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