pda_power.c

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/*
 * Common power driver for PDAs and phones with one or two external
 * power supplies (AC/USB) connected to main and backup batteries,
 * and optional builtin charger.
 *
 * Copyright © 2007 Anton Vorontsov <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/power_supply.h>
#include <linux/pda_power.h>
#include <linux/regulator/consumer.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/usb/otg.h>

static inline unsigned int get_irq_flags(struct resource *res)
{
    return IRQF_SHARED | (res->flags & IRQF_TRIGGER_MASK);
}

static struct device *dev;
static struct pda_power_pdata *pdata;
static struct resource *ac_irq, *usb_irq;
static struct timer_list charger_timer;
static struct timer_list supply_timer;
static struct timer_list polling_timer;
static int polling;

#ifdef CONFIG_USB_OTG_UTILS
static struct usb_phy *transceiver;
static struct notifier_block otg_nb;
#endif

static struct regulator *ac_draw;

enum {
    PDA_PSY_OFFLINE = 0,
    PDA_PSY_ONLINE = 1,
    PDA_PSY_TO_CHANGE,
};
static int new_ac_status = -1;
static int new_usb_status = -1;
static int ac_status = -1;
static int usb_status = -1;

static int pda_power_get_property(struct power_supply *psy,
                  enum power_supply_property psp,
                  union power_supply_propval *val)
{
    switch (psp) {
    case POWER_SUPPLY_PROP_ONLINE:
        if (psy->type == POWER_SUPPLY_TYPE_MAINS)
            val->intval = pdata->is_ac_online ?
                      pdata->is_ac_online() : 0;
        else
            val->intval = pdata->is_usb_online ?
                      pdata->is_usb_online() : 0;
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static enum power_supply_property pda_power_props[] = {
    POWER_SUPPLY_PROP_ONLINE,
};

static char *pda_power_supplied_to[] = {
    "main-battery",
    "backup-battery",
};

static struct power_supply pda_psy_ac = {
    .name = "ac",
    .type = POWER_SUPPLY_TYPE_MAINS,
    .supplied_to = pda_power_supplied_to,
    .num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
    .properties = pda_power_props,
    .num_properties = ARRAY_SIZE(pda_power_props),
    .get_property = pda_power_get_property,
};

static struct power_supply pda_psy_usb = {
    .name = "usb",
    .type = POWER_SUPPLY_TYPE_USB,
    .supplied_to = pda_power_supplied_to,
    .num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
    .properties = pda_power_props,
    .num_properties = ARRAY_SIZE(pda_power_props),
    .get_property = pda_power_get_property,
};

static void update_status(void)
{
    if (pdata->is_ac_online)
        new_ac_status = !!pdata->is_ac_online();

    if (pdata->is_usb_online)
        new_usb_status = !!pdata->is_usb_online();
}

static void update_charger(void)
{
    static int regulator_enabled;
    int max_uA = pdata->ac_max_uA;

    if (pdata->set_charge) {
        if (new_ac_status > 0) {
            dev_dbg(dev, "charger on (AC)\n");
            pdata->set_charge(PDA_POWER_CHARGE_AC);
        } else if (new_usb_status > 0) {
            dev_dbg(dev, "charger on (USB)\n");
            pdata->set_charge(PDA_POWER_CHARGE_USB);
        } else {
            dev_dbg(dev, "charger off\n");
            pdata->set_charge(0);
        }
    } else if (ac_draw) {
        if (new_ac_status > 0) {
            regulator_set_current_limit(ac_draw, max_uA, max_uA);
            if (!regulator_enabled) {
                dev_dbg(dev, "charger on (AC)\n");
                WARN_ON(regulator_enable(ac_draw));
                regulator_enabled = 1;
            }
        } else {
            if (regulator_enabled) {
                dev_dbg(dev, "charger off\n");
                WARN_ON(regulator_disable(ac_draw));
                regulator_enabled = 0;
            }
        }
    }
}

static void supply_timer_func(unsigned long unused)
{
    if (ac_status == PDA_PSY_TO_CHANGE) {
        ac_status = new_ac_status;
        power_supply_changed(&pda_psy_ac);
    }

    if (usb_status == PDA_PSY_TO_CHANGE) {
        usb_status = new_usb_status;
        power_supply_changed(&pda_psy_usb);
    }
}

static void psy_changed(void)
{
    update_charger();

    /*
     * Okay, charger set. Now wait a bit before notifying supplicants,
     * charge power should stabilize.
     */
    mod_timer(&supply_timer,
          jiffies + msecs_to_jiffies(pdata->wait_for_charger));
}

static void charger_timer_func(unsigned long unused)
{
    update_status();
    psy_changed();
}

static irqreturn_t power_changed_isr(int irq, void *power_supply)
{
    if (power_supply == &pda_psy_ac)
        ac_status = PDA_PSY_TO_CHANGE;
    else if (power_supply == &pda_psy_usb)
        usb_status = PDA_PSY_TO_CHANGE;
    else
        return IRQ_NONE;

    /*
     * Wait a bit before reading ac/usb line status and setting charger,
     * because ac/usb status readings may lag from irq.
     */
    mod_timer(&charger_timer,
          jiffies + msecs_to_jiffies(pdata->wait_for_status));

    return IRQ_HANDLED;
}

static void polling_timer_func(unsigned long unused)
{
    int changed = 0;

    dev_dbg(dev, "polling...\n");

    update_status();

    if (!ac_irq && new_ac_status != ac_status) {
        ac_status = PDA_PSY_TO_CHANGE;
        changed = 1;
    }

    if (!usb_irq && new_usb_status != usb_status) {
        usb_status = PDA_PSY_TO_CHANGE;
        changed = 1;
    }

    if (changed)
        psy_changed();

    mod_timer(&polling_timer,
          jiffies + msecs_to_jiffies(pdata->polling_interval));
}

#ifdef CONFIG_USB_OTG_UTILS
static int otg_is_usb_online(void)
{
    return (transceiver->last_event == USB_EVENT_VBUS ||
        transceiver->last_event == USB_EVENT_ENUMERATED);
}

static int otg_is_ac_online(void)
{
    return (transceiver->last_event == USB_EVENT_CHARGER);
}

static int otg_handle_notification(struct notifier_block *nb,
        unsigned long event, void *unused)
{
    switch (event) {
    case USB_EVENT_CHARGER:
        ac_status = PDA_PSY_TO_CHANGE;
        break;
    case USB_EVENT_VBUS:
    case USB_EVENT_ENUMERATED:
        usb_status = PDA_PSY_TO_CHANGE;
        break;
    case USB_EVENT_NONE:
        ac_status = PDA_PSY_TO_CHANGE;
        usb_status = PDA_PSY_TO_CHANGE;
        break;
    default:
        return NOTIFY_OK;
    }

    /*
     * Wait a bit before reading ac/usb line status and setting charger,
     * because ac/usb status readings may lag from irq.
     */
    mod_timer(&charger_timer,
          jiffies + msecs_to_jiffies(pdata->wait_for_status));

    return NOTIFY_OK;
}
#endif

static int pda_power_probe(struct platform_device *pdev)
{
    int ret = 0;

    dev = &pdev->dev;

    if (pdev->id != -1) {
        dev_err(dev, "it's meaningless to register several "
            "pda_powers; use id = -1\n");
        ret = -EINVAL;
        goto wrongid;
    }

    pdata = pdev->dev.platform_data;

    if (pdata->init) {
        ret = pdata->init(dev);
        if (ret < 0)
            goto init_failed;
    }

    ac_draw = regulator_get(dev, "ac_draw");
    if (IS_ERR(ac_draw)) {
        dev_dbg(dev, "couldn't get ac_draw regulator\n");
        ac_draw = NULL;
    }

    update_status();
    update_charger();

    if (!pdata->wait_for_status)
        pdata->wait_for_status = 500;

    if (!pdata->wait_for_charger)
        pdata->wait_for_charger = 500;

    if (!pdata->polling_interval)
        pdata->polling_interval = 2000;

    if (!pdata->ac_max_uA)
        pdata->ac_max_uA = 500000;

    setup_timer(&charger_timer, charger_timer_func, 0);
    setup_timer(&supply_timer, supply_timer_func, 0);

    ac_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "ac");
    usb_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "usb");

    if (pdata->supplied_to) {
        pda_psy_ac.supplied_to = pdata->supplied_to;
        pda_psy_ac.num_supplicants = pdata->num_supplicants;
        pda_psy_usb.supplied_to = pdata->supplied_to;
        pda_psy_usb.num_supplicants = pdata->num_supplicants;
    }

#ifdef CONFIG_USB_OTG_UTILS
    transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
    if (!IS_ERR_OR_NULL(transceiver)) {
        if (!pdata->is_usb_online)
            pdata->is_usb_online = otg_is_usb_online;
        if (!pdata->is_ac_online)
            pdata->is_ac_online = otg_is_ac_online;
    }
#endif

    if (pdata->is_ac_online) {
        ret = power_supply_register(&pdev->dev, &pda_psy_ac);
        if (ret) {
            dev_err(dev, "failed to register %s power supply\n",
                pda_psy_ac.name);
            goto ac_supply_failed;
        }

        if (ac_irq) {
            ret = request_irq(ac_irq->start, power_changed_isr,
                      get_irq_flags(ac_irq), ac_irq->name,
                      &pda_psy_ac);
            if (ret) {
                dev_err(dev, "request ac irq failed\n");
                goto ac_irq_failed;
            }
        } else {
            polling = 1;
        }
    }

    if (pdata->is_usb_online) {
        ret = power_supply_register(&pdev->dev, &pda_psy_usb);
        if (ret) {
            dev_err(dev, "failed to register %s power supply\n",
                pda_psy_usb.name);
            goto usb_supply_failed;
        }

        if (usb_irq) {
            ret = request_irq(usb_irq->start, power_changed_isr,
                      get_irq_flags(usb_irq),
                      usb_irq->name, &pda_psy_usb);
            if (ret) {
                dev_err(dev, "request usb irq failed\n");
                goto usb_irq_failed;
            }
        } else {
            polling = 1;
        }
    }

#ifdef CONFIG_USB_OTG_UTILS
    if (!IS_ERR_OR_NULL(transceiver) && pdata->use_otg_notifier) {
        otg_nb.notifier_call = otg_handle_notification;
        ret = usb_register_notifier(transceiver, &otg_nb);
        if (ret) {
            dev_err(dev, "failure to register otg notifier\n");
            goto otg_reg_notifier_failed;
        }
        polling = 0;
    }
#endif

    if (polling) {
        dev_dbg(dev, "will poll for status\n");
        setup_timer(&polling_timer, polling_timer_func, 0);
        mod_timer(&polling_timer,
              jiffies + msecs_to_jiffies(pdata->polling_interval));
    }

    if (ac_irq || usb_irq)
        device_init_wakeup(&pdev->dev, 1);

    return 0;

#ifdef CONFIG_USB_OTG_UTILS
otg_reg_notifier_failed:
    if (pdata->is_usb_online && usb_irq)
        free_irq(usb_irq->start, &pda_psy_usb);
#endif
usb_irq_failed:
    if (pdata->is_usb_online)
        power_supply_unregister(&pda_psy_usb);
usb_supply_failed:
    if (pdata->is_ac_online && ac_irq)
        free_irq(ac_irq->start, &pda_psy_ac);
#ifdef CONFIG_USB_OTG_UTILS
    if (!IS_ERR_OR_NULL(transceiver))
        usb_put_phy(transceiver);
#endif
ac_irq_failed:
    if (pdata->is_ac_online)
        power_supply_unregister(&pda_psy_ac);
ac_supply_failed:
    if (ac_draw) {
        regulator_put(ac_draw);
        ac_draw = NULL;
    }
    if (pdata->exit)
        pdata->exit(dev);
init_failed:
wrongid:
    return ret;
}

static int pda_power_remove(struct platform_device *pdev)
{
    if (pdata->is_usb_online && usb_irq)
        free_irq(usb_irq->start, &pda_psy_usb);
    if (pdata->is_ac_online && ac_irq)
        free_irq(ac_irq->start, &pda_psy_ac);

    if (polling)
        del_timer_sync(&polling_timer);
    del_timer_sync(&charger_timer);
    del_timer_sync(&supply_timer);

    if (pdata->is_usb_online)
        power_supply_unregister(&pda_psy_usb);
    if (pdata->is_ac_online)
        power_supply_unregister(&pda_psy_ac);
#ifdef CONFIG_USB_OTG_UTILS
    if (!IS_ERR_OR_NULL(transceiver))
        usb_put_phy(transceiver);
#endif
    if (ac_draw) {
        regulator_put(ac_draw);
        ac_draw = NULL;
    }
    if (pdata->exit)
        pdata->exit(dev);

    return 0;
}

#ifdef CONFIG_PM
static int ac_wakeup_enabled;
static int usb_wakeup_enabled;

static int pda_power_suspend(struct platform_device *pdev, pm_message_t state)
{
    if (pdata->suspend) {
        int ret = pdata->suspend(state);

        if (ret)
            return ret;
    }

    if (device_may_wakeup(&pdev->dev)) {
        if (ac_irq)
            ac_wakeup_enabled = !enable_irq_wake(ac_irq->start);
        if (usb_irq)
            usb_wakeup_enabled = !enable_irq_wake(usb_irq->start);
    }

    return 0;
}

static int pda_power_resume(struct platform_device *pdev)
{
    if (device_may_wakeup(&pdev->dev)) {
        if (usb_irq && usb_wakeup_enabled)
            disable_irq_wake(usb_irq->start);
        if (ac_irq && ac_wakeup_enabled)
            disable_irq_wake(ac_irq->start);
    }

    if (pdata->resume)
        return pdata->resume();

    return 0;
}
#else
#define pda_power_suspend NULL
#define pda_power_resume NULL
#endif /* CONFIG_PM */

static struct platform_driver pda_power_pdrv = {
    .driver = {
        .name = "pda-power",
    },
    .probe = pda_power_probe,
    .remove = pda_power_remove,
    .suspend = pda_power_suspend,
    .resume = pda_power_resume,
};

module_platform_driver(pda_power_pdrv);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anton Vorontsov <[email protected]>");
MODULE_ALIAS("platform:pda-power");