root/drivers/power/supply/tps65090-charger.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Battery charger driver for TI's tps65090
 *
 * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.

 */
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/freezer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>

#include <linux/mfd/tps65090.h>

#define TPS65090_CHARGER_ENABLE BIT(0)
#define TPS65090_VACG           BIT(1)
#define TPS65090_NOITERM        BIT(5)

#define POLL_INTERVAL           (HZ * 2)        /* Used when no irq */

struct tps65090_charger {
        struct  device  *dev;
        int     ac_online;
        int     prev_ac_online;
        int     irq;
        struct task_struct      *poll_task;
        bool                    passive_mode;
        struct power_supply     *ac;
        struct tps65090_platform_data *pdata;
};

static enum power_supply_property tps65090_ac_props[] = {
        POWER_SUPPLY_PROP_ONLINE,
};

static int tps65090_low_chrg_current(struct tps65090_charger *charger)
{
        int ret;

        if (charger->passive_mode)
                return 0;

        ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL5,
                        TPS65090_NOITERM);
        if (ret < 0) {
                dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
                        __func__, TPS65090_REG_CG_CTRL5);
                return ret;
        }
        return 0;
}

static int tps65090_enable_charging(struct tps65090_charger *charger)
{
        int ret;
        uint8_t ctrl0 = 0;

        if (charger->passive_mode)
                return 0;

        ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_CTRL0,
                            &ctrl0);
        if (ret < 0) {
                dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
                                __func__, TPS65090_REG_CG_CTRL0);
                return ret;
        }

        ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL0,
                                (ctrl0 | TPS65090_CHARGER_ENABLE));
        if (ret < 0) {
                dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
                                __func__, TPS65090_REG_CG_CTRL0);
                return ret;
        }
        return 0;
}

static int tps65090_config_charger(struct tps65090_charger *charger)
{
        uint8_t intrmask = 0;
        int ret;

        if (charger->passive_mode)
                return 0;

        if (charger->pdata->enable_low_current_chrg) {
                ret = tps65090_low_chrg_current(charger);
                if (ret < 0) {
                        dev_err(charger->dev,
                                "error configuring low charge current\n");
                        return ret;
                }
        }

        /* Enable the VACG interrupt for AC power detect */
        ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_MASK,
                            &intrmask);
        if (ret < 0) {
                dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
                        __func__, TPS65090_REG_INTR_MASK);
                return ret;
        }

        ret = tps65090_write(charger->dev->parent, TPS65090_REG_INTR_MASK,
                             (intrmask | TPS65090_VACG));
        if (ret < 0) {
                dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
                        __func__, TPS65090_REG_CG_CTRL0);
                return ret;
        }

        return 0;
}

static int tps65090_ac_get_property(struct power_supply *psy,
                        enum power_supply_property psp,
                        union power_supply_propval *val)
{
        struct tps65090_charger *charger = power_supply_get_drvdata(psy);

        if (psp == POWER_SUPPLY_PROP_ONLINE) {
                val->intval = charger->ac_online;
                charger->prev_ac_online = charger->ac_online;
                return 0;
        }
        return -EINVAL;
}

static irqreturn_t tps65090_charger_isr(int irq, void *dev_id)
{
        struct tps65090_charger *charger = dev_id;
        int ret;
        uint8_t status1 = 0;
        uint8_t intrsts = 0;

        ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_STATUS1,
                            &status1);
        if (ret < 0) {
                dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
                                __func__, TPS65090_REG_CG_STATUS1);
                return IRQ_HANDLED;
        }
        msleep(75);
        ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_STS,
                            &intrsts);
        if (ret < 0) {
                dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
                                __func__, TPS65090_REG_INTR_STS);
                return IRQ_HANDLED;
        }

        if (intrsts & TPS65090_VACG) {
                ret = tps65090_enable_charging(charger);
                if (ret < 0)
                        return IRQ_HANDLED;
                charger->ac_online = 1;
        } else {
                charger->ac_online = 0;
        }

        /* Clear interrupts. */
        if (!charger->passive_mode) {
                ret = tps65090_write(charger->dev->parent,
                                     TPS65090_REG_INTR_STS, 0x00);
                if (ret < 0) {
                        dev_err(charger->dev,
                                "%s(): Error in writing reg 0x%x\n",
                                __func__, TPS65090_REG_INTR_STS);
                }
        }

        if (charger->prev_ac_online != charger->ac_online)
                power_supply_changed(charger->ac);

        return IRQ_HANDLED;
}

static struct tps65090_platform_data *
                tps65090_parse_dt_charger_data(struct platform_device *pdev)
{
        struct tps65090_platform_data *pdata;
        struct device_node *np = pdev->dev.of_node;
        unsigned int prop;

        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
                dev_err(&pdev->dev, "Memory alloc for tps65090_pdata failed\n");
                return NULL;
        }

        prop = of_property_read_bool(np, "ti,enable-low-current-chrg");
        pdata->enable_low_current_chrg = prop;

        pdata->irq_base = -1;

        return pdata;

}

static int tps65090_charger_poll_task(void *data)
{
        set_freezable();

        while (!kthread_should_stop()) {
                schedule_timeout_interruptible(POLL_INTERVAL);
                try_to_freeze();
                tps65090_charger_isr(-1, data);
        }
        return 0;
}

static const struct power_supply_desc tps65090_charger_desc = {
        .name                   = "tps65090-ac",
        .type                   = POWER_SUPPLY_TYPE_MAINS,
        .get_property           = tps65090_ac_get_property,
        .properties             = tps65090_ac_props,
        .num_properties         = ARRAY_SIZE(tps65090_ac_props),
};

static int tps65090_charger_probe(struct platform_device *pdev)
{
        struct tps65090_charger *cdata;
        struct tps65090_platform_data *pdata;
        struct power_supply_config psy_cfg = {};
        uint8_t status1 = 0;
        int ret;
        int irq;

        pdata = dev_get_platdata(pdev->dev.parent);

        if (IS_ENABLED(CONFIG_OF) && !pdata && pdev->dev.of_node)
                pdata = tps65090_parse_dt_charger_data(pdev);

        if (!pdata) {
                dev_err(&pdev->dev, "%s():no platform data available\n",
                                __func__);
                return -ENODEV;
        }

        cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
        if (!cdata) {
                dev_err(&pdev->dev, "failed to allocate memory status\n");
                return -ENOMEM;
        }

        platform_set_drvdata(pdev, cdata);

        cdata->dev                      = &pdev->dev;
        cdata->pdata                    = pdata;

        psy_cfg.supplied_to             = pdata->supplied_to;
        psy_cfg.num_supplicants         = pdata->num_supplicants;
        psy_cfg.fwnode                  = dev_fwnode(&pdev->dev);
        psy_cfg.drv_data                = cdata;

        cdata->ac = devm_power_supply_register(&pdev->dev, &tps65090_charger_desc,
                        &psy_cfg);
        if (IS_ERR(cdata->ac)) {
                dev_err(&pdev->dev, "failed: power supply register\n");
                return PTR_ERR(cdata->ac);
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                irq = -ENXIO;
        cdata->irq = irq;

        ret = tps65090_config_charger(cdata);
        if (ret < 0) {
                dev_err(&pdev->dev, "charger config failed, err %d\n", ret);
                return ret;
        }

        /* Check for charger presence */
        ret = tps65090_read(cdata->dev->parent, TPS65090_REG_CG_STATUS1,
                        &status1);
        if (ret < 0) {
                dev_err(cdata->dev, "%s(): Error in reading reg 0x%x", __func__,
                        TPS65090_REG_CG_STATUS1);
                return ret;
        }

        if (status1 != 0) {
                ret = tps65090_enable_charging(cdata);
                if (ret < 0) {
                        dev_err(cdata->dev, "error enabling charger\n");
                        return ret;
                }
                cdata->ac_online = 1;
                power_supply_changed(cdata->ac);
        }

        if (irq != -ENXIO) {
                ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
                        tps65090_charger_isr, IRQF_ONESHOT, "tps65090-charger", cdata);
                if (ret) {
                        dev_err(cdata->dev,
                                "Unable to register irq %d err %d\n", irq,
                                ret);
                        return ret;
                }
        } else {
                cdata->poll_task = kthread_run(tps65090_charger_poll_task,
                                              cdata, "ktps65090charger");
                cdata->passive_mode = true;
                if (IS_ERR(cdata->poll_task)) {
                        ret = PTR_ERR(cdata->poll_task);
                        dev_err(cdata->dev,
                                "Unable to run kthread err %d\n", ret);
                        return ret;
                }
        }

        return 0;
}

static void tps65090_charger_remove(struct platform_device *pdev)
{
        struct tps65090_charger *cdata = platform_get_drvdata(pdev);

        if (cdata->irq == -ENXIO)
                kthread_stop(cdata->poll_task);
}

static const struct of_device_id of_tps65090_charger_match[] = {
        { .compatible = "ti,tps65090-charger", },
        { /* end */ }
};
MODULE_DEVICE_TABLE(of, of_tps65090_charger_match);

static struct platform_driver tps65090_charger_driver = {
        .driver = {
                .name   = "tps65090-charger",
                .of_match_table = of_tps65090_charger_match,
        },
        .probe  = tps65090_charger_probe,
        .remove = tps65090_charger_remove,
};
module_platform_driver(tps65090_charger_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com>");
MODULE_DESCRIPTION("tps65090 battery charger driver");