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         of_node_put(sbdev->dev.of_node);
 287         device_unregister(&sbdev->dev);
 288 }
 289
 290 static int slim_ctrl_remove_device(struct device *dev, void *null)
 291 {
 292         slim_remove_device(to_slim_device(dev));
 293         return 0;
 294 }
 295
 296 /**
 297  * slim_unregister_controller() - Controller tear-down.
 298  *
 299  * @ctrl: Controller to tear-down.
 300  */
 301 int slim_unregister_controller(struct slim_controller *ctrl)
 302 {
 303         /* Remove all clients */
 304         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
 305         ida_simple_remove(&ctrl_ida, ctrl->id);
 306
 307         return 0;
 308 }
 309 EXPORT_SYMBOL_GPL(slim_unregister_controller);
 310
 311 /**
 312  * slim_report_absent() - Controller calls this function when a device
 313  *      reports absent, OR when the device cannot be communicated with
 314  *
 315  * @sbdev: Device that cannot be reached, or sent report absent
 316  */
 317 void slim_report_absent(struct slim_device *sbdev)
 318 {
 319         struct slim_controller *ctrl = sbdev->ctrl;
 320
 321         if (!ctrl)
 322                 return;
 323
 324         /* invalidate logical addresses */
 325         mutex_lock(&ctrl->lock);
 326         sbdev->is_laddr_valid = false;
 327         mutex_unlock(&ctrl->lock);
 328         if (!ctrl->get_laddr)
 329                 ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
 330         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
 331 }
 332 EXPORT_SYMBOL_GPL(slim_report_absent);
 333
 334 static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
 335 {
 336         return (a->manf_id == b->manf_id &&
 337                 a->prod_code == b->prod_code &&
 338                 a->dev_index == b->dev_index &&
 339                 a->instance == b->instance);
 340 }
 341
 342 static int slim_match_dev(struct device *dev, void *data)
 343 {
 344         struct slim_eaddr *e_addr = data;
 345         struct slim_device *sbdev = to_slim_device(dev);
 346
 347         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
 348 }
 349
 350 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
 351                                             struct slim_eaddr *eaddr)
 352 {
 353         struct slim_device *sbdev;
 354         struct device *dev;
 355
 356         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
 357         if (dev) {
 358                 sbdev = to_slim_device(dev);
 359                 return sbdev;
 360         }
 361
 362         return NULL;
 363 }
 364
 365 /**
 366  * slim_get_device() - get handle to a device.
 367  *
 368  * @ctrl: Controller on which this device will be added/queried
 369  * @e_addr: Enumeration address of the device to be queried
 370  *
 371  * Return: pointer to a device if it has already reported. Creates a new
 372  * device and returns pointer to it if the device has not yet enumerated.
 373  */
 374 struct slim_device *slim_get_device(struct slim_controller *ctrl,
 375                                     struct slim_eaddr *e_addr)
 376 {
 377         struct slim_device *sbdev;
 378
 379         sbdev = find_slim_device(ctrl, e_addr);
 380         if (!sbdev) {
 381                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
 382                 if (!sbdev)
 383                         return ERR_PTR(-ENOMEM);
 384         }
 385
 386         return sbdev;
 387 }
 388 EXPORT_SYMBOL_GPL(slim_get_device);
 389
 390 static int of_slim_match_dev(struct device *dev, void *data)
 391 {
 392         struct device_node *np = data;
 393         struct slim_device *sbdev = to_slim_device(dev);
 394
 395         return (sbdev->dev.of_node == np);
 396 }
 397
 398 static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
 399                                                struct device_node *np)
 400 {
 401         struct slim_device *sbdev;
 402         struct device *dev;
 403
 404         dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
 405         if (dev) {
 406                 sbdev = to_slim_device(dev);
 407                 return sbdev;
 408         }
 409
 410         return NULL;
 411 }
 412
 413 /**
 414  * of_slim_get_device() - get handle to a device using dt node.
 415  *
 416  * @ctrl: Controller on which this device will be added/queried
 417  * @np: node pointer to device
 418  *
 419  * Return: pointer to a device if it has already reported. Creates a new
 420  * device and returns pointer to it if the device has not yet enumerated.
 421  */
 422 struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
 423                                        struct device_node *np)
 424 {
 425         return of_find_slim_device(ctrl, np);
 426 }
 427 EXPORT_SYMBOL_GPL(of_slim_get_device);
 428
 429 static int slim_device_alloc_laddr(struct slim_device *sbdev,
 430                                    bool report_present)
 431 {
 432         struct slim_controller *ctrl = sbdev->ctrl;
 433         u8 laddr;
 434         int ret;
 435
 436         mutex_lock(&ctrl->lock);
 437         if (ctrl->get_laddr) {
 438                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
 439                 if (ret < 0)
 440                         goto err;
 441         } else if (report_present) {
 442                 ret = ida_simple_get(&ctrl->laddr_ida,
 443                                      0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
 444                 if (ret < 0)
 445                         goto err;
 446
 447                 laddr = ret;
 448         } else {
 449                 ret = -EINVAL;
 450                 goto err;
 451         }
 452
 453         if (ctrl->set_laddr) {
 454                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
 455                 if (ret) {
 456                         ret = -EINVAL;
 457                         goto err;
 458                 }
 459         }
 460
 461         sbdev->laddr = laddr;
 462         sbdev->is_laddr_valid = true;
 463         mutex_unlock(&ctrl->lock);
 464
 465         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 466
 467         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
 468                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
 469                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
 470
 471         return 0;
 472
 473 err:
 474         mutex_unlock(&ctrl->lock);
 475         return ret;
 476
 477 }
 478
 479 /**
 480  * slim_device_report_present() - Report enumerated device.
 481  *
 482  * @ctrl: Controller with which device is enumerated.
 483  * @e_addr: Enumeration address of the device.
 484  * @laddr: Return logical address (if valid flag is false)
 485  *
 486  * Called by controller in response to REPORT_PRESENT. Framework will assign
 487  * a logical address to this enumeration address.
 488  * Function returns -EXFULL to indicate that all logical addresses are already
 489  * taken.
 490  */
 491 int slim_device_report_present(struct slim_controller *ctrl,
 492                                struct slim_eaddr *e_addr, u8 *laddr)
 493 {
 494         struct slim_device *sbdev;
 495         int ret;
 496
 497         ret = pm_runtime_get_sync(ctrl->dev);
 498
 499         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
 500                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
 501                                     ctrl->sched.clk_state, ret);
 502                 goto slimbus_not_active;
 503         }
 504
 505         sbdev = slim_get_device(ctrl, e_addr);
 506         if (IS_ERR(sbdev))
 507                 return -ENODEV;
 508
 509         if (sbdev->is_laddr_valid) {
 510                 *laddr = sbdev->laddr;
 511                 return 0;
 512         }
 513
 514         ret = slim_device_alloc_laddr(sbdev, true);
 515
 516 slimbus_not_active:
 517         pm_runtime_mark_last_busy(ctrl->dev);
 518         pm_runtime_put_autosuspend(ctrl->dev);
 519         return ret;
 520 }
 521 EXPORT_SYMBOL_GPL(slim_device_report_present);
 522
 523 /**
 524  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
 525  *
 526  * @sbdev: client handle requesting the address.
 527  *
 528  * Return: zero if a logical address is valid or a new logical address
 529  * has been assigned. error code in case of error.
 530  */
 531 int slim_get_logical_addr(struct slim_device *sbdev)
 532 {
 533         if (!sbdev->is_laddr_valid)
 534                 return slim_device_alloc_laddr(sbdev, false);
 535
 536         return 0;
 537 }
 538 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
 539
 540 static void __exit slimbus_exit(void)
 541 {
 542         bus_unregister(&slimbus_bus);
 543 }
 544 module_exit(slimbus_exit);
 545
 546 static int __init slimbus_init(void)
 547 {
 548         return bus_register(&slimbus_bus);
 549 }
 550 postcore_initcall(slimbus_init);
 551
 552 MODULE_LICENSE("GPL v2");
 553 MODULE_DESCRIPTION("SLIMbus core");