drivers/spmi/spmi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/errno.h>
   7 #include <linux/idr.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/of_device.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/spmi.h>
  14 #include <linux/pm_runtime.h>
  15
  16 #include <dt-bindings/spmi/spmi.h>
  17 #define CREATE_TRACE_POINTS
  18 #include <trace/events/spmi.h>
  19
  20 static bool is_registered;
  21 static DEFINE_IDA(ctrl_ida);
  22
  23 static void spmi_dev_release(struct device *dev)
  24 {
  25         struct spmi_device *sdev = to_spmi_device(dev);
  26         kfree(sdev);
  27 }
  28
  29 static const struct device_type spmi_dev_type = {
  30         .release        = spmi_dev_release,
  31 };
  32
  33 static void spmi_ctrl_release(struct device *dev)
  34 {
  35         struct spmi_controller *ctrl = to_spmi_controller(dev);
  36         ida_simple_remove(&ctrl_ida, ctrl->nr);
  37         kfree(ctrl);
  38 }
  39
  40 static const struct device_type spmi_ctrl_type = {
  41         .release        = spmi_ctrl_release,
  42 };
  43
  44 static int spmi_device_match(struct device *dev, struct device_driver *drv)
  45 {
  46         if (of_driver_match_device(dev, drv))
  47                 return 1;
  48
  49         if (drv->name)
  50                 return strncmp(dev_name(dev), drv->name,
  51                                SPMI_NAME_SIZE) == 0;
  52
  53         return 0;
  54 }
  55
  56 /**
  57  * spmi_device_add() - add a device previously constructed via spmi_device_alloc()
  58  * @sdev:       spmi_device to be added
  59  */
  60 int spmi_device_add(struct spmi_device *sdev)
  61 {
  62         struct spmi_controller *ctrl = sdev->ctrl;
  63         int err;
  64
  65         dev_set_name(&sdev->dev, "%d-%02x", ctrl->nr, sdev->usid);
  66
  67         err = device_add(&sdev->dev);
  68         if (err < 0) {
  69                 dev_err(&sdev->dev, "Can't add %s, status %d\n",
  70                         dev_name(&sdev->dev), err);
  71                 goto err_device_add;
  72         }
  73
  74         dev_dbg(&sdev->dev, "device %s registered\n", dev_name(&sdev->dev));
  75
  76 err_device_add:
  77         return err;
  78 }
  79 EXPORT_SYMBOL_GPL(spmi_device_add);
  80
  81 /**
  82  * spmi_device_remove(): remove an SPMI device
  83  * @sdev:       spmi_device to be removed
  84  */
  85 void spmi_device_remove(struct spmi_device *sdev)
  86 {
  87         device_unregister(&sdev->dev);
  88 }
  89 EXPORT_SYMBOL_GPL(spmi_device_remove);
  90
  91 static inline int
  92 spmi_cmd(struct spmi_controller *ctrl, u8 opcode, u8 sid)
  93 {
  94         int ret;
  95
  96         if (!ctrl || !ctrl->cmd || ctrl->dev.type != &spmi_ctrl_type)
  97                 return -EINVAL;
  98
  99         ret = ctrl->cmd(ctrl, opcode, sid);
 100         trace_spmi_cmd(opcode, sid, ret);
 101         return ret;
 102 }
 103
 104 static inline int spmi_read_cmd(struct spmi_controller *ctrl, u8 opcode,
 105                                 u8 sid, u16 addr, u8 *buf, size_t len)
 106 {
 107         int ret;
 108
 109         if (!ctrl || !ctrl->read_cmd || ctrl->dev.type != &spmi_ctrl_type)
 110                 return -EINVAL;
 111
 112         trace_spmi_read_begin(opcode, sid, addr);
 113         ret = ctrl->read_cmd(ctrl, opcode, sid, addr, buf, len);
 114         trace_spmi_read_end(opcode, sid, addr, ret, len, buf);
 115         return ret;
 116 }
 117
 118 static inline int spmi_write_cmd(struct spmi_controller *ctrl, u8 opcode,
 119                                  u8 sid, u16 addr, const u8 *buf, size_t len)
 120 {
 121         int ret;
 122
 123         if (!ctrl || !ctrl->write_cmd || ctrl->dev.type != &spmi_ctrl_type)
 124                 return -EINVAL;
 125
 126         trace_spmi_write_begin(opcode, sid, addr, len, buf);
 127         ret = ctrl->write_cmd(ctrl, opcode, sid, addr, buf, len);
 128         trace_spmi_write_end(opcode, sid, addr, ret);
 129         return ret;
 130 }
 131
 132 /**
 133  * spmi_register_read() - register read
 134  * @sdev:       SPMI device.
 135  * @addr:       slave register address (5-bit address).
 136  * @buf:        buffer to be populated with data from the Slave.
 137  *
 138  * Reads 1 byte of data from a Slave device register.
 139  */
 140 int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf)
 141 {
 142         /* 5-bit register address */
 143         if (addr > 0x1F)
 144                 return -EINVAL;
 145
 146         return spmi_read_cmd(sdev->ctrl, SPMI_CMD_READ, sdev->usid, addr,
 147                              buf, 1);
 148 }
 149 EXPORT_SYMBOL_GPL(spmi_register_read);
 150
 151 /**
 152  * spmi_ext_register_read() - extended register read
 153  * @sdev:       SPMI device.
 154  * @addr:       slave register address (8-bit address).
 155  * @buf:        buffer to be populated with data from the Slave.
 156  * @len:        the request number of bytes to read (up to 16 bytes).
 157  *
 158  * Reads up to 16 bytes of data from the extended register space on a
 159  * Slave device.
 160  */
 161 int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,
 162                            size_t len)
 163 {
 164         /* 8-bit register address, up to 16 bytes */
 165         if (len == 0 || len > 16)
 166                 return -EINVAL;
 167
 168         return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READ, sdev->usid, addr,
 169                              buf, len);
 170 }
 171 EXPORT_SYMBOL_GPL(spmi_ext_register_read);
 172
 173 /**
 174  * spmi_ext_register_readl() - extended register read long
 175  * @sdev:       SPMI device.
 176  * @addr:       slave register address (16-bit address).
 177  * @buf:        buffer to be populated with data from the Slave.
 178  * @len:        the request number of bytes to read (up to 8 bytes).
 179  *
 180  * Reads up to 8 bytes of data from the extended register space on a
 181  * Slave device using 16-bit address.
 182  */
 183 int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,
 184                             size_t len)
 185 {
 186         /* 16-bit register address, up to 8 bytes */
 187         if (len == 0 || len > 8)
 188                 return -EINVAL;
 189
 190         return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READL, sdev->usid, addr,
 191                              buf, len);
 192 }
 193 EXPORT_SYMBOL_GPL(spmi_ext_register_readl);
 194
 195 /**
 196  * spmi_register_write() - register write
 197  * @sdev:       SPMI device
 198  * @addr:       slave register address (5-bit address).
 199  * @data:       buffer containing the data to be transferred to the Slave.
 200  *
 201  * Writes 1 byte of data to a Slave device register.
 202  */
 203 int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data)
 204 {
 205         /* 5-bit register address */
 206         if (addr > 0x1F)
 207                 return -EINVAL;
 208
 209         return spmi_write_cmd(sdev->ctrl, SPMI_CMD_WRITE, sdev->usid, addr,
 210                               &data, 1);
 211 }
 212 EXPORT_SYMBOL_GPL(spmi_register_write);
 213
 214 /**
 215  * spmi_register_zero_write() - register zero write
 216  * @sdev:       SPMI device.
 217  * @data:       the data to be written to register 0 (7-bits).
 218  *
 219  * Writes data to register 0 of the Slave device.
 220  */
 221 int spmi_register_zero_write(struct spmi_device *sdev, u8 data)
 222 {
 223         return spmi_write_cmd(sdev->ctrl, SPMI_CMD_ZERO_WRITE, sdev->usid, 0,
 224                               &data, 1);
 225 }
 226 EXPORT_SYMBOL_GPL(spmi_register_zero_write);
 227
 228 /**
 229  * spmi_ext_register_write() - extended register write
 230  * @sdev:       SPMI device.
 231  * @addr:       slave register address (8-bit address).
 232  * @buf:        buffer containing the data to be transferred to the Slave.
 233  * @len:        the request number of bytes to read (up to 16 bytes).
 234  *
 235  * Writes up to 16 bytes of data to the extended register space of a
 236  * Slave device.
 237  */
 238 int spmi_ext_register_write(struct spmi_device *sdev, u8 addr, const u8 *buf,
 239                             size_t len)
 240 {
 241         /* 8-bit register address, up to 16 bytes */
 242         if (len == 0 || len > 16)
 243                 return -EINVAL;
 244
 245         return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITE, sdev->usid, addr,
 246                               buf, len);
 247 }
 248 EXPORT_SYMBOL_GPL(spmi_ext_register_write);
 249
 250 /**
 251  * spmi_ext_register_writel() - extended register write long
 252  * @sdev:       SPMI device.
 253  * @addr:       slave register address (16-bit address).
 254  * @buf:        buffer containing the data to be transferred to the Slave.
 255  * @len:        the request number of bytes to read (up to 8 bytes).
 256  *
 257  * Writes up to 8 bytes of data to the extended register space of a
 258  * Slave device using 16-bit address.
 259  */
 260 int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr, const u8 *buf,
 261                              size_t len)
 262 {
 263         /* 4-bit Slave Identifier, 16-bit register address, up to 8 bytes */
 264         if (len == 0 || len > 8)
 265                 return -EINVAL;
 266
 267         return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITEL, sdev->usid,
 268                               addr, buf, len);
 269 }
 270 EXPORT_SYMBOL_GPL(spmi_ext_register_writel);
 271
 272 /**
 273  * spmi_command_reset() - sends RESET command to the specified slave
 274  * @sdev:       SPMI device.
 275  *
 276  * The Reset command initializes the Slave and forces all registers to
 277  * their reset values. The Slave shall enter the STARTUP state after
 278  * receiving a Reset command.
 279  */
 280 int spmi_command_reset(struct spmi_device *sdev)
 281 {
 282         return spmi_cmd(sdev->ctrl, SPMI_CMD_RESET, sdev->usid);
 283 }
 284 EXPORT_SYMBOL_GPL(spmi_command_reset);
 285
 286 /**
 287  * spmi_command_sleep() - sends SLEEP command to the specified SPMI device
 288  * @sdev:       SPMI device.
 289  *
 290  * The Sleep command causes the Slave to enter the user defined SLEEP state.
 291  */
 292 int spmi_command_sleep(struct spmi_device *sdev)
 293 {
 294         return spmi_cmd(sdev->ctrl, SPMI_CMD_SLEEP, sdev->usid);
 295 }
 296 EXPORT_SYMBOL_GPL(spmi_command_sleep);
 297
 298 /**
 299  * spmi_command_wakeup() - sends WAKEUP command to the specified SPMI device
 300  * @sdev:       SPMI device.
 301  *
 302  * The Wakeup command causes the Slave to move from the SLEEP state to
 303  * the ACTIVE state.
 304  */
 305 int spmi_command_wakeup(struct spmi_device *sdev)
 306 {
 307         return spmi_cmd(sdev->ctrl, SPMI_CMD_WAKEUP, sdev->usid);
 308 }
 309 EXPORT_SYMBOL_GPL(spmi_command_wakeup);
 310
 311 /**
 312  * spmi_command_shutdown() - sends SHUTDOWN command to the specified SPMI device
 313  * @sdev:       SPMI device.
 314  *
 315  * The Shutdown command causes the Slave to enter the SHUTDOWN state.
 316  */
 317 int spmi_command_shutdown(struct spmi_device *sdev)
 318 {
 319         return spmi_cmd(sdev->ctrl, SPMI_CMD_SHUTDOWN, sdev->usid);
 320 }
 321 EXPORT_SYMBOL_GPL(spmi_command_shutdown);
 322
 323 static int spmi_drv_probe(struct device *dev)
 324 {
 325         const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
 326         struct spmi_device *sdev = to_spmi_device(dev);
 327         int err;
 328
 329         pm_runtime_get_noresume(dev);
 330         pm_runtime_set_active(dev);
 331         pm_runtime_enable(dev);
 332
 333         err = sdrv->probe(sdev);
 334         if (err)
 335                 goto fail_probe;
 336
 337         return 0;
 338
 339 fail_probe:
 340         pm_runtime_disable(dev);
 341         pm_runtime_set_suspended(dev);
 342         pm_runtime_put_noidle(dev);
 343         return err;
 344 }
 345
 346 static int spmi_drv_remove(struct device *dev)
 347 {
 348         const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
 349
 350         pm_runtime_get_sync(dev);
 351         sdrv->remove(to_spmi_device(dev));
 352         pm_runtime_put_noidle(dev);
 353
 354         pm_runtime_disable(dev);
 355         pm_runtime_set_suspended(dev);
 356         pm_runtime_put_noidle(dev);
 357         return 0;
 358 }
 359
 360 static int spmi_drv_uevent(struct device *dev, struct kobj_uevent_env *env)
 361 {
 362         int ret;
 363
 364         ret = of_device_uevent_modalias(dev, env);
 365         if (ret != -ENODEV)
 366                 return ret;
 367
 368         return 0;
 369 }
 370
 371 static struct bus_type spmi_bus_type = {
 372         .name           = "spmi",
 373         .match          = spmi_device_match,
 374         .probe          = spmi_drv_probe,
 375         .remove         = spmi_drv_remove,
 376         .uevent         = spmi_drv_uevent,
 377 };
 378
 379 /**
 380  * spmi_controller_alloc() - Allocate a new SPMI device
 381  * @ctrl:       associated controller
 382  *
 383  * Caller is responsible for either calling spmi_device_add() to add the
 384  * newly allocated controller, or calling spmi_device_put() to discard it.
 385  */
 386 struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl)
 387 {
 388         struct spmi_device *sdev;
 389
 390         sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
 391         if (!sdev)
 392                 return NULL;
 393
 394         sdev->ctrl = ctrl;
 395         device_initialize(&sdev->dev);
 396         sdev->dev.parent = &ctrl->dev;
 397         sdev->dev.bus = &spmi_bus_type;
 398         sdev->dev.type = &spmi_dev_type;
 399         return sdev;
 400 }
 401 EXPORT_SYMBOL_GPL(spmi_device_alloc);
 402
 403 /**
 404  * spmi_controller_alloc() - Allocate a new SPMI controller
 405  * @parent:     parent device
 406  * @size:       size of private data
 407  *
 408  * Caller is responsible for either calling spmi_controller_add() to add the
 409  * newly allocated controller, or calling spmi_controller_put() to discard it.
 410  * The allocated private data region may be accessed via
 411  * spmi_controller_get_drvdata()
 412  */
 413 struct spmi_controller *spmi_controller_alloc(struct device *parent,
 414                                               size_t size)
 415 {
 416         struct spmi_controller *ctrl;
 417         int id;
 418
 419         if (WARN_ON(!parent))
 420                 return NULL;
 421
 422         ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
 423         if (!ctrl)
 424                 return NULL;
 425
 426         device_initialize(&ctrl->dev);
 427         ctrl->dev.type = &spmi_ctrl_type;
 428         ctrl->dev.bus = &spmi_bus_type;
 429         ctrl->dev.parent = parent;
 430         ctrl->dev.of_node = parent->of_node;
 431         spmi_controller_set_drvdata(ctrl, &ctrl[1]);
 432
 433         id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
 434         if (id < 0) {
 435                 dev_err(parent,
 436                         "unable to allocate SPMI controller identifier.\n");
 437                 spmi_controller_put(ctrl);
 438                 return NULL;
 439         }
 440
 441         ctrl->nr = id;
 442         dev_set_name(&ctrl->dev, "spmi-%d", id);
 443
 444         dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
 445         return ctrl;
 446 }
 447 EXPORT_SYMBOL_GPL(spmi_controller_alloc);
 448
 449 static void of_spmi_register_devices(struct spmi_controller *ctrl)
 450 {
 451         struct device_node *node;
 452         int err;
 453
 454         if (!ctrl->dev.of_node)
 455                 return;
 456
 457         for_each_available_child_of_node(ctrl->dev.of_node, node) {
 458                 struct spmi_device *sdev;
 459                 u32 reg[2];
 460
 461                 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
 462
 463                 err = of_property_read_u32_array(node, "reg", reg, 2);
 464                 if (err) {
 465                         dev_err(&ctrl->dev,
 466                                 "node %pOF err (%d) does not have 'reg' property\n",
 467                                 node, err);
 468                         continue;
 469                 }
 470
 471                 if (reg[1] != SPMI_USID) {
 472                         dev_err(&ctrl->dev,
 473                                 "node %pOF contains unsupported 'reg' entry\n",
 474                                 node);
 475                         continue;
 476                 }
 477
 478                 if (reg[0] >= SPMI_MAX_SLAVE_ID) {
 479                         dev_err(&ctrl->dev, "invalid usid on node %pOF\n", node);
 480                         continue;
 481                 }
 482
 483                 dev_dbg(&ctrl->dev, "read usid %02x\n", reg[0]);
 484
 485                 sdev = spmi_device_alloc(ctrl);
 486                 if (!sdev)
 487                         continue;
 488
 489                 sdev->dev.of_node = node;
 490                 sdev->usid = (u8) reg[0];
 491
 492                 err = spmi_device_add(sdev);
 493                 if (err) {
 494                         dev_err(&sdev->dev,
 495                                 "failure adding device. status %d\n", err);
 496                         spmi_device_put(sdev);
 497                 }
 498         }
 499 }
 500
 501 /**
 502  * spmi_controller_add() - Add an SPMI controller
 503  * @ctrl:       controller to be registered.
 504  *
 505  * Register a controller previously allocated via spmi_controller_alloc() with
 506  * the SPMI core.
 507  */
 508 int spmi_controller_add(struct spmi_controller *ctrl)
 509 {
 510         int ret;
 511
 512         /* Can't register until after driver model init */
 513         if (WARN_ON(!is_registered))
 514                 return -EAGAIN;
 515
 516         ret = device_add(&ctrl->dev);
 517         if (ret)
 518                 return ret;
 519
 520         if (IS_ENABLED(CONFIG_OF))
 521                 of_spmi_register_devices(ctrl);
 522
 523         dev_dbg(&ctrl->dev, "spmi-%d registered: dev:%p\n",
 524                 ctrl->nr, &ctrl->dev);
 525
 526         return 0;
 527 };
 528 EXPORT_SYMBOL_GPL(spmi_controller_add);
 529
 530 /* Remove a device associated with a controller */
 531 static int spmi_ctrl_remove_device(struct device *dev, void *data)
 532 {
 533         struct spmi_device *spmidev = to_spmi_device(dev);
 534         if (dev->type == &spmi_dev_type)
 535                 spmi_device_remove(spmidev);
 536         return 0;
 537 }
 538
 539 /**
 540  * spmi_controller_remove(): remove an SPMI controller
 541  * @ctrl:       controller to remove
 542  *
 543  * Remove a SPMI controller.  Caller is responsible for calling
 544  * spmi_controller_put() to discard the allocated controller.
 545  */
 546 void spmi_controller_remove(struct spmi_controller *ctrl)
 547 {
 548         int dummy;
 549
 550         if (!ctrl)
 551                 return;
 552
 553         dummy = device_for_each_child(&ctrl->dev, NULL,
 554                                       spmi_ctrl_remove_device);
 555         device_del(&ctrl->dev);
 556 }
 557 EXPORT_SYMBOL_GPL(spmi_controller_remove);
 558
 559 /**
 560  * spmi_driver_register() - Register client driver with SPMI core
 561  * @sdrv:       client driver to be associated with client-device.
 562  *
 563  * This API will register the client driver with the SPMI framework.
 564  * It is typically called from the driver's module-init function.
 565  */
 566 int __spmi_driver_register(struct spmi_driver *sdrv, struct module *owner)
 567 {
 568         sdrv->driver.bus = &spmi_bus_type;
 569         sdrv->driver.owner = owner;
 570         return driver_register(&sdrv->driver);
 571 }
 572 EXPORT_SYMBOL_GPL(__spmi_driver_register);
 573
 574 static void __exit spmi_exit(void)
 575 {
 576         bus_unregister(&spmi_bus_type);
 577 }
 578 module_exit(spmi_exit);
 579
 580 static int __init spmi_init(void)
 581 {
 582         int ret;
 583
 584         ret = bus_register(&spmi_bus_type);
 585         if (ret)
 586                 return ret;
 587
 588         is_registered = true;
 589         return 0;
 590 }
 591 postcore_initcall(spmi_init);
 592
 593 MODULE_LICENSE("GPL v2");
 594 MODULE_DESCRIPTION("SPMI module");
 595 MODULE_ALIAS("platform:spmi");