drivers/staging/greybus/arche-platform.c

   1 /*
   2  * Arche Platform driver to enable Unipro link.
   3  *
   4  * Copyright 2014-2015 Google Inc.
   5  * Copyright 2014-2015 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/delay.h>
  12 #include <linux/gpio.h>
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/of_gpio.h>
  16 #include <linux/of_platform.h>
  17 #include <linux/pinctrl/consumer.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pm.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/suspend.h>
  23 #include <linux/time.h>
  24 #include "arche_platform.h"
  25 #include "greybus.h"
  26
  27 #include <linux/usb/usb3613.h>
  28
  29 #define WD_COLDBOOT_PULSE_WIDTH_MS      30
  30
  31 enum svc_wakedetect_state {
  32         WD_STATE_IDLE,                  /* Default state = pulled high/low */
  33         WD_STATE_BOOT_INIT,             /* WD = falling edge (low) */
  34         WD_STATE_COLDBOOT_TRIG,         /* WD = rising edge (high), > 30msec */
  35         WD_STATE_STANDBYBOOT_TRIG,      /* As of now not used ?? */
  36         WD_STATE_COLDBOOT_START,        /* Cold boot process started */
  37         WD_STATE_STANDBYBOOT_START,     /* Not used */
  38         WD_STATE_TIMESYNC,
  39 };
  40
  41 struct arche_platform_drvdata {
  42         /* Control GPIO signals to and from AP <=> SVC */
  43         int svc_reset_gpio;
  44         bool is_reset_act_hi;
  45         int svc_sysboot_gpio;
  46         int wake_detect_gpio; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
  47
  48         enum arche_platform_state state;
  49
  50         int svc_refclk_req;
  51         struct clk *svc_ref_clk;
  52
  53         struct pinctrl *pinctrl;
  54         struct pinctrl_state *pin_default;
  55
  56         int num_apbs;
  57
  58         enum svc_wakedetect_state wake_detect_state;
  59         int wake_detect_irq;
  60         spinlock_t wake_lock;                   /* Protect wake_detect_state */
  61         struct mutex platform_state_mutex;      /* Protect state */
  62         wait_queue_head_t wq;                   /* WQ for arche_pdata->state */
  63         unsigned long wake_detect_start;
  64         struct notifier_block pm_notifier;
  65
  66         struct device *dev;
  67         struct gb_timesync_svc *timesync_svc_pdata;
  68 };
  69
  70 static int arche_apb_bootret_assert(struct device *dev, void *data)
  71 {
  72         apb_bootret_assert(dev);
  73         return 0;
  74 }
  75
  76 static int arche_apb_bootret_deassert(struct device *dev, void *data)
  77 {
  78         apb_bootret_deassert(dev);
  79         return 0;
  80 }
  81
  82 /* Requires calling context to hold arche_pdata->platform_state_mutex */
  83 static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata,
  84                                      enum arche_platform_state state)
  85 {
  86         arche_pdata->state = state;
  87 }
  88
  89 /*
  90  * arche_platform_change_state: Change the operational state
  91  *
  92  * This exported function allows external drivers to change the state
  93  * of the arche-platform driver.
  94  * Note that this function only supports transitions between two states
  95  * with limited functionality.
  96  *
  97  *  - ARCHE_PLATFORM_STATE_TIME_SYNC:
  98  *    Once set, allows timesync operations between SVC <=> AP and makes
  99  *    sure that arche-platform driver ignores any subsequent events/pulses
 100  *    from SVC over wake/detect.
 101  *
 102  *  - ARCHE_PLATFORM_STATE_ACTIVE:
 103  *    Puts back driver to active state, where any pulse from SVC on wake/detect
 104  *    line would trigger either cold/standby boot.
 105  *    Note: Transition request from this function does not trigger cold/standby
 106  *          boot. It just puts back driver book keeping variable back to ACTIVE
 107  *          state and restores the interrupt.
 108  *
 109  * Returns -ENODEV if device not found, -EAGAIN if the driver cannot currently
 110  * satisfy the requested state-transition or -EINVAL for all other
 111  * state-transition requests.
 112  */
 113 int arche_platform_change_state(enum arche_platform_state state,
 114                                 struct gb_timesync_svc *timesync_svc_pdata)
 115 {
 116         struct arche_platform_drvdata *arche_pdata;
 117         struct platform_device *pdev;
 118         struct device_node *np;
 119         int ret = -EAGAIN;
 120         unsigned long flags;
 121
 122         np = of_find_compatible_node(NULL, NULL, "google,arche-platform");
 123         if (!np) {
 124                 pr_err("google,arche-platform device node not found\n");
 125                 return -ENODEV;
 126         }
 127
 128         pdev = of_find_device_by_node(np);
 129         if (!pdev) {
 130                 pr_err("arche-platform device not found\n");
 131                 of_node_put(np);
 132                 return -ENODEV;
 133         }
 134
 135         arche_pdata = platform_get_drvdata(pdev);
 136
 137         mutex_lock(&arche_pdata->platform_state_mutex);
 138         spin_lock_irqsave(&arche_pdata->wake_lock, flags);
 139
 140         if (arche_pdata->state == state) {
 141                 ret = 0;
 142                 goto exit;
 143         }
 144
 145         switch (state) {
 146         case ARCHE_PLATFORM_STATE_TIME_SYNC:
 147                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) {
 148                         ret = -EINVAL;
 149                         goto exit;
 150                 }
 151                 if (arche_pdata->wake_detect_state != WD_STATE_IDLE) {
 152                         dev_err(arche_pdata->dev,
 153                                 "driver busy with wake/detect line ops\n");
 154                         goto  exit;
 155                 }
 156                 device_for_each_child(arche_pdata->dev, NULL,
 157                                       arche_apb_bootret_assert);
 158                 arche_pdata->wake_detect_state = WD_STATE_TIMESYNC;
 159                 break;
 160         case ARCHE_PLATFORM_STATE_ACTIVE:
 161                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_TIME_SYNC) {
 162                         ret = -EINVAL;
 163                         goto exit;
 164                 }
 165                 device_for_each_child(arche_pdata->dev, NULL,
 166                                       arche_apb_bootret_deassert);
 167                 arche_pdata->wake_detect_state = WD_STATE_IDLE;
 168                 break;
 169         case ARCHE_PLATFORM_STATE_OFF:
 170         case ARCHE_PLATFORM_STATE_STANDBY:
 171         case ARCHE_PLATFORM_STATE_FW_FLASHING:
 172                 dev_err(arche_pdata->dev, "busy, request to retry later\n");
 173                 goto exit;
 174         default:
 175                 ret = -EINVAL;
 176                 dev_err(arche_pdata->dev,
 177                         "invalid state transition request\n");
 178                 goto exit;
 179         }
 180         arche_pdata->timesync_svc_pdata = timesync_svc_pdata;
 181         arche_platform_set_state(arche_pdata, state);
 182         if (state == ARCHE_PLATFORM_STATE_ACTIVE)
 183                 wake_up(&arche_pdata->wq);
 184
 185         ret = 0;
 186 exit:
 187         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 188         mutex_unlock(&arche_pdata->platform_state_mutex);
 189         of_node_put(np);
 190         return ret;
 191 }
 192 EXPORT_SYMBOL_GPL(arche_platform_change_state);
 193
 194 /* Requires arche_pdata->wake_lock is held by calling context */
 195 static void arche_platform_set_wake_detect_state(
 196                                 struct arche_platform_drvdata *arche_pdata,
 197                                 enum svc_wakedetect_state state)
 198 {
 199         arche_pdata->wake_detect_state = state;
 200 }
 201
 202 static inline void svc_reset_onoff(unsigned int gpio, bool onoff)
 203 {
 204         gpio_set_value(gpio, onoff);
 205 }
 206
 207 static int apb_cold_boot(struct device *dev, void *data)
 208 {
 209         int ret;
 210
 211         ret = apb_ctrl_coldboot(dev);
 212         if (ret)
 213                 dev_warn(dev, "failed to coldboot\n");
 214
 215         /*Child nodes are independent, so do not exit coldboot operation */
 216         return 0;
 217 }
 218
 219 static int apb_poweroff(struct device *dev, void *data)
 220 {
 221         apb_ctrl_poweroff(dev);
 222
 223         /* Enable HUB3613 into HUB mode. */
 224         if (usb3613_hub_mode_ctrl(false))
 225                 dev_warn(dev, "failed to control hub device\n");
 226
 227         return 0;
 228 }
 229
 230 static void arche_platform_wd_irq_en(struct arche_platform_drvdata *arche_pdata)
 231 {
 232         /* Enable interrupt here, to read event back from SVC */
 233         gpio_direction_input(arche_pdata->wake_detect_gpio);
 234         enable_irq(arche_pdata->wake_detect_irq);
 235 }
 236
 237 static irqreturn_t arche_platform_wd_irq_thread(int irq, void *devid)
 238 {
 239         struct arche_platform_drvdata *arche_pdata = devid;
 240         unsigned long flags;
 241
 242         spin_lock_irqsave(&arche_pdata->wake_lock, flags);
 243         if (arche_pdata->wake_detect_state != WD_STATE_COLDBOOT_TRIG) {
 244                 /* Something is wrong */
 245                 spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 246                 return IRQ_HANDLED;
 247         }
 248
 249         arche_platform_set_wake_detect_state(arche_pdata,
 250                                              WD_STATE_COLDBOOT_START);
 251         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 252
 253         /* It should complete power cycle, so first make sure it is poweroff */
 254         device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
 255
 256         /* Bring APB out of reset: cold boot sequence */
 257         device_for_each_child(arche_pdata->dev, NULL, apb_cold_boot);
 258
 259         /* Enable HUB3613 into HUB mode. */
 260         if (usb3613_hub_mode_ctrl(true))
 261                 dev_warn(arche_pdata->dev, "failed to control hub device\n");
 262
 263         spin_lock_irqsave(&arche_pdata->wake_lock, flags);
 264         arche_platform_set_wake_detect_state(arche_pdata, WD_STATE_IDLE);
 265         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 266
 267         return IRQ_HANDLED;
 268 }
 269
 270 static irqreturn_t arche_platform_wd_irq(int irq, void *devid)
 271 {
 272         struct arche_platform_drvdata *arche_pdata = devid;
 273         unsigned long flags;
 274
 275         spin_lock_irqsave(&arche_pdata->wake_lock, flags);
 276
 277         if (arche_pdata->wake_detect_state == WD_STATE_TIMESYNC) {
 278                 gb_timesync_irq(arche_pdata->timesync_svc_pdata);
 279                 goto exit;
 280         }
 281
 282         if (gpio_get_value(arche_pdata->wake_detect_gpio)) {
 283                 /* wake/detect rising */
 284
 285                 /*
 286                  * If wake/detect line goes high after low, within less than
 287                  * 30msec, then standby boot sequence is initiated, which is not
 288                  * supported/implemented as of now. So ignore it.
 289                  */
 290                 if (arche_pdata->wake_detect_state == WD_STATE_BOOT_INIT) {
 291                         if (time_before(jiffies,
 292                                         arche_pdata->wake_detect_start +
 293                                         msecs_to_jiffies(WD_COLDBOOT_PULSE_WIDTH_MS))) {
 294                                 arche_platform_set_wake_detect_state(arche_pdata,
 295                                                                      WD_STATE_IDLE);
 296                         } else {
 297                                 /* Check we are not in middle of irq thread already */
 298                                 if (arche_pdata->wake_detect_state !=
 299                                                 WD_STATE_COLDBOOT_START) {
 300                                         arche_platform_set_wake_detect_state(arche_pdata,
 301                                                                              WD_STATE_COLDBOOT_TRIG);
 302                                         spin_unlock_irqrestore(
 303                                                 &arche_pdata->wake_lock,
 304                                                 flags);
 305                                         return IRQ_WAKE_THREAD;
 306                                 }
 307                         }
 308                 }
 309         } else {
 310                 /* wake/detect falling */
 311                 if (arche_pdata->wake_detect_state == WD_STATE_IDLE) {
 312                         arche_pdata->wake_detect_start = jiffies;
 313                         /*
 314                          * In the begining, when wake/detect goes low (first time), we assume
 315                          * it is meant for coldboot and set the flag. If wake/detect line stays low
 316                          * beyond 30msec, then it is coldboot else fallback to standby boot.
 317                          */
 318                         arche_platform_set_wake_detect_state(arche_pdata,
 319                                                              WD_STATE_BOOT_INIT);
 320                 }
 321         }
 322
 323 exit:
 324         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 325
 326         return IRQ_HANDLED;
 327 }
 328
 329 /*
 330  * Requires arche_pdata->platform_state_mutex to be held
 331  */
 332 static int arche_platform_coldboot_seq(struct arche_platform_drvdata *arche_pdata)
 333 {
 334         int ret;
 335
 336         if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
 337                 return 0;
 338
 339         dev_info(arche_pdata->dev, "Booting from cold boot state\n");
 340
 341         svc_reset_onoff(arche_pdata->svc_reset_gpio,
 342                         arche_pdata->is_reset_act_hi);
 343
 344         gpio_set_value(arche_pdata->svc_sysboot_gpio, 0);
 345         usleep_range(100, 200);
 346
 347         ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
 348         if (ret) {
 349                 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
 350                                 ret);
 351                 return ret;
 352         }
 353
 354         /* bring SVC out of reset */
 355         svc_reset_onoff(arche_pdata->svc_reset_gpio,
 356                         !arche_pdata->is_reset_act_hi);
 357
 358         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_ACTIVE);
 359
 360         return 0;
 361 }
 362
 363 /*
 364  * Requires arche_pdata->platform_state_mutex to be held
 365  */
 366 static int arche_platform_fw_flashing_seq(struct arche_platform_drvdata *arche_pdata)
 367 {
 368         int ret;
 369
 370         if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
 371                 return 0;
 372
 373         dev_info(arche_pdata->dev, "Switching to FW flashing state\n");
 374
 375         svc_reset_onoff(arche_pdata->svc_reset_gpio,
 376                         arche_pdata->is_reset_act_hi);
 377
 378         gpio_set_value(arche_pdata->svc_sysboot_gpio, 1);
 379
 380         usleep_range(100, 200);
 381
 382         ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
 383         if (ret) {
 384                 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
 385                                 ret);
 386                 return ret;
 387         }
 388
 389         svc_reset_onoff(arche_pdata->svc_reset_gpio,
 390                         !arche_pdata->is_reset_act_hi);
 391
 392         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_FW_FLASHING);
 393
 394         return 0;
 395 }
 396
 397 /*
 398  * Requires arche_pdata->platform_state_mutex to be held
 399  */
 400 static void arche_platform_poweroff_seq(struct arche_platform_drvdata *arche_pdata)
 401 {
 402         unsigned long flags;
 403
 404         if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
 405                 return;
 406
 407         /* If in fw_flashing mode, then no need to repeate things again */
 408         if (arche_pdata->state != ARCHE_PLATFORM_STATE_FW_FLASHING) {
 409                 disable_irq(arche_pdata->wake_detect_irq);
 410
 411                 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
 412                 arche_platform_set_wake_detect_state(arche_pdata,
 413                                                      WD_STATE_IDLE);
 414                 spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
 415         }
 416
 417         clk_disable_unprepare(arche_pdata->svc_ref_clk);
 418
 419         /* As part of exit, put APB back in reset state */
 420         svc_reset_onoff(arche_pdata->svc_reset_gpio,
 421                         arche_pdata->is_reset_act_hi);
 422
 423         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
 424 }
 425
 426 static ssize_t state_store(struct device *dev,
 427                 struct device_attribute *attr, const char *buf, size_t count)
 428 {
 429         struct platform_device *pdev = to_platform_device(dev);
 430         struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
 431         int ret = 0;
 432
 433 retry:
 434         mutex_lock(&arche_pdata->platform_state_mutex);
 435         if (arche_pdata->state == ARCHE_PLATFORM_STATE_TIME_SYNC) {
 436                 mutex_unlock(&arche_pdata->platform_state_mutex);
 437                 ret = wait_event_interruptible(
 438                         arche_pdata->wq,
 439                         arche_pdata->state != ARCHE_PLATFORM_STATE_TIME_SYNC);
 440                 if (ret)
 441                         return ret;
 442                 goto retry;
 443         }
 444
 445         if (sysfs_streq(buf, "off")) {
 446                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
 447                         goto exit;
 448
 449                 /*  If SVC goes down, bring down APB's as well */
 450                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
 451
 452                 arche_platform_poweroff_seq(arche_pdata);
 453
 454         } else if (sysfs_streq(buf, "active")) {
 455                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
 456                         goto exit;
 457
 458                 /* First we want to make sure we power off everything
 459                  * and then activate back again */
 460                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
 461                 arche_platform_poweroff_seq(arche_pdata);
 462
 463                 arche_platform_wd_irq_en(arche_pdata);
 464                 ret = arche_platform_coldboot_seq(arche_pdata);
 465                 if (ret)
 466                         goto exit;
 467
 468         } else if (sysfs_streq(buf, "standby")) {
 469                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_STANDBY)
 470                         goto exit;
 471
 472                 dev_warn(arche_pdata->dev, "standby state not supported\n");
 473         } else if (sysfs_streq(buf, "fw_flashing")) {
 474                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
 475                         goto exit;
 476
 477                 /*
 478                  * Here we only control SVC.
 479                  *
 480                  * In case of FW_FLASHING mode we do not want to control
 481                  * APBs, as in case of V2, SPI bus is shared between both
 482                  * the APBs. So let user chose which APB he wants to flash.
 483                  */
 484                 arche_platform_poweroff_seq(arche_pdata);
 485
 486                 ret = arche_platform_fw_flashing_seq(arche_pdata);
 487                 if (ret)
 488                         goto exit;
 489         } else {
 490                 dev_err(arche_pdata->dev, "unknown state\n");
 491                 ret = -EINVAL;
 492         }
 493
 494 exit:
 495         mutex_unlock(&arche_pdata->platform_state_mutex);
 496         return ret ? ret : count;
 497 }
 498
 499 static ssize_t state_show(struct device *dev,
 500                 struct device_attribute *attr, char *buf)
 501 {
 502         struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
 503
 504         switch (arche_pdata->state) {
 505         case ARCHE_PLATFORM_STATE_OFF:
 506                 return sprintf(buf, "off\n");
 507         case ARCHE_PLATFORM_STATE_ACTIVE:
 508                 return sprintf(buf, "active\n");
 509         case ARCHE_PLATFORM_STATE_STANDBY:
 510                 return sprintf(buf, "standby\n");
 511         case ARCHE_PLATFORM_STATE_FW_FLASHING:
 512                 return sprintf(buf, "fw_flashing\n");
 513         case ARCHE_PLATFORM_STATE_TIME_SYNC:
 514                 return sprintf(buf, "time_sync\n");
 515         default:
 516                 return sprintf(buf, "unknown state\n");
 517         }
 518 }
 519
 520 static DEVICE_ATTR_RW(state);
 521
 522 static int arche_platform_pm_notifier(struct notifier_block *notifier,
 523                                       unsigned long pm_event, void *unused)
 524 {
 525         struct arche_platform_drvdata *arche_pdata =
 526                 container_of(notifier, struct arche_platform_drvdata,
 527                              pm_notifier);
 528         int ret = NOTIFY_DONE;
 529
 530         mutex_lock(&arche_pdata->platform_state_mutex);
 531         switch (pm_event) {
 532         case PM_SUSPEND_PREPARE:
 533                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) {
 534                         ret = NOTIFY_STOP;
 535                         break;
 536                 }
 537                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
 538                 arche_platform_poweroff_seq(arche_pdata);
 539                 break;
 540         case PM_POST_SUSPEND:
 541                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_OFF)
 542                         break;
 543
 544                 arche_platform_wd_irq_en(arche_pdata);
 545                 arche_platform_coldboot_seq(arche_pdata);
 546                 break;
 547         default:
 548                 break;
 549         }
 550         mutex_unlock(&arche_pdata->platform_state_mutex);
 551
 552         return ret;
 553 }
 554
 555 static int arche_platform_probe(struct platform_device *pdev)
 556 {
 557         struct arche_platform_drvdata *arche_pdata;
 558         struct device *dev = &pdev->dev;
 559         struct device_node *np = dev->of_node;
 560         int ret;
 561
 562         arche_pdata = devm_kzalloc(&pdev->dev, sizeof(*arche_pdata), GFP_KERNEL);
 563         if (!arche_pdata)
 564                 return -ENOMEM;
 565
 566         /* setup svc reset gpio */
 567         arche_pdata->is_reset_act_hi = of_property_read_bool(np,
 568                                         "svc,reset-active-high");
 569         arche_pdata->svc_reset_gpio = of_get_named_gpio(np, "svc,reset-gpio", 0);
 570         if (arche_pdata->svc_reset_gpio < 0) {
 571                 dev_err(dev, "failed to get reset-gpio\n");
 572                 return arche_pdata->svc_reset_gpio;
 573         }
 574         ret = devm_gpio_request(dev, arche_pdata->svc_reset_gpio, "svc-reset");
 575         if (ret) {
 576                 dev_err(dev, "failed to request svc-reset gpio:%d\n", ret);
 577                 return ret;
 578         }
 579         ret = gpio_direction_output(arche_pdata->svc_reset_gpio,
 580                                         arche_pdata->is_reset_act_hi);
 581         if (ret) {
 582                 dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
 583                 return ret;
 584         }
 585         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
 586
 587         arche_pdata->svc_sysboot_gpio = of_get_named_gpio(np,
 588                                         "svc,sysboot-gpio", 0);
 589         if (arche_pdata->svc_sysboot_gpio < 0) {
 590                 dev_err(dev, "failed to get sysboot gpio\n");
 591                 return arche_pdata->svc_sysboot_gpio;
 592         }
 593         ret = devm_gpio_request(dev, arche_pdata->svc_sysboot_gpio, "sysboot0");
 594         if (ret) {
 595                 dev_err(dev, "failed to request sysboot0 gpio:%d\n", ret);
 596                 return ret;
 597         }
 598         ret = gpio_direction_output(arche_pdata->svc_sysboot_gpio, 0);
 599         if (ret) {
 600                 dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
 601                 return ret;
 602         }
 603
 604         /* setup the clock request gpio first */
 605         arche_pdata->svc_refclk_req = of_get_named_gpio(np,
 606                                         "svc,refclk-req-gpio", 0);
 607         if (arche_pdata->svc_refclk_req < 0) {
 608                 dev_err(dev, "failed to get svc clock-req gpio\n");
 609                 return arche_pdata->svc_refclk_req;
 610         }
 611         ret = devm_gpio_request(dev, arche_pdata->svc_refclk_req, "svc-clk-req");
 612         if (ret) {
 613                 dev_err(dev, "failed to request svc-clk-req gpio: %d\n", ret);
 614                 return ret;
 615         }
 616         ret = gpio_direction_input(arche_pdata->svc_refclk_req);
 617         if (ret) {
 618                 dev_err(dev, "failed to set svc-clk-req gpio dir :%d\n", ret);
 619                 return ret;
 620         }
 621
 622         /* setup refclk2 to follow the pin */
 623         arche_pdata->svc_ref_clk = devm_clk_get(dev, "svc_ref_clk");
 624         if (IS_ERR(arche_pdata->svc_ref_clk)) {
 625                 ret = PTR_ERR(arche_pdata->svc_ref_clk);
 626                 dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
 627                 return ret;
 628         }
 629
 630         platform_set_drvdata(pdev, arche_pdata);
 631
 632         arche_pdata->num_apbs = of_get_child_count(np);
 633         dev_dbg(dev, "Number of APB's available - %d\n", arche_pdata->num_apbs);
 634
 635         arche_pdata->wake_detect_gpio = of_get_named_gpio(np, "svc,wake-detect-gpio", 0);
 636         if (arche_pdata->wake_detect_gpio < 0) {
 637                 dev_err(dev, "failed to get wake detect gpio\n");
 638                 return arche_pdata->wake_detect_gpio;
 639         }
 640
 641         ret = devm_gpio_request(dev, arche_pdata->wake_detect_gpio, "wake detect");
 642         if (ret) {
 643                 dev_err(dev, "Failed requesting wake_detect gpio %d\n",
 644                                 arche_pdata->wake_detect_gpio);
 645                 return ret;
 646         }
 647
 648         arche_platform_set_wake_detect_state(arche_pdata, WD_STATE_IDLE);
 649
 650         arche_pdata->dev = &pdev->dev;
 651
 652         spin_lock_init(&arche_pdata->wake_lock);
 653         mutex_init(&arche_pdata->platform_state_mutex);
 654         init_waitqueue_head(&arche_pdata->wq);
 655         arche_pdata->wake_detect_irq =
 656                 gpio_to_irq(arche_pdata->wake_detect_gpio);
 657
 658         ret = devm_request_threaded_irq(dev, arche_pdata->wake_detect_irq,
 659                         arche_platform_wd_irq,
 660                         arche_platform_wd_irq_thread,
 661                         IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 662                         dev_name(dev), arche_pdata);
 663         if (ret) {
 664                 dev_err(dev, "failed to request wake detect IRQ %d\n", ret);
 665                 return ret;
 666         }
 667         disable_irq(arche_pdata->wake_detect_irq);
 668
 669         ret = device_create_file(dev, &dev_attr_state);
 670         if (ret) {
 671                 dev_err(dev, "failed to create state file in sysfs\n");
 672                 return ret;
 673         }
 674
 675         ret = of_platform_populate(np, NULL, NULL, dev);
 676         if (ret) {
 677                 dev_err(dev, "failed to populate child nodes %d\n", ret);
 678                 goto err_device_remove;
 679         }
 680
 681         arche_pdata->pm_notifier.notifier_call = arche_platform_pm_notifier;
 682         ret = register_pm_notifier(&arche_pdata->pm_notifier);
 683
 684         if (ret) {
 685                 dev_err(dev, "failed to register pm notifier %d\n", ret);
 686                 goto err_device_remove;
 687         }
 688
 689         /* Register callback pointer */
 690         arche_platform_change_state_cb = arche_platform_change_state;
 691
 692         /* Explicitly power off if requested */
 693         if (!of_property_read_bool(pdev->dev.of_node, "arche,init-off")) {
 694                 mutex_lock(&arche_pdata->platform_state_mutex);
 695                 ret = arche_platform_coldboot_seq(arche_pdata);
 696                 if (ret) {
 697                         dev_err(dev, "Failed to cold boot svc %d\n", ret);
 698                         goto err_coldboot;
 699                 }
 700                 arche_platform_wd_irq_en(arche_pdata);
 701                 mutex_unlock(&arche_pdata->platform_state_mutex);
 702         }
 703
 704         dev_info(dev, "Device registered successfully\n");
 705         return 0;
 706
 707 err_coldboot:
 708         mutex_unlock(&arche_pdata->platform_state_mutex);
 709 err_device_remove:
 710         device_remove_file(&pdev->dev, &dev_attr_state);
 711         return ret;
 712 }
 713
 714 static int arche_remove_child(struct device *dev, void *unused)
 715 {
 716         struct platform_device *pdev = to_platform_device(dev);
 717
 718         platform_device_unregister(pdev);
 719
 720         return 0;
 721 }
 722
 723 static int arche_platform_remove(struct platform_device *pdev)
 724 {
 725         struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
 726
 727         unregister_pm_notifier(&arche_pdata->pm_notifier);
 728         device_remove_file(&pdev->dev, &dev_attr_state);
 729         device_for_each_child(&pdev->dev, NULL, arche_remove_child);
 730         arche_platform_poweroff_seq(arche_pdata);
 731         platform_set_drvdata(pdev, NULL);
 732
 733         if (usb3613_hub_mode_ctrl(false))
 734                 dev_warn(arche_pdata->dev, "failed to control hub device\n");
 735                 /* TODO: Should we do anything more here ?? */
 736         return 0;
 737 }
 738
 739 static int arche_platform_suspend(struct device *dev)
 740 {
 741         /*
 742          * If timing profile premits, we may shutdown bridge
 743          * completely
 744          *
 745          * TODO: sequence ??
 746          *
 747          * Also, need to make sure we meet precondition for unipro suspend
 748          * Precondition: Definition ???
 749          */
 750         return 0;
 751 }
 752
 753 static int arche_platform_resume(struct device *dev)
 754 {
 755         /*
 756          * Atleast for ES2 we have to meet the delay requirement between
 757          * unipro switch and AP bridge init, depending on whether bridge is in
 758          * OFF state or standby state.
 759          *
 760          * Based on whether bridge is in standby or OFF state we may have to
 761          * assert multiple signals. Please refer to WDM spec, for more info.
 762          *
 763          */
 764         return 0;
 765 }
 766
 767 static void arche_platform_shutdown(struct platform_device *pdev)
 768 {
 769         struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
 770
 771         arche_platform_poweroff_seq(arche_pdata);
 772
 773         usb3613_hub_mode_ctrl(false);
 774 }
 775
 776 static SIMPLE_DEV_PM_OPS(arche_platform_pm_ops,
 777                         arche_platform_suspend,
 778                         arche_platform_resume);
 779
 780 static const struct of_device_id arche_platform_of_match[] = {
 781         { .compatible = "google,arche-platform", }, /* Use PID/VID of SVC device */
 782         { },
 783 };
 784
 785 static const struct of_device_id arche_combined_id[] = {
 786         { .compatible = "google,arche-platform", }, /* Use PID/VID of SVC device */
 787         { .compatible = "usbffff,2", },
 788         { },
 789 };
 790 MODULE_DEVICE_TABLE(of, arche_combined_id);
 791
 792 static struct platform_driver arche_platform_device_driver = {
 793         .probe          = arche_platform_probe,
 794         .remove         = arche_platform_remove,
 795         .shutdown       = arche_platform_shutdown,
 796         .driver         = {
 797                 .name   = "arche-platform-ctrl",
 798                 .pm     = &arche_platform_pm_ops,
 799                 .of_match_table = arche_platform_of_match,
 800         }
 801 };
 802
 803 static int __init arche_init(void)
 804 {
 805         int retval;
 806
 807         retval = platform_driver_register(&arche_platform_device_driver);
 808         if (retval)
 809                 return retval;
 810
 811         retval = arche_apb_init();
 812         if (retval)
 813                 platform_driver_unregister(&arche_platform_device_driver);
 814
 815         return retval;
 816 }
 817 module_init(arche_init);
 818
 819 static void __exit arche_exit(void)
 820 {
 821         arche_apb_exit();
 822         platform_driver_unregister(&arche_platform_device_driver);
 823 }
 824 module_exit(arche_exit);
 825
 826 MODULE_LICENSE("GPL v2");
 827 MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
 828 MODULE_DESCRIPTION("Arche Platform Driver");