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