);
  35
  36         /* Attempt an OF style match first */
  37         if (of_driver_match_device(dev, drv))
  38                 return 1;
  39
  40         return !!slim_match(sbdrv->id_table, sbdev);
  41 }
  42
  43 static int slim_device_probe(struct device *dev)
  44 {
  45         struct slim_device      *sbdev = to_slim_device(dev);
  46         struct slim_driver      *sbdrv = to_slim_driver(dev->driver);
  47         int ret;
  48
  49         ret = sbdrv->probe(sbdev);
  50         if (ret)
  51                 return ret;
  52
  53         /* try getting the logical address after probe */
  54         ret = slim_get_logical_addr(sbdev);
  55         if (!ret) {
  56                 if (sbdrv->device_status)
  57                         sbdrv->device_status(sbdev, sbdev->status);
  58         } else {
  59                 dev_err(&sbdev->dev, "Failed to get logical address\n");
  60                 ret = -EPROBE_DEFER;
  61         }
  62
  63         return ret;
  64 }
  65
  66 static int slim_device_remove(struct device *dev)
  67 {
  68         struct slim_device *sbdev = to_slim_device(dev);
  69         struct slim_driver *sbdrv;
  70
  71         if (dev->driver) {
  72                 sbdrv = to_slim_driver(dev->driver);
  73                 if (sbdrv->remove)
  74                         sbdrv->remove(sbdev);
  75         }
  76
  77         return 0;
  78 }
  79
  80 static int slim_device_uevent(struct device *dev, struct kobj_uevent_env *env)
  81 {
  82         struct slim_device *sbdev = to_slim_device(dev);
  83         int ret;
  84
  85         ret = of_device_uevent_modalias(dev, env);
  86         if (ret != -ENODEV)
  87                 return ret;
  88
  89         return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev));
  90 }
  91
  92 struct bus_type slimbus_bus = {
  93         .name           = "slimbus",
  94         .match          = slim_device_match,
  95         .probe          = slim_device_probe,
  96         .remove         = slim_device_remove,
  97         .uevent         = slim_device_uevent,
  98 };
  99 EXPORT_SYMBOL_GPL(slimbus_bus);
 100
 101 /*
 102  * __slim_driver_register() - Client driver registration with SLIMbus
 103  *
 104  * @drv:Client driver to be associated with client-device.
 105  * @owner: owning module/driver
 106  *
 107  * This API will register the client driver with the SLIMbus
 108  * It is called from the driver's module-init function.
 109  */
 110 int __slim_driver_register(struct slim_driver *drv, struct module *owner)
 111 {
 112         /* ID table and probe are mandatory */
 113         if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe)
 114                 return -EINVAL;
 115
 116         drv->driver.bus = &slimbus_bus;
 117         drv->driver.owner = owner;
 118
 119         return driver_register(&drv->driver);
 120 }
 121 EXPORT_SYMBOL_GPL(__slim_driver_register);
 122
 123 /*
 124  * slim_driver_unregister() - Undo effect of slim_driver_register
 125  *
 126  * @drv: Client driver to be unregistered
 127  */
 128 void slim_driver_unregister(struct slim_driver *drv)
 129 {
 130         driver_unregister(&drv->driver);
 131 }
 132 EXPORT_SYMBOL_GPL(slim_driver_unregister);
 133
 134 static void slim_dev_release(struct device *dev)
 135 {
 136         struct slim_device *sbdev = to_slim_device(dev);
 137
 138         kfree(sbdev);
 139 }
 140
 141 static int slim_add_device(struct slim_controller *ctrl,
 142                            struct slim_device *sbdev,
 143                            struct device_node *node)
 144 {
 145         sbdev->dev.bus = &slimbus_bus;
 146         sbdev->dev.parent = ctrl->dev;
 147         sbdev->dev.release = slim_dev_release;
 148         sbdev->dev.driver = NULL;
 149         sbdev->ctrl = ctrl;
 150         INIT_LIST_HEAD(&sbdev->stream_list);
 151         spin_lock_init(&sbdev->stream_list_lock);
 152
 153         if (node)
 154                 sbdev->dev.of_node = of_node_get(node);
 155
 156         dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
 157                                   sbdev->e_addr.manf_id,
 158                                   sbdev->e_addr.prod_code,
 159                                   sbdev->e_addr.dev_index,
 160                                   sbdev->e_addr.instance);
 161
 162         return device_register(&sbdev->dev);
 163 }
 164
 165 static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
 166                                              struct slim_eaddr *eaddr,
 167                                              struct device_node *node)
 168 {
 169         struct slim_device *sbdev;
 170         int ret;
 171
 172         sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
 173         if (!sbdev)
 174                 return NULL;
 175
 176         sbdev->e_addr = *eaddr;
 177         ret = slim_add_device(ctrl, sbdev, node);
 178         if (ret) {
 179                 put_device(&sbdev->dev);
 180                 return NULL;
 181         }
 182
 183         return sbdev;
 184 }
 185
 186 static void of_register_slim_devices(struct slim_controller *ctrl)
 187 {
 188         struct device *dev = ctrl->dev;
 189         struct device_node *node;
 190
 191         if (!ctrl->dev->of_node)
 192                 return;
 193
 194         for_each_child_of_node(ctrl->dev->of_node, node) {
 195                 struct slim_device *sbdev;
 196                 struct slim_eaddr e_addr;
 197                 const char *compat = NULL;
 198                 int reg[2], ret;
 199                 int manf_id, prod_code;
 200
 201                 compat = of_get_property(node, "compatible", NULL);
 202                 if (!compat)
 203                         continue;
 204
 205                 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
 206                 if (ret != 2) {
 207                         dev_err(dev, "Manf ID & Product code not found %s\n",
 208                                 compat);
 209                         continue;
 210                 }
 211
 212                 ret = of_property_read_u32_array(node, "reg", reg, 2);
 213                 if (ret) {
 214                         dev_err(dev, "Device and Instance id not found:%d\n",
 215                                 ret);
 216                         continue;
 217                 }
 218
 219                 e_addr.dev_index = reg[0];
 220                 e_addr.instance = reg[1];
 221                 e_addr.manf_id = manf_id;
 222                 e_addr.prod_code = prod_code;
 223
 224                 sbdev = slim_alloc_device(ctrl, &e_addr, node);
 225                 if (!sbdev)
 226                         continue;
 227         }
 228 }
 229
 230 /*
 231  * slim_register_controller() - Controller bring-up and registration.
 232  *
 233  * @ctrl: Controller to be registered.
 234  *
 235  * A controller is registered with the framework using this API.
 236  * If devices on a controller were registered before controller,
 237  * this will make sure that they get probed when controller is up
 238  */
 239 int slim_register_controller(struct slim_controller *ctrl)
 240 {
 241         int id;
 242
 243         id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
 244         if (id < 0)
 245                 return id;
 246
 247         ctrl->id = id;
 248
 249         if (!ctrl->min_cg)
 250                 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
 251         if (!ctrl->max_cg)
 252                 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
 253
 254         ida_init(&ctrl->laddr_ida);
 255         idr_init(&ctrl->tid_idr);
 256         mutex_init(&ctrl->lock);
 257         mutex_init(&ctrl->sched.m_reconf);
 258         init_completion(&ctrl->sched.pause_comp);
 259
 260         dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
 261                 ctrl->name, ctrl->dev);
 262
 263         of_register_slim_devices(ctrl);
 264
 265         return 0;
 266 }
 267 EXPORT_SYMBOL_GPL(slim_register_controller);
 268
 269 /* slim_remove_device: Remove the effect of slim_add_device() */
 270 static void slim_remove_device(struct slim_device *sbdev)
 271 {
 272         device_unregister(&sbdev->dev);
 273 }
 274
 275 static int slim_ctrl_remove_device(struct device *dev, void *null)
 276 {
 277         slim_remove_device(to_slim_device(dev));
 278         return 0;
 279 }
 280
 281 /**
 282  * slim_unregister_controller() - Controller tear-down.
 283  *
 284  * @ctrl: Controller to tear-down.
 285  */
 286 int slim_unregister_controller(struct slim_controller *ctrl)
 287 {
 288         /* Remove all clients */
 289         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
 290         /* Enter Clock Pause */
 291         slim_ctrl_clk_pause(ctrl, false, 0);
 292         ida_simple_remove(&ctrl_ida, ctrl->id);
 293
 294         return 0;
 295 }
 296 EXPORT_SYMBOL_GPL(slim_unregister_controller);
 297
 298 static void slim_device_update_status(struct slim_device *sbdev,
 299                                       enum slim_device_status status)
 300 {
 301         struct slim_driver *sbdrv;
 302
 303         if (sbdev->status == status)
 304                 return;
 305
 306         sbdev->status = status;
 307         if (!sbdev->dev.driver)
 308                 return;
 309
 310         sbdrv = to_slim_driver(sbdev->dev.driver);
 311         if (sbdrv->device_status)
 312                 sbdrv->device_status(sbdev, sbdev->status);
 313 }
 314
 315 /**
 316  * slim_report_absent() - Controller calls this function when a device
 317  *      reports absent, OR when the device cannot be communicated with
 318  *
 319  * @sbdev: Device that cannot be reached, or sent report absent
 320  */
 321 void slim_report_absent(struct slim_device *sbdev)
 322 {
 323         struct slim_controller *ctrl = sbdev->ctrl;
 324
 325         if (!ctrl)
 326                 return;
 327
 328         /* invalidate logical addresses */
 329         mutex_lock(&ctrl->lock);
 330         sbdev->is_laddr_valid = false;
 331         mutex_unlock(&ctrl->lock);
 332
 333         ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
 334         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
 335 }
 336 EXPORT_SYMBOL_GPL(slim_report_absent);
 337
 338 static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
 339 {
 340         return (a->manf_id == b->manf_id &&
 341                 a->prod_code == b->prod_code &&
 342                 a->dev_index == b->dev_index &&
 343                 a->instance == b->instance);
 344 }
 345
 346 static int slim_match_dev(struct device *dev, void *data)
 347 {
 348         struct slim_eaddr *e_addr = data;
 349         struct slim_device *sbdev = to_slim_device(dev);
 350
 351         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
 352 }
 353
 354 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
 355                                             struct slim_eaddr *eaddr)
 356 {
 357         struct slim_device *sbdev;
 358         struct device *dev;
 359
 360         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
 361         if (dev) {
 362                 sbdev = to_slim_device(dev);
 363                 return sbdev;
 364         }
 365
 366         return NULL;
 367 }
 368
 369 /**
 370  * slim_get_device() - get handle to a device.
 371  *
 372  * @ctrl: Controller on which this device will be added/queried
 373  * @e_addr: Enumeration address of the device to be queried
 374  *
 375  * Return: pointer to a device if it has already reported. Creates a new
 376  * device and returns pointer to it if the device has not yet enumerated.
 377  */
 378 struct slim_device *slim_get_device(struct slim_controller *ctrl,
 379                                     struct slim_eaddr *e_addr)
 380 {
 381         struct slim_device *sbdev;
 382
 383         sbdev = find_slim_device(ctrl, e_addr);
 384         if (!sbdev) {
 385                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
 386                 if (!sbdev)
 387                         return ERR_PTR(-ENOMEM);
 388         }
 389
 390         return sbdev;
 391 }
 392 EXPORT_SYMBOL_GPL(slim_get_device);
 393
 394 static int of_slim_match_dev(struct device *dev, void *data)
 395 {
 396         struct device_node *np = data;
 397         struct slim_device *sbdev = to_slim_device(dev);
 398
 399         return (sbdev->dev.of_node == np);
 400 }
 401
 402 static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
 403                                                struct device_node *np)
 404 {
 405         struct slim_device *sbdev;
 406         struct device *dev;
 407
 408         dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
 409         if (dev) {
 410                 sbdev = to_slim_device(dev);
 411                 return sbdev;
 412         }
 413
 414         return NULL;
 415 }
 416
 417 /**
 418  * of_slim_get_device() - get handle to a device using dt node.
 419  *
 420  * @ctrl: Controller on which this device will be added/queried
 421  * @np: node pointer to device
 422  *
 423  * Return: pointer to a device if it has already reported. Creates a new
 424  * device and returns pointer to it if the device has not yet enumerated.
 425  */
 426 struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
 427                                        struct device_node *np)
 428 {
 429         return of_find_slim_device(ctrl, np);
 430 }
 431 EXPORT_SYMBOL_GPL(of_slim_get_device);
 432
 433 static int slim_device_alloc_laddr(struct slim_device *sbdev,
 434                                    bool report_present)
 435 {
 436         struct slim_controller *ctrl = sbdev->ctrl;
 437         u8 laddr;
 438         int ret;
 439
 440         mutex_lock(&ctrl->lock);
 441         if (ctrl->get_laddr) {
 442                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
 443                 if (ret < 0)
 444                         goto err;
 445         } else if (report_present) {
 446                 ret = ida_simple_get(&ctrl->laddr_ida,
 447                                      0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
 448                 if (ret < 0)
 449                         goto err;
 450
 451                 laddr = ret;
 452         } else {
 453                 ret = -EINVAL;
 454                 goto err;
 455         }
 456
 457         if (ctrl->set_laddr) {
 458                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
 459                 if (ret) {
 460                         ret = -EINVAL;
 461                         goto err;
 462                 }
 463         }
 464
 465         sbdev->laddr = laddr;
 466         sbdev->is_laddr_valid = true;
 467
 468         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 469
 470         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
 471                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
 472                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
 473
 474 err:
 475         mutex_unlock(&ctrl->lock);
 476         return ret;
 477
 478 }
 479
 480 /**
 481  * slim_device_report_present() - Report enumerated device.
 482  *
 483  * @ctrl: Controller with which device is enumerated.
 484  * @e_addr: Enumeration address of the device.
 485  * @laddr: Return logical address (if valid flag is false)
 486  *
 487  * Called by controller in response to REPORT_PRESENT. Framework will assign
 488  * a logical address to this enumeration address.
 489  * Function returns -EXFULL to indicate that all logical addresses are already
 490  * taken.
 491  */
 492 int slim_device_report_present(struct slim_controller *ctrl,
 493                                struct slim_eaddr *e_addr, u8 *laddr)
 494 {
 495         struct slim_device *sbdev;
 496         int ret;
 497
 498         ret = pm_runtime_get_sync(ctrl->dev);
 499
 500         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
 501                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
 502                                     ctrl->sched.clk_state, ret);
 503                 goto slimbus_not_active;
 504         }
 505
 506         sbdev = slim_get_device(ctrl, e_addr);
 507         if (IS_ERR(sbdev))
 508                 return -ENODEV;
 509
 510         if (sbdev->is_laddr_valid) {
 511                 *laddr = sbdev->laddr;
 512                 return 0;
 513         }
 514
 515         ret = slim_device_alloc_laddr(sbdev, true);
 516
 517 slimbus_not_active:
 518         pm_runtime_mark_last_busy(ctrl->dev);
 519         pm_runtime_put_autosuspend(ctrl->dev);
 520         return ret;
 521 }
 522 EXPORT_SYMBOL_GPL(slim_device_report_present);
 523
 524 /**
 525  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
 526  *
 527  * @sbdev: client handle requesting the address.
 528  *
 529  * Return: zero if a logical address is valid or a new logical address
 530  * has been assigned. error code in case of error.
 531  */
 532 int slim_get_logical_addr(struct slim_device *sbdev)
 533 {
 534         if (!sbdev->is_laddr_valid)
 535                 return slim_device_alloc_laddr(sbdev, false);
 536
 537         return 0;
 538 }
 539 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
 540
 541 static void __exit slimbus_exit(void)
 542 {
 543         bus_unregister(&slimbus_bus);
 544 }
 545 module_exit(slimbus_exit);
 546
 547 static int __init slimbus_init(void)
 548 {
 549         return bus_register(&slimbus_bus);
 550 }
 551 postcore_initcall(slimbus_init);
 552
 553 MODULE_LICENSE("GPL v2");
 554 MODULE_DESCRIPTION("SLIMbus core");