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         device_unregister(&sbdev->dev);
 240 }
 241
 242 static int slim_ctrl_remove_device(struct device *dev, void *null)
 243 {
 244         slim_remove_device(to_slim_device(dev));
 245         return 0;
 246 }
 247
 248 /**
 249  * slim_unregister_controller() - Controller tear-down.
 250  *
 251  * @ctrl: Controller to tear-down.
 252  */
 253 int slim_unregister_controller(struct slim_controller *ctrl)
 254 {
 255         /* Remove all clients */
 256         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
 257         /* Enter Clock Pause */
 258         slim_ctrl_clk_pause(ctrl, false, 0);
 259         ida_simple_remove(&ctrl_ida, ctrl->id);
 260
 261         return 0;
 262 }
 263 EXPORT_SYMBOL_GPL(slim_unregister_controller);
 264
 265 static void slim_device_update_status(struct slim_device *sbdev,
 266                                       enum slim_device_status status)
 267 {
 268         struct slim_driver *sbdrv;
 269
 270         if (sbdev->status == status)
 271                 return;
 272
 273         sbdev->status = status;
 274         if (!sbdev->dev.driver)
 275                 return;
 276
 277         sbdrv = to_slim_driver(sbdev->dev.driver);
 278         if (sbdrv->device_status)
 279                 sbdrv->device_status(sbdev, sbdev->status);
 280 }
 281
 282 /**
 283  * slim_report_absent() - Controller calls this function when a device
 284  *      reports absent, OR when the device cannot be communicated with
 285  *
 286  * @sbdev: Device that cannot be reached, or sent report absent
 287  */
 288 void slim_report_absent(struct slim_device *sbdev)
 289 {
 290         struct slim_controller *ctrl = sbdev->ctrl;
 291
 292         if (!ctrl)
 293                 return;
 294
 295         /* invalidate logical addresses */
 296         mutex_lock(&ctrl->lock);
 297         sbdev->is_laddr_valid = false;
 298         mutex_unlock(&ctrl->lock);
 299
 300         ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
 301         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
 302 }
 303 EXPORT_SYMBOL_GPL(slim_report_absent);
 304
 305 static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
 306 {
 307         return (a->manf_id == b->manf_id &&
 308                 a->prod_code == b->prod_code &&
 309                 a->dev_index == b->dev_index &&
 310                 a->instance == b->instance);
 311 }
 312
 313 static int slim_match_dev(struct device *dev, void *data)
 314 {
 315         struct slim_eaddr *e_addr = data;
 316         struct slim_device *sbdev = to_slim_device(dev);
 317
 318         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
 319 }
 320
 321 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
 322                                             struct slim_eaddr *eaddr)
 323 {
 324         struct slim_device *sbdev;
 325         struct device *dev;
 326
 327         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
 328         if (dev) {
 329                 sbdev = to_slim_device(dev);
 330                 return sbdev;
 331         }
 332
 333         return NULL;
 334 }
 335
 336 /**
 337  * slim_get_device() - get handle to a device.
 338  *
 339  * @ctrl: Controller on which this device will be added/queried
 340  * @e_addr: Enumeration address of the device to be queried
 341  *
 342  * Return: pointer to a device if it has already reported. Creates a new
 343  * device and returns pointer to it if the device has not yet enumerated.
 344  */
 345 struct slim_device *slim_get_device(struct slim_controller *ctrl,
 346                                     struct slim_eaddr *e_addr)
 347 {
 348         struct slim_device *sbdev;
 349
 350         sbdev = find_slim_device(ctrl, e_addr);
 351         if (!sbdev) {
 352                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
 353                 if (!sbdev)
 354                         return ERR_PTR(-ENOMEM);
 355         }
 356
 357         return sbdev;
 358 }
 359 EXPORT_SYMBOL_GPL(slim_get_device);
 360
 361 static int of_slim_match_dev(struct device *dev, void *data)
 362 {
 363         struct device_node *np = data;
 364         struct slim_device *sbdev = to_slim_device(dev);
 365
 366         return (sbdev->dev.of_node == np);
 367 }
 368
 369 static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
 370                                                struct device_node *np)
 371 {
 372         struct slim_device *sbdev;
 373         struct device *dev;
 374
 375         dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
 376         if (dev) {
 377                 sbdev = to_slim_device(dev);
 378                 return sbdev;
 379         }
 380
 381         return NULL;
 382 }
 383
 384 /**
 385  * of_slim_get_device() - get handle to a device using dt node.
 386  *
 387  * @ctrl: Controller on which this device will be added/queried
 388  * @np: node pointer to device
 389  *
 390  * Return: pointer to a device if it has already reported. Creates a new
 391  * device and returns pointer to it if the device has not yet enumerated.
 392  */
 393 struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
 394                                        struct device_node *np)
 395 {
 396         return of_find_slim_device(ctrl, np);
 397 }
 398 EXPORT_SYMBOL_GPL(of_slim_get_device);
 399
 400 static int slim_device_alloc_laddr(struct slim_device *sbdev,
 401                                    bool report_present)
 402 {
 403         struct slim_controller *ctrl = sbdev->ctrl;
 404         u8 laddr;
 405         int ret;
 406
 407         mutex_lock(&ctrl->lock);
 408         if (ctrl->get_laddr) {
 409                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
 410                 if (ret < 0)
 411                         goto err;
 412         } else if (report_present) {
 413                 ret = ida_simple_get(&ctrl->laddr_ida,
 414                                      0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
 415                 if (ret < 0)
 416                         goto err;
 417
 418                 laddr = ret;
 419         } else {
 420                 ret = -EINVAL;
 421                 goto err;
 422         }
 423
 424         if (ctrl->set_laddr) {
 425                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
 426                 if (ret) {
 427                         ret = -EINVAL;
 428                         goto err;
 429                 }
 430         }
 431
 432         sbdev->laddr = laddr;
 433         sbdev->is_laddr_valid = true;
 434
 435         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 436
 437         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
 438                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
 439                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
 440
 441 err:
 442         mutex_unlock(&ctrl->lock);
 443         return ret;
 444
 445 }
 446
 447 /**
 448  * slim_device_report_present() - Report enumerated device.
 449  *
 450  * @ctrl: Controller with which device is enumerated.
 451  * @e_addr: Enumeration address of the device.
 452  * @laddr: Return logical address (if valid flag is false)
 453  *
 454  * Called by controller in response to REPORT_PRESENT. Framework will assign
 455  * a logical address to this enumeration address.
 456  * Function returns -EXFULL to indicate that all logical addresses are already
 457  * taken.
 458  */
 459 int slim_device_report_present(struct slim_controller *ctrl,
 460                                struct slim_eaddr *e_addr, u8 *laddr)
 461 {
 462         struct slim_device *sbdev;
 463         int ret;
 464
 465         ret = pm_runtime_get_sync(ctrl->dev);
 466
 467         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
 468                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
 469                                     ctrl->sched.clk_state, ret);
 470                 goto slimbus_not_active;
 471         }
 472
 473         sbdev = slim_get_device(ctrl, e_addr);
 474         if (IS_ERR(sbdev))
 475                 return -ENODEV;
 476
 477         if (sbdev->is_laddr_valid) {
 478                 *laddr = sbdev->laddr;
 479                 return 0;
 480         }
 481
 482         ret = slim_device_alloc_laddr(sbdev, true);
 483
 484 slimbus_not_active:
 485         pm_runtime_mark_last_busy(ctrl->dev);
 486         pm_runtime_put_autosuspend(ctrl->dev);
 487         return ret;
 488 }
 489 EXPORT_SYMBOL_GPL(slim_device_report_present);
 490
 491 /**
 492  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
 493  *
 494  * @sbdev: client handle requesting the address.
 495  *
 496  * Return: zero if a logical address is valid or a new logical address
 497  * has been assigned. error code in case of error.
 498  */
 499 int slim_get_logical_addr(struct slim_device *sbdev)
 500 {
 501         if (!sbdev->is_laddr_valid)
 502                 return slim_device_alloc_laddr(sbdev, false);
 503
 504         return 0;
 505 }
 506 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
 507
 508 static void __exit slimbus_exit(void)
 509 {
 510         bus_unregister(&slimbus_bus);
 511 }
 512 module_exit(slimbus_exit);
 513
 514 static int __init slimbus_init(void)
 515 {
 516         return bus_register(&slimbus_bus);
 517 }
 518 postcore_initcall(slimbus_init);
 519
 520 MODULE_LICENSE("GPL v2");
 521 MODULE_DESCRIPTION("SLIMbus core");