linux/drivers/power/supply/pda_power.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Common power driver for PDAs and phones with one or two external
   4 * power supplies (AC/USB) connected to main and backup batteries,
   5 * and optional builtin charger.
   6 *
   7 * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/platform_device.h>
  12#include <linux/err.h>
  13#include <linux/interrupt.h>
  14#include <linux/notifier.h>
  15#include <linux/power_supply.h>
  16#include <linux/pda_power.h>
  17#include <linux/regulator/consumer.h>
  18#include <linux/timer.h>
  19#include <linux/jiffies.h>
  20#include <linux/usb/otg.h>
  21
  22static inline unsigned int get_irq_flags(struct resource *res)
  23{
  24        return IRQF_SHARED | (res->flags & IRQF_TRIGGER_MASK);
  25}
  26
  27static struct device *dev;
  28static struct pda_power_pdata *pdata;
  29static struct resource *ac_irq, *usb_irq;
  30static struct delayed_work charger_work;
  31static struct delayed_work polling_work;
  32static struct delayed_work supply_work;
  33static int polling;
  34static struct power_supply *pda_psy_ac, *pda_psy_usb;
  35
  36#if IS_ENABLED(CONFIG_USB_PHY)
  37static struct usb_phy *transceiver;
  38static struct notifier_block otg_nb;
  39#endif
  40
  41static struct regulator *ac_draw;
  42
  43enum {
  44        PDA_PSY_OFFLINE = 0,
  45        PDA_PSY_ONLINE = 1,
  46        PDA_PSY_TO_CHANGE,
  47};
  48static int new_ac_status = -1;
  49static int new_usb_status = -1;
  50static int ac_status = -1;
  51static int usb_status = -1;
  52
  53static int pda_power_get_property(struct power_supply *psy,
  54                                  enum power_supply_property psp,
  55                                  union power_supply_propval *val)
  56{
  57        switch (psp) {
  58        case POWER_SUPPLY_PROP_ONLINE:
  59                if (psy->desc->type == POWER_SUPPLY_TYPE_MAINS)
  60                        val->intval = pdata->is_ac_online ?
  61                                      pdata->is_ac_online() : 0;
  62                else
  63                        val->intval = pdata->is_usb_online ?
  64                                      pdata->is_usb_online() : 0;
  65                break;
  66        default:
  67                return -EINVAL;
  68        }
  69        return 0;
  70}
  71
  72static enum power_supply_property pda_power_props[] = {
  73        POWER_SUPPLY_PROP_ONLINE,
  74};
  75
  76static char *pda_power_supplied_to[] = {
  77        "main-battery",
  78        "backup-battery",
  79};
  80
  81static const struct power_supply_desc pda_psy_ac_desc = {
  82        .name = "ac",
  83        .type = POWER_SUPPLY_TYPE_MAINS,
  84        .properties = pda_power_props,
  85        .num_properties = ARRAY_SIZE(pda_power_props),
  86        .get_property = pda_power_get_property,
  87};
  88
  89static const struct power_supply_desc pda_psy_usb_desc = {
  90        .name = "usb",
  91        .type = POWER_SUPPLY_TYPE_USB,
  92        .properties = pda_power_props,
  93        .num_properties = ARRAY_SIZE(pda_power_props),
  94        .get_property = pda_power_get_property,
  95};
  96
  97static void update_status(void)
  98{
  99        if (pdata->is_ac_online)
 100                new_ac_status = !!pdata->is_ac_online();
 101
 102        if (pdata->is_usb_online)
 103                new_usb_status = !!pdata->is_usb_online();
 104}
 105
 106static void update_charger(void)
 107{
 108        static int regulator_enabled;
 109        int max_uA = pdata->ac_max_uA;
 110
 111        if (pdata->set_charge) {
 112                if (new_ac_status > 0) {
 113                        dev_dbg(dev, "charger on (AC)\n");
 114                        pdata->set_charge(PDA_POWER_CHARGE_AC);
 115                } else if (new_usb_status > 0) {
 116                        dev_dbg(dev, "charger on (USB)\n");
 117                        pdata->set_charge(PDA_POWER_CHARGE_USB);
 118                } else {
 119                        dev_dbg(dev, "charger off\n");
 120                        pdata->set_charge(0);
 121                }
 122        } else if (ac_draw) {
 123                if (new_ac_status > 0) {
 124                        regulator_set_current_limit(ac_draw, max_uA, max_uA);
 125                        if (!regulator_enabled) {
 126                                dev_dbg(dev, "charger on (AC)\n");
 127                                WARN_ON(regulator_enable(ac_draw));
 128                                regulator_enabled = 1;
 129                        }
 130                } else {
 131                        if (regulator_enabled) {
 132                                dev_dbg(dev, "charger off\n");
 133                                WARN_ON(regulator_disable(ac_draw));
 134                                regulator_enabled = 0;
 135                        }
 136                }
 137        }
 138}
 139
 140static void supply_work_func(struct work_struct *work)
 141{
 142        if (ac_status == PDA_PSY_TO_CHANGE) {
 143                ac_status = new_ac_status;
 144                power_supply_changed(pda_psy_ac);
 145        }
 146
 147        if (usb_status == PDA_PSY_TO_CHANGE) {
 148                usb_status = new_usb_status;
 149                power_supply_changed(pda_psy_usb);
 150        }
 151}
 152
 153static void psy_changed(void)
 154{
 155        update_charger();
 156
 157        /*
 158         * Okay, charger set. Now wait a bit before notifying supplicants,
 159         * charge power should stabilize.
 160         */
 161        cancel_delayed_work(&supply_work);
 162        schedule_delayed_work(&supply_work,
 163                              msecs_to_jiffies(pdata->wait_for_charger));
 164}
 165
 166static void charger_work_func(struct work_struct *work)
 167{
 168        update_status();
 169        psy_changed();
 170}
 171
 172static irqreturn_t power_changed_isr(int irq, void *power_supply)
 173{
 174        if (power_supply == pda_psy_ac)
 175                ac_status = PDA_PSY_TO_CHANGE;
 176        else if (power_supply == pda_psy_usb)
 177                usb_status = PDA_PSY_TO_CHANGE;
 178        else
 179                return IRQ_NONE;
 180
 181        /*
 182         * Wait a bit before reading ac/usb line status and setting charger,
 183         * because ac/usb status readings may lag from irq.
 184         */
 185        cancel_delayed_work(&charger_work);
 186        schedule_delayed_work(&charger_work,
 187                              msecs_to_jiffies(pdata->wait_for_status));
 188
 189        return IRQ_HANDLED;
 190}
 191
 192static void polling_work_func(struct work_struct *work)
 193{
 194        int changed = 0;
 195
 196        dev_dbg(dev, "polling...\n");
 197
 198        update_status();
 199
 200        if (!ac_irq && new_ac_status != ac_status) {
 201                ac_status = PDA_PSY_TO_CHANGE;
 202                changed = 1;
 203        }
 204
 205        if (!usb_irq && new_usb_status != usb_status) {
 206                usb_status = PDA_PSY_TO_CHANGE;
 207                changed = 1;
 208        }
 209
 210        if (changed)
 211                psy_changed();
 212
 213        cancel_delayed_work(&polling_work);
 214        schedule_delayed_work(&polling_work,
 215                              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        cancel_delayed_work(&charger_work);
 254        schedule_delayed_work(&charger_work,
 255                              msecs_to_jiffies(pdata->wait_for_status));
 256
 257        return NOTIFY_OK;
 258}
 259#endif
 260
 261static int pda_power_probe(struct platform_device *pdev)
 262{
 263        struct power_supply_config psy_cfg = {};
 264        int ret = 0;
 265
 266        dev = &pdev->dev;
 267
 268        if (pdev->id != -1) {
 269                dev_err(dev, "it's meaningless to register several "
 270                        "pda_powers; use id = -1\n");
 271                ret = -EINVAL;
 272                goto wrongid;
 273        }
 274
 275        pdata = pdev->dev.platform_data;
 276
 277        if (pdata->init) {
 278                ret = pdata->init(dev);
 279                if (ret < 0)
 280                        goto init_failed;
 281        }
 282
 283        ac_draw = regulator_get(dev, "ac_draw");
 284        if (IS_ERR(ac_draw)) {
 285                dev_dbg(dev, "couldn't get ac_draw regulator\n");
 286                ac_draw = NULL;
 287        }
 288
 289        update_status();
 290        update_charger();
 291
 292        if (!pdata->wait_for_status)
 293                pdata->wait_for_status = 500;
 294
 295        if (!pdata->wait_for_charger)
 296                pdata->wait_for_charger = 500;
 297
 298        if (!pdata->polling_interval)
 299                pdata->polling_interval = 2000;
 300
 301        if (!pdata->ac_max_uA)
 302                pdata->ac_max_uA = 500000;
 303
 304        INIT_DELAYED_WORK(&charger_work, charger_work_func);
 305        INIT_DELAYED_WORK(&supply_work, supply_work_func);
 306
 307        ac_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "ac");
 308        usb_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "usb");
 309
 310        if (pdata->supplied_to) {
 311                psy_cfg.supplied_to = pdata->supplied_to;
 312                psy_cfg.num_supplicants = pdata->num_supplicants;
 313        } else {
 314                psy_cfg.supplied_to = pda_power_supplied_to;
 315                psy_cfg.num_supplicants = ARRAY_SIZE(pda_power_supplied_to);
 316        }
 317
 318#if IS_ENABLED(CONFIG_USB_PHY)
 319        transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
 320        if (!IS_ERR_OR_NULL(transceiver)) {
 321                if (!pdata->is_usb_online)
 322                        pdata->is_usb_online = otg_is_usb_online;
 323                if (!pdata->is_ac_online)
 324                        pdata->is_ac_online = otg_is_ac_online;
 325        }
 326#endif
 327
 328        if (pdata->is_ac_online) {
 329                pda_psy_ac = power_supply_register(&pdev->dev,
 330                                                   &pda_psy_ac_desc, &psy_cfg);
 331                if (IS_ERR(pda_psy_ac)) {
 332                        dev_err(dev, "failed to register %s power supply\n",
 333                                pda_psy_ac_desc.name);
 334                        ret = PTR_ERR(pda_psy_ac);
 335                        goto ac_supply_failed;
 336                }
 337
 338                if (ac_irq) {
 339                        ret = request_irq(ac_irq->start, power_changed_isr,
 340                                          get_irq_flags(ac_irq), ac_irq->name,
 341                                          pda_psy_ac);
 342                        if (ret) {
 343                                dev_err(dev, "request ac irq failed\n");
 344                                goto ac_irq_failed;
 345                        }
 346                } else {
 347                        polling = 1;
 348                }
 349        }
 350
 351        if (pdata->is_usb_online) {
 352                pda_psy_usb = power_supply_register(&pdev->dev,
 353                                                    &pda_psy_usb_desc,
 354                                                    &psy_cfg);
 355                if (IS_ERR(pda_psy_usb)) {
 356                        dev_err(dev, "failed to register %s power supply\n",
 357                                pda_psy_usb_desc.name);
 358                        ret = PTR_ERR(pda_psy_usb);
 359                        goto usb_supply_failed;
 360                }
 361
 362                if (usb_irq) {
 363                        ret = request_irq(usb_irq->start, power_changed_isr,
 364                                          get_irq_flags(usb_irq),
 365                                          usb_irq->name, pda_psy_usb);
 366                        if (ret) {
 367                                dev_err(dev, "request usb irq failed\n");
 368                                goto usb_irq_failed;
 369                        }
 370                } else {
 371                        polling = 1;
 372                }
 373        }
 374
 375#if IS_ENABLED(CONFIG_USB_PHY)
 376        if (!IS_ERR_OR_NULL(transceiver) && pdata->use_otg_notifier) {
 377                otg_nb.notifier_call = otg_handle_notification;
 378                ret = usb_register_notifier(transceiver, &otg_nb);
 379                if (ret) {
 380                        dev_err(dev, "failure to register otg notifier\n");
 381                        goto otg_reg_notifier_failed;
 382                }
 383                polling = 0;
 384        }
 385#endif
 386
 387        if (polling) {
 388                dev_dbg(dev, "will poll for status\n");
 389                INIT_DELAYED_WORK(&polling_work, polling_work_func);
 390                cancel_delayed_work(&polling_work);
 391                schedule_delayed_work(&polling_work,
 392                                      msecs_to_jiffies(pdata->polling_interval));
 393        }
 394
 395        if (ac_irq || usb_irq)
 396                device_init_wakeup(&pdev->dev, 1);
 397
 398        return 0;
 399
 400#if IS_ENABLED(CONFIG_USB_PHY)
 401otg_reg_notifier_failed:
 402        if (pdata->is_usb_online && usb_irq)
 403                free_irq(usb_irq->start, pda_psy_usb);
 404#endif
 405usb_irq_failed:
 406        if (pdata->is_usb_online)
 407                power_supply_unregister(pda_psy_usb);
 408usb_supply_failed:
 409        if (pdata->is_ac_online && ac_irq)
 410                free_irq(ac_irq->start, pda_psy_ac);
 411#if IS_ENABLED(CONFIG_USB_PHY)
 412        if (!IS_ERR_OR_NULL(transceiver))
 413                usb_put_phy(transceiver);
 414#endif
 415ac_irq_failed:
 416        if (pdata->is_ac_online)
 417                power_supply_unregister(pda_psy_ac);
 418ac_supply_failed:
 419        if (ac_draw) {
 420                regulator_put(ac_draw);
 421                ac_draw = NULL;
 422        }
 423        if (pdata->exit)
 424                pdata->exit(dev);
 425init_failed:
 426wrongid:
 427        return ret;
 428}
 429
 430static int pda_power_remove(struct platform_device *pdev)
 431{
 432#if IS_ENABLED(CONFIG_USB_PHY)
 433        if (!IS_ERR_OR_NULL(transceiver) && pdata->use_otg_notifier)
 434                usb_unregister_notifier(transceiver, &otg_nb);
 435#endif
 436        if (pdata->is_usb_online && usb_irq)
 437                free_irq(usb_irq->start, pda_psy_usb);
 438        if (pdata->is_ac_online && ac_irq)
 439                free_irq(ac_irq->start, pda_psy_ac);
 440
 441        if (polling)
 442                cancel_delayed_work_sync(&polling_work);
 443        cancel_delayed_work_sync(&charger_work);
 444        cancel_delayed_work_sync(&supply_work);
 445
 446        if (pdata->is_usb_online)
 447                power_supply_unregister(pda_psy_usb);
 448        if (pdata->is_ac_online)
 449                power_supply_unregister(pda_psy_ac);
 450#if IS_ENABLED(CONFIG_USB_PHY)
 451        if (!IS_ERR_OR_NULL(transceiver))
 452                usb_put_phy(transceiver);
 453#endif
 454        if (ac_draw) {
 455                regulator_put(ac_draw);
 456                ac_draw = NULL;
 457        }
 458        if (pdata->exit)
 459                pdata->exit(dev);
 460
 461        return 0;
 462}
 463
 464#ifdef CONFIG_PM
 465static int ac_wakeup_enabled;
 466static int usb_wakeup_enabled;
 467
 468static int pda_power_suspend(struct platform_device *pdev, pm_message_t state)
 469{
 470        if (pdata->suspend) {
 471                int ret = pdata->suspend(state);
 472
 473                if (ret)
 474                        return ret;
 475        }
 476
 477        if (device_may_wakeup(&pdev->dev)) {
 478                if (ac_irq)
 479                        ac_wakeup_enabled = !enable_irq_wake(ac_irq->start);
 480                if (usb_irq)
 481                        usb_wakeup_enabled = !enable_irq_wake(usb_irq->start);
 482        }
 483
 484        return 0;
 485}
 486
 487static int pda_power_resume(struct platform_device *pdev)
 488{
 489        if (device_may_wakeup(&pdev->dev)) {
 490                if (usb_irq && usb_wakeup_enabled)
 491                        disable_irq_wake(usb_irq->start);
 492                if (ac_irq && ac_wakeup_enabled)
 493                        disable_irq_wake(ac_irq->start);
 494        }
 495
 496        if (pdata->resume)
 497                return pdata->resume();
 498
 499        return 0;
 500}
 501#else
 502#define pda_power_suspend NULL
 503#define pda_power_resume NULL
 504#endif /* CONFIG_PM */
 505
 506static struct platform_driver pda_power_pdrv = {
 507        .driver = {
 508                .name = "pda-power",
 509        },
 510        .probe = pda_power_probe,
 511        .remove = pda_power_remove,
 512        .suspend = pda_power_suspend,
 513        .resume = pda_power_resume,
 514};
 515
 516module_platform_driver(pda_power_pdrv);
 517
 518MODULE_LICENSE("GPL");
 519MODULE_AUTHOR("Anton Vorontsov <cbou@mail.ru>");
 520MODULE_ALIAS("platform:pda-power");
 521