linux/drivers/power/pda_power.c
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   1/*
   2 * Common power driver for PDAs and phones with one or two external
   3 * power supplies (AC/USB) connected to main and backup batteries,
   4 * and optional builtin charger.
   5 *
   6 * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/platform_device.h>
  15#include <linux/err.h>
  16#include <linux/interrupt.h>
  17#include <linux/notifier.h>
  18#include <linux/power_supply.h>
  19#include <linux/pda_power.h>
  20#include <linux/regulator/consumer.h>
  21#include <linux/timer.h>
  22#include <linux/jiffies.h>
  23#include <linux/usb/otg.h>
  24
  25static inline unsigned int get_irq_flags(struct resource *res)
  26{
  27        return IRQF_SHARED | (res->flags & IRQF_TRIGGER_MASK);
  28}
  29
  30static struct device *dev;
  31static struct pda_power_pdata *pdata;
  32static struct resource *ac_irq, *usb_irq;
  33static struct timer_list charger_timer;
  34static struct timer_list supply_timer;
  35static struct timer_list polling_timer;
  36static int polling;
  37static struct power_supply *pda_psy_ac, *pda_psy_usb;
  38
  39#if IS_ENABLED(CONFIG_USB_PHY)
  40static struct usb_phy *transceiver;
  41static struct notifier_block otg_nb;
  42#endif
  43
  44static struct regulator *ac_draw;
  45
  46enum {
  47        PDA_PSY_OFFLINE = 0,
  48        PDA_PSY_ONLINE = 1,
  49        PDA_PSY_TO_CHANGE,
  50};
  51static int new_ac_status = -1;
  52static int new_usb_status = -1;
  53static int ac_status = -1;
  54static int usb_status = -1;
  55
  56static int pda_power_get_property(struct power_supply *psy,
  57                                  enum power_supply_property psp,
  58                                  union power_supply_propval *val)
  59{
  60        switch (psp) {
  61        case POWER_SUPPLY_PROP_ONLINE:
  62                if (psy->desc->type == POWER_SUPPLY_TYPE_MAINS)
  63                        val->intval = pdata->is_ac_online ?
  64                                      pdata->is_ac_online() : 0;
  65                else
  66                        val->intval = pdata->is_usb_online ?
  67                                      pdata->is_usb_online() : 0;
  68                break;
  69        default:
  70                return -EINVAL;
  71        }
  72        return 0;
  73}
  74
  75static enum power_supply_property pda_power_props[] = {
  76        POWER_SUPPLY_PROP_ONLINE,
  77};
  78
  79static char *pda_power_supplied_to[] = {
  80        "main-battery",
  81        "backup-battery",
  82};
  83
  84static const struct power_supply_desc pda_psy_ac_desc = {
  85        .name = "ac",
  86        .type = POWER_SUPPLY_TYPE_MAINS,
  87        .properties = pda_power_props,
  88        .num_properties = ARRAY_SIZE(pda_power_props),
  89        .get_property = pda_power_get_property,
  90};
  91
  92static const struct power_supply_desc pda_psy_usb_desc = {
  93        .name = "usb",
  94        .type = POWER_SUPPLY_TYPE_USB,
  95        .properties = pda_power_props,
  96        .num_properties = ARRAY_SIZE(pda_power_props),
  97        .get_property = pda_power_get_property,
  98};
  99
 100static void update_status(void)
 101{
 102        if (pdata->is_ac_online)
 103                new_ac_status = !!pdata->is_ac_online();
 104
 105        if (pdata->is_usb_online)
 106                new_usb_status = !!pdata->is_usb_online();
 107}
 108
 109static void update_charger(void)
 110{
 111        static int regulator_enabled;
 112        int max_uA = pdata->ac_max_uA;
 113
 114        if (pdata->set_charge) {
 115                if (new_ac_status > 0) {
 116                        dev_dbg(dev, "charger on (AC)\n");
 117                        pdata->set_charge(PDA_POWER_CHARGE_AC);
 118                } else if (new_usb_status > 0) {
 119                        dev_dbg(dev, "charger on (USB)\n");
 120                        pdata->set_charge(PDA_POWER_CHARGE_USB);
 121                } else {
 122                        dev_dbg(dev, "charger off\n");
 123                        pdata->set_charge(0);
 124                }
 125        } else if (ac_draw) {
 126                if (new_ac_status > 0) {
 127                        regulator_set_current_limit(ac_draw, max_uA, max_uA);
 128                        if (!regulator_enabled) {
 129                                dev_dbg(dev, "charger on (AC)\n");
 130                                WARN_ON(regulator_enable(ac_draw));
 131                                regulator_enabled = 1;
 132                        }
 133                } else {
 134                        if (regulator_enabled) {
 135                                dev_dbg(dev, "charger off\n");
 136                                WARN_ON(regulator_disable(ac_draw));
 137                                regulator_enabled = 0;
 138                        }
 139                }
 140        }
 141}
 142
 143static void supply_timer_func(unsigned long unused)
 144{
 145        if (ac_status == PDA_PSY_TO_CHANGE) {
 146                ac_status = new_ac_status;
 147                power_supply_changed(pda_psy_ac);
 148        }
 149
 150        if (usb_status == PDA_PSY_TO_CHANGE) {
 151                usb_status = new_usb_status;
 152                power_supply_changed(pda_psy_usb);
 153        }
 154}
 155
 156static void psy_changed(void)
 157{
 158        update_charger();
 159
 160        /*
 161         * Okay, charger set. Now wait a bit before notifying supplicants,
 162         * charge power should stabilize.
 163         */
 164        mod_timer(&supply_timer,
 165                  jiffies + msecs_to_jiffies(pdata->wait_for_charger));
 166}
 167
 168static void charger_timer_func(unsigned long unused)
 169{
 170        update_status();
 171        psy_changed();
 172}
 173
 174static irqreturn_t power_changed_isr(int irq, void *power_supply)
 175{
 176        if (power_supply == pda_psy_ac)
 177                ac_status = PDA_PSY_TO_CHANGE;
 178        else if (power_supply == pda_psy_usb)
 179                usb_status = PDA_PSY_TO_CHANGE;
 180        else
 181                return IRQ_NONE;
 182
 183        /*
 184         * Wait a bit before reading ac/usb line status and setting charger,
 185         * because ac/usb status readings may lag from irq.
 186         */
 187        mod_timer(&charger_timer,
 188                  jiffies + msecs_to_jiffies(pdata->wait_for_status));
 189
 190        return IRQ_HANDLED;
 191}
 192
 193static void polling_timer_func(unsigned long unused)
 194{
 195        int changed = 0;
 196
 197        dev_dbg(dev, "polling...\n");
 198
 199        update_status();
 200
 201        if (!ac_irq && new_ac_status != ac_status) {
 202                ac_status = PDA_PSY_TO_CHANGE;
 203                changed = 1;
 204        }
 205
 206        if (!usb_irq && new_usb_status != usb_status) {
 207                usb_status = PDA_PSY_TO_CHANGE;
 208                changed = 1;
 209        }
 210
 211        if (changed)
 212                psy_changed();
 213
 214        mod_timer(&polling_timer,
 215                  jiffies + msecs_to_jiffies(pdata->polling_interval));
 216}
 217
 218#if IS_ENABLED(CONFIG_USB_PHY)
 219static int otg_is_usb_online(void)
 220{
 221        return (transceiver->last_event == USB_EVENT_VBUS ||
 222                transceiver->last_event == USB_EVENT_ENUMERATED);
 223}
 224
 225static int otg_is_ac_online(void)
 226{
 227        return (transceiver->last_event == USB_EVENT_CHARGER);
 228}
 229
 230static int otg_handle_notification(struct notifier_block *nb,
 231                unsigned long event, void *unused)
 232{
 233        switch (event) {
 234        case USB_EVENT_CHARGER:
 235                ac_status = PDA_PSY_TO_CHANGE;
 236                break;
 237        case USB_EVENT_VBUS:
 238        case USB_EVENT_ENUMERATED:
 239                usb_status = PDA_PSY_TO_CHANGE;
 240                break;
 241        case USB_EVENT_NONE:
 242                ac_status = PDA_PSY_TO_CHANGE;
 243                usb_status = PDA_PSY_TO_CHANGE;
 244                break;
 245        default:
 246                return NOTIFY_OK;
 247        }
 248
 249        /*
 250         * Wait a bit before reading ac/usb line status and setting charger,
 251         * because ac/usb status readings may lag from irq.
 252         */
 253        mod_timer(&charger_timer,
 254                  jiffies + msecs_to_jiffies(pdata->wait_for_status));
 255
 256        return NOTIFY_OK;
 257}
 258#endif
 259
 260static int pda_power_probe(struct platform_device *pdev)
 261{
 262        struct power_supply_config psy_cfg = {};
 263        int ret = 0;
 264
 265        dev = &pdev->dev;
 266
 267        if (pdev->id != -1) {
 268                dev_err(dev, "it's meaningless to register several "
 269                        "pda_powers; use id = -1\n");
 270                ret = -EINVAL;
 271                goto wrongid;
 272        }
 273
 274        pdata = pdev->dev.platform_data;
 275
 276        if (pdata->init) {
 277                ret = pdata->init(dev);
 278                if (ret < 0)
 279                        goto init_failed;
 280        }
 281
 282        ac_draw = regulator_get(dev, "ac_draw");
 283        if (IS_ERR(ac_draw)) {
 284                dev_dbg(dev, "couldn't get ac_draw regulator\n");
 285                ac_draw = NULL;
 286        }
 287
 288        update_status();
 289        update_charger();
 290
 291        if (!pdata->wait_for_status)
 292                pdata->wait_for_status = 500;
 293
 294        if (!pdata->wait_for_charger)
 295                pdata->wait_for_charger = 500;
 296
 297        if (!pdata->polling_interval)
 298                pdata->polling_interval = 2000;
 299
 300        if (!pdata->ac_max_uA)
 301                pdata->ac_max_uA = 500000;
 302
 303        setup_timer(&charger_timer, charger_timer_func, 0);
 304        setup_timer(&supply_timer, supply_timer_func, 0);
 305
 306        ac_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "ac");
 307        usb_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "usb");
 308
 309        if (pdata->supplied_to) {
 310                psy_cfg.supplied_to = pdata->supplied_to;
 311                psy_cfg.num_supplicants = pdata->num_supplicants;
 312        } else {
 313                psy_cfg.supplied_to = pda_power_supplied_to;
 314                psy_cfg.num_supplicants = ARRAY_SIZE(pda_power_supplied_to);
 315        }
 316
 317#if IS_ENABLED(CONFIG_USB_PHY)
 318        transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
 319        if (!IS_ERR_OR_NULL(transceiver)) {
 320                if (!pdata->is_usb_online)
 321                        pdata->is_usb_online = otg_is_usb_online;
 322                if (!pdata->is_ac_online)
 323                        pdata->is_ac_online = otg_is_ac_online;
 324        }
 325#endif
 326
 327        if (pdata->is_ac_online) {
 328                pda_psy_ac = power_supply_register(&pdev->dev,
 329                                                   &pda_psy_ac_desc, &psy_cfg);
 330                if (IS_ERR(pda_psy_ac)) {
 331                        dev_err(dev, "failed to register %s power supply\n",
 332                                pda_psy_ac_desc.name);
 333                        ret = PTR_ERR(pda_psy_ac);
 334                        goto ac_supply_failed;
 335                }
 336
 337                if (ac_irq) {
 338                        ret = request_irq(ac_irq->start, power_changed_isr,
 339                                          get_irq_flags(ac_irq), ac_irq->name,
 340                                          pda_psy_ac);
 341                        if (ret) {
 342                                dev_err(dev, "request ac irq failed\n");
 343                                goto ac_irq_failed;
 344                        }
 345                } else {
 346                        polling = 1;
 347                }
 348        }
 349
 350        if (pdata->is_usb_online) {
 351                pda_psy_usb = power_supply_register(&pdev->dev,
 352                                                    &pda_psy_usb_desc,
 353                                                    &psy_cfg);
 354                if (IS_ERR(pda_psy_usb)) {
 355                        dev_err(dev, "failed to register %s power supply\n",
 356                                pda_psy_usb_desc.name);
 357                        ret = PTR_ERR(pda_psy_usb);
 358                        goto usb_supply_failed;
 359                }
 360
 361                if (usb_irq) {
 362                        ret = request_irq(usb_irq->start, power_changed_isr,
 363                                          get_irq_flags(usb_irq),
 364                                          usb_irq->name, pda_psy_usb);
 365                        if (ret) {
 366                                dev_err(dev, "request usb irq failed\n");
 367                                goto usb_irq_failed;
 368                        }
 369                } else {
 370                        polling = 1;
 371                }
 372        }
 373
 374#if IS_ENABLED(CONFIG_USB_PHY)
 375        if (!IS_ERR_OR_NULL(transceiver) && pdata->use_otg_notifier) {
 376                otg_nb.notifier_call = otg_handle_notification;
 377                ret = usb_register_notifier(transceiver, &otg_nb);
 378                if (ret) {
 379                        dev_err(dev, "failure to register otg notifier\n");
 380                        goto otg_reg_notifier_failed;
 381                }
 382                polling = 0;
 383        }
 384#endif
 385
 386        if (polling) {
 387                dev_dbg(dev, "will poll for status\n");
 388                setup_timer(&polling_timer, polling_timer_func, 0);
 389                mod_timer(&polling_timer,
 390                          jiffies + msecs_to_jiffies(pdata->polling_interval));
 391        }
 392
 393        if (ac_irq || usb_irq)
 394                device_init_wakeup(&pdev->dev, 1);
 395
 396        return 0;
 397
 398#if IS_ENABLED(CONFIG_USB_PHY)
 399otg_reg_notifier_failed:
 400        if (pdata->is_usb_online && usb_irq)
 401                free_irq(usb_irq->start, pda_psy_usb);
 402#endif
 403usb_irq_failed:
 404        if (pdata->is_usb_online)
 405                power_supply_unregister(pda_psy_usb);
 406usb_supply_failed:
 407        if (pdata->is_ac_online && ac_irq)
 408                free_irq(ac_irq->start, pda_psy_ac);
 409#if IS_ENABLED(CONFIG_USB_PHY)
 410        if (!IS_ERR_OR_NULL(transceiver))
 411                usb_put_phy(transceiver);
 412#endif
 413ac_irq_failed:
 414        if (pdata->is_ac_online)
 415                power_supply_unregister(pda_psy_ac);
 416ac_supply_failed:
 417        if (ac_draw) {
 418                regulator_put(ac_draw);
 419                ac_draw = NULL;
 420        }
 421        if (pdata->exit)
 422                pdata->exit(dev);
 423init_failed:
 424wrongid:
 425        return ret;
 426}
 427
 428static int pda_power_remove(struct platform_device *pdev)
 429{
 430        if (pdata->is_usb_online && usb_irq)
 431                free_irq(usb_irq->start, pda_psy_usb);
 432        if (pdata->is_ac_online && ac_irq)
 433                free_irq(ac_irq->start, pda_psy_ac);
 434
 435        if (polling)
 436                del_timer_sync(&polling_timer);
 437        del_timer_sync(&charger_timer);
 438        del_timer_sync(&supply_timer);
 439
 440        if (pdata->is_usb_online)
 441                power_supply_unregister(pda_psy_usb);
 442        if (pdata->is_ac_online)
 443                power_supply_unregister(pda_psy_ac);
 444#if IS_ENABLED(CONFIG_USB_PHY)
 445        if (!IS_ERR_OR_NULL(transceiver))
 446                usb_put_phy(transceiver);
 447#endif
 448        if (ac_draw) {
 449                regulator_put(ac_draw);
 450                ac_draw = NULL;
 451        }
 452        if (pdata->exit)
 453                pdata->exit(dev);
 454
 455        return 0;
 456}
 457
 458#ifdef CONFIG_PM
 459static int ac_wakeup_enabled;
 460static int usb_wakeup_enabled;
 461
 462static int pda_power_suspend(struct platform_device *pdev, pm_message_t state)
 463{
 464        if (pdata->suspend) {
 465                int ret = pdata->suspend(state);
 466
 467                if (ret)
 468                        return ret;
 469        }
 470
 471        if (device_may_wakeup(&pdev->dev)) {
 472                if (ac_irq)
 473                        ac_wakeup_enabled = !enable_irq_wake(ac_irq->start);
 474                if (usb_irq)
 475                        usb_wakeup_enabled = !enable_irq_wake(usb_irq->start);
 476        }
 477
 478        return 0;
 479}
 480
 481static int pda_power_resume(struct platform_device *pdev)
 482{
 483        if (device_may_wakeup(&pdev->dev)) {
 484                if (usb_irq && usb_wakeup_enabled)
 485                        disable_irq_wake(usb_irq->start);
 486                if (ac_irq && ac_wakeup_enabled)
 487                        disable_irq_wake(ac_irq->start);
 488        }
 489
 490        if (pdata->resume)
 491                return pdata->resume();
 492
 493        return 0;
 494}
 495#else
 496#define pda_power_suspend NULL
 497#define pda_power_resume NULL
 498#endif /* CONFIG_PM */
 499
 500static struct platform_driver pda_power_pdrv = {
 501        .driver = {
 502                .name = "pda-power",
 503        },
 504        .probe = pda_power_probe,
 505        .remove = pda_power_remove,
 506        .suspend = pda_power_suspend,
 507        .resume = pda_power_resume,
 508};
 509
 510module_platform_driver(pda_power_pdrv);
 511
 512MODULE_LICENSE("GPL");
 513MODULE_AUTHOR("Anton Vorontsov <cbou@mail.ru>");
 514MODULE_ALIAS("platform:pda-power");
 515