// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
 */

#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/spmi.h>
#include <linux/types.h>
#include <linux/regmap.h>
#include <soc/qcom/qcom-spmi-pmic.h>

#define PMIC_REV2               0x101
#define PMIC_REV3               0x102
#define PMIC_REV4               0x103
#define PMIC_TYPE               0x104
#define PMIC_SUBTYPE            0x105
#define PMIC_FAB_ID             0x1f2

#define PMIC_TYPE_VALUE         0x51

#define PMIC_REV4_V2            0x02

struct qcom_spmi_dev {
        int num_usids;
        struct qcom_spmi_pmic pmic;
};

static DEFINE_MUTEX(pmic_spmi_revid_lock);

#define N_USIDS(n)              ((void *)n)

static const struct of_device_id pmic_spmi_id_table[] = {
        { .compatible = "qcom,pm660", .data = N_USIDS(2) },
        { .compatible = "qcom,pm660l", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8004", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8005", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8019", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8028", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8110", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8150", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8150b", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8150c", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8150l", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8226", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8841", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8901", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8909", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8916", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8937", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8941", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8950", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8994", .data = N_USIDS(2) },
        { .compatible = "qcom,pm8998", .data = N_USIDS(2) },
        { .compatible = "qcom,pma8084", .data = N_USIDS(2) },
        { .compatible = "qcom,pmd9635", .data = N_USIDS(2) },
        { .compatible = "qcom,pmi8950", .data = N_USIDS(2) },
        { .compatible = "qcom,pmi8962", .data = N_USIDS(2) },
        { .compatible = "qcom,pmi8994", .data = N_USIDS(2) },
        { .compatible = "qcom,pmi8998", .data = N_USIDS(2) },
        { .compatible = "qcom,pmk8002", .data = N_USIDS(2) },
        { .compatible = "qcom,pmp8074", .data = N_USIDS(2) },
        { .compatible = "qcom,smb2351", .data = N_USIDS(2) },
        { .compatible = "qcom,spmi-pmic", .data = N_USIDS(1) },
        { }
};

/*
 * A PMIC can be represented by multiple SPMI devices, but
 * only the base PMIC device will contain a reference to
 * the revision information.
 *
 * This function takes a pointer to a pmic device and
 * returns a pointer to the base PMIC device.
 *
 * This only supports PMICs with 1 or 2 USIDs.
 */
static struct spmi_device *qcom_pmic_get_base_usid(struct spmi_device *sdev, struct qcom_spmi_dev *ctx)
{
        struct device_node *spmi_bus;
        int function_parent_usid, ret;
        u32 pmic_addr;

        /*
         * Quick return if the function device is already in the base
         * USID. This will always be hit for PMICs with only 1 USID.
         */
        if (sdev->usid % ctx->num_usids == 0) {
                get_device(&sdev->dev);
                return sdev;
        }

        function_parent_usid = sdev->usid;

        /*
         * Walk through the list of PMICs until we find the sibling USID.
         * The goal is to find the first USID which is less than the
         * number of USIDs in the PMIC array, e.g. for a PMIC with 2 USIDs
         * where the function device is under USID 3, we want to find the
         * device for USID 2.
         */
        spmi_bus = of_get_parent(sdev->dev.of_node);
        sdev = ERR_PTR(-ENODATA);
        for_each_child_of_node_scoped(spmi_bus, child) {
                ret = of_property_read_u32_index(child, "reg", 0, &pmic_addr);
                if (ret) {
                        sdev = ERR_PTR(ret);
                        break;
                }

                if (pmic_addr == function_parent_usid - (ctx->num_usids - 1)) {
                        sdev = spmi_find_device_by_of_node(child);
                        if (!sdev) {
                                /*
                                 * If the base USID for this PMIC hasn't been
                                 * registered yet then we need to defer.
                                 */
                                sdev = ERR_PTR(-EPROBE_DEFER);
                        }
                        break;
                }
        }

        of_node_put(spmi_bus);

        return sdev;
}

static int pmic_spmi_get_base_revid(struct spmi_device *sdev, struct qcom_spmi_dev *ctx)
{
        struct qcom_spmi_dev *base_ctx;
        struct spmi_device *base;
        int ret = 0;

        base = qcom_pmic_get_base_usid(sdev, ctx);
        if (IS_ERR(base))
                return PTR_ERR(base);

        /*
         * Copy revid info from base device if it has probed and is still
         * bound to its driver.
         */
        mutex_lock(&pmic_spmi_revid_lock);
        base_ctx = spmi_device_get_drvdata(base);
        if (!base_ctx) {
                ret = -EPROBE_DEFER;
                goto out_unlock;
        }
        memcpy(&ctx->pmic, &base_ctx->pmic, sizeof(ctx->pmic));
out_unlock:
        mutex_unlock(&pmic_spmi_revid_lock);

        put_device(&base->dev);

        return ret;
}

static int pmic_spmi_load_revid(struct regmap *map, struct device *dev,
                                 struct qcom_spmi_pmic *pmic)
{
        int ret;

        ret = regmap_read(map, PMIC_TYPE, &pmic->type);
        if (ret < 0)
                return ret;

        if (pmic->type != PMIC_TYPE_VALUE)
                return ret;

        ret = regmap_read(map, PMIC_SUBTYPE, &pmic->subtype);
        if (ret < 0)
                return ret;

        pmic->name = of_match_device(pmic_spmi_id_table, dev)->compatible;

        ret = regmap_read(map, PMIC_REV2, &pmic->rev2);
        if (ret < 0)
                return ret;

        ret = regmap_read(map, PMIC_REV3, &pmic->minor);
        if (ret < 0)
                return ret;

        ret = regmap_read(map, PMIC_REV4, &pmic->major);
        if (ret < 0)
                return ret;

        if (pmic->subtype == PMI8998_SUBTYPE || pmic->subtype == PM660_SUBTYPE) {
                ret = regmap_read(map, PMIC_FAB_ID, &pmic->fab_id);
                if (ret < 0)
                        return ret;
        }

        /*
         * In early versions of PM8941 and PM8226, the major revision number
         * started incrementing from 0 (eg 0 = v1.0, 1 = v2.0).
         * Increment the major revision number here if the chip is an early
         * version of PM8941 or PM8226.
         */
        if ((pmic->subtype == PM8941_SUBTYPE || pmic->subtype == PM8226_SUBTYPE) &&
            pmic->major < PMIC_REV4_V2)
                pmic->major++;

        if (pmic->subtype == PM8110_SUBTYPE)
                pmic->minor = pmic->rev2;

        dev_dbg(dev, "%x: %s v%d.%d\n",
                pmic->subtype, pmic->name, pmic->major, pmic->minor);

        return 0;
}

/**
 * qcom_pmic_get() - Get a pointer to the base PMIC device
 *
 * This function takes a struct device for a driver which is a child of a PMIC.
 * And locates the PMIC revision information for it.
 *
 * @dev: the pmic function device
 * @return: the struct qcom_spmi_pmic* pointer associated with the function device
 */
const struct qcom_spmi_pmic *qcom_pmic_get(struct device *dev)
{
        struct spmi_device *sdev;
        struct qcom_spmi_dev *spmi;

        /*
         * Make sure the device is actually a child of a PMIC
         */
        if (!of_match_device(pmic_spmi_id_table, dev->parent))
                return ERR_PTR(-EINVAL);

        sdev = to_spmi_device(dev->parent);
        spmi = dev_get_drvdata(&sdev->dev);

        return &spmi->pmic;
}
EXPORT_SYMBOL_GPL(qcom_pmic_get);

static const struct regmap_config spmi_regmap_config = {
        .reg_bits       = 16,
        .val_bits       = 8,
        .max_register   = 0xffff,
        .fast_io        = true,
};

static int pmic_spmi_probe(struct spmi_device *sdev)
{
        struct regmap *regmap;
        struct qcom_spmi_dev *ctx;
        int ret;

        regmap = devm_regmap_init_spmi_ext(sdev, &spmi_regmap_config);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

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

        ctx->num_usids = (uintptr_t)device_get_match_data(&sdev->dev);

        /* Only the first slave id for a PMIC contains this information */
        if (sdev->usid % ctx->num_usids == 0) {
                ret = pmic_spmi_load_revid(regmap, &sdev->dev, &ctx->pmic);
                if (ret < 0)
                        return ret;
        } else {
                ret = pmic_spmi_get_base_revid(sdev, ctx);
                if (ret)
                        return ret;
        }

        mutex_lock(&pmic_spmi_revid_lock);
        spmi_device_set_drvdata(sdev, ctx);
        mutex_unlock(&pmic_spmi_revid_lock);

        return devm_of_platform_populate(&sdev->dev);
}

static void pmic_spmi_remove(struct spmi_device *sdev)
{
        mutex_lock(&pmic_spmi_revid_lock);
        spmi_device_set_drvdata(sdev, NULL);
        mutex_unlock(&pmic_spmi_revid_lock);
}

MODULE_DEVICE_TABLE(of, pmic_spmi_id_table);

static struct spmi_driver pmic_spmi_driver = {
        .probe = pmic_spmi_probe,
        .remove = pmic_spmi_remove,
        .driver = {
                .name = "pmic-spmi",
                .of_match_table = pmic_spmi_id_table,
        },
};
module_spmi_driver(pmic_spmi_driver);

MODULE_DESCRIPTION("Qualcomm SPMI PMIC driver");
MODULE_ALIAS("spmi:spmi-pmic");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Josh Cartwright <joshc@codeaurora.org>");
MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");