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
  37 /* Vendor specific Power Control register */
  38 #define ISP1704_PWR_CTRL                0x3d
  39 #define ISP1704_PWR_CTRL_SWCTRL         (1 << 0)
  40 #define ISP1704_PWR_CTRL_DET_COMP       (1 << 1)
  41 #define ISP1704_PWR_CTRL_BVALID_RISE    (1 << 2)
  42 #define ISP1704_PWR_CTRL_BVALID_FALL    (1 << 3)
  43 #define ISP1704_PWR_CTRL_DP_WKPU_EN     (1 << 4)
  44 #define ISP1704_PWR_CTRL_VDAT_DET       (1 << 5)
  45 #define ISP1704_PWR_CTRL_DPVSRC_EN      (1 << 6)
  46 #define ISP1704_PWR_CTRL_HWDETECT       (1 << 7)
  47
  48 #define NXP_VENDOR_ID                   0x04cc
  49
  50 static u16 isp170x_id[] = {
  51         0x1704,
  52         0x1707,
  53 };
  54
  55 struct isp1704_charger {
  56         struct device           *dev;
  57         struct power_supply     psy;
  58         struct otg_transceiver  *otg;
  59         struct notifier_block   nb;
  60         struct work_struct      work;
  61
  62         /* properties */
  63         char                    model[8];
  64         unsigned                present:1;
  65         unsigned                online:1;
  66         unsigned                current_max;
  67
  68         /* temp storage variables */
  69         unsigned long           event;
  70         unsigned                max_power;
  71 };
  72
  73 /*
  74  * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
  75  * chargers).
  76  *
  77  * REVISIT: The method is defined in Battery Charging Specification and is
  78  * applicable to any ULPI transceiver. Nothing isp170x specific here.
  79  */
  80 static inline int isp1704_charger_type(struct isp1704_charger *isp)
  81 {
  82         u8 reg;
  83         u8 func_ctrl;
  84         u8 otg_ctrl;
  85         int type = POWER_SUPPLY_TYPE_USB_DCP;
  86
  87         func_ctrl = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
  88         otg_ctrl = otg_io_read(isp->otg, ULPI_OTG_CTRL);
  89
  90         /* disable pulldowns */
  91         reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
  92         otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), reg);
  93
  94         /* full speed */
  95         otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
  96                         ULPI_FUNC_CTRL_XCVRSEL_MASK);
  97         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL),
  98                         ULPI_FUNC_CTRL_FULL_SPEED);
  99
 100         /* Enable strong pull-up on DP (1.5K) and reset */
 101         reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 102         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), reg);
 103         usleep_range(1000, 2000);
 104
 105         reg = otg_io_read(isp->otg, ULPI_DEBUG);
 106         if ((reg & 3) != 3)
 107                 type = POWER_SUPPLY_TYPE_USB_CDP;
 108
 109         /* recover original state */
 110         otg_io_write(isp->otg, ULPI_FUNC_CTRL, func_ctrl);
 111         otg_io_write(isp->otg, ULPI_OTG_CTRL, otg_ctrl);
 112
 113         return type;
 114 }
 115
 116 /*
 117  * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
 118  * is actually a dedicated charger, the following steps need to be taken.
 119  */
 120 static inline int isp1704_charger_verify(struct isp1704_charger *isp)
 121 {
 122         int     ret = 0;
 123         u8      r;
 124
 125         /* Reset the transceiver */
 126         r = otg_io_read(isp->otg, ULPI_FUNC_CTRL);
 127         r |= ULPI_FUNC_CTRL_RESET;
 128         otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
 129         usleep_range(1000, 2000);
 130
 131         /* Set normal mode */
 132         r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
 133         otg_io_write(isp->otg, ULPI_FUNC_CTRL, r);
 134
 135         /* Clear the DP and DM pull-down bits */
 136         r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
 137         otg_io_write(isp->otg, ULPI_CLR(ULPI_OTG_CTRL), r);
 138
 139         /* Enable strong pull-up on DP (1.5K) and reset */
 140         r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 141         otg_io_write(isp->otg, ULPI_SET(ULPI_FUNC_CTRL), r);
 142         usleep_range(1000, 2000);
 143
 144         /* Read the line state */
 145         if (!otg_io_read(isp->otg, ULPI_DEBUG)) {
 146                 /* Disable strong pull-up on DP (1.5K) */
 147                 otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 148                                 ULPI_FUNC_CTRL_TERMSELECT);
 149                 return 1;
 150         }
 151
 152         /* Is it a charger or PS/2 connection */
 153
 154         /* Enable weak pull-up resistor on DP */
 155         otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
 156                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 157
 158         /* Disable strong pull-up on DP (1.5K) */
 159         otg_io_write(isp->otg, ULPI_CLR(ULPI_FUNC_CTRL),
 160                         ULPI_FUNC_CTRL_TERMSELECT);
 161
 162         /* Enable weak pull-down resistor on DM */
 163         otg_io_write(isp->otg, ULPI_SET(ULPI_OTG_CTRL),
 164                         ULPI_OTG_CTRL_DM_PULLDOWN);
 165
 166         /* It's a charger if the line states are clear */
 167         if (!(otg_io_read(isp->otg, ULPI_DEBUG)))
 168                 ret = 1;
 169
 170         /* Disable weak pull-up resistor on DP */
 171         otg_io_write(isp->otg, ULPI_CLR(ISP1704_PWR_CTRL),
 172                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 173
 174         return ret;
 175 }
 176
 177 static inline int isp1704_charger_detect(struct isp1704_charger *isp)
 178 {
 179         unsigned long   timeout;
 180         u8              pwr_ctrl;
 181         int             ret = 0;
 182
 183         pwr_ctrl = otg_io_read(isp->otg, ISP1704_PWR_CTRL);
 184
 185         /* set SW control bit in PWR_CTRL register */
 186         otg_io_write(isp->otg, ISP1704_PWR_CTRL,
 187                         ISP1704_PWR_CTRL_SWCTRL);
 188
 189         /* enable manual charger detection */
 190         otg_io_write(isp->otg, ULPI_SET(ISP1704_PWR_CTRL),
 191                         ISP1704_PWR_CTRL_SWCTRL
 192                         | ISP1704_PWR_CTRL_DPVSRC_EN);
 193         usleep_range(1000, 2000);
 194
 195         timeout = jiffies + msecs_to_jiffies(300);
 196         do {
 197                 /* Check if there is a charger */
 198                 if (otg_io_read(isp->otg, ISP1704_PWR_CTRL)
 199                                 & ISP1704_PWR_CTRL_VDAT_DET) {
 200                         ret = isp1704_charger_verify(isp);
 201                         break;
 202                 }
 203         } while (!time_after(jiffies, timeout) && isp->online);
 204
 205         /* recover original state */
 206         otg_io_write(isp->otg, ISP1704_PWR_CTRL, pwr_ctrl);
 207
 208         return ret;
 209 }
 210
 211 static void isp1704_charger_work(struct work_struct *data)
 212 {
 213         int                     detect;
 214         unsigned long           event;
 215         unsigned                power;
 216         struct isp1704_charger  *isp =
 217                 container_of(data, struct isp1704_charger, work);
 218         static DEFINE_MUTEX(lock);
 219
 220         event = isp->event;
 221         power = isp->max_power;
 222
 223         mutex_lock(&lock);
 224
 225         switch (event) {
 226         case USB_EVENT_VBUS:
 227                 isp->online = true;
 228
 229                 /* detect charger */
 230                 detect = isp1704_charger_detect(isp);
 231
 232                 if (detect) {
 233                         isp->present = detect;
 234                         isp->psy.type = isp1704_charger_type(isp);
 235                 }
 236
 237                 switch (isp->psy.type) {
 238                 case POWER_SUPPLY_TYPE_USB_DCP:
 239                         isp->current_max = 1800;
 240                         break;
 241                 case POWER_SUPPLY_TYPE_USB_CDP:
 242                         /*
 243                          * Only 500mA here or high speed chirp
 244                          * handshaking may break
 245                          */
 246                         isp->current_max = 500;
 247                         /* FALLTHROUGH */
 248                 case POWER_SUPPLY_TYPE_USB:
 249                 default:
 250                         /* enable data pullups */
 251                         if (isp->otg->gadget)
 252                                 usb_gadget_connect(isp->otg->gadget);
 253                 }
 254                 break;
 255         case USB_EVENT_NONE:
 256                 isp->online = false;
 257                 isp->current_max = 0;
 258                 isp->present = 0;
 259                 isp->current_max = 0;
 260                 isp->psy.type = POWER_SUPPLY_TYPE_USB;
 261
 262                 /*
 263                  * Disable data pullups. We need to prevent the controller from
 264                  * enumerating.
 265                  *
 266                  * FIXME: This is here to allow charger detection with Host/HUB
 267                  * chargers. The pullups may be enabled elsewhere, so this can
 268                  * not be the final solution.
 269                  */
 270                 if (isp->otg->gadget)
 271                         usb_gadget_disconnect(isp->otg->gadget);
 272                 break;
 273         case USB_EVENT_ENUMERATED:
 274                 if (isp->present)
 275                         isp->current_max = 1800;
 276                 else
 277                         isp->current_max = power;
 278                 break;
 279         default:
 280                 goto out;
 281         }
 282
 283         power_supply_changed(&isp->psy);
 284 out:
 285         mutex_unlock(&lock);
 286 }
 287
 288 static int isp1704_notifier_call(struct notifier_block *nb,
 289                 unsigned long event, void *power)
 290 {
 291         struct isp1704_charger *isp =
 292                 container_of(nb, struct isp1704_charger, nb);
 293
 294         isp->event = event;
 295
 296         if (power)
 297                 isp->max_power = *((unsigned *)power);
 298
 299         schedule_work(&isp->work);
 300
 301         return NOTIFY_OK;
 302 }
 303
 304 static int isp1704_charger_get_property(struct power_supply *psy,
 305                                 enum power_supply_property psp,
 306                                 union power_supply_propval *val)
 307 {
 308         struct isp1704_charger *isp =
 309                 container_of(psy, struct isp1704_charger, psy);
 310
 311         switch (psp) {
 312         case POWER_SUPPLY_PROP_PRESENT:
 313                 val->intval = isp->present;
 314                 break;
 315         case POWER_SUPPLY_PROP_ONLINE:
 316                 val->intval = isp->online;
 317                 break;
 318         case POWER_SUPPLY_PROP_CURRENT_MAX:
 319                 val->intval = isp->current_max;
 320                 break;
 321         case POWER_SUPPLY_PROP_MODEL_NAME:
 322                 val->strval = isp->model;
 323                 break;
 324         case POWER_SUPPLY_PROP_MANUFACTURER:
 325                 val->strval = "NXP";
 326                 break;
 327         default:
 328                 return -EINVAL;
 329         }
 330         return 0;
 331 }
 332
 333 static enum power_supply_property power_props[] = {
 334         POWER_SUPPLY_PROP_PRESENT,
 335         POWER_SUPPLY_PROP_ONLINE,
 336         POWER_SUPPLY_PROP_CURRENT_MAX,
 337         POWER_SUPPLY_PROP_MODEL_NAME,
 338         POWER_SUPPLY_PROP_MANUFACTURER,
 339 };
 340
 341 static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
 342 {
 343         int vendor;
 344         int product;
 345         int i;
 346         int ret = -ENODEV;
 347
 348         /* Test ULPI interface */
 349         ret = otg_io_write(isp->otg, ULPI_SCRATCH, 0xaa);
 350         if (ret < 0)
 351                 return ret;
 352
 353         ret = otg_io_read(isp->otg, ULPI_SCRATCH);
 354         if (ret < 0)
 355                 return ret;
 356
 357         if (ret != 0xaa)
 358                 return -ENODEV;
 359
 360         /* Verify the product and vendor id matches */
 361         vendor = otg_io_read(isp->otg, ULPI_VENDOR_ID_LOW);
 362         vendor |= otg_io_read(isp->otg, ULPI_VENDOR_ID_HIGH) << 8;
 363         if (vendor != NXP_VENDOR_ID)
 364                 return -ENODEV;
 365
 366         product = otg_io_read(isp->otg, ULPI_PRODUCT_ID_LOW);
 367         product |= otg_io_read(isp->otg, ULPI_PRODUCT_ID_HIGH) << 8;
 368
 369         for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
 370                 if (product == isp170x_id[i]) {
 371                         sprintf(isp->model, "isp%x", product);
 372                         return product;
 373                 }
 374         }
 375
 376         dev_err(isp->dev, "product id %x not matching known ids", product);
 377
 378         return -ENODEV;
 379 }
 380
 381 static int __devinit isp1704_charger_probe(struct platform_device *pdev)
 382 {
 383         struct isp1704_charger  *isp;
 384         int                     ret = -ENODEV;
 385
 386         isp = kzalloc(sizeof *isp, GFP_KERNEL);
 387         if (!isp)
 388                 return -ENOMEM;
 389
 390         isp->otg = otg_get_transceiver();
 391         if (!isp->otg)
 392                 goto fail0;
 393
 394         isp->dev = &pdev->dev;
 395         platform_set_drvdata(pdev, isp);
 396
 397         ret = isp1704_test_ulpi(isp);
 398         if (ret < 0)
 399                 goto fail1;
 400
 401         isp->psy.name           = "isp1704";
 402         isp->psy.type           = POWER_SUPPLY_TYPE_USB;
 403         isp->psy.properties     = power_props;
 404         isp->psy.num_properties = ARRAY_SIZE(power_props);
 405         isp->psy.get_property   = isp1704_charger_get_property;
 406
 407         ret = power_supply_register(isp->dev, &isp->psy);
 408         if (ret)
 409                 goto fail1;
 410
 411         /*
 412          * REVISIT: using work in order to allow the otg notifications to be
 413          * made atomically in the future.
 414          */
 415         INIT_WORK(&isp->work, isp1704_charger_work);
 416
 417         isp->nb.notifier_call = isp1704_notifier_call;
 418
 419         ret = otg_register_notifier(isp->otg, &isp->nb);
 420         if (ret)
 421                 goto fail2;
 422
 423         dev_info(isp->dev, "registered with product id %s\n", isp->model);
 424
 425         /*
 426          * Taking over the D+ pullup.
 427          *
 428          * FIXME: The device will be disconnected if it was already
 429          * enumerated. The charger driver should be always loaded before any
 430          * gadget is loaded.
 431          */
 432         if (isp->otg->gadget)
 433                 usb_gadget_disconnect(isp->otg->gadget);
 434
 435         /* Detect charger if VBUS is valid (the cable was already plugged). */
 436         ret = otg_io_read(isp->otg, ULPI_USB_INT_STS);
 437         if ((ret & ULPI_INT_VBUS_VALID) && !isp->otg->default_a) {
 438                 isp->event = USB_EVENT_VBUS;
 439                 schedule_work(&isp->work);
 440         }
 441
 442         return 0;
 443 fail2:
 444         power_supply_unregister(&isp->psy);
 445 fail1:
 446         otg_put_transceiver(isp->otg);
 447 fail0:
 448         kfree(isp);
 449
 450         dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 451
 452         return ret;
 453 }
 454
 455 static int __devexit isp1704_charger_remove(struct platform_device *pdev)
 456 {
 457         struct isp1704_charger *isp = platform_get_drvdata(pdev);
 458
 459         otg_unregister_notifier(isp->otg, &isp->nb);
 460         power_supply_unregister(&isp->psy);
 461         otg_put_transceiver(isp->otg);
 462         kfree(isp);
 463
 464         return 0;
 465 }
 466
 467 static struct platform_driver isp1704_charger_driver = {
 468         .driver = {
 469                 .name = "isp1704_charger",
 470         },
 471         .probe = isp1704_charger_probe,
 472         .remove = __devexit_p(isp1704_charger_remove),
 473 };
 474
 475 static int __init isp1704_charger_init(void)
 476 {
 477         return platform_driver_register(&isp1704_charger_driver);
 478 }
 479 module_init(isp1704_charger_init);
 480
 481 static void __exit isp1704_charger_exit(void)
 482 {
 483         platform_driver_unregister(&isp1704_charger_driver);
 484 }
 485 module_exit(isp1704_charger_exit);
 486
 487 MODULE_ALIAS("platform:isp1704_charger");
 488 MODULE_AUTHOR("Nokia Corporation");
 489 MODULE_DESCRIPTION("ISP170x USB Charger driver");
 490 MODULE_LICENSE("GPL");