drivers/power/twl4030_charger.c

   1 /*
   2  * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
   3  *
   4  * Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
   5  *
   6  * based on twl4030_bci_battery.c by TI
   7  * Copyright (C) 2008 Texas Instruments, Inc.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/i2c/twl.h>
  21 #include <linux/power_supply.h>
  22 #include <linux/notifier.h>
  23 #include <linux/usb/otg.h>
  24
  25 #define TWL4030_BCIMSTATEC      0x02
  26 #define TWL4030_BCIICHG         0x08
  27 #define TWL4030_BCIVAC          0x0a
  28 #define TWL4030_BCIVBUS         0x0c
  29 #define TWL4030_BCIMFSTS4       0x10
  30 #define TWL4030_BCICTL1         0x23
  31
  32 #define TWL4030_BCIAUTOWEN      BIT(5)
  33 #define TWL4030_CONFIG_DONE     BIT(4)
  34 #define TWL4030_BCIAUTOUSB      BIT(1)
  35 #define TWL4030_BCIAUTOAC       BIT(0)
  36 #define TWL4030_CGAIN           BIT(5)
  37 #define TWL4030_USBFASTMCHG     BIT(2)
  38 #define TWL4030_STS_VBUS        BIT(7)
  39 #define TWL4030_STS_USB_ID      BIT(2)
  40
  41 /* BCI interrupts */
  42 #define TWL4030_WOVF            BIT(0) /* Watchdog overflow */
  43 #define TWL4030_TMOVF           BIT(1) /* Timer overflow */
  44 #define TWL4030_ICHGHIGH        BIT(2) /* Battery charge current high */
  45 #define TWL4030_ICHGLOW         BIT(3) /* Battery cc. low / FSM state change */
  46 #define TWL4030_ICHGEOC         BIT(4) /* Battery current end-of-charge */
  47 #define TWL4030_TBATOR2         BIT(5) /* Battery temperature out of range 2 */
  48 #define TWL4030_TBATOR1         BIT(6) /* Battery temperature out of range 1 */
  49 #define TWL4030_BATSTS          BIT(7) /* Battery status */
  50
  51 #define TWL4030_VBATLVL         BIT(0) /* VBAT level */
  52 #define TWL4030_VBATOV          BIT(1) /* VBAT overvoltage */
  53 #define TWL4030_VBUSOV          BIT(2) /* VBUS overvoltage */
  54 #define TWL4030_ACCHGOV         BIT(3) /* Ac charger overvoltage */
  55
  56 #define TWL4030_MSTATEC_USB             BIT(4)
  57 #define TWL4030_MSTATEC_AC              BIT(5)
  58 #define TWL4030_MSTATEC_MASK            0x0f
  59 #define TWL4030_MSTATEC_QUICK1          0x02
  60 #define TWL4030_MSTATEC_QUICK7          0x07
  61 #define TWL4030_MSTATEC_COMPLETE1       0x0b
  62 #define TWL4030_MSTATEC_COMPLETE4       0x0e
  63
  64 static bool allow_usb;
  65 module_param(allow_usb, bool, 0644);
  66 MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");
  67
  68 struct twl4030_bci {
  69         struct device           *dev;
  70         struct power_supply     ac;
  71         struct power_supply     usb;
  72         struct otg_transceiver  *transceiver;
  73         struct notifier_block   otg_nb;
  74         struct work_struct      work;
  75         int                     irq_chg;
  76         int                     irq_bci;
  77
  78         unsigned long           event;
  79 };
  80
  81 /*
  82  * clear and set bits on an given register on a given module
  83  */
  84 static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
  85 {
  86         u8 val = 0;
  87         int ret;
  88
  89         ret = twl_i2c_read_u8(mod_no, &val, reg);
  90         if (ret)
  91                 return ret;
  92
  93         val &= ~clear;
  94         val |= set;
  95
  96         return twl_i2c_write_u8(mod_no, val, reg);
  97 }
  98
  99 static int twl4030_bci_read(u8 reg, u8 *val)
 100 {
 101         return twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, val, reg);
 102 }
 103
 104 static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
 105 {
 106         return twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
 107                         TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
 108                         TWL4030_PM_MASTER_BOOT_BCI);
 109 }
 110
 111 static int twl4030bci_read_adc_val(u8 reg)
 112 {
 113         int ret, temp;
 114         u8 val;
 115
 116         /* read MSB */
 117         ret = twl4030_bci_read(reg + 1, &val);
 118         if (ret)
 119                 return ret;
 120
 121         temp = (int)(val & 0x03) << 8;
 122
 123         /* read LSB */
 124         ret = twl4030_bci_read(reg, &val);
 125         if (ret)
 126                 return ret;
 127
 128         return temp | val;
 129 }
 130
 131 /*
 132  * Check if VBUS power is present
 133  */
 134 static int twl4030_bci_have_vbus(struct twl4030_bci *bci)
 135 {
 136         int ret;
 137         u8 hwsts;
 138
 139         ret = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
 140                               TWL4030_PM_MASTER_STS_HW_CONDITIONS);
 141         if (ret < 0)
 142                 return 0;
 143
 144         dev_dbg(bci->dev, "check_vbus: HW_CONDITIONS %02x\n", hwsts);
 145
 146         /* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
 147         if ((hwsts & TWL4030_STS_VBUS) && !(hwsts & TWL4030_STS_USB_ID))
 148                 return 1;
 149
 150         return 0;
 151 }
 152
 153 /*
 154  * Enable/Disable USB Charge funtionality.
 155  */
 156 static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
 157 {
 158         int ret;
 159
 160         if (enable) {
 161                 /* Check for USB charger conneted */
 162                 if (!twl4030_bci_have_vbus(bci))
 163                         return -ENODEV;
 164
 165                 /*
 166                  * Until we can find out what current the device can provide,
 167                  * require a module param to enable USB charging.
 168                  */
 169                 if (!allow_usb) {
 170                         dev_warn(bci->dev, "USB charging is disabled.\n");
 171                         return -EACCES;
 172                 }
 173
 174                 /* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
 175                 ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
 176                 if (ret < 0)
 177                         return ret;
 178
 179                 /* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
 180                 ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
 181                         TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
 182         } else {
 183                 ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
 184         }
 185
 186         return ret;
 187 }
 188
 189 /*
 190  * Enable/Disable AC Charge funtionality.
 191  */
 192 static int twl4030_charger_enable_ac(bool enable)
 193 {
 194         int ret;
 195
 196         if (enable)
 197                 ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
 198         else
 199                 ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);
 200
 201         return ret;
 202 }
 203
 204 /*
 205  * TWL4030 CHG_PRES (AC charger presence) events
 206  */
 207 static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
 208 {
 209         struct twl4030_bci *bci = arg;
 210
 211         dev_dbg(bci->dev, "CHG_PRES irq\n");
 212         power_supply_changed(&bci->ac);
 213         power_supply_changed(&bci->usb);
 214
 215         return IRQ_HANDLED;
 216 }
 217
 218 /*
 219  * TWL4030 BCI monitoring events
 220  */
 221 static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
 222 {
 223         struct twl4030_bci *bci = arg;
 224         u8 irqs1, irqs2;
 225         int ret;
 226
 227         ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
 228                               TWL4030_INTERRUPTS_BCIISR1A);
 229         if (ret < 0)
 230                 return IRQ_HANDLED;
 231
 232         ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
 233                               TWL4030_INTERRUPTS_BCIISR2A);
 234         if (ret < 0)
 235                 return IRQ_HANDLED;
 236
 237         dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);
 238
 239         if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
 240                 /* charger state change, inform the core */
 241                 power_supply_changed(&bci->ac);
 242                 power_supply_changed(&bci->usb);
 243         }
 244
 245         /* various monitoring events, for now we just log them here */
 246         if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
 247                 dev_warn(bci->dev, "battery temperature out of range\n");
 248
 249         if (irqs1 & TWL4030_BATSTS)
 250                 dev_crit(bci->dev, "battery disconnected\n");
 251
 252         if (irqs2 & TWL4030_VBATOV)
 253                 dev_crit(bci->dev, "VBAT overvoltage\n");
 254
 255         if (irqs2 & TWL4030_VBUSOV)
 256                 dev_crit(bci->dev, "VBUS overvoltage\n");
 257
 258         if (irqs2 & TWL4030_ACCHGOV)
 259                 dev_crit(bci->dev, "Ac charger overvoltage\n");
 260
 261         return IRQ_HANDLED;
 262 }
 263
 264 static void twl4030_bci_usb_work(struct work_struct *data)
 265 {
 266         struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
 267
 268         switch (bci->event) {
 269         case USB_EVENT_VBUS:
 270         case USB_EVENT_CHARGER:
 271                 twl4030_charger_enable_usb(bci, true);
 272                 break;
 273         case USB_EVENT_NONE:
 274                 twl4030_charger_enable_usb(bci, false);
 275                 break;
 276         }
 277 }
 278
 279 static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
 280                                void *priv)
 281 {
 282         struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, otg_nb);
 283
 284         dev_dbg(bci->dev, "OTG notify %lu\n", val);
 285
 286         bci->event = val;
 287         schedule_work(&bci->work);
 288
 289         return NOTIFY_OK;
 290 }
 291
 292 /*
 293  * TI provided formulas:
 294  * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
 295  * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
 296  * Here we use integer approximation of:
 297  * CGAIN == 0: val * 1.6618 - 0.85
 298  * CGAIN == 1: (val * 1.6618 - 0.85) * 2
 299  */
 300 static int twl4030_charger_get_current(void)
 301 {
 302         int curr;
 303         int ret;
 304         u8 bcictl1;
 305
 306         curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
 307         if (curr < 0)
 308                 return curr;
 309
 310         ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
 311         if (ret)
 312                 return ret;
 313
 314         ret = (curr * 16618 - 850 * 10000) / 10;
 315         if (bcictl1 & TWL4030_CGAIN)
 316                 ret *= 2;
 317
 318         return ret;
 319 }
 320
 321 /*
 322  * Returns the main charge FSM state
 323  * Or < 0 on failure.
 324  */
 325 static int twl4030bci_state(struct twl4030_bci *bci)
 326 {
 327         int ret;
 328         u8 state;
 329
 330         ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
 331         if (ret) {
 332                 pr_err("twl4030_bci: error reading BCIMSTATEC\n");
 333                 return ret;
 334         }
 335
 336         dev_dbg(bci->dev, "state: %02x\n", state);
 337
 338         return state;
 339 }
 340
 341 static int twl4030_bci_state_to_status(int state)
 342 {
 343         state &= TWL4030_MSTATEC_MASK;
 344         if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
 345                 return POWER_SUPPLY_STATUS_CHARGING;
 346         else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
 347                                         state <= TWL4030_MSTATEC_COMPLETE4)
 348                 return POWER_SUPPLY_STATUS_FULL;
 349         else
 350                 return POWER_SUPPLY_STATUS_NOT_CHARGING;
 351 }
 352
 353 static int twl4030_bci_get_property(struct power_supply *psy,
 354                                     enum power_supply_property psp,
 355                                     union power_supply_propval *val)
 356 {
 357         struct twl4030_bci *bci = dev_get_drvdata(psy->dev->parent);
 358         int is_charging;
 359         int state;
 360         int ret;
 361
 362         state = twl4030bci_state(bci);
 363         if (state < 0)
 364                 return state;
 365
 366         if (psy->type == POWER_SUPPLY_TYPE_USB)
 367                 is_charging = state & TWL4030_MSTATEC_USB;
 368         else
 369                 is_charging = state & TWL4030_MSTATEC_AC;
 370
 371         switch (psp) {
 372         case POWER_SUPPLY_PROP_STATUS:
 373                 if (is_charging)
 374                         val->intval = twl4030_bci_state_to_status(state);
 375                 else
 376                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 377                 break;
 378         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 379                 /* charging must be active for meaningful result */
 380                 if (!is_charging)
 381                         return -ENODATA;
 382                 if (psy->type == POWER_SUPPLY_TYPE_USB) {
 383                         ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
 384                         if (ret < 0)
 385                                 return ret;
 386                         /* BCIVBUS uses ADCIN8, 7/1023 V/step */
 387                         val->intval = ret * 6843;
 388                 } else {
 389                         ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
 390                         if (ret < 0)
 391                                 return ret;
 392                         /* BCIVAC uses ADCIN11, 10/1023 V/step */
 393                         val->intval = ret * 9775;
 394                 }
 395                 break;
 396         case POWER_SUPPLY_PROP_CURRENT_NOW:
 397                 if (!is_charging)
 398                         return -ENODATA;
 399                 /* current measurement is shared between AC and USB */
 400                 ret = twl4030_charger_get_current();
 401                 if (ret < 0)
 402                         return ret;
 403                 val->intval = ret;
 404                 break;
 405         case POWER_SUPPLY_PROP_ONLINE:
 406                 val->intval = is_charging &&
 407                         twl4030_bci_state_to_status(state) !=
 408                                 POWER_SUPPLY_STATUS_NOT_CHARGING;
 409                 break;
 410         default:
 411                 return -EINVAL;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static enum power_supply_property twl4030_charger_props[] = {
 418         POWER_SUPPLY_PROP_STATUS,
 419         POWER_SUPPLY_PROP_ONLINE,
 420         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 421         POWER_SUPPLY_PROP_CURRENT_NOW,
 422 };
 423
 424 static int __init twl4030_bci_probe(struct platform_device *pdev)
 425 {
 426         struct twl4030_bci *bci;
 427         int ret;
 428         u32 reg;
 429
 430         bci = kzalloc(sizeof(*bci), GFP_KERNEL);
 431         if (bci == NULL)
 432                 return -ENOMEM;
 433
 434         bci->dev = &pdev->dev;
 435         bci->irq_chg = platform_get_irq(pdev, 0);
 436         bci->irq_bci = platform_get_irq(pdev, 1);
 437
 438         platform_set_drvdata(pdev, bci);
 439
 440         bci->ac.name = "twl4030_ac";
 441         bci->ac.type = POWER_SUPPLY_TYPE_MAINS;
 442         bci->ac.properties = twl4030_charger_props;
 443         bci->ac.num_properties = ARRAY_SIZE(twl4030_charger_props);
 444         bci->ac.get_property = twl4030_bci_get_property;
 445
 446         ret = power_supply_register(&pdev->dev, &bci->ac);
 447         if (ret) {
 448                 dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
 449                 goto fail_register_ac;
 450         }
 451
 452         bci->usb.name = "twl4030_usb";
 453         bci->usb.type = POWER_SUPPLY_TYPE_USB;
 454         bci->usb.properties = twl4030_charger_props;
 455         bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
 456         bci->usb.get_property = twl4030_bci_get_property;
 457
 458         ret = power_supply_register(&pdev->dev, &bci->usb);
 459         if (ret) {
 460                 dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
 461                 goto fail_register_usb;
 462         }
 463
 464         ret = request_threaded_irq(bci->irq_chg, NULL,
 465                         twl4030_charger_interrupt, 0, pdev->name, bci);
 466         if (ret < 0) {
 467                 dev_err(&pdev->dev, "could not request irq %d, status %d\n",
 468                         bci->irq_chg, ret);
 469                 goto fail_chg_irq;
 470         }
 471
 472         ret = request_threaded_irq(bci->irq_bci, NULL,
 473                         twl4030_bci_interrupt, 0, pdev->name, bci);
 474         if (ret < 0) {
 475                 dev_err(&pdev->dev, "could not request irq %d, status %d\n",
 476                         bci->irq_bci, ret);
 477                 goto fail_bci_irq;
 478         }
 479
 480         INIT_WORK(&bci->work, twl4030_bci_usb_work);
 481
 482         bci->transceiver = otg_get_transceiver();
 483         if (bci->transceiver != NULL) {
 484                 bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
 485                 otg_register_notifier(bci->transceiver, &bci->otg_nb);
 486         }
 487
 488         /* Enable interrupts now. */
 489         reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
 490                 TWL4030_TBATOR1 | TWL4030_BATSTS);
 491         ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
 492                                TWL4030_INTERRUPTS_BCIIMR1A);
 493         if (ret < 0) {
 494                 dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
 495                 goto fail_unmask_interrupts;
 496         }
 497
 498         reg = ~(u32)(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
 499         ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
 500                                TWL4030_INTERRUPTS_BCIIMR2A);
 501         if (ret < 0)
 502                 dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
 503
 504         twl4030_charger_enable_ac(true);
 505         twl4030_charger_enable_usb(bci, true);
 506
 507         return 0;
 508
 509 fail_unmask_interrupts:
 510         if (bci->transceiver != NULL) {
 511                 otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
 512                 otg_put_transceiver(bci->transceiver);
 513         }
 514         free_irq(bci->irq_bci, bci);
 515 fail_bci_irq:
 516         free_irq(bci->irq_chg, bci);
 517 fail_chg_irq:
 518         power_supply_unregister(&bci->usb);
 519 fail_register_usb:
 520         power_supply_unregister(&bci->ac);
 521 fail_register_ac:
 522         platform_set_drvdata(pdev, NULL);
 523         kfree(bci);
 524
 525         return ret;
 526 }
 527
 528 static int __exit twl4030_bci_remove(struct platform_device *pdev)
 529 {
 530         struct twl4030_bci *bci = platform_get_drvdata(pdev);
 531
 532         twl4030_charger_enable_ac(false);
 533         twl4030_charger_enable_usb(bci, false);
 534
 535         /* mask interrupts */
 536         twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
 537                          TWL4030_INTERRUPTS_BCIIMR1A);
 538         twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
 539                          TWL4030_INTERRUPTS_BCIIMR2A);
 540
 541         if (bci->transceiver != NULL) {
 542                 otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
 543                 otg_put_transceiver(bci->transceiver);
 544         }
 545         free_irq(bci->irq_bci, bci);
 546         free_irq(bci->irq_chg, bci);
 547         power_supply_unregister(&bci->usb);
 548         power_supply_unregister(&bci->ac);
 549         platform_set_drvdata(pdev, NULL);
 550         kfree(bci);
 551
 552         return 0;
 553 }
 554
 555 static struct platform_driver twl4030_bci_driver = {
 556         .driver = {
 557                 .name   = "twl4030_bci",
 558                 .owner  = THIS_MODULE,
 559         },
 560         .remove = __exit_p(twl4030_bci_remove),
 561 };
 562
 563 static int __init twl4030_bci_init(void)
 564 {
 565         return platform_driver_probe(&twl4030_bci_driver, twl4030_bci_probe);
 566 }
 567 module_init(twl4030_bci_init);
 568
 569 static void __exit twl4030_bci_exit(void)
 570 {
 571         platform_driver_unregister(&twl4030_bci_driver);
 572 }
 573 module_exit(twl4030_bci_exit);
 574
 575 MODULE_AUTHOR("Gražvydas Ignotas");
 576 MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
 577 MODULE_LICENSE("GPL");
 578 MODULE_ALIAS("platform:twl4030_bci");