drivers/power/supply/cpcap-charger.c

root/drivers/power/supply/cpcap-charger.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Motorola CPCAP PMIC battery charger driver
 *
 * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
 *
 * Rewritten for Linux power framework with some parts based on
 * earlier driver found in the Motorola Linux kernel:
 *
 * Copyright (C) 2009-2010 Motorola, Inc.
 */

#include <linux/atomic.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string_choices.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>

#include <linux/gpio/consumer.h>
#include <linux/usb/phy_companion.h>
#include <linux/phy/omap_usb.h>
#include <linux/usb/otg.h>
#include <linux/iio/consumer.h>
#include <linux/mfd/motorola-cpcap.h>

/*
 * CPCAP_REG_CRM register bits. For documentation of somewhat similar hardware,
 * see NXP "MC13783 Power Management and Audio Circuit Users's Guide"
 * MC13783UG.pdf chapter "8.5 Battery Interface Register Summary". The registers
 * and values for CPCAP are different, but some of the internal components seem
 * similar. Also see the Motorola Linux kernel cpcap-regbits.h. CPCAP_REG_CHRGR_1
 * bits that seem to describe the CRM register.
 */
#define CPCAP_REG_CRM_UNUSED_641_15     BIT(15) /* 641 = register number */
#define CPCAP_REG_CRM_UNUSED_641_14     BIT(14) /* 641 = register number */
#define CPCAP_REG_CRM_CHRG_LED_EN       BIT(13) /* Charger LED */
#define CPCAP_REG_CRM_RVRSMODE          BIT(12) /* USB VBUS output enable */
#define CPCAP_REG_CRM_ICHRG_TR1         BIT(11) /* Trickle charge current */
#define CPCAP_REG_CRM_ICHRG_TR0         BIT(10)
#define CPCAP_REG_CRM_FET_OVRD          BIT(9)  /* 0 = hardware, 1 = FET_CTRL */
#define CPCAP_REG_CRM_FET_CTRL          BIT(8)  /* BPFET 1 if FET_OVRD set */
#define CPCAP_REG_CRM_VCHRG3            BIT(7)  /* Charge voltage bits */
#define CPCAP_REG_CRM_VCHRG2            BIT(6)
#define CPCAP_REG_CRM_VCHRG1            BIT(5)
#define CPCAP_REG_CRM_VCHRG0            BIT(4)
#define CPCAP_REG_CRM_ICHRG3            BIT(3)  /* Charge current bits */
#define CPCAP_REG_CRM_ICHRG2            BIT(2)
#define CPCAP_REG_CRM_ICHRG1            BIT(1)
#define CPCAP_REG_CRM_ICHRG0            BIT(0)

/* CPCAP_REG_CRM trickle charge voltages */
#define CPCAP_REG_CRM_TR(val)           (((val) & 0x3) << 10)
#define CPCAP_REG_CRM_TR_0A00           CPCAP_REG_CRM_TR(0x0)
#define CPCAP_REG_CRM_TR_0A24           CPCAP_REG_CRM_TR(0x1)
#define CPCAP_REG_CRM_TR_0A48           CPCAP_REG_CRM_TR(0x2)
#define CPCAP_REG_CRM_TR_0A72           CPCAP_REG_CRM_TR(0x4)

/*
 * CPCAP_REG_CRM charge voltages based on the ADC channel 1 values.
 * Note that these register bits don't match MC13783UG.pdf VCHRG
 * register bits.
 */
#define CPCAP_REG_CRM_VCHRG(val)        (((val) & 0xf) << 4)
#define CPCAP_REG_CRM_VCHRG_3V80        CPCAP_REG_CRM_VCHRG(0x0)
#define CPCAP_REG_CRM_VCHRG_4V10        CPCAP_REG_CRM_VCHRG(0x1)
#define CPCAP_REG_CRM_VCHRG_4V12        CPCAP_REG_CRM_VCHRG(0x2)
#define CPCAP_REG_CRM_VCHRG_4V15        CPCAP_REG_CRM_VCHRG(0x3)
#define CPCAP_REG_CRM_VCHRG_4V17        CPCAP_REG_CRM_VCHRG(0x4)
#define CPCAP_REG_CRM_VCHRG_4V20        CPCAP_REG_CRM_VCHRG(0x5)
#define CPCAP_REG_CRM_VCHRG_4V23        CPCAP_REG_CRM_VCHRG(0x6)
#define CPCAP_REG_CRM_VCHRG_4V25        CPCAP_REG_CRM_VCHRG(0x7)
#define CPCAP_REG_CRM_VCHRG_4V27        CPCAP_REG_CRM_VCHRG(0x8)
#define CPCAP_REG_CRM_VCHRG_4V30        CPCAP_REG_CRM_VCHRG(0x9)
#define CPCAP_REG_CRM_VCHRG_4V33        CPCAP_REG_CRM_VCHRG(0xa)
#define CPCAP_REG_CRM_VCHRG_4V35        CPCAP_REG_CRM_VCHRG(0xb)
#define CPCAP_REG_CRM_VCHRG_4V38        CPCAP_REG_CRM_VCHRG(0xc)
#define CPCAP_REG_CRM_VCHRG_4V40        CPCAP_REG_CRM_VCHRG(0xd)
#define CPCAP_REG_CRM_VCHRG_4V42        CPCAP_REG_CRM_VCHRG(0xe)
#define CPCAP_REG_CRM_VCHRG_4V44        CPCAP_REG_CRM_VCHRG(0xf)

/*
 * CPCAP_REG_CRM charge currents. These seem to match MC13783UG.pdf
 * values in "Table 8-3. Charge Path Regulator Current Limit
 * Characteristics" for the nominal values.
 *
 * Except 70mA and 1.596A and unlimited, these are simply 88.7mA / step.
 */
#define CPCAP_REG_CRM_ICHRG(val)        (((val) & 0xf) << 0)
#define CPCAP_REG_CRM_ICHRG_0A000       CPCAP_REG_CRM_ICHRG(0x0)
#define CPCAP_REG_CRM_ICHRG_0A070       CPCAP_REG_CRM_ICHRG(0x1)
#define CPCAP_REG_CRM_ICHRG_0A177       CPCAP_REG_CRM_ICHRG(0x2)
#define CPCAP_REG_CRM_ICHRG_0A266       CPCAP_REG_CRM_ICHRG(0x3)
#define CPCAP_REG_CRM_ICHRG_0A355       CPCAP_REG_CRM_ICHRG(0x4)
#define CPCAP_REG_CRM_ICHRG_0A443       CPCAP_REG_CRM_ICHRG(0x5)
#define CPCAP_REG_CRM_ICHRG_0A532       CPCAP_REG_CRM_ICHRG(0x6)
#define CPCAP_REG_CRM_ICHRG_0A621       CPCAP_REG_CRM_ICHRG(0x7)
#define CPCAP_REG_CRM_ICHRG_0A709       CPCAP_REG_CRM_ICHRG(0x8)
#define CPCAP_REG_CRM_ICHRG_0A798       CPCAP_REG_CRM_ICHRG(0x9)
#define CPCAP_REG_CRM_ICHRG_0A886       CPCAP_REG_CRM_ICHRG(0xa)
#define CPCAP_REG_CRM_ICHRG_0A975       CPCAP_REG_CRM_ICHRG(0xb)
#define CPCAP_REG_CRM_ICHRG_1A064       CPCAP_REG_CRM_ICHRG(0xc)
#define CPCAP_REG_CRM_ICHRG_1A152       CPCAP_REG_CRM_ICHRG(0xd)
#define CPCAP_REG_CRM_ICHRG_1A596       CPCAP_REG_CRM_ICHRG(0xe)
#define CPCAP_REG_CRM_ICHRG_NO_LIMIT    CPCAP_REG_CRM_ICHRG(0xf)

/* CPCAP_REG_VUSBC register bits needed for VBUS */
#define CPCAP_BIT_VBUS_SWITCH           BIT(0)  /* VBUS boost to 5V */

enum {
        CPCAP_CHARGER_IIO_BATTDET,
        CPCAP_CHARGER_IIO_VOLTAGE,
        CPCAP_CHARGER_IIO_VBUS,
        CPCAP_CHARGER_IIO_CHRG_CURRENT,
        CPCAP_CHARGER_IIO_BATT_CURRENT,
        CPCAP_CHARGER_IIO_NR,
};

struct cpcap_charger_ddata {
        struct device *dev;
        struct regmap *reg;
        struct list_head irq_list;
        struct delayed_work detect_work;
        struct delayed_work vbus_work;
        struct gpio_desc *gpio[2];              /* gpio_reven0 & 1 */

        struct iio_channel *channels[CPCAP_CHARGER_IIO_NR];

        struct power_supply *usb;

        struct phy_companion comparator;        /* For USB VBUS */
        unsigned int vbus_enabled:1;
        unsigned int feeding_vbus:1;
        atomic_t active;

        int status;
        int voltage;
        int limit_current;
};

struct cpcap_interrupt_desc {
        int irq;
        struct list_head node;
        const char *name;
};

struct cpcap_charger_ints_state {
        bool chrg_det;
        bool rvrs_chrg;
        bool vbusov;

        bool chrg_se1b;
        bool rvrs_mode;
        bool chrgcurr2;
        bool chrgcurr1;
        bool vbusvld;

        bool battdetb;
};

static enum power_supply_property cpcap_charger_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
        POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
};

static int cpcap_charger_get_charge_voltage(struct cpcap_charger_ddata *ddata)
{
        struct iio_channel *channel;
        int error, value = 0;

        channel = ddata->channels[CPCAP_CHARGER_IIO_VOLTAGE];
        error = iio_read_channel_processed(channel, &value);
        if (error < 0) {
                dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);

                return 0;
        }

        return value;
}

static int cpcap_charger_get_charge_current(struct cpcap_charger_ddata *ddata)
{
        struct iio_channel *channel;
        int error, value = 0;

        channel = ddata->channels[CPCAP_CHARGER_IIO_CHRG_CURRENT];
        error = iio_read_channel_processed(channel, &value);
        if (error < 0) {
                dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);

                return 0;
        }

        return value;
}

static int cpcap_charger_get_property(struct power_supply *psy,
                                      enum power_supply_property psp,
                                      union power_supply_propval *val)
{
        struct cpcap_charger_ddata *ddata = dev_get_drvdata(psy->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = ddata->status;
                break;
        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                val->intval = ddata->limit_current;
                break;
        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                val->intval = ddata->voltage;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                if (ddata->status == POWER_SUPPLY_STATUS_CHARGING)
                        val->intval = cpcap_charger_get_charge_voltage(ddata) *
                                1000;
                else
                        val->intval = 0;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                if (ddata->status == POWER_SUPPLY_STATUS_CHARGING)
                        val->intval = cpcap_charger_get_charge_current(ddata) *
                                1000;
                else
                        val->intval = 0;
                break;
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = ddata->status == POWER_SUPPLY_STATUS_CHARGING;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int cpcap_charger_match_voltage(int voltage)
{
        switch (voltage) {
        case 0 ... 4100000 - 1: return 3800000;
        case 4100000 ... 4120000 - 1: return 4100000;
        case 4120000 ... 4150000 - 1: return 4120000;
        case 4150000 ... 4170000 - 1: return 4150000;
        case 4170000 ... 4200000 - 1: return 4170000;
        case 4200000 ... 4230000 - 1: return 4200000;
        case 4230000 ... 4250000 - 1: return 4230000;
        case 4250000 ... 4270000 - 1: return 4250000;
        case 4270000 ... 4300000 - 1: return 4270000;
        case 4300000 ... 4330000 - 1: return 4300000;
        case 4330000 ... 4350000 - 1: return 4330000;
        case 4350000 ... 4380000 - 1: return 4350000;
        case 4380000 ... 4400000 - 1: return 4380000;
        case 4400000 ... 4420000 - 1: return 4400000;
        case 4420000 ... 4440000 - 1: return 4420000;
        case 4440000: return 4440000;
        default: return 0;
        }
}

static int
cpcap_charger_get_bat_const_charge_voltage(struct cpcap_charger_ddata *ddata)
{
        union power_supply_propval prop;
        struct power_supply *battery;
        int voltage = ddata->voltage;
        int error;

        battery = power_supply_get_by_name("battery");
        if (battery) {
                error = power_supply_get_property(battery,
                                POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
                                &prop);
                if (!error)
                        voltage = prop.intval;

                power_supply_put(battery);
        }

        return voltage;
}

static int cpcap_charger_current_to_regval(int microamp)
{
        int miliamp = microamp / 1000;
        int res;

        if (miliamp < 0)
                return -EINVAL;
        if (miliamp < 70)
                return CPCAP_REG_CRM_ICHRG(0x0);
        if (miliamp < 177)
                return CPCAP_REG_CRM_ICHRG(0x1);
        if (miliamp >= 1596)
                return CPCAP_REG_CRM_ICHRG(0xe);

        res = microamp / 88666;
        if (res > 0xd)
                res = 0xd;
        return CPCAP_REG_CRM_ICHRG(res);
}

static int cpcap_charger_set_property(struct power_supply *psy,
                                      enum power_supply_property psp,
                                      const union power_supply_propval *val)
{
        struct cpcap_charger_ddata *ddata = dev_get_drvdata(psy->dev.parent);
        int voltage, batvolt;

        switch (psp) {
        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                if (cpcap_charger_current_to_regval(val->intval) < 0)
                        return -EINVAL;
                ddata->limit_current = val->intval;
                schedule_delayed_work(&ddata->detect_work, 0);
                break;
        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                voltage = cpcap_charger_match_voltage(val->intval);
                batvolt = cpcap_charger_get_bat_const_charge_voltage(ddata);
                if (voltage > batvolt)
                        voltage = batvolt;
                ddata->voltage = voltage;
                schedule_delayed_work(&ddata->detect_work, 0);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int cpcap_charger_property_is_writeable(struct power_supply *psy,
                                               enum power_supply_property psp)
{
        switch (psp) {
        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                return 1;
        default:
                return 0;
        }
}

static void cpcap_charger_set_cable_path(struct cpcap_charger_ddata *ddata,
                                         bool enabled)
{
        if (!ddata->gpio[0])
                return;

        gpiod_set_value(ddata->gpio[0], enabled);
}

static void cpcap_charger_set_inductive_path(struct cpcap_charger_ddata *ddata,
                                             bool enabled)
{
        if (!ddata->gpio[1])
                return;

        gpiod_set_value(ddata->gpio[1], enabled);
}

static void cpcap_charger_update_state(struct cpcap_charger_ddata *ddata,
                                       int state)
{
        const char *status;

        if (state > POWER_SUPPLY_STATUS_FULL) {
                dev_warn(ddata->dev, "unknown state: %i\n", state);

                return;
        }

        ddata->status = state;

        switch (state) {
        case POWER_SUPPLY_STATUS_DISCHARGING:
                status = "DISCONNECTED";
                break;
        case POWER_SUPPLY_STATUS_NOT_CHARGING:
                status = "DETECTING";
                break;
        case POWER_SUPPLY_STATUS_CHARGING:
                status = "CHARGING";
                break;
        case POWER_SUPPLY_STATUS_FULL:
                status = "DONE";
                break;
        default:
                return;
        }

        dev_dbg(ddata->dev, "state: %s\n", status);
}

static int cpcap_charger_disable(struct cpcap_charger_ddata *ddata)
{
        int error;

        error = regmap_update_bits(ddata->reg, CPCAP_REG_CRM, 0x3fff,
                                   CPCAP_REG_CRM_FET_OVRD |
                                   CPCAP_REG_CRM_FET_CTRL);
        if (error)
                dev_err(ddata->dev, "%s failed with %i\n", __func__, error);

        return error;
}

static int cpcap_charger_enable(struct cpcap_charger_ddata *ddata,
                                int max_voltage, int charge_current,
                                int trickle_current)
{
        int error;

        if (!max_voltage || !charge_current)
                return -EINVAL;

        dev_dbg(ddata->dev, "enable: %i %i %i\n",
                max_voltage, charge_current, trickle_current);

        error = regmap_update_bits(ddata->reg, CPCAP_REG_CRM, 0x3fff,
                                   CPCAP_REG_CRM_CHRG_LED_EN |
                                   trickle_current |
                                   CPCAP_REG_CRM_FET_OVRD |
                                   CPCAP_REG_CRM_FET_CTRL |
                                   max_voltage |
                                   charge_current);
        if (error)
                dev_err(ddata->dev, "%s failed with %i\n", __func__, error);

        return error;
}

static bool cpcap_charger_vbus_valid(struct cpcap_charger_ddata *ddata)
{
        int error, value = 0;
        struct iio_channel *channel =
                ddata->channels[CPCAP_CHARGER_IIO_VBUS];

        error = iio_read_channel_processed(channel, &value);
        if (error >= 0)
                return value > 3900;

        dev_err(ddata->dev, "error reading VBUS: %i\n", error);

        return false;
}

/* VBUS control functions for the USB PHY companion */
static void cpcap_charger_vbus_work(struct work_struct *work)
{
        struct cpcap_charger_ddata *ddata;
        bool vbus = false;
        int error;

        ddata = container_of(work, struct cpcap_charger_ddata,
                             vbus_work.work);

        if (ddata->vbus_enabled) {
                vbus = cpcap_charger_vbus_valid(ddata);
                if (vbus) {
                        dev_dbg(ddata->dev, "VBUS already provided\n");

                        return;
                }

                ddata->feeding_vbus = true;
                cpcap_charger_set_cable_path(ddata, false);
                cpcap_charger_set_inductive_path(ddata, false);

                error = cpcap_charger_disable(ddata);
                if (error)
                        goto out_err;

                cpcap_charger_update_state(ddata,
                                           POWER_SUPPLY_STATUS_DISCHARGING);

                error = regmap_update_bits(ddata->reg, CPCAP_REG_VUSBC,
                                           CPCAP_BIT_VBUS_SWITCH,
                                           CPCAP_BIT_VBUS_SWITCH);
                if (error)
                        goto out_err;

                error = regmap_update_bits(ddata->reg, CPCAP_REG_CRM,
                                           CPCAP_REG_CRM_RVRSMODE,
                                           CPCAP_REG_CRM_RVRSMODE);
                if (error)
                        goto out_err;
        } else {
                error = regmap_update_bits(ddata->reg, CPCAP_REG_VUSBC,
                                           CPCAP_BIT_VBUS_SWITCH, 0);
                if (error)
                        goto out_err;

                error = regmap_update_bits(ddata->reg, CPCAP_REG_CRM,
                                           CPCAP_REG_CRM_RVRSMODE, 0);
                if (error)
                        goto out_err;

                cpcap_charger_set_cable_path(ddata, true);
                cpcap_charger_set_inductive_path(ddata, true);
                ddata->feeding_vbus = false;
        }

        return;

out_err:
        cpcap_charger_update_state(ddata, POWER_SUPPLY_STATUS_UNKNOWN);
        dev_err(ddata->dev, "%s could not %s vbus: %i\n", __func__,
                str_enable_disable(ddata->vbus_enabled), error);
}

static int cpcap_charger_set_vbus(struct phy_companion *comparator,
                                  bool enabled)
{
        struct cpcap_charger_ddata *ddata =
                container_of(comparator, struct cpcap_charger_ddata,
                             comparator);

        ddata->vbus_enabled = enabled;
        schedule_delayed_work(&ddata->vbus_work, 0);

        return 0;
}

/* Charger interrupt handling functions */

static int cpcap_charger_get_ints_state(struct cpcap_charger_ddata *ddata,
                                        struct cpcap_charger_ints_state *s)
{
        int val, error;

        error = regmap_read(ddata->reg, CPCAP_REG_INTS1, &val);
        if (error)
                return error;

        s->chrg_det = val & BIT(13);
        s->rvrs_chrg = val & BIT(12);
        s->vbusov = val & BIT(11);

        error = regmap_read(ddata->reg, CPCAP_REG_INTS2, &val);
        if (error)
                return error;

        s->chrg_se1b = val & BIT(13);
        s->rvrs_mode = val & BIT(6);
        s->chrgcurr2 = val & BIT(5);
        s->chrgcurr1 = val & BIT(4);
        s->vbusvld = val & BIT(3);

        error = regmap_read(ddata->reg, CPCAP_REG_INTS4, &val);
        if (error)
                return error;

        s->battdetb = val & BIT(6);

        return 0;
}

static int cpcap_charger_voltage_to_regval(int voltage)
{
        int offset;

        switch (voltage) {
        case 0 ... 4100000 - 1:
                return 0;
        case 4100000 ... 4200000 - 1:
                offset = 1;
                break;
        case 4200000 ... 4300000 - 1:
                offset = 0;
                break;
        case 4300000 ... 4380000 - 1:
                offset = -1;
                break;
        case 4380000 ... 4440000:
                offset = -2;
                break;
        default:
                return 0;
        }

        return ((voltage - 4100000) / 20000) + offset;
}

static void cpcap_charger_disconnect(struct cpcap_charger_ddata *ddata,
                                     int state, unsigned long delay)
{
        int error;

        /* Update battery state before disconnecting the charger */
        switch (state) {
        case POWER_SUPPLY_STATUS_DISCHARGING:
        case POWER_SUPPLY_STATUS_FULL:
                power_supply_changed(ddata->usb);
                break;
        default:
                break;
        }

        error = cpcap_charger_disable(ddata);
        if (error) {
                cpcap_charger_update_state(ddata, POWER_SUPPLY_STATUS_UNKNOWN);
                return;
        }

        cpcap_charger_update_state(ddata, state);
        power_supply_changed(ddata->usb);
        schedule_delayed_work(&ddata->detect_work, delay);
}

static void cpcap_usb_detect(struct work_struct *work)
{
        struct cpcap_charger_ddata *ddata;
        struct cpcap_charger_ints_state s;
        int error, new_state;

        ddata = container_of(work, struct cpcap_charger_ddata,
                             detect_work.work);

        error = cpcap_charger_get_ints_state(ddata, &s);
        if (error)
                return;

        /* Just init the state if a charger is connected with no chrg_det set */
        if (!s.chrg_det && s.chrgcurr1 && s.vbusvld) {
                cpcap_charger_update_state(ddata,
                                           POWER_SUPPLY_STATUS_NOT_CHARGING);

                return;
        }

        /*
         * If battery voltage is higher than charge voltage, it may have been
         * charged to 4.35V by Android. Try again in 10 minutes.
         */
        if (cpcap_charger_get_charge_voltage(ddata) > ddata->voltage) {
                cpcap_charger_disconnect(ddata,
                                         POWER_SUPPLY_STATUS_NOT_CHARGING,
                                         HZ * 60 * 10);

                return;
        }

        /* Delay for 80ms to avoid vbus bouncing when usb cable is plugged in */
        usleep_range(80000, 120000);

        /* Throttle chrgcurr2 interrupt for charger done and retry */
        switch (ddata->status) {
        case POWER_SUPPLY_STATUS_CHARGING:
                if (s.chrgcurr2)
                        break;
                new_state = POWER_SUPPLY_STATUS_FULL;

                if (s.chrgcurr1 && s.vbusvld) {
                        cpcap_charger_disconnect(ddata, new_state, HZ * 5);
                        return;
                }
                break;
        case POWER_SUPPLY_STATUS_FULL:
                if (!s.chrgcurr2)
                        break;
                if (s.vbusvld)
                        new_state = POWER_SUPPLY_STATUS_NOT_CHARGING;
                else
                        new_state = POWER_SUPPLY_STATUS_DISCHARGING;

                cpcap_charger_disconnect(ddata, new_state, HZ * 5);

                return;
        default:
                break;
        }

        if (!ddata->feeding_vbus && cpcap_charger_vbus_valid(ddata) &&
            s.chrgcurr1) {
                int max_current;
                int vchrg, ichrg;
                union power_supply_propval val;
                struct power_supply *battery;

                battery = power_supply_get_by_name("battery");
                if (!battery) {
                        dev_err(ddata->dev, "battery power_supply not available\n");
                        return;
                }

                error = power_supply_get_property(battery, POWER_SUPPLY_PROP_PRESENT, &val);
                power_supply_put(battery);
                if (error)
                        goto out_err;

                if (val.intval) {
                        max_current = 1596000;
                } else {
                        dev_info(ddata->dev, "battery not inserted, charging disabled\n");
                        max_current = 0;
                }

                if (max_current > ddata->limit_current)
                        max_current = ddata->limit_current;

                ichrg = cpcap_charger_current_to_regval(max_current);
                vchrg = cpcap_charger_voltage_to_regval(ddata->voltage);
                error = cpcap_charger_enable(ddata,
                                             CPCAP_REG_CRM_VCHRG(vchrg),
                                             ichrg, 0);
                if (error)
                        goto out_err;
                cpcap_charger_update_state(ddata,
                                           POWER_SUPPLY_STATUS_CHARGING);
        } else {
                error = cpcap_charger_disable(ddata);
                if (error)
                        goto out_err;
                cpcap_charger_update_state(ddata,
                                           POWER_SUPPLY_STATUS_DISCHARGING);
        }

        power_supply_changed(ddata->usb);
        return;

out_err:
        cpcap_charger_update_state(ddata, POWER_SUPPLY_STATUS_UNKNOWN);
        dev_err(ddata->dev, "%s failed with %i\n", __func__, error);
}

static irqreturn_t cpcap_charger_irq_thread(int irq, void *data)
{
        struct cpcap_charger_ddata *ddata = data;

        if (!atomic_read(&ddata->active))
                return IRQ_NONE;

        schedule_delayed_work(&ddata->detect_work, 0);

        return IRQ_HANDLED;
}

static int cpcap_usb_init_irq(struct platform_device *pdev,
                              struct cpcap_charger_ddata *ddata,
                              const char *name)
{
        struct cpcap_interrupt_desc *d;
        int irq, error;

        irq = platform_get_irq_byname(pdev, name);
        if (irq < 0)
                return -ENODEV;

        error = devm_request_threaded_irq(ddata->dev, irq, NULL,
                                          cpcap_charger_irq_thread,
                                          IRQF_SHARED | IRQF_ONESHOT,
                                          name, ddata);
        if (error) {
                dev_err(ddata->dev, "could not get irq %s: %i\n",
                        name, error);

                return error;
        }

        d = devm_kzalloc(ddata->dev, sizeof(*d), GFP_KERNEL);
        if (!d)
                return -ENOMEM;

        d->name = name;
        d->irq = irq;
        list_add(&d->node, &ddata->irq_list);

        return 0;
}

static const char * const cpcap_charger_irqs[] = {
        /* REG_INT_0 */
        "chrg_det", "rvrs_chrg",

        /* REG_INT1 */
        "chrg_se1b", "se0conn", "rvrs_mode", "chrgcurr2", "chrgcurr1", "vbusvld",

        /* REG_INT_3 */
        "battdetb",
};

static int cpcap_usb_init_interrupts(struct platform_device *pdev,
                                     struct cpcap_charger_ddata *ddata)
{
        int i, error;

        for (i = 0; i < ARRAY_SIZE(cpcap_charger_irqs); i++) {
                error = cpcap_usb_init_irq(pdev, ddata, cpcap_charger_irqs[i]);
                if (error)
                        return error;
        }

        return 0;
}

static void cpcap_charger_init_optional_gpios(struct cpcap_charger_ddata *ddata)
{
        int i;

        for (i = 0; i < 2; i++) {
                ddata->gpio[i] = devm_gpiod_get_index(ddata->dev, "mode",
                                                      i, GPIOD_OUT_HIGH);
                if (IS_ERR(ddata->gpio[i])) {
                        dev_info(ddata->dev, "no mode change GPIO%i: %li\n",
                                 i, PTR_ERR(ddata->gpio[i]));
                        ddata->gpio[i] = NULL;
                }
        }
}

static int cpcap_charger_init_iio(struct cpcap_charger_ddata *ddata)
{
        const char * const names[CPCAP_CHARGER_IIO_NR] = {
                "battdetb", "battp", "vbus", "chg_isense", "batti",
        };
        int error, i;

        for (i = 0; i < CPCAP_CHARGER_IIO_NR; i++) {
                ddata->channels[i] = devm_iio_channel_get(ddata->dev,
                                                          names[i]);
                if (IS_ERR(ddata->channels[i])) {
                        error = PTR_ERR(ddata->channels[i]);
                        goto out_err;
                }

                if (!ddata->channels[i]->indio_dev) {
                        error = -ENXIO;
                        goto out_err;
                }
        }

        return 0;

out_err:
        if (error != -EPROBE_DEFER)
                dev_err(ddata->dev, "could not initialize VBUS or ID IIO: %i\n",
                        error);

        return error;
}

static char *cpcap_charger_supplied_to[] = {
        "battery",
};

static const struct power_supply_desc cpcap_charger_usb_desc = {
        .name           = "usb",
        .type           = POWER_SUPPLY_TYPE_USB,
        .properties     = cpcap_charger_props,
        .num_properties = ARRAY_SIZE(cpcap_charger_props),
        .get_property   = cpcap_charger_get_property,
        .set_property   = cpcap_charger_set_property,
        .property_is_writeable = cpcap_charger_property_is_writeable,
};

static const struct of_device_id cpcap_charger_id_table[] = {
        {
                .compatible = "motorola,mapphone-cpcap-charger",
        },
        {},
};
MODULE_DEVICE_TABLE(of, cpcap_charger_id_table);

static int cpcap_charger_probe(struct platform_device *pdev)
{
        struct cpcap_charger_ddata *ddata;
        struct power_supply_config psy_cfg = {};
        int error;

        ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
        if (!ddata)
                return -ENOMEM;

        ddata->dev = &pdev->dev;
        ddata->voltage = 4200000;
        ddata->limit_current = 532000;

        ddata->reg = dev_get_regmap(ddata->dev->parent, NULL);
        if (!ddata->reg)
                return -ENODEV;

        INIT_LIST_HEAD(&ddata->irq_list);
        INIT_DELAYED_WORK(&ddata->detect_work, cpcap_usb_detect);
        INIT_DELAYED_WORK(&ddata->vbus_work, cpcap_charger_vbus_work);
        platform_set_drvdata(pdev, ddata);

        error = cpcap_charger_init_iio(ddata);
        if (error)
                return error;

        atomic_set(&ddata->active, 1);

        psy_cfg.fwnode = dev_fwnode(&pdev->dev);
        psy_cfg.drv_data = ddata;
        psy_cfg.supplied_to = cpcap_charger_supplied_to;
        psy_cfg.num_supplicants = ARRAY_SIZE(cpcap_charger_supplied_to);

        ddata->usb = devm_power_supply_register(ddata->dev,
                                                &cpcap_charger_usb_desc,
                                                &psy_cfg);
        if (IS_ERR(ddata->usb)) {
                error = PTR_ERR(ddata->usb);
                dev_err(ddata->dev, "failed to register USB charger: %i\n",
                        error);

                return error;
        }

        error = cpcap_usb_init_interrupts(pdev, ddata);
        if (error)
                return error;

        ddata->comparator.set_vbus = cpcap_charger_set_vbus;
        error = omap_usb2_set_comparator(&ddata->comparator);
        if (error == -ENODEV) {
                dev_info(ddata->dev, "charger needs phy, deferring probe\n");
                return -EPROBE_DEFER;
        }

        cpcap_charger_init_optional_gpios(ddata);

        schedule_delayed_work(&ddata->detect_work, 0);

        return 0;
}

static void cpcap_charger_shutdown(struct platform_device *pdev)
{
        struct cpcap_charger_ddata *ddata = platform_get_drvdata(pdev);
        int error;

        atomic_set(&ddata->active, 0);
        error = omap_usb2_set_comparator(NULL);
        if (error)
                dev_warn(ddata->dev, "could not clear USB comparator: %i\n",
                         error);

        error = cpcap_charger_disable(ddata);
        if (error) {
                cpcap_charger_update_state(ddata, POWER_SUPPLY_STATUS_UNKNOWN);
                dev_warn(ddata->dev, "could not clear charger: %i\n",
                         error);
        }
        cpcap_charger_update_state(ddata, POWER_SUPPLY_STATUS_DISCHARGING);
        cancel_delayed_work_sync(&ddata->vbus_work);
        cancel_delayed_work_sync(&ddata->detect_work);
}

static void cpcap_charger_remove(struct platform_device *pdev)
{
        cpcap_charger_shutdown(pdev);
}

static struct platform_driver cpcap_charger_driver = {
        .probe = cpcap_charger_probe,
        .driver = {
                .name   = "cpcap-charger",
                .of_match_table = cpcap_charger_id_table,
        },
        .shutdown = cpcap_charger_shutdown,
        .remove = cpcap_charger_remove,
};
module_platform_driver(cpcap_charger_driver);

MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
MODULE_DESCRIPTION("CPCAP Battery Charger Interface driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:cpcap-charger");