// SPDX-License-Identifier: GPL-2.0
/*
 * ESM (Error Signal Monitor) driver for TI TPS6594/TPS6593/LP8764 PMICs
 *
 * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
 */

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>

#include <linux/mfd/tps6594.h>

#define TPS6594_DEV_REV_1 0x08

static irqreturn_t tps6594_esm_isr(int irq, void *dev_id)
{
        struct platform_device *pdev = dev_id;
        int i;

        for (i = 0 ; i < pdev->num_resources ; i++) {
                if (irq == platform_get_irq_byname(pdev, pdev->resource[i].name)) {
                        dev_err(pdev->dev.parent, "%s error detected\n", pdev->resource[i].name);
                        return IRQ_HANDLED;
                }
        }

        return IRQ_NONE;
}

static int tps6594_esm_probe(struct platform_device *pdev)
{
        struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
        struct device *dev = &pdev->dev;
        unsigned int rev;
        int irq;
        int ret;
        int i;

        /*
         * Due to a bug in revision 1 of the PMIC, the GPIO3 used for the
         * SoC ESM function is used to power the load switch instead.
         * As a consequence, ESM can not be used on those PMIC.
         * Check the version and return an error in case of revision 1.
         */
        ret = regmap_read(tps->regmap, TPS6594_REG_DEV_REV, &rev);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Failed to read PMIC revision\n");
        if (rev == TPS6594_DEV_REV_1)
                return dev_err_probe(dev, -ENODEV,
                              "ESM not supported for revision 1 PMIC\n");

        for (i = 0; i < pdev->num_resources; i++) {
                irq = platform_get_irq_byname(pdev, pdev->resource[i].name);
                if (irq < 0)
                        return irq;

                ret = devm_request_threaded_irq(dev, irq, NULL,
                                                tps6594_esm_isr, IRQF_ONESHOT,
                                                pdev->resource[i].name, pdev);
                if (ret)
                        return dev_err_probe(dev, ret, "Failed to request irq\n");
        }

        ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
                              TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to configure ESM\n");

        ret = regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
                              TPS6594_BIT_ESM_SOC_START);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to start ESM\n");

        pm_runtime_enable(dev);
        pm_runtime_get_sync(dev);

        return 0;
}

static void tps6594_esm_remove(struct platform_device *pdev)
{
        struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
        struct device *dev = &pdev->dev;
        int ret;

        ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
                                TPS6594_BIT_ESM_SOC_START);
        if (ret) {
                dev_err(dev, "Failed to stop ESM\n");
                goto out;
        }

        ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_MODE_CFG,
                                TPS6594_BIT_ESM_SOC_EN | TPS6594_BIT_ESM_SOC_ENDRV);
        if (ret)
                dev_err(dev, "Failed to unconfigure ESM\n");

out:
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
}

static int tps6594_esm_suspend(struct device *dev)
{
        struct tps6594 *tps = dev_get_drvdata(dev->parent);
        int ret;

        ret = regmap_clear_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
                                TPS6594_BIT_ESM_SOC_START);

        pm_runtime_put_sync(dev);

        return ret;
}

static int tps6594_esm_resume(struct device *dev)
{
        struct tps6594 *tps = dev_get_drvdata(dev->parent);

        pm_runtime_get_sync(dev);

        return regmap_set_bits(tps->regmap, TPS6594_REG_ESM_SOC_START_REG,
                               TPS6594_BIT_ESM_SOC_START);
}

static DEFINE_SIMPLE_DEV_PM_OPS(tps6594_esm_pm_ops, tps6594_esm_suspend, tps6594_esm_resume);

static struct platform_driver tps6594_esm_driver = {
        .driver = {
                .name = "tps6594-esm",
                .pm = pm_sleep_ptr(&tps6594_esm_pm_ops),
        },
        .probe = tps6594_esm_probe,
        .remove = tps6594_esm_remove,
};

module_platform_driver(tps6594_esm_driver);

MODULE_ALIAS("platform:tps6594-esm");
MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
MODULE_DESCRIPTION("TPS6594 Error Signal Monitor Driver");
MODULE_LICENSE("GPL");