// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2021 ROHM Semiconductors
 *
 * ROHM BD9576MUF and BD9573MUF PMIC driver
 */

#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rohm-bd957x.h>
#include <linux/mfd/rohm-generic.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/types.h>

enum {
        BD957X_REGULATOR_CELL,
        BD957X_WDT_CELL,
};

/*
 * Due to the BD9576MUF nasty IRQ behaviour we don't always populate IRQs.
 * These will be added to regulator resources only if IRQ information for the
 * PMIC is populated in device-tree.
 */
static const struct resource bd9576_regulator_irqs[] = {
        DEFINE_RES_IRQ_NAMED(BD9576_INT_THERM, "bd9576-temp"),
        DEFINE_RES_IRQ_NAMED(BD9576_INT_OVD, "bd9576-ovd"),
        DEFINE_RES_IRQ_NAMED(BD9576_INT_UVD, "bd9576-uvd"),
};

static struct mfd_cell bd9573_mfd_cells[] = {
        [BD957X_REGULATOR_CELL] = { .name = "bd9573-regulator", },
        [BD957X_WDT_CELL]       = { .name = "bd9576-wdt", },
};

static struct mfd_cell bd9576_mfd_cells[] = {
        [BD957X_REGULATOR_CELL] = { .name = "bd9576-regulator", },
        [BD957X_WDT_CELL]       = { .name = "bd9576-wdt", },
};

static const struct regmap_range volatile_ranges[] = {
        regmap_reg_range(BD957X_REG_SMRB_ASSERT, BD957X_REG_SMRB_ASSERT),
        regmap_reg_range(BD957X_REG_PMIC_INTERNAL_STAT,
                         BD957X_REG_PMIC_INTERNAL_STAT),
        regmap_reg_range(BD957X_REG_INT_THERM_STAT, BD957X_REG_INT_THERM_STAT),
        regmap_reg_range(BD957X_REG_INT_OVP_STAT, BD957X_REG_INT_SYS_STAT),
        regmap_reg_range(BD957X_REG_INT_MAIN_STAT, BD957X_REG_INT_MAIN_STAT),
};

static const struct regmap_access_table volatile_regs = {
        .yes_ranges = &volatile_ranges[0],
        .n_yes_ranges = ARRAY_SIZE(volatile_ranges),
};

static const struct regmap_config bd957x_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .volatile_table = &volatile_regs,
        .max_register = BD957X_MAX_REGISTER,
        .cache_type = REGCACHE_MAPLE,
};

static const struct regmap_irq bd9576_irqs[] = {
        REGMAP_IRQ_REG(BD9576_INT_THERM, 0, BD957X_MASK_INT_MAIN_THERM),
        REGMAP_IRQ_REG(BD9576_INT_OVP, 0, BD957X_MASK_INT_MAIN_OVP),
        REGMAP_IRQ_REG(BD9576_INT_SCP, 0, BD957X_MASK_INT_MAIN_SCP),
        REGMAP_IRQ_REG(BD9576_INT_OCP, 0, BD957X_MASK_INT_MAIN_OCP),
        REGMAP_IRQ_REG(BD9576_INT_OVD, 0, BD957X_MASK_INT_MAIN_OVD),
        REGMAP_IRQ_REG(BD9576_INT_UVD, 0, BD957X_MASK_INT_MAIN_UVD),
        REGMAP_IRQ_REG(BD9576_INT_UVP, 0, BD957X_MASK_INT_MAIN_UVP),
        REGMAP_IRQ_REG(BD9576_INT_SYS, 0, BD957X_MASK_INT_MAIN_SYS),
};

static const struct regmap_irq_chip bd9576_irq_chip = {
        .name = "bd9576_irq",
        .irqs = &bd9576_irqs[0],
        .num_irqs = ARRAY_SIZE(bd9576_irqs),
        .status_base = BD957X_REG_INT_MAIN_STAT,
        .mask_base = BD957X_REG_INT_MAIN_MASK,
        .ack_base = BD957X_REG_INT_MAIN_STAT,
        .init_ack_masked = true,
        .num_regs = 1,
        .irq_reg_stride = 1,
};

static int bd957x_i2c_probe(struct i2c_client *i2c)
{
        int ret;
        struct regmap *regmap;
        struct mfd_cell *cells;
        int num_cells;
        unsigned long chip_type;
        struct irq_domain *domain;
        bool usable_irqs;

        chip_type = (unsigned long)of_device_get_match_data(&i2c->dev);

        switch (chip_type) {
        case ROHM_CHIP_TYPE_BD9576:
                cells = bd9576_mfd_cells;
                num_cells = ARRAY_SIZE(bd9576_mfd_cells);
                usable_irqs = !!i2c->irq;
                break;
        case ROHM_CHIP_TYPE_BD9573:
                cells = bd9573_mfd_cells;
                num_cells = ARRAY_SIZE(bd9573_mfd_cells);
                /*
                 * BD9573 only supports fatal IRQs which we can not handle
                 * because SoC is going to lose the power.
                 */
                usable_irqs = false;
                break;
        default:
                dev_err(&i2c->dev, "Unknown device type");
                return -EINVAL;
        }

        regmap = devm_regmap_init_i2c(i2c, &bd957x_regmap);
        if (IS_ERR(regmap))
                return dev_err_probe(&i2c->dev, PTR_ERR(regmap),
                                     "Failed to initialize Regmap\n");

        /*
         * BD9576 behaves badly. It kepts IRQ line asserted for the whole
         * duration of detected HW condition (like over temperature). So we
         * don't require IRQ to be populated.
         * If IRQ information is not given, then we mask all IRQs and do not
         * provide IRQ resources to regulator driver - which then just omits
         * the notifiers.
         */
        if (usable_irqs) {
                struct regmap_irq_chip_data *irq_data;
                struct mfd_cell *regulators;

                regulators = &bd9576_mfd_cells[BD957X_REGULATOR_CELL];
                regulators->resources = bd9576_regulator_irqs;
                regulators->num_resources = ARRAY_SIZE(bd9576_regulator_irqs);

                ret = devm_regmap_add_irq_chip(&i2c->dev, regmap, i2c->irq,
                                               IRQF_ONESHOT, 0,
                                               &bd9576_irq_chip, &irq_data);
                if (ret)
                        return dev_err_probe(&i2c->dev, ret,
                                             "Failed to add IRQ chip\n");

                domain = regmap_irq_get_domain(irq_data);
        } else {
                ret = regmap_update_bits(regmap, BD957X_REG_INT_MAIN_MASK,
                                         BD957X_MASK_INT_ALL,
                                         BD957X_MASK_INT_ALL);
                if (ret)
                        return ret;
                domain = NULL;
        }

        ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO, cells,
                                   num_cells, NULL, 0, domain);
        if (ret)
                dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");

        return ret;
}

static const struct of_device_id bd957x_of_match[] = {
        { .compatible = "rohm,bd9576", .data = (void *)ROHM_CHIP_TYPE_BD9576, },
        { .compatible = "rohm,bd9573", .data = (void *)ROHM_CHIP_TYPE_BD9573, },
        { },
};
MODULE_DEVICE_TABLE(of, bd957x_of_match);

static struct i2c_driver bd957x_drv = {
        .driver = {
                .name = "rohm-bd957x",
                .of_match_table = bd957x_of_match,
        },
        .probe = bd957x_i2c_probe,
};
module_i2c_driver(bd957x_drv);

MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
MODULE_DESCRIPTION("ROHM BD9576MUF and BD9573MUF Power Management IC driver");
MODULE_LICENSE("GPL");