drivers/power/isp1704_charger.c

   1 /*
   2  * ISP1704 USB Charger Detection driver
   3  *
   4  * Copyright (C) 2010 Nokia Corporation
   5  * Copyright (C) 2012 - 2013 Pali Rohár <pali.rohar@gmail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/err.h>
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/device.h>
  28 #include <linux/sysfs.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/power_supply.h>
  31 #include <linux/delay.h>
  32
  33 #include <linux/usb/otg.h>
  34 #include <linux/usb/ulpi.h>
  35 #include <linux/usb/ch9.h>
  36 #include <linux/usb/gadget.h>
  37 #include <linux/power/isp1704_charger.h>
  38
  39 /* Vendor specific Power Control register */
  40 #define ISP1704_PWR_CTRL                0x3d
  41 #define ISP1704_PWR_CTRL_SWCTRL         (1 << 0)
  42 #define ISP1704_PWR_CTRL_DET_COMP       (1 << 1)
  43 #define ISP1704_PWR_CTRL_BVALID_RISE    (1 << 2)
  44 #define ISP1704_PWR_CTRL_BVALID_FALL    (1 << 3)
  45 #define ISP1704_PWR_CTRL_DP_WKPU_EN     (1 << 4)
  46 #define ISP1704_PWR_CTRL_VDAT_DET       (1 << 5)
  47 #define ISP1704_PWR_CTRL_DPVSRC_EN      (1 << 6)
  48 #define ISP1704_PWR_CTRL_HWDETECT       (1 << 7)
  49
  50 #define NXP_VENDOR_ID                   0x04cc
  51
  52 static u16 isp170x_id[] = {
  53         0x1704,
  54         0x1707,
  55 };
  56
  57 struct isp1704_charger {
  58         struct device           *dev;
  59         struct power_supply     psy;
  60         struct usb_phy          *phy;
  61         struct notifier_block   nb;
  62         struct work_struct      work;
  63
  64         /* properties */
  65         char                    model[8];
  66         unsigned                present:1;
  67         unsigned                online:1;
  68         unsigned                current_max;
  69 };
  70
  71 static inline int isp1704_read(struct isp1704_charger *isp, u32 reg)
  72 {
  73         return usb_phy_io_read(isp->phy, reg);
  74 }
  75
  76 static inline int isp1704_write(struct isp1704_charger *isp, u32 val, u32 reg)
  77 {
  78         return usb_phy_io_write(isp->phy, val, reg);
  79 }
  80
  81 /*
  82  * Disable/enable the power from the isp1704 if a function for it
  83  * has been provided with platform data.
  84  */
  85 static void isp1704_charger_set_power(struct isp1704_charger *isp, bool on)
  86 {
  87         struct isp1704_charger_data     *board = isp->dev->platform_data;
  88
  89         if (board && board->set_power)
  90                 board->set_power(on);
  91 }
  92
  93 /*
  94  * Determine is the charging port DCP (dedicated charger) or CDP (Host/HUB
  95  * chargers).
  96  *
  97  * REVISIT: The method is defined in Battery Charging Specification and is
  98  * applicable to any ULPI transceiver. Nothing isp170x specific here.
  99  */
 100 static inline int isp1704_charger_type(struct isp1704_charger *isp)
 101 {
 102         u8 reg;
 103         u8 func_ctrl;
 104         u8 otg_ctrl;
 105         int type = POWER_SUPPLY_TYPE_USB_DCP;
 106
 107         func_ctrl = isp1704_read(isp, ULPI_FUNC_CTRL);
 108         otg_ctrl = isp1704_read(isp, ULPI_OTG_CTRL);
 109
 110         /* disable pulldowns */
 111         reg = ULPI_OTG_CTRL_DM_PULLDOWN | ULPI_OTG_CTRL_DP_PULLDOWN;
 112         isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), reg);
 113
 114         /* full speed */
 115         isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 116                         ULPI_FUNC_CTRL_XCVRSEL_MASK);
 117         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL),
 118                         ULPI_FUNC_CTRL_FULL_SPEED);
 119
 120         /* Enable strong pull-up on DP (1.5K) and reset */
 121         reg = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 122         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), reg);
 123         usleep_range(1000, 2000);
 124
 125         reg = isp1704_read(isp, ULPI_DEBUG);
 126         if ((reg & 3) != 3)
 127                 type = POWER_SUPPLY_TYPE_USB_CDP;
 128
 129         /* recover original state */
 130         isp1704_write(isp, ULPI_FUNC_CTRL, func_ctrl);
 131         isp1704_write(isp, ULPI_OTG_CTRL, otg_ctrl);
 132
 133         return type;
 134 }
 135
 136 /*
 137  * ISP1704 detects PS/2 adapters as charger. To make sure the detected charger
 138  * is actually a dedicated charger, the following steps need to be taken.
 139  */
 140 static inline int isp1704_charger_verify(struct isp1704_charger *isp)
 141 {
 142         int     ret = 0;
 143         u8      r;
 144
 145         /* Reset the transceiver */
 146         r = isp1704_read(isp, ULPI_FUNC_CTRL);
 147         r |= ULPI_FUNC_CTRL_RESET;
 148         isp1704_write(isp, ULPI_FUNC_CTRL, r);
 149         usleep_range(1000, 2000);
 150
 151         /* Set normal mode */
 152         r &= ~(ULPI_FUNC_CTRL_RESET | ULPI_FUNC_CTRL_OPMODE_MASK);
 153         isp1704_write(isp, ULPI_FUNC_CTRL, r);
 154
 155         /* Clear the DP and DM pull-down bits */
 156         r = ULPI_OTG_CTRL_DP_PULLDOWN | ULPI_OTG_CTRL_DM_PULLDOWN;
 157         isp1704_write(isp, ULPI_CLR(ULPI_OTG_CTRL), r);
 158
 159         /* Enable strong pull-up on DP (1.5K) and reset */
 160         r = ULPI_FUNC_CTRL_TERMSELECT | ULPI_FUNC_CTRL_RESET;
 161         isp1704_write(isp, ULPI_SET(ULPI_FUNC_CTRL), r);
 162         usleep_range(1000, 2000);
 163
 164         /* Read the line state */
 165         if (!isp1704_read(isp, ULPI_DEBUG)) {
 166                 /* Disable strong pull-up on DP (1.5K) */
 167                 isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 168                                 ULPI_FUNC_CTRL_TERMSELECT);
 169                 return 1;
 170         }
 171
 172         /* Is it a charger or PS/2 connection */
 173
 174         /* Enable weak pull-up resistor on DP */
 175         isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
 176                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 177
 178         /* Disable strong pull-up on DP (1.5K) */
 179         isp1704_write(isp, ULPI_CLR(ULPI_FUNC_CTRL),
 180                         ULPI_FUNC_CTRL_TERMSELECT);
 181
 182         /* Enable weak pull-down resistor on DM */
 183         isp1704_write(isp, ULPI_SET(ULPI_OTG_CTRL),
 184                         ULPI_OTG_CTRL_DM_PULLDOWN);
 185
 186         /* It's a charger if the line states are clear */
 187         if (!(isp1704_read(isp, ULPI_DEBUG)))
 188                 ret = 1;
 189
 190         /* Disable weak pull-up resistor on DP */
 191         isp1704_write(isp, ULPI_CLR(ISP1704_PWR_CTRL),
 192                         ISP1704_PWR_CTRL_DP_WKPU_EN);
 193
 194         return ret;
 195 }
 196
 197 static inline int isp1704_charger_detect(struct isp1704_charger *isp)
 198 {
 199         unsigned long   timeout;
 200         u8              pwr_ctrl;
 201         int             ret = 0;
 202
 203         pwr_ctrl = isp1704_read(isp, ISP1704_PWR_CTRL);
 204
 205         /* set SW control bit in PWR_CTRL register */
 206         isp1704_write(isp, ISP1704_PWR_CTRL,
 207                         ISP1704_PWR_CTRL_SWCTRL);
 208
 209         /* enable manual charger detection */
 210         isp1704_write(isp, ULPI_SET(ISP1704_PWR_CTRL),
 211                         ISP1704_PWR_CTRL_SWCTRL
 212                         | ISP1704_PWR_CTRL_DPVSRC_EN);
 213         usleep_range(1000, 2000);
 214
 215         timeout = jiffies + msecs_to_jiffies(300);
 216         do {
 217                 /* Check if there is a charger */
 218                 if (isp1704_read(isp, ISP1704_PWR_CTRL)
 219                                 & ISP1704_PWR_CTRL_VDAT_DET) {
 220                         ret = isp1704_charger_verify(isp);
 221                         break;
 222                 }
 223         } while (!time_after(jiffies, timeout) && isp->online);
 224
 225         /* recover original state */
 226         isp1704_write(isp, ISP1704_PWR_CTRL, pwr_ctrl);
 227
 228         return ret;
 229 }
 230
 231 static inline int isp1704_charger_detect_dcp(struct isp1704_charger *isp)
 232 {
 233         if (isp1704_charger_detect(isp) &&
 234                         isp1704_charger_type(isp) == POWER_SUPPLY_TYPE_USB_DCP)
 235                 return true;
 236         else
 237                 return false;
 238 }
 239
 240 static void isp1704_charger_work(struct work_struct *data)
 241 {
 242         struct isp1704_charger  *isp =
 243                 container_of(data, struct isp1704_charger, work);
 244         static DEFINE_MUTEX(lock);
 245
 246         mutex_lock(&lock);
 247
 248         switch (isp->phy->last_event) {
 249         case USB_EVENT_VBUS:
 250                 /* do not call wall charger detection more times */
 251                 if (!isp->present) {
 252                         isp->online = true;
 253                         isp->present = 1;
 254                         isp1704_charger_set_power(isp, 1);
 255
 256                         /* detect wall charger */
 257                         if (isp1704_charger_detect_dcp(isp)) {
 258                                 isp->psy.type = POWER_SUPPLY_TYPE_USB_DCP;
 259                                 isp->current_max = 1800;
 260                         } else {
 261                                 isp->psy.type = POWER_SUPPLY_TYPE_USB;
 262                                 isp->current_max = 500;
 263                         }
 264
 265                         /* enable data pullups */
 266                         if (isp->phy->otg->gadget)
 267                                 usb_gadget_connect(isp->phy->otg->gadget);
 268                 }
 269
 270                 if (isp->psy.type != POWER_SUPPLY_TYPE_USB_DCP) {
 271                         /*
 272                          * Only 500mA here or high speed chirp
 273                          * handshaking may break
 274                          */
 275                         if (isp->current_max > 500)
 276                                 isp->current_max = 500;
 277
 278                         if (isp->current_max > 100)
 279                                 isp->psy.type = POWER_SUPPLY_TYPE_USB_CDP;
 280                 }
 281                 break;
 282         case USB_EVENT_NONE:
 283                 isp->online = false;
 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         default:
 302                 goto out;
 303         }
 304
 305         power_supply_changed(&isp->psy);
 306 out:
 307         mutex_unlock(&lock);
 308 }
 309
 310 static int isp1704_notifier_call(struct notifier_block *nb,
 311                 unsigned long val, void *v)
 312 {
 313         struct isp1704_charger *isp =
 314                 container_of(nb, struct isp1704_charger, nb);
 315
 316         schedule_work(&isp->work);
 317
 318         return NOTIFY_OK;
 319 }
 320
 321 static int isp1704_charger_get_property(struct power_supply *psy,
 322                                 enum power_supply_property psp,
 323                                 union power_supply_propval *val)
 324 {
 325         struct isp1704_charger *isp =
 326                 container_of(psy, struct isp1704_charger, psy);
 327
 328         switch (psp) {
 329         case POWER_SUPPLY_PROP_PRESENT:
 330                 val->intval = isp->present;
 331                 break;
 332         case POWER_SUPPLY_PROP_ONLINE:
 333                 val->intval = isp->online;
 334                 break;
 335         case POWER_SUPPLY_PROP_CURRENT_MAX:
 336                 val->intval = isp->current_max;
 337                 break;
 338         case POWER_SUPPLY_PROP_MODEL_NAME:
 339                 val->strval = isp->model;
 340                 break;
 341         case POWER_SUPPLY_PROP_MANUFACTURER:
 342                 val->strval = "NXP";
 343                 break;
 344         default:
 345                 return -EINVAL;
 346         }
 347         return 0;
 348 }
 349
 350 static enum power_supply_property power_props[] = {
 351         POWER_SUPPLY_PROP_PRESENT,
 352         POWER_SUPPLY_PROP_ONLINE,
 353         POWER_SUPPLY_PROP_CURRENT_MAX,
 354         POWER_SUPPLY_PROP_MODEL_NAME,
 355         POWER_SUPPLY_PROP_MANUFACTURER,
 356 };
 357
 358 static inline int isp1704_test_ulpi(struct isp1704_charger *isp)
 359 {
 360         int vendor;
 361         int product;
 362         int i;
 363         int ret = -ENODEV;
 364
 365         /* Test ULPI interface */
 366         ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
 367         if (ret < 0)
 368                 return ret;
 369
 370         ret = isp1704_read(isp, ULPI_SCRATCH);
 371         if (ret < 0)
 372                 return ret;
 373
 374         if (ret != 0xaa)
 375                 return -ENODEV;
 376
 377         /* Verify the product and vendor id matches */
 378         vendor = isp1704_read(isp, ULPI_VENDOR_ID_LOW);
 379         vendor |= isp1704_read(isp, ULPI_VENDOR_ID_HIGH) << 8;
 380         if (vendor != NXP_VENDOR_ID)
 381                 return -ENODEV;
 382
 383         product = isp1704_read(isp, ULPI_PRODUCT_ID_LOW);
 384         product |= isp1704_read(isp, ULPI_PRODUCT_ID_HIGH) << 8;
 385
 386         for (i = 0; i < ARRAY_SIZE(isp170x_id); i++) {
 387                 if (product == isp170x_id[i]) {
 388                         sprintf(isp->model, "isp%x", product);
 389                         return product;
 390                 }
 391         }
 392
 393         dev_err(isp->dev, "product id %x not matching known ids", product);
 394
 395         return -ENODEV;
 396 }
 397
 398 static int isp1704_charger_probe(struct platform_device *pdev)
 399 {
 400         struct isp1704_charger  *isp;
 401         int                     ret = -ENODEV;
 402
 403         isp = devm_kzalloc(&pdev->dev, sizeof(*isp), GFP_KERNEL);
 404         if (!isp)
 405                 return -ENOMEM;
 406
 407         isp->phy = usb_get_phy(USB_PHY_TYPE_USB2);
 408         if (IS_ERR_OR_NULL(isp->phy))
 409                 goto fail0;
 410
 411         isp->dev = &pdev->dev;
 412         platform_set_drvdata(pdev, isp);
 413
 414         isp1704_charger_set_power(isp, 1);
 415
 416         ret = isp1704_test_ulpi(isp);
 417         if (ret < 0)
 418                 goto fail1;
 419
 420         isp->psy.name           = "isp1704";
 421         isp->psy.type           = POWER_SUPPLY_TYPE_USB;
 422         isp->psy.properties     = power_props;
 423         isp->psy.num_properties = ARRAY_SIZE(power_props);
 424         isp->psy.get_property   = isp1704_charger_get_property;
 425
 426         ret = power_supply_register(isp->dev, &isp->psy);
 427         if (ret)
 428                 goto fail1;
 429
 430         /*
 431          * REVISIT: using work in order to allow the usb notifications to be
 432          * made atomically in the future.
 433          */
 434         INIT_WORK(&isp->work, isp1704_charger_work);
 435
 436         isp->nb.notifier_call = isp1704_notifier_call;
 437
 438         ret = usb_register_notifier(isp->phy, &isp->nb);
 439         if (ret)
 440                 goto fail2;
 441
 442         dev_info(isp->dev, "registered with product id %s\n", isp->model);
 443
 444         /*
 445          * Taking over the D+ pullup.
 446          *
 447          * FIXME: The device will be disconnected if it was already
 448          * enumerated. The charger driver should be always loaded before any
 449          * gadget is loaded.
 450          */
 451         if (isp->phy->otg->gadget)
 452                 usb_gadget_disconnect(isp->phy->otg->gadget);
 453
 454         if (isp->phy->last_event == USB_EVENT_NONE)
 455                 isp1704_charger_set_power(isp, 0);
 456
 457         /* Detect charger if VBUS is valid (the cable was already plugged). */
 458         if (isp->phy->last_event == USB_EVENT_VBUS &&
 459                         !isp->phy->otg->default_a)
 460                 schedule_work(&isp->work);
 461
 462         return 0;
 463 fail2:
 464         power_supply_unregister(&isp->psy);
 465 fail1:
 466         isp1704_charger_set_power(isp, 0);
 467         usb_put_phy(isp->phy);
 468 fail0:
 469         dev_err(&pdev->dev, "failed to register isp1704 with error %d\n", ret);
 470
 471         return ret;
 472 }
 473
 474 static int isp1704_charger_remove(struct platform_device *pdev)
 475 {
 476         struct isp1704_charger *isp = platform_get_drvdata(pdev);
 477
 478         usb_unregister_notifier(isp->phy, &isp->nb);
 479         power_supply_unregister(&isp->psy);
 480         usb_put_phy(isp->phy);
 481         isp1704_charger_set_power(isp, 0);
 482
 483         return 0;
 484 }
 485
 486 static struct platform_driver isp1704_charger_driver = {
 487         .driver = {
 488                 .name = "isp1704_charger",
 489         },
 490         .probe = isp1704_charger_probe,
 491         .remove = isp1704_charger_remove,
 492 };
 493
 494 module_platform_driver(isp1704_charger_driver);
 495
 496 MODULE_ALIAS("platform:isp1704_charger");
 497 MODULE_AUTHOR("Nokia Corporation");
 498 MODULE_DESCRIPTION("ISP170x USB Charger driver");
 499 MODULE_LICENSE("GPL");