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