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 usb_phy          *phy;
  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 static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
  75 {
  76         return usb_phy_io_read(isp->phy, reg);
  77 }
  78
  79 static inline int isp1704_write(struct isp1704_charger *isp, u32 val, u32 reg)
  80 {
  81         return usb_phy_io_write(isp->phy, val, reg);
  82 }
  83
  84 /*
  85  * Disable/enable the power from the isp1704 if a function for it
  86  * has been provided with platform data.
  87  */
  88 static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
  89 {
  90         struct isp1704_charger_data     *board = isp->dev->platform_data;
  91
  92         if (board && board->set_power)
  93                 board->set_power(on);
  94 }
  95
  96 /*
  97  * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
  98  * chargers).
  99  *
 100  * REVISIT: The method is defined in Battery Charging Specification and is
 101  * applicable to any ULPI transceiver. Nothing isp170x specific here.
 102  */
 103 static inline int isp1704_charger_type(struct isp1704_charger *isp)
 104 {
 105         u8 reg;
 106         u8 func_ctrl;
 107         u8 otg_ctrl;
 108         int type = POWER_SUPPLY_TYPE_USB_DCP;
 109
 110         func_ctrl = isp1704_read(isp, ULPI_FUNC_CTRL);
 111         otg_ctrl = isp1704_read(isp, ULPI_OTG_CTRL);
 112
 113         /* disable pulldowns */
 114         reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
 115         isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), reg);
 116
 117         /* full speed */
 118         isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 119                         ULPI_FUNC_CTRL_XCVRSEL_MASK);
 120         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL),
 121                         ULPI_FUNC_CTRL_FULL_SPEED);
 122
 123         /* Enable strong pull-up on DP (1.5K) and reset */
 124         reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 125         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), reg);
 126         usleep_range(1000, 2000);
 127
 128         reg = isp1704_read(isp, ULPI_DEBUG);
 129         if ((reg & 3) != 3)
 130                 type = POWER_SUPPLY_TYPE_USB_CDP;
 131
 132         /* recover original state */
 133         isp1704_write(isp, ULPI_FUNC_CTRL, func_ctrl);
 134         isp1704_write(isp, ULPI_OTG_CTRL, otg_ctrl);
 135
 136         return type;
 137 }
 138
 139 /*
 140  * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
 141  * is actually a dedicated charger, the following steps need to be taken.
 142  */
 143 static inline int isp1704_charger_verify(struct isp1704_charger *isp)
 144 {
 145         int     ret = 0;
 146         u8      r;
 147
 148         /* Reset the transceiver */
 149         r = isp1704_read(isp, ULPI_FUNC_CTRL);
 150         r |= ULPI_FUNC_CTRL_RESET;
 151         isp1704_write(isp, ULPI_FUNC_CTRL, r);
 152         usleep_range(1000, 2000);
 153
 154         /* Set normal mode */
 155         r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
 156         isp1704_write(isp, ULPI_FUNC_CTRL, r);
 157
 158         /* Clear the DP and DM pull-down bits */
 159         r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
 160         isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), r);
 161
 162         /* Enable strong pull-up on DP (1.5K) and reset */
 163         r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 164         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), r);
 165         usleep_range(1000, 2000);
 166
 167         /* Read the line state */
 168         if (!isp1704_read(isp, ULPI_DEBUG)) {
 169                 /* Disable strong pull-up on DP (1.5K) */
 170                 isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 171                                 ULPI_FUNC_CTRL_TERMSELECT);
 172                 return 1;
 173         }
 174
 175         /* Is it a charger or PS/2 connection */
 176
 177         /* Enable weak pull-up resistor on DP */
 178         isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
 179                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 180
 181         /* Disable strong pull-up on DP (1.5K) */
 182         isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 183                         ULPI_FUNC_CTRL_TERMSELECT);
 184
 185         /* Enable weak pull-down resistor on DM */
 186         isp1704_write(isp, ULPI_SET(ULPI_OTG_CTRL),
 187                         ULPI_OTG_CTRL_DM_PULLDOWN);
 188
 189         /* It's a charger if the line states are clear */
 190         if (!(isp1704_read(isp, ULPI_DEBUG)))
 191                 ret = 1;
 192
 193         /* Disable weak pull-up resistor on DP */
 194         isp1704_write(isp, ULPI_CLR(ISP1704_PWR_CTRL),
 195                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 196
 197         return ret;
 198 }
 199
 200 static inline int isp1704_charger_detect(struct isp1704_charger *isp)
 201 {
 202         unsigned long   timeout;
 203         u8              pwr_ctrl;
 204         int             ret = 0;
 205
 206         pwr_ctrl = isp1704_read(isp, ISP1704_PWR_CTRL);
 207
 208         /* set SW control bit in PWR_CTRL register */
 209         isp1704_write(isp, ISP1704_PWR_CTRL,
 210                         ISP1704_PWR_CTRL_SWCTRL);
 211
 212         /* enable manual charger detection */
 213         isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
 214                         ISP1704_PWR_CTRL_SWCTRL
 215                         | ISP1704_PWR_CTRL_DPVSRC_EN);
 216         usleep_range(1000, 2000);
 217
 218         timeout = jiffies + msecs_to_jiffies(300);
 219         do {
 220                 /* Check if there is a charger */
 221                 if (isp1704_read(isp, ISP1704_PWR_CTRL)
 222                                 & ISP1704_PWR_CTRL_VDAT_DET) {
 223                         ret = isp1704_charger_verify(isp);
 224                         break;
 225                 }
 226         } while (!time_after(jiffies, timeout) && isp->online);
 227
 228         /* recover original state */
 229         isp1704_write(isp, ISP1704_PWR_CTRL, pwr_ctrl);
 230
 231         return ret;
 232 }
 233
 234 static void isp1704_charger_work(struct work_struct *data)
 235 {
 236         int                     detect;
 237         unsigned long           event;
 238         unsigned                power;
 239         struct isp1704_charger  *isp =
 240                 container_of(data, struct isp1704_charger, work);
 241         static DEFINE_MUTEX(lock);
 242
 243         event = isp->event;
 244         power = isp->max_power;
 245
 246         mutex_lock(&lock);
 247
 248         if (event != USB_EVENT_NONE)
 249                 isp1704_charger_set_power(isp, 1);
 250
 251         switch (event) {
 252         case USB_EVENT_VBUS:
 253                 isp->online = true;
 254
 255                 /* detect charger */
 256                 detect = isp1704_charger_detect(isp);
 257
 258                 if (detect) {
 259                         isp->present = detect;
 260                         isp->psy.type = isp1704_charger_type(isp);
 261                 }
 262
 263                 switch (isp->psy.type) {
 264                 case POWER_SUPPLY_TYPE_USB_DCP:
 265                         isp->current_max = 1800;
 266                         break;
 267                 case POWER_SUPPLY_TYPE_USB_CDP:
 268                         /*
 269                          * Only 500mA here or high speed chirp
 270                          * handshaking may break
 271                          */
 272                         isp->current_max = 500;
 273                         /* FALLTHROUGH */
 274                 case POWER_SUPPLY_TYPE_USB:
 275                 default:
 276                         /* enable data pullups */
 277                         if (isp->phy->otg->gadget)
 278                                 usb_gadget_connect(isp->phy->otg->gadget);
 279                 }
 280                 break;
 281         case USB_EVENT_NONE:
 282                 isp->online = false;
 283                 isp->current_max = 0;
 284                 isp->present = 0;
 285                 isp->current_max = 0;
 286                 isp->psy.type = POWER_SUPPLY_TYPE_USB;
 287
 288                 /*
 289                  * Disable data pullups. We need to prevent the controller from
 290                  * enumerating.
 291                  *
 292                  * FIXME: This is here to allow charger detection with Host/HUB
 293                  * chargers. The pullups may be enabled elsewhere, so this can
 294                  * not be the final solution.
 295                  */
 296                 if (isp->phy->otg->gadget)
 297                         usb_gadget_disconnect(isp->phy->otg->gadget);
 298
 299                 isp1704_charger_set_power(isp, 0);
 300                 break;
 301         case USB_EVENT_ENUMERATED:
 302                 if (isp->present)
 303                         isp->current_max = 1800;
 304                 else
 305                         isp->current_max = power;
 306                 break;
 307         default:
 308                 goto out;
 309         }
 310
 311         power_supply_changed(&isp->psy);
 312 out:
 313         mutex_unlock(&lock);
 314 }
 315
 316 static int isp1704_notifier_call(struct notifier_block *nb,
 317                 unsigned long event, void *power)
 318 {
 319         struct isp1704_charger *isp =
 320                 container_of(nb, struct isp1704_charger, nb);
 321
 322         isp->event = event;
 323
 324         if (power)
 325                 isp->max_power = *((unsigned *)power);
 326
 327         schedule_work(&isp->work);
 328
 329         return NOTIFY_OK;
 330 }
 331
 332 static int isp1704_charger_get_property(struct power_supply *psy,
 333                                 enum power_supply_property psp,
 334                                 union power_supply_propval *val)
 335 {
 336         struct isp1704_charger *isp =
 337                 container_of(psy, struct isp1704_charger, psy);
 338
 339         switch (psp) {
 340         case POWER_SUPPLY_PROP_PRESENT:
 341                 val->intval = isp->present;
 342                 break;
 343         case POWER_SUPPLY_PROP_ONLINE:
 344                 val->intval = isp->online;
 345                 break;
 346         case POWER_SUPPLY_PROP_CURRENT_MAX:
 347                 val->intval = isp->current_max;
 348                 break;
 349         case POWER_SUPPLY_PROP_MODEL_NAME:
 350                 val->strval = isp->model;
 351                 break;
 352         case POWER_SUPPLY_PROP_MANUFACTURER:
 353                 val->strval = "NXP";
 354                 break;
 355         default:
 356                 return -EINVAL;
 357         }
 358         return 0;
 359 }
 360
 361 static enum power_supply_property power_props[] = {
 362         POWER_SUPPLY_PROP_PRESENT,
 363         POWER_SUPPLY_PROP_ONLINE,
 364         POWER_SUPPLY_PROP_CURRENT_MAX,
 365         POWER_SUPPLY_PROP_MODEL_NAME,
 366         POWER_SUPPLY_PROP_MANUFACTURER,
 367 };
 368
 369 static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
 370 {
 371         int vendor;
 372         int product;
 373         int i;
 374         int ret = -ENODEV;
 375
 376         /* Test ULPI interface */
 377         ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
 378         if (ret < 0)
 379                 return ret;
 380
 381         ret = isp1704_read(isp, ULPI_SCRATCH);
 382         if (ret < 0)
 383                 return ret;
 384
 385         if (ret != 0xaa)
 386                 return -ENODEV;
 387
 388         /* Verify the product and vendor id matches */
 389         vendor = isp1704_read(isp, ULPI_VENDOR_ID_LOW);
 390         vendor |= isp1704_read(isp, ULPI_VENDOR_ID_HIGH) << 8;
 391         if (vendor != NXP_VENDOR_ID)
 392                 return -ENODEV;
 393
 394         product = isp1704_read(isp, ULPI_PRODUCT_ID_LOW);
 395         product |= isp1704_read(isp, ULPI_PRODUCT_ID_HIGH) << 8;
 396
 397         for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
 398                 if (product == isp170x_id[i]) {
 399                         sprintf(isp->model, "isp%x", product);
 400                         return product;
 401                 }
 402         }
 403
 404         dev_err(isp->dev, "product id %x not matching known ids", product);
 405
 406         return -ENODEV;
 407 }
 408
 409 static int isp1704_charger_probe(struct platform_device *pdev)
 410 {
 411         struct isp1704_charger  *isp;
 412         int                     ret = -ENODEV;
 413
 414         isp = kzalloc(sizeof *isp, GFP_KERNEL);
 415         if (!isp)
 416                 return -ENOMEM;
 417
 418         isp->phy = usb_get_phy(USB_PHY_TYPE_USB2);
 419         if (IS_ERR_OR_NULL(isp->phy))
 420                 goto fail0;
 421
 422         isp->dev = &pdev->dev;
 423         platform_set_drvdata(pdev, isp);
 424
 425         isp1704_charger_set_power(isp, 1);
 426
 427         ret = isp1704_test_ulpi(isp);
 428         if (ret < 0)
 429                 goto fail1;
 430
 431         isp->psy.name           = "isp1704";
 432         isp->psy.type           = POWER_SUPPLY_TYPE_USB;
 433         isp->psy.properties     = power_props;
 434         isp->psy.num_properties = ARRAY_SIZE(power_props);
 435         isp->psy.get_property   = isp1704_charger_get_property;
 436
 437         ret = power_supply_register(isp->dev, &isp->psy);
 438         if (ret)
 439                 goto fail1;
 440
 441         /*
 442          * REVISIT: using work in order to allow the usb notifications to be
 443          * made atomically in the future.
 444          */
 445         INIT_WORK(&isp->work, isp1704_charger_work);
 446
 447         isp->nb.notifier_call = isp1704_notifier_call;
 448
 449         ret = usb_register_notifier(isp->phy, &isp->nb);
 450         if (ret)
 451                 goto fail2;
 452
 453         dev_info(isp->dev, "registered with product id %s\n", isp->model);
 454
 455         /*
 456          * Taking over the D+ pullup.
 457          *
 458          * FIXME: The device will be disconnected if it was already
 459          * enumerated. The charger driver should be always loaded before any
 460          * gadget is loaded.
 461          */
 462         if (isp->phy->otg->gadget)
 463                 usb_gadget_disconnect(isp->phy->otg->gadget);
 464
 465         /* Detect charger if VBUS is valid (the cable was already plugged). */
 466         ret = isp1704_read(isp, ULPI_USB_INT_STS);
 467         isp1704_charger_set_power(isp, 0);
 468         if ((ret & ULPI_INT_VBUS_VALID) && !isp->phy->otg->default_a) {
 469                 isp->event = USB_EVENT_VBUS;
 470                 schedule_work(&isp->work);
 471         }
 472
 473         return 0;
 474 fail2:
 475         power_supply_unregister(&isp->psy);
 476 fail1:
 477         isp1704_charger_set_power(isp, 0);
 478         usb_put_phy(isp->phy);
 479 fail0:
 480         kfree(isp);
 481
 482         dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 483
 484         return ret;
 485 }
 486
 487 static int isp1704_charger_remove(struct platform_device *pdev)
 488 {
 489         struct isp1704_charger *isp = platform_get_drvdata(pdev);
 490
 491         usb_unregister_notifier(isp->phy, &isp->nb);
 492         power_supply_unregister(&isp->psy);
 493         usb_put_phy(isp->phy);
 494         isp1704_charger_set_power(isp, 0);
 495         kfree(isp);
 496
 497         return 0;
 498 }
 499
 500 static struct platform_driver isp1704_charger_driver = {
 501         .driver = {
 502                 .name = "isp1704_charger",
 503         },
 504         .probe = isp1704_charger_probe,
 505         .remove = isp1704_charger_remove,
 506 };
 507
 508 module_platform_driver(isp1704_charger_driver);
 509
 510 MODULE_ALIAS("platform:isp1704_charger");
 511 MODULE_AUTHOR("Nokia Corporation");
 512 MODULE_DESCRIPTION("ISP170x USB Charger driver");
 513 MODULE_LICENSE("GPL");