// 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/spmi.h>
#include <linux/types.h>
#include <linux/regmap.h>
#include <linux/of_platform.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;
};

#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,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 device *dev)
{
	struct spmi_device *sdev;
	struct qcom_spmi_dev *ctx;
	struct device_node *spmi_bus;
	struct device_node *other_usid = NULL;
	int function_parent_usid, ret;
	u32 pmic_addr;

	sdev = to_spmi_device(dev);
	ctx = dev_get_drvdata(&sdev->dev);

	/*
	 * 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)
		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);
	do {
		other_usid = of_get_next_child(spmi_bus, other_usid);

		ret = of_property_read_u32_index(other_usid, "reg", 0, &pmic_addr);
		if (ret)
			return ERR_PTR(ret);

		sdev = spmi_device_from_of(other_usid);
		if (pmic_addr == function_parent_usid - (ctx->num_usids - 1)) {
			if (!sdev)
				/*
				 * If the base USID for this PMIC hasn't probed yet
				 * but the secondary USID has, then we need to defer
				 * the function driver so that it will attempt to
				 * probe again when the base USID is ready.
				 */
				return ERR_PTR(-EPROBE_DEFER);
			return sdev;
		}
	} while (other_usid->sibling);

	return ERR_PTR(-ENODATA);
}

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 = qcom_pmic_get_base_usid(dev->parent);

	if (IS_ERR(sdev))
		return ERR_CAST(sdev);

	spmi = dev_get_drvdata(&sdev->dev);

	return &spmi->pmic;
}
EXPORT_SYMBOL(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)of_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;
	}
	spmi_device_set_drvdata(sdev, ctx);

	return devm_of_platform_populate(&sdev->dev);
}

MODULE_DEVICE_TABLE(of, pmic_spmi_id_table);

static struct spmi_driver pmic_spmi_driver = {
	.probe = pmic_spmi_probe,
	.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>"