drivers/spmi/spmi.c

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