root/drivers/power/supply/mp2629_charger.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * MP2629 battery charger driver
 *
 * Copyright 2020 Monolithic Power Systems, Inc
 *
 * Author: Saravanan Sekar <sravanhome@gmail.com>
 */

#include <linux/bits.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
#include <linux/interrupt.h>
#include <linux/mfd/mp2629.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>

#define MP2629_REG_INPUT_ILIM           0x00
#define MP2629_REG_INPUT_VLIM           0x01
#define MP2629_REG_CHARGE_CTRL          0x04
#define MP2629_REG_CHARGE_ILIM          0x05
#define MP2629_REG_PRECHARGE            0x06
#define MP2629_REG_TERM_CURRENT         0x06
#define MP2629_REG_CHARGE_VLIM          0x07
#define MP2629_REG_TIMER_CTRL           0x08
#define MP2629_REG_IMPEDANCE_COMP       0x09
#define MP2629_REG_INTERRUPT            0x0b
#define MP2629_REG_STATUS               0x0c
#define MP2629_REG_FAULT                0x0d

#define MP2629_MASK_INPUT_TYPE          GENMASK(7, 5)
#define MP2629_MASK_CHARGE_TYPE         GENMASK(4, 3)
#define MP2629_MASK_CHARGE_CTRL         GENMASK(5, 4)
#define MP2629_MASK_WDOG_CTRL           GENMASK(5, 4)
#define MP2629_MASK_IMPEDANCE           GENMASK(7, 4)

#define MP2629_INPUTSOURCE_CHANGE       GENMASK(7, 5)
#define MP2629_CHARGING_CHANGE          GENMASK(4, 3)
#define MP2629_FAULT_BATTERY            BIT(3)
#define MP2629_FAULT_THERMAL            BIT(4)
#define MP2629_FAULT_INPUT              BIT(5)
#define MP2629_FAULT_OTG                BIT(6)

#define MP2629_MAX_BATT_CAPACITY        100

#define MP2629_PROPS(_idx, _min, _max, _step)           \
        [_idx] = {                                      \
                .min    = _min,                         \
                .max    = _max,                         \
                .step   = _step,                        \
}

enum mp2629_source_type {
        MP2629_SOURCE_TYPE_NO_INPUT,
        MP2629_SOURCE_TYPE_NON_STD,
        MP2629_SOURCE_TYPE_SDP,
        MP2629_SOURCE_TYPE_CDP,
        MP2629_SOURCE_TYPE_DCP,
        MP2629_SOURCE_TYPE_OTG = 7,
};

enum mp2629_field {
        INPUT_ILIM,
        INPUT_VLIM,
        CHARGE_ILIM,
        CHARGE_VLIM,
        PRECHARGE,
        TERM_CURRENT,
        MP2629_MAX_FIELD
};

struct mp2629_charger {
        struct device *dev;
        int status;
        int fault;

        struct regmap *regmap;
        struct regmap_field *regmap_fields[MP2629_MAX_FIELD];
        struct mutex lock;
        struct power_supply *usb;
        struct power_supply *battery;
        struct iio_channel *iiochan[MP2629_ADC_CHAN_END];
};

struct mp2629_prop {
        int reg;
        int mask;
        int min;
        int max;
        int step;
        int shift;
};

static enum power_supply_property mp2629_charger_usb_props[] = {
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_USB_TYPE,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
        POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,
};

static enum power_supply_property mp2629_charger_bat_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_CHARGE_TYPE,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_PRECHARGE_CURRENT,
        POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
};

static struct mp2629_prop props[] = {
        MP2629_PROPS(INPUT_ILIM, 100000, 3250000, 50000),
        MP2629_PROPS(INPUT_VLIM, 3800000, 5300000, 100000),
        MP2629_PROPS(CHARGE_ILIM, 320000, 4520000, 40000),
        MP2629_PROPS(CHARGE_VLIM, 3400000, 4670000, 10000),
        MP2629_PROPS(PRECHARGE, 120000, 720000, 40000),
        MP2629_PROPS(TERM_CURRENT, 80000, 680000, 40000),
};

static const struct reg_field mp2629_reg_fields[] = {
        [INPUT_ILIM]    = REG_FIELD(MP2629_REG_INPUT_ILIM, 0, 5),
        [INPUT_VLIM]    = REG_FIELD(MP2629_REG_INPUT_VLIM, 0, 3),
        [CHARGE_ILIM]   = REG_FIELD(MP2629_REG_CHARGE_ILIM, 0, 6),
        [CHARGE_VLIM]   = REG_FIELD(MP2629_REG_CHARGE_VLIM, 1, 7),
        [PRECHARGE]     = REG_FIELD(MP2629_REG_PRECHARGE, 4, 7),
        [TERM_CURRENT]  = REG_FIELD(MP2629_REG_TERM_CURRENT, 0, 3),
};

static char *adc_chan_name[] = {
        "mp2629-batt-volt",
        "mp2629-system-volt",
        "mp2629-input-volt",
        "mp2629-batt-current",
        "mp2629-input-current",
};

static int mp2629_read_adc(struct mp2629_charger *charger,
                           enum mp2629_adc_chan ch,
                           union power_supply_propval *val)
{
        int ret;
        int chval;

        ret = iio_read_channel_processed(charger->iiochan[ch], &chval);
        if (ret)
                return ret;

        val->intval = chval * 1000;

        return 0;
}

static int mp2629_get_prop(struct mp2629_charger *charger,
                           enum mp2629_field fld,
                           union power_supply_propval *val)
{
        int ret;
        unsigned int rval;

        ret = regmap_field_read(charger->regmap_fields[fld], &rval);
        if (ret)
                return ret;

        val->intval = rval * props[fld].step + props[fld].min;

        return 0;
}

static int mp2629_set_prop(struct mp2629_charger *charger,
                           enum mp2629_field fld,
                           const union power_supply_propval *val)
{
        unsigned int rval;

        if (val->intval < props[fld].min || val->intval > props[fld].max)
                return -EINVAL;

        rval = (val->intval - props[fld].min) / props[fld].step;
        return regmap_field_write(charger->regmap_fields[fld], rval);
}

static int mp2629_get_battery_capacity(struct mp2629_charger *charger,
                                       union power_supply_propval *val)
{
        union power_supply_propval vnow, vlim;
        int ret;

        ret = mp2629_read_adc(charger, MP2629_BATT_VOLT, &vnow);
        if (ret)
                return ret;

        ret = mp2629_get_prop(charger, CHARGE_VLIM, &vlim);
        if (ret)
                return ret;

        val->intval = (vnow.intval * 100) / vlim.intval;
        val->intval = min(val->intval, MP2629_MAX_BATT_CAPACITY);

        return 0;
}

static int mp2629_charger_battery_get_prop(struct power_supply *psy,
                                        enum power_supply_property psp,
                                        union power_supply_propval *val)
{
        struct mp2629_charger *charger = dev_get_drvdata(psy->dev.parent);
        unsigned int rval;
        int ret = 0;

        switch (psp) {
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                ret = mp2629_read_adc(charger, MP2629_BATT_VOLT, val);
                break;

        case POWER_SUPPLY_PROP_CURRENT_NOW:
                ret = mp2629_read_adc(charger, MP2629_BATT_CURRENT, val);
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
                val->intval = 4520000;
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
                val->intval = 4670000;
                break;

        case POWER_SUPPLY_PROP_CAPACITY:
                ret = mp2629_get_battery_capacity(charger, val);
                break;

        case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
                ret = mp2629_get_prop(charger, TERM_CURRENT, val);
                break;

        case POWER_SUPPLY_PROP_PRECHARGE_CURRENT:
                ret = mp2629_get_prop(charger, PRECHARGE, val);
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                ret = mp2629_get_prop(charger, CHARGE_VLIM, val);
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
                ret = mp2629_get_prop(charger, CHARGE_ILIM, val);
                break;

        case POWER_SUPPLY_PROP_HEALTH:
                if (!charger->fault)
                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
                if (MP2629_FAULT_BATTERY & charger->fault)
                        val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                else if (MP2629_FAULT_THERMAL & charger->fault)
                        val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
                else if (MP2629_FAULT_INPUT & charger->fault)
                        val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                break;

        case POWER_SUPPLY_PROP_STATUS:
                ret = regmap_read(charger->regmap, MP2629_REG_STATUS, &rval);
                if (ret)
                        break;

                rval = (rval & MP2629_MASK_CHARGE_TYPE) >> 3;
                switch (rval) {
                case 0x00:
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                        break;
                case 0x01:
                case 0x10:
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                        break;
                case 0x11:
                        val->intval = POWER_SUPPLY_STATUS_FULL;
                }
                break;

        case POWER_SUPPLY_PROP_CHARGE_TYPE:
                ret = regmap_read(charger->regmap, MP2629_REG_STATUS, &rval);
                if (ret)
                        break;

                rval = (rval & MP2629_MASK_CHARGE_TYPE) >> 3;
                switch (rval) {
                case 0x00:
                        val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
                        break;
                case 0x01:
                        val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
                        break;
                case 0x10:
                        val->intval = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
                        break;
                default:
                        val->intval = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
                }
                break;

        default:
                return -EINVAL;
        }

        return ret;
}

static int mp2629_charger_battery_set_prop(struct power_supply *psy,
                                        enum power_supply_property psp,
                                        const union power_supply_propval *val)
{
        struct mp2629_charger *charger = dev_get_drvdata(psy->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
                return mp2629_set_prop(charger, TERM_CURRENT, val);

        case POWER_SUPPLY_PROP_PRECHARGE_CURRENT:
                return mp2629_set_prop(charger, PRECHARGE, val);

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                return mp2629_set_prop(charger, CHARGE_VLIM, val);

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
                return mp2629_set_prop(charger, CHARGE_ILIM, val);

        default:
                return -EINVAL;
        }
}

static int mp2629_charger_usb_get_prop(struct power_supply *psy,
                                enum power_supply_property psp,
                                union power_supply_propval *val)
{
        struct mp2629_charger *charger = dev_get_drvdata(psy->dev.parent);
        unsigned int rval;
        int ret;

        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
                ret = regmap_read(charger->regmap, MP2629_REG_STATUS, &rval);
                if (ret)
                        break;

                val->intval = !!(rval & MP2629_MASK_INPUT_TYPE);
                break;

        case POWER_SUPPLY_PROP_USB_TYPE:
                ret = regmap_read(charger->regmap, MP2629_REG_STATUS, &rval);
                if (ret)
                        break;

                rval = (rval & MP2629_MASK_INPUT_TYPE) >> 5;
                switch (rval) {
                case MP2629_SOURCE_TYPE_SDP:
                        val->intval = POWER_SUPPLY_USB_TYPE_SDP;
                        break;
                case MP2629_SOURCE_TYPE_CDP:
                        val->intval = POWER_SUPPLY_USB_TYPE_CDP;
                        break;
                case MP2629_SOURCE_TYPE_DCP:
                        val->intval = POWER_SUPPLY_USB_TYPE_DCP;
                        break;
                case MP2629_SOURCE_TYPE_OTG:
                        val->intval = POWER_SUPPLY_USB_TYPE_PD_DRP;
                        break;
                default:
                        val->intval = POWER_SUPPLY_USB_TYPE_UNKNOWN;
                        break;
                }
                break;

        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                ret = mp2629_read_adc(charger, MP2629_INPUT_VOLT, val);
                break;

        case POWER_SUPPLY_PROP_CURRENT_NOW:
                ret = mp2629_read_adc(charger, MP2629_INPUT_CURRENT, val);
                break;

        case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:
                ret = mp2629_get_prop(charger, INPUT_VLIM, val);
                break;

        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                ret = mp2629_get_prop(charger, INPUT_ILIM, val);
                break;

        default:
                return -EINVAL;
        }

        return ret;
}

static int mp2629_charger_usb_set_prop(struct power_supply *psy,
                                enum power_supply_property psp,
                                const union power_supply_propval *val)
{
        struct mp2629_charger *charger = dev_get_drvdata(psy->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:
                return mp2629_set_prop(charger, INPUT_VLIM, val);

        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                return mp2629_set_prop(charger, INPUT_ILIM, val);

        default:
                return -EINVAL;
        }
}

static int mp2629_charger_battery_prop_writeable(struct power_supply *psy,
                                     enum power_supply_property psp)
{
        return (psp == POWER_SUPPLY_PROP_PRECHARGE_CURRENT) ||
               (psp == POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT) ||
               (psp == POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT) ||
               (psp == POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE);
}

static int mp2629_charger_usb_prop_writeable(struct power_supply *psy,
                                     enum power_supply_property psp)
{
        return (psp == POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT) ||
               (psp == POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT);
}

static irqreturn_t mp2629_irq_handler(int irq, void *dev_id)
{
        struct mp2629_charger *charger = dev_id;
        unsigned int rval;
        int ret;

        mutex_lock(&charger->lock);

        ret = regmap_read(charger->regmap, MP2629_REG_FAULT, &rval);
        if (ret)
                goto unlock;

        if (rval) {
                charger->fault = rval;
                if (MP2629_FAULT_BATTERY & rval)
                        dev_err(charger->dev, "Battery fault OVP\n");
                else if (MP2629_FAULT_THERMAL & rval)
                        dev_err(charger->dev, "Thermal shutdown fault\n");
                else if (MP2629_FAULT_INPUT & rval)
                        dev_err(charger->dev, "no input or input OVP\n");
                else if (MP2629_FAULT_OTG & rval)
                        dev_err(charger->dev, "VIN overloaded\n");

                goto unlock;
        }

        ret = regmap_read(charger->regmap, MP2629_REG_STATUS, &rval);
        if (ret)
                goto unlock;

        if (rval & MP2629_INPUTSOURCE_CHANGE)
                power_supply_changed(charger->usb);
        else if (rval & MP2629_CHARGING_CHANGE)
                power_supply_changed(charger->battery);

unlock:
        mutex_unlock(&charger->lock);

        return IRQ_HANDLED;
}

static const struct power_supply_desc mp2629_usb_desc = {
        .name           = "mp2629_usb",
        .type           = POWER_SUPPLY_TYPE_USB,
        .usb_types      = BIT(POWER_SUPPLY_USB_TYPE_SDP) |
                          BIT(POWER_SUPPLY_USB_TYPE_CDP) |
                          BIT(POWER_SUPPLY_USB_TYPE_DCP) |
                          BIT(POWER_SUPPLY_USB_TYPE_PD_DRP) |
                          BIT(POWER_SUPPLY_USB_TYPE_UNKNOWN),
        .properties     = mp2629_charger_usb_props,
        .num_properties = ARRAY_SIZE(mp2629_charger_usb_props),
        .get_property   = mp2629_charger_usb_get_prop,
        .set_property   = mp2629_charger_usb_set_prop,
        .property_is_writeable = mp2629_charger_usb_prop_writeable,
};

static const struct power_supply_desc mp2629_battery_desc = {
        .name           = "mp2629_battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .properties     = mp2629_charger_bat_props,
        .num_properties = ARRAY_SIZE(mp2629_charger_bat_props),
        .get_property   = mp2629_charger_battery_get_prop,
        .set_property   = mp2629_charger_battery_set_prop,
        .property_is_writeable = mp2629_charger_battery_prop_writeable,
};

static ssize_t batt_impedance_compensation_show(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct mp2629_charger *charger = dev_get_drvdata(dev->parent);
        unsigned int rval;
        int ret;

        ret = regmap_read(charger->regmap, MP2629_REG_IMPEDANCE_COMP, &rval);
        if (ret)
                return ret;

        rval = (rval >> 4) * 10;
        return sysfs_emit(buf, "%d mohm\n", rval);
}

static ssize_t batt_impedance_compensation_store(struct device *dev,
                                            struct device_attribute *attr,
                                            const char *buf,
                                            size_t count)
{
        struct mp2629_charger *charger = dev_get_drvdata(dev->parent);
        unsigned int val;
        int ret;

        ret = kstrtouint(buf, 10, &val);
        if (ret)
                return ret;

        if (val > 140)
                return -ERANGE;

        /* multiples of 10 mohm so round off */
        val = val / 10;
        ret = regmap_update_bits(charger->regmap, MP2629_REG_IMPEDANCE_COMP,
                                        MP2629_MASK_IMPEDANCE, val << 4);
        if (ret)
                return ret;

        return count;
}

static DEVICE_ATTR_RW(batt_impedance_compensation);

static struct attribute *mp2629_charger_sysfs_attrs[] = {
        &dev_attr_batt_impedance_compensation.attr,
        NULL
};
ATTRIBUTE_GROUPS(mp2629_charger_sysfs);

static void mp2629_charger_disable(void *data)
{
        struct mp2629_charger *charger = data;

        regmap_update_bits(charger->regmap, MP2629_REG_CHARGE_CTRL,
                                        MP2629_MASK_CHARGE_CTRL, 0);
}

static int mp2629_charger_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
        struct mp2629_charger *charger;
        struct power_supply_config psy_cfg = {};
        int ret, i, irq;

        charger = devm_kzalloc(dev, sizeof(*charger), GFP_KERNEL);
        if (!charger)
                return -ENOMEM;

        charger->regmap = ddata->regmap;
        charger->dev = dev;
        platform_set_drvdata(pdev, charger);

        irq = platform_get_irq(to_platform_device(dev->parent), 0);
        if (irq < 0)
                return irq;

        for (i = 0; i < MP2629_MAX_FIELD; i++) {
                charger->regmap_fields[i] = devm_regmap_field_alloc(dev,
                                        charger->regmap, mp2629_reg_fields[i]);
                if (IS_ERR(charger->regmap_fields[i])) {
                        dev_err(dev, "regmap field alloc fail %d\n", i);
                        return PTR_ERR(charger->regmap_fields[i]);
                }
        }

        for (i = 0; i < MP2629_ADC_CHAN_END; i++) {
                charger->iiochan[i] = devm_iio_channel_get(dev,
                                                        adc_chan_name[i]);
                if (IS_ERR(charger->iiochan[i])) {
                        dev_err(dev, "iio chan get %s err\n", adc_chan_name[i]);
                        return PTR_ERR(charger->iiochan[i]);
                }
        }

        ret = devm_add_action_or_reset(dev, mp2629_charger_disable, charger);
        if (ret)
                return ret;

        charger->usb = devm_power_supply_register(dev, &mp2629_usb_desc, NULL);
        if (IS_ERR(charger->usb)) {
                dev_err(dev, "power supply register usb failed\n");
                return PTR_ERR(charger->usb);
        }

        psy_cfg.drv_data = charger;
        psy_cfg.attr_grp = mp2629_charger_sysfs_groups;
        charger->battery = devm_power_supply_register(dev,
                                         &mp2629_battery_desc, &psy_cfg);
        if (IS_ERR(charger->battery)) {
                dev_err(dev, "power supply register battery failed\n");
                return PTR_ERR(charger->battery);
        }

        ret = regmap_update_bits(charger->regmap, MP2629_REG_CHARGE_CTRL,
                                        MP2629_MASK_CHARGE_CTRL, BIT(4));
        if (ret) {
                dev_err(dev, "enable charge fail: %d\n", ret);
                return ret;
        }

        regmap_update_bits(charger->regmap, MP2629_REG_TIMER_CTRL,
                                        MP2629_MASK_WDOG_CTRL, 0);

        mutex_init(&charger->lock);

        ret = devm_request_threaded_irq(dev, irq, NULL, mp2629_irq_handler,
                                        IRQF_ONESHOT | IRQF_TRIGGER_RISING,
                                        "mp2629-charger", charger);
        if (ret) {
                dev_err(dev, "failed to request gpio IRQ\n");
                return ret;
        }

        regmap_update_bits(charger->regmap, MP2629_REG_INTERRUPT,
                                GENMASK(6, 5), BIT(6) | BIT(5));

        return 0;
}

static const struct of_device_id mp2629_charger_of_match[] = {
        { .compatible = "mps,mp2629_charger"},
        {}
};
MODULE_DEVICE_TABLE(of, mp2629_charger_of_match);

static struct platform_driver mp2629_charger_driver = {
        .driver = {
                .name = "mp2629_charger",
                .of_match_table = mp2629_charger_of_match,
        },
        .probe          = mp2629_charger_probe,
};
module_platform_driver(mp2629_charger_driver);

MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
MODULE_DESCRIPTION("MP2629 Charger driver");
MODULE_LICENSE("GPL");