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