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
 118         if (node)
 119                 sbdev->dev.of_node = of_node_get(node);
 120
 121         dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
 122                                   sbdev->e_addr.manf_id,
 123                                   sbdev->e_addr.prod_code,
 124                                   sbdev->e_addr.dev_index,
 125                                   sbdev->e_addr.instance);
 126
 127         return device_register(&sbdev->dev);
 128 }
 129
 130 static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
 131                                              struct slim_eaddr *eaddr,
 132                                              struct device_node *node)
 133 {
 134         struct slim_device *sbdev;
 135         int ret;
 136
 137         sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
 138         if (!sbdev)
 139                 return NULL;
 140
 141         sbdev->e_addr = *eaddr;
 142         ret = slim_add_device(ctrl, sbdev, node);
 143         if (ret) {
 144                 kfree(sbdev);
 145                 return NULL;
 146         }
 147
 148         return sbdev;
 149 }
 150
 151 static void of_register_slim_devices(struct slim_controller *ctrl)
 152 {
 153         struct device *dev = ctrl->dev;
 154         struct device_node *node;
 155
 156         if (!ctrl->dev->of_node)
 157                 return;
 158
 159         for_each_child_of_node(ctrl->dev->of_node, node) {
 160                 struct slim_device *sbdev;
 161                 struct slim_eaddr e_addr;
 162                 const char *compat = NULL;
 163                 int reg[2], ret;
 164                 int manf_id, prod_code;
 165
 166                 compat = of_get_property(node, "compatible", NULL);
 167                 if (!compat)
 168                         continue;
 169
 170                 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
 171                 if (ret != 2) {
 172                         dev_err(dev, "Manf ID & Product code not found %s\n",
 173                                 compat);
 174                         continue;
 175                 }
 176
 177                 ret = of_property_read_u32_array(node, "reg", reg, 2);
 178                 if (ret) {
 179                         dev_err(dev, "Device and Instance id not found:%d\n",
 180                                 ret);
 181                         continue;
 182                 }
 183
 184                 e_addr.dev_index = reg[0];
 185                 e_addr.instance = reg[1];
 186                 e_addr.manf_id = manf_id;
 187                 e_addr.prod_code = prod_code;
 188
 189                 sbdev = slim_alloc_device(ctrl, &e_addr, node);
 190                 if (!sbdev)
 191                         continue;
 192         }
 193 }
 194
 195 /*
 196  * slim_register_controller() - Controller bring-up and registration.
 197  *
 198  * @ctrl: Controller to be registered.
 199  *
 200  * A controller is registered with the framework using this API.
 201  * If devices on a controller were registered before controller,
 202  * this will make sure that they get probed when controller is up
 203  */
 204 int slim_register_controller(struct slim_controller *ctrl)
 205 {
 206         int id;
 207
 208         id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
 209         if (id < 0)
 210                 return id;
 211
 212         ctrl->id = id;
 213
 214         if (!ctrl->min_cg)
 215                 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
 216         if (!ctrl->max_cg)
 217                 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
 218
 219         ida_init(&ctrl->laddr_ida);
 220         idr_init(&ctrl->tid_idr);
 221         mutex_init(&ctrl->lock);
 222         mutex_init(&ctrl->sched.m_reconf);
 223         init_completion(&ctrl->sched.pause_comp);
 224
 225         dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
 226                 ctrl->name, ctrl->dev);
 227
 228         of_register_slim_devices(ctrl);
 229
 230         return 0;
 231 }
 232 EXPORT_SYMBOL_GPL(slim_register_controller);
 233
 234 /* slim_remove_device: Remove the effect of slim_add_device() */
 235 static void slim_remove_device(struct slim_device *sbdev)
 236 {
 237         device_unregister(&sbdev->dev);
 238 }
 239
 240 static int slim_ctrl_remove_device(struct device *dev, void *null)
 241 {
 242         slim_remove_device(to_slim_device(dev));
 243         return 0;
 244 }
 245
 246 /**
 247  * slim_unregister_controller() - Controller tear-down.
 248  *
 249  * @ctrl: Controller to tear-down.
 250  */
 251 int slim_unregister_controller(struct slim_controller *ctrl)
 252 {
 253         /* Remove all clients */
 254         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
 255         /* Enter Clock Pause */
 256         slim_ctrl_clk_pause(ctrl, false, 0);
 257         ida_simple_remove(&ctrl_ida, ctrl->id);
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL_GPL(slim_unregister_controller);
 262
 263 static void slim_device_update_status(struct slim_device *sbdev,
 264                                       enum slim_device_status status)
 265 {
 266         struct slim_driver *sbdrv;
 267
 268         if (sbdev->status == status)
 269                 return;
 270
 271         sbdev->status = status;
 272         if (!sbdev->dev.driver)
 273                 return;
 274
 275         sbdrv = to_slim_driver(sbdev->dev.driver);
 276         if (sbdrv->device_status)
 277                 sbdrv->device_status(sbdev, sbdev->status);
 278 }
 279
 280 /**
 281  * slim_report_absent() - Controller calls this function when a device
 282  *      reports absent, OR when the device cannot be communicated with
 283  *
 284  * @sbdev: Device that cannot be reached, or sent report absent
 285  */
 286 void slim_report_absent(struct slim_device *sbdev)
 287 {
 288         struct slim_controller *ctrl = sbdev->ctrl;
 289
 290         if (!ctrl)
 291                 return;
 292
 293         /* invalidate logical addresses */
 294         mutex_lock(&ctrl->lock);
 295         sbdev->is_laddr_valid = false;
 296         mutex_unlock(&ctrl->lock);
 297
 298         ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
 299         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
 300 }
 301 EXPORT_SYMBOL_GPL(slim_report_absent);
 302
 303 static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
 304 {
 305         return (a->manf_id == b->manf_id &&
 306                 a->prod_code == b->prod_code &&
 307                 a->dev_index == b->dev_index &&
 308                 a->instance == b->instance);
 309 }
 310
 311 static int slim_match_dev(struct device *dev, void *data)
 312 {
 313         struct slim_eaddr *e_addr = data;
 314         struct slim_device *sbdev = to_slim_device(dev);
 315
 316         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
 317 }
 318
 319 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
 320                                             struct slim_eaddr *eaddr)
 321 {
 322         struct slim_device *sbdev;
 323         struct device *dev;
 324
 325         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
 326         if (dev) {
 327                 sbdev = to_slim_device(dev);
 328                 return sbdev;
 329         }
 330
 331         return NULL;
 332 }
 333
 334 /**
 335  * slim_get_device() - get handle to a device.
 336  *
 337  * @ctrl: Controller on which this device will be added/queried
 338  * @e_addr: Enumeration address of the device to be queried
 339  *
 340  * Return: pointer to a device if it has already reported. Creates a new
 341  * device and returns pointer to it if the device has not yet enumerated.
 342  */
 343 struct slim_device *slim_get_device(struct slim_controller *ctrl,
 344                                     struct slim_eaddr *e_addr)
 345 {
 346         struct slim_device *sbdev;
 347
 348         sbdev = find_slim_device(ctrl, e_addr);
 349         if (!sbdev) {
 350                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
 351                 if (!sbdev)
 352                         return ERR_PTR(-ENOMEM);
 353         }
 354
 355         return sbdev;
 356 }
 357 EXPORT_SYMBOL_GPL(slim_get_device);
 358
 359 static int slim_device_alloc_laddr(struct slim_device *sbdev,
 360                                    bool report_present)
 361 {
 362         struct slim_controller *ctrl = sbdev->ctrl;
 363         u8 laddr;
 364         int ret;
 365
 366         mutex_lock(&ctrl->lock);
 367         if (ctrl->get_laddr) {
 368                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
 369                 if (ret < 0)
 370                         goto err;
 371         } else if (report_present) {
 372                 ret = ida_simple_get(&ctrl->laddr_ida,
 373                                      0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
 374                 if (ret < 0)
 375                         goto err;
 376
 377                 laddr = ret;
 378         } else {
 379                 ret = -EINVAL;
 380                 goto err;
 381         }
 382
 383         if (ctrl->set_laddr) {
 384                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
 385                 if (ret) {
 386                         ret = -EINVAL;
 387                         goto err;
 388                 }
 389         }
 390
 391         sbdev->laddr = laddr;
 392         sbdev->is_laddr_valid = true;
 393
 394         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 395
 396         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
 397                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
 398                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
 399
 400 err:
 401         mutex_unlock(&ctrl->lock);
 402         return ret;
 403
 404 }
 405
 406 /**
 407  * slim_device_report_present() - Report enumerated device.
 408  *
 409  * @ctrl: Controller with which device is enumerated.
 410  * @e_addr: Enumeration address of the device.
 411  * @laddr: Return logical address (if valid flag is false)
 412  *
 413  * Called by controller in response to REPORT_PRESENT. Framework will assign
 414  * a logical address to this enumeration address.
 415  * Function returns -EXFULL to indicate that all logical addresses are already
 416  * taken.
 417  */
 418 int slim_device_report_present(struct slim_controller *ctrl,
 419                                struct slim_eaddr *e_addr, u8 *laddr)
 420 {
 421         struct slim_device *sbdev;
 422         int ret;
 423
 424         ret = pm_runtime_get_sync(ctrl->dev);
 425
 426         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
 427                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
 428                                     ctrl->sched.clk_state, ret);
 429                 goto slimbus_not_active;
 430         }
 431
 432         sbdev = slim_get_device(ctrl, e_addr);
 433         if (IS_ERR(sbdev))
 434                 return -ENODEV;
 435
 436         if (sbdev->is_laddr_valid) {
 437                 *laddr = sbdev->laddr;
 438                 return 0;
 439         }
 440
 441         ret = slim_device_alloc_laddr(sbdev, true);
 442
 443 slimbus_not_active:
 444         pm_runtime_mark_last_busy(ctrl->dev);
 445         pm_runtime_put_autosuspend(ctrl->dev);
 446         return ret;
 447 }
 448 EXPORT_SYMBOL_GPL(slim_device_report_present);
 449
 450 /**
 451  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
 452  *
 453  * @sbdev: client handle requesting the address.
 454  *
 455  * Return: zero if a logical address is valid or a new logical address
 456  * has been assigned. error code in case of error.
 457  */
 458 int slim_get_logical_addr(struct slim_device *sbdev)
 459 {
 460         if (!sbdev->is_laddr_valid)
 461                 return slim_device_alloc_laddr(sbdev, false);
 462
 463         return 0;
 464 }
 465 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
 466
 467 static void __exit slimbus_exit(void)
 468 {
 469         bus_unregister(&slimbus_bus);
 470 }
 471 module_exit(slimbus_exit);
 472
 473 static int __init slimbus_init(void)
 474 {
 475         return bus_register(&slimbus_bus);
 476 }
 477 postcore_initcall(slimbus_init);
 478
 479 MODULE_LICENSE("GPL v2");
 480 MODULE_DESCRIPTION("SLIMbus core");