drivers/power/isp1704_charger.c

   1 /*
   2  * ISP1704 USB Charger Detection driver
   3  *
   4  * Copyright (C) 2010 Nokia Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/err.h>
  24 #include <linux/init.h>
  25 #include <linux/types.h>
  26 #include <linux/device.h>
  27 #include <linux/sysfs.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/power_supply.h>
  30 #include <linux/delay.h>
  31
  32 #include <linux/usb/otg.h>
  33 #include <linux/usb/ulpi.h>
  34 #include <linux/usb/ch9.h>
  35 #include <linux/usb/gadget.h>
  36 #include <linux/power/isp1704_charger.h>
  37
  38 /* Vendor specific Power Control register */
  39 #define ISP1704_PWR_CTRL                0x3d
  40 #define ISP1704_PWR_CTRL_SWCTRL         (1 << 0)
  41 #define ISP1704_PWR_CTRL_DET_COMP       (1 << 1)
  42 #define ISP1704_PWR_CTRL_BVALID_RISE    (1 << 2)
  43 #define ISP1704_PWR_CTRL_BVALID_FALL    (1 << 3)
  44 #define ISP1704_PWR_CTRL_DP_WKPU_EN     (1 << 4)
  45 #define ISP1704_PWR_CTRL_VDAT_DET       (1 << 5)
  46 #define ISP1704_PWR_CTRL_DPVSRC_EN      (1 << 6)
  47 #define ISP1704_PWR_CTRL_HWDETECT       (1 << 7)
  48
  49 #define NXP_VENDOR_ID                   0x04cc
  50
  51 static u16 isp170x_id[] = {
  52         0x1704,
  53         0x1707,
  54 };
  55
  56 struct isp1704_charger {
  57         struct device           *dev;
  58         struct power_supply     psy;
  59         struct otg_transceiver  *otg;
  60         struct notifier_block   nb;
  61         struct work_struct      work;
  62
  63         /* properties */
  64         char                    model[8];
  65         unsigned                present:1;
  66         unsigned                online:1;
  67         unsigned                current_max;
  68
  69         /* temp storage variables */
  70         unsigned long           event;
  71         unsigned                max_power;
  72 };
  73
  74 /*
  75  * Disable/enable the power from the isp1704 if a function for it
  76  * has been provided with platform data.
  77  */
  78 static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
  79 {
  80         struct isp1704_charger_data     *board = isp->dev->platform_data;
  81
  82         if (board && board->set_power)
  83                 board->set_power(on);
  84 }
  85
  86 /*
  87  * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
  88  * chargers).
  89  *
  90  * REVISIT: The method is defined in Battery Charging Specification and is
  91  * applicable to any ULPI transceiver. Nothing isp170x specific here.
  92  */
  93 static inline int isp1704_charger_type(struct isp1704_charger *isp)
  94 {
  95         u8 reg;
  96         u8 func_ctrl;
  97         u8 otg_ctrl;
  98         int type = POWER_SUPPLY_TYPE_USB_DCP;
  99
 100         func_ctrl = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
 101         otg_ctrl = otg_io_read(isp->otg, ULPI_OTG_CTRL);
 102
 103         /* disable pulldowns */
 104         reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
 105         otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), reg);
 106
 107         /* full speed */
 108         otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 109                         ULPI_FUNC_CTRL_XCVRSEL_MASK);
 110         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL),
 111                         ULPI_FUNC_CTRL_FULL_SPEED);
 112
 113         /* Enable strong pull-up on DP (1.5K) and reset */
 114         reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 115         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), reg);
 116         usleep_range(1000, 2000);
 117
 118         reg = otg_io_read(isp->otg, ULPI_DEBUG);
 119         if ((reg & 3) != 3)
 120                 type = POWER_SUPPLY_TYPE_USB_CDP;
 121
 122         /* recover original state */
 123         otg_io_write(isp->otg, ULPI_FUNC_CTRL, func_ctrl);
 124         otg_io_write(isp->otg, ULPI_OTG_CTRL, otg_ctrl);
 125
 126         return type;
 127 }
 128
 129 /*
 130  * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
 131  * is actually a dedicated charger, the following steps need to be taken.
 132  */
 133 static inline int isp1704_charger_verify(struct isp1704_charger *isp)
 134 {
 135         int     ret = 0;
 136         u8      r;
 137
 138         /* Reset the transceiver */
 139         r = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
 140         r |= ULPI_FUNC_CTRL_RESET;
 141         otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
 142         usleep_range(1000, 2000);
 143
 144         /* Set normal mode */
 145         r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
 146         otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
 147
 148         /* Clear the DP and DM pull-down bits */
 149         r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
 150         otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), r);
 151
 152         /* Enable strong pull-up on DP (1.5K) and reset */
 153         r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 154         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), r);
 155         usleep_range(1000, 2000);
 156
 157         /* Read the line state */
 158         if (!otg_io_read(isp->otg, ULPI_DEBUG)) {
 159                 /* Disable strong pull-up on DP (1.5K) */
 160                 otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 161                                 ULPI_FUNC_CTRL_TERMSELECT);
 162                 return 1;
 163         }
 164
 165         /* Is it a charger or PS/2 connection */
 166
 167         /* Enable weak pull-up resistor on DP */
 168         otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
 169                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 170
 171         /* Disable strong pull-up on DP (1.5K) */
 172         otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 173                         ULPI_FUNC_CTRL_TERMSELECT);
 174
 175         /* Enable weak pull-down resistor on DM */
 176         otg_io_write(isp->otg, ULPI_SET(ULPI_OTG_CTRL),
 177                         ULPI_OTG_CTRL_DM_PULLDOWN);
 178
 179         /* It's a charger if the line states are clear */
 180         if (!(otg_io_read(isp->otg, ULPI_DEBUG)))
 181                 ret = 1;
 182
 183         /* Disable weak pull-up resistor on DP */
 184         otg_io_write(isp->otg, ULPI_CLR(ISP1704_PWR_CTRL),
 185                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 186
 187         return ret;
 188 }
 189
 190 static inline int isp1704_charger_detect(struct isp1704_charger *isp)
 191 {
 192         unsigned long   timeout;
 193         u8              pwr_ctrl;
 194         int             ret = 0;
 195
 196         pwr_ctrl = otg_io_read(isp->otg, ISP1704_PWR_CTRL);
 197
 198         /* set SW control bit in PWR_CTRL register */
 199         otg_io_write(isp->otg, ISP1704_PWR_CTRL,
 200                         ISP1704_PWR_CTRL_SWCTRL);
 201
 202         /* enable manual charger detection */
 203         otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
 204                         ISP1704_PWR_CTRL_SWCTRL
 205                         | ISP1704_PWR_CTRL_DPVSRC_EN);
 206         usleep_range(1000, 2000);
 207
 208         timeout = jiffies + msecs_to_jiffies(300);
 209         do {
 210                 /* Check if there is a charger */
 211                 if (otg_io_read(isp->otg, ISP1704_PWR_CTRL)
 212                                 & ISP1704_PWR_CTRL_VDAT_DET) {
 213                         ret = isp1704_charger_verify(isp);
 214                         break;
 215                 }
 216         } while (!time_after(jiffies, timeout) && isp->online);
 217
 218         /* recover original state */
 219         otg_io_write(isp->otg, ISP1704_PWR_CTRL, pwr_ctrl);
 220
 221         return ret;
 222 }
 223
 224 static void isp1704_charger_work(struct work_struct *data)
 225 {
 226         int                     detect;
 227         unsigned long           event;
 228         unsigned                power;
 229         struct isp1704_charger  *isp =
 230                 container_of(data, struct isp1704_charger, work);
 231         static DEFINE_MUTEX(lock);
 232
 233         event = isp->event;
 234         power = isp->max_power;
 235
 236         mutex_lock(&lock);
 237
 238         if (event != USB_EVENT_NONE)
 239                 isp1704_charger_set_power(isp, 1);
 240
 241         switch (event) {
 242         case USB_EVENT_VBUS:
 243                 isp->online = true;
 244
 245                 /* detect charger */
 246                 detect = isp1704_charger_detect(isp);
 247
 248                 if (detect) {
 249                         isp->present = detect;
 250                         isp->psy.type = isp1704_charger_type(isp);
 251                 }
 252
 253                 switch (isp->psy.type) {
 254                 case POWER_SUPPLY_TYPE_USB_DCP:
 255                         isp->current_max = 1800;
 256                         break;
 257                 case POWER_SUPPLY_TYPE_USB_CDP:
 258                         /*
 259                          * Only 500mA here or high speed chirp
 260                          * handshaking may break
 261                          */
 262                         isp->current_max = 500;
 263                         /* FALLTHROUGH */
 264                 case POWER_SUPPLY_TYPE_USB:
 265                 default:
 266                         /* enable data pullups */
 267                         if (isp->otg->gadget)
 268                                 usb_gadget_connect(isp->otg->gadget);
 269                 }
 270                 break;
 271         case USB_EVENT_NONE:
 272                 isp->online = false;
 273                 isp->current_max = 0;
 274                 isp->present = 0;
 275                 isp->current_max = 0;
 276                 isp->psy.type = POWER_SUPPLY_TYPE_USB;
 277
 278                 /*
 279                  * Disable data pullups. We need to prevent the controller from
 280                  * enumerating.
 281                  *
 282                  * FIXME: This is here to allow charger detection with Host/HUB
 283                  * chargers. The pullups may be enabled elsewhere, so this can
 284                  * not be the final solution.
 285                  */
 286                 if (isp->otg->gadget)
 287                         usb_gadget_disconnect(isp->otg->gadget);
 288
 289                 isp1704_charger_set_power(isp, 0);
 290                 break;
 291         case USB_EVENT_ENUMERATED:
 292                 if (isp->present)
 293                         isp->current_max = 1800;
 294                 else
 295                         isp->current_max = power;
 296                 break;
 297         default:
 298                 goto out;
 299         }
 300
 301         power_supply_changed(&isp->psy);
 302 out:
 303         mutex_unlock(&lock);
 304 }
 305
 306 static int isp1704_notifier_call(struct notifier_block *nb,
 307                 unsigned long event, void *power)
 308 {
 309         struct isp1704_charger *isp =
 310                 container_of(nb, struct isp1704_charger, nb);
 311
 312         isp->event = event;
 313
 314         if (power)
 315                 isp->max_power = *((unsigned *)power);
 316
 317         schedule_work(&isp->work);
 318
 319         return NOTIFY_OK;
 320 }
 321
 322 static int isp1704_charger_get_property(struct power_supply *psy,
 323                                 enum power_supply_property psp,
 324                                 union power_supply_propval *val)
 325 {
 326         struct isp1704_charger *isp =
 327                 container_of(psy, struct isp1704_charger, psy);
 328
 329         switch (psp) {
 330         case POWER_SUPPLY_PROP_PRESENT:
 331                 val->intval = isp->present;
 332                 break;
 333         case POWER_SUPPLY_PROP_ONLINE:
 334                 val->intval = isp->online;
 335                 break;
 336         case POWER_SUPPLY_PROP_CURRENT_MAX:
 337                 val->intval = isp->current_max;
 338                 break;
 339         case POWER_SUPPLY_PROP_MODEL_NAME:
 340                 val->strval = isp->model;
 341                 break;
 342         case POWER_SUPPLY_PROP_MANUFACTURER:
 343                 val->strval = "NXP";
 344                 break;
 345         default:
 346                 return -EINVAL;
 347         }
 348         return 0;
 349 }
 350
 351 static enum power_supply_property power_props[] = {
 352         POWER_SUPPLY_PROP_PRESENT,
 353         POWER_SUPPLY_PROP_ONLINE,
 354         POWER_SUPPLY_PROP_CURRENT_MAX,
 355         POWER_SUPPLY_PROP_MODEL_NAME,
 356         POWER_SUPPLY_PROP_MANUFACTURER,
 357 };
 358
 359 static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
 360 {
 361         int vendor;
 362         int product;
 363         int i;
 364         int ret = -ENODEV;
 365
 366         /* Test ULPI interface */
 367         ret = otg_io_write(isp->otg, ULPI_SCRATCH, 0xaa);
 368         if (ret < 0)
 369                 return ret;
 370
 371         ret = otg_io_read(isp->otg, ULPI_SCRATCH);
 372         if (ret < 0)
 373                 return ret;
 374
 375         if (ret != 0xaa)
 376                 return -ENODEV;
 377
 378         /* Verify the product and vendor id matches */
 379         vendor = otg_io_read(isp->otg, ULPI_VENDOR_ID_LOW);
 380         vendor |= otg_io_read(isp->otg, ULPI_VENDOR_ID_HIGH) << 8;
 381         if (vendor != NXP_VENDOR_ID)
 382                 return -ENODEV;
 383
 384         product = otg_io_read(isp->otg, ULPI_PRODUCT_ID_LOW);
 385         product |= otg_io_read(isp->otg, ULPI_PRODUCT_ID_HIGH) << 8;
 386
 387         for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
 388                 if (product == isp170x_id[i]) {
 389                         sprintf(isp->model, "isp%x", product);
 390                         return product;
 391                 }
 392         }
 393
 394         dev_err(isp->dev, "product id %x not matching known ids", product);
 395
 396         return -ENODEV;
 397 }
 398
 399 static int __devinit isp1704_charger_probe(struct platform_device *pdev)
 400 {
 401         struct isp1704_charger  *isp;
 402         int                     ret = -ENODEV;
 403
 404         isp = kzalloc(sizeof *isp, GFP_KERNEL);
 405         if (!isp)
 406                 return -ENOMEM;
 407
 408         isp->otg = otg_get_transceiver();
 409         if (!isp->otg)
 410                 goto fail0;
 411
 412         isp->dev = &pdev->dev;
 413         platform_set_drvdata(pdev, isp);
 414
 415         isp1704_charger_set_power(isp, 1);
 416
 417         ret = isp1704_test_ulpi(isp);
 418         if (ret < 0)
 419                 goto fail1;
 420
 421         isp->psy.name           = "isp1704";
 422         isp->psy.type           = POWER_SUPPLY_TYPE_USB;
 423         isp->psy.properties     = power_props;
 424         isp->psy.num_properties = ARRAY_SIZE(power_props);
 425         isp->psy.get_property   = isp1704_charger_get_property;
 426
 427         ret = power_supply_register(isp->dev, &isp->psy);
 428         if (ret)
 429                 goto fail1;
 430
 431         /*
 432          * REVISIT: using work in order to allow the otg notifications to be
 433          * made atomically in the future.
 434          */
 435         INIT_WORK(&isp->work, isp1704_charger_work);
 436
 437         isp->nb.notifier_call = isp1704_notifier_call;
 438
 439         ret = otg_register_notifier(isp->otg, &isp->nb);
 440         if (ret)
 441                 goto fail2;
 442
 443         dev_info(isp->dev, "registered with product id %s\n", isp->model);
 444
 445         /*
 446          * Taking over the D+ pullup.
 447          *
 448          * FIXME: The device will be disconnected if it was already
 449          * enumerated. The charger driver should be always loaded before any
 450          * gadget is loaded.
 451          */
 452         if (isp->otg->gadget)
 453                 usb_gadget_disconnect(isp->otg->gadget);
 454
 455         /* Detect charger if VBUS is valid (the cable was already plugged). */
 456         ret = otg_io_read(isp->otg, ULPI_USB_INT_STS);
 457         isp1704_charger_set_power(isp, 0);
 458         if ((ret & ULPI_INT_VBUS_VALID) && !isp->otg->default_a) {
 459                 isp->event = USB_EVENT_VBUS;
 460                 schedule_work(&isp->work);
 461         }
 462
 463         return 0;
 464 fail2:
 465         power_supply_unregister(&isp->psy);
 466 fail1:
 467         otg_put_transceiver(isp->otg);
 468 fail0:
 469         kfree(isp);
 470
 471         dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 472
 473         return ret;
 474 }
 475
 476 static int __devexit isp1704_charger_remove(struct platform_device *pdev)
 477 {
 478         struct isp1704_charger *isp = platform_get_drvdata(pdev);
 479
 480         otg_unregister_notifier(isp->otg, &isp->nb);
 481         power_supply_unregister(&isp->psy);
 482         otg_put_transceiver(isp->otg);
 483         isp1704_charger_set_power(isp, 0);
 484         kfree(isp);
 485
 486         return 0;
 487 }
 488
 489 static struct platform_driver isp1704_charger_driver = {
 490         .driver = {
 491                 .name = "isp1704_charger",
 492         },
 493         .probe = isp1704_charger_probe,
 494         .remove = __devexit_p(isp1704_charger_remove),
 495 };
 496
 497 module_platform_driver(isp1704_charger_driver);
 498
 499 MODULE_ALIAS("platform:isp1704_charger");
 500 MODULE_AUTHOR("Nokia Corporation");
 501 MODULE_DESCRIPTION("ISP170x USB Charger driver");
 502 MODULE_LICENSE("GPL");