// SPDX-License-Identifier: GPL-2.0
/*
 * ROHM BD9571MWV-M and BD9574MWF-M regulator driver
 *
 * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
 *
 * Based on the TPS65086 driver
 *
 * NOTE: VD09 is missing
 */

#include <linux/mfd/rohm-generic.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>

#include <linux/mfd/bd9571mwv.h>

struct bd9571mwv_reg {
        struct regmap *regmap;

        /* DDR Backup Power */
        u8 bkup_mode_cnt_keepon;        /* from "rohm,ddr-backup-power" */
        u8 bkup_mode_cnt_saved;
        bool bkup_mode_enabled;

        /* Power switch type */
        bool rstbmode_level;
        bool rstbmode_pulse;
};

enum bd9571mwv_regulators { VD09, VD18, VD25, VD33, DVFS };

#define BD9571MWV_REG(_name, _of, _id, _ops, _vr, _vm, _nv, _min, _step, _lmin)\
        {                                                       \
                .name                   = _name,                \
                .of_match               = of_match_ptr(_of),    \
                .regulators_node        = "regulators",         \
                .id                     = _id,                  \
                .ops                    = &_ops,                \
                .n_voltages             = _nv,                  \
                .type                   = REGULATOR_VOLTAGE,    \
                .owner                  = THIS_MODULE,          \
                .vsel_reg               = _vr,                  \
                .vsel_mask              = _vm,                  \
                .min_uV                 = _min,                 \
                .uV_step                = _step,                \
                .linear_min_sel         = _lmin,                \
        }

static int bd9571mwv_avs_get_moni_state(struct regulator_dev *rdev)
{
        unsigned int val;
        int ret;

        ret = regmap_read(rdev->regmap, BD9571MWV_AVS_SET_MONI, &val);
        if (ret != 0)
                return ret;

        return val & BD9571MWV_AVS_SET_MONI_MASK;
}

static int bd9571mwv_avs_set_voltage_sel_regmap(struct regulator_dev *rdev,
                                                unsigned int sel)
{
        int ret;

        ret = bd9571mwv_avs_get_moni_state(rdev);
        if (ret < 0)
                return ret;

        return regmap_write_bits(rdev->regmap, BD9571MWV_AVS_VD09_VID(ret),
                                 rdev->desc->vsel_mask, sel);
}

static int bd9571mwv_avs_get_voltage_sel_regmap(struct regulator_dev *rdev)
{
        unsigned int val;
        int ret;

        ret = bd9571mwv_avs_get_moni_state(rdev);
        if (ret < 0)
                return ret;

        ret = regmap_read(rdev->regmap, BD9571MWV_AVS_VD09_VID(ret), &val);
        if (ret != 0)
                return ret;

        val &= rdev->desc->vsel_mask;
        val >>= ffs(rdev->desc->vsel_mask) - 1;

        return val;
}

static int bd9571mwv_reg_set_voltage_sel_regmap(struct regulator_dev *rdev,
                                                unsigned int sel)
{
        return regmap_write_bits(rdev->regmap, BD9571MWV_DVFS_SETVID,
                                 rdev->desc->vsel_mask, sel);
}

/* Operations permitted on AVS voltage regulator */
static const struct regulator_ops avs_ops = {
        .set_voltage_sel        = bd9571mwv_avs_set_voltage_sel_regmap,
        .map_voltage            = regulator_map_voltage_linear,
        .get_voltage_sel        = bd9571mwv_avs_get_voltage_sel_regmap,
        .list_voltage           = regulator_list_voltage_linear,
};

/* Operations permitted on voltage regulators */
static const struct regulator_ops reg_ops = {
        .set_voltage_sel        = bd9571mwv_reg_set_voltage_sel_regmap,
        .map_voltage            = regulator_map_voltage_linear,
        .get_voltage_sel        = regulator_get_voltage_sel_regmap,
        .list_voltage           = regulator_list_voltage_linear,
};

/* Operations permitted on voltage monitors */
static const struct regulator_ops vid_ops = {
        .map_voltage            = regulator_map_voltage_linear,
        .get_voltage_sel        = regulator_get_voltage_sel_regmap,
        .list_voltage           = regulator_list_voltage_linear,
};

static const struct regulator_desc regulators[] = {
        BD9571MWV_REG("VD09", "vd09", VD09, avs_ops, 0, 0x7f,
                      0x6f, 600000, 10000, 0x3c),
        BD9571MWV_REG("VD18", "vd18", VD18, vid_ops, BD9571MWV_VD18_VID, 0xf,
                      16, 1625000, 25000, 0),
        BD9571MWV_REG("VD25", "vd25", VD25, vid_ops, BD9571MWV_VD25_VID, 0xf,
                      16, 2150000, 50000, 0),
        BD9571MWV_REG("VD33", "vd33", VD33, vid_ops, BD9571MWV_VD33_VID, 0xf,
                      11, 2800000, 100000, 0),
        BD9571MWV_REG("DVFS", "dvfs", DVFS, reg_ops,
                      BD9571MWV_DVFS_MONIVDAC, 0x7f,
                      0x6f, 600000, 10000, 0x3c),
};

#ifdef CONFIG_PM_SLEEP
static int bd9571mwv_bkup_mode_read(struct bd9571mwv_reg *bdreg,
                                    unsigned int *mode)
{
        int ret;

        ret = regmap_read(bdreg->regmap, BD9571MWV_BKUP_MODE_CNT, mode);
        if (ret) {
                dev_err(regmap_get_device(bdreg->regmap),
                        "failed to read backup mode (%d)\n", ret);
                return ret;
        }

        return 0;
}

static int bd9571mwv_bkup_mode_write(struct bd9571mwv_reg *bdreg,
                                     unsigned int mode)
{
        int ret;

        ret = regmap_write(bdreg->regmap, BD9571MWV_BKUP_MODE_CNT, mode);
        if (ret) {
                dev_err(regmap_get_device(bdreg->regmap),
                        "failed to configure backup mode 0x%x (%d)\n",
                        mode, ret);
                return ret;
        }

        return 0;
}

static ssize_t backup_mode_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%s\n", bdreg->bkup_mode_enabled ? "on" : "off");
}

static ssize_t backup_mode_store(struct device *dev,
                                 struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
        unsigned int mode;
        int ret;

        if (!count)
                return 0;

        ret = kstrtobool(buf, &bdreg->bkup_mode_enabled);
        if (ret)
                return ret;

        if (!bdreg->rstbmode_level)
                return count;

        /*
         * Configure DDR Backup Mode, to change the role of the accessory power
         * switch from a power switch to a wake-up switch, or vice versa
         */
        ret = bd9571mwv_bkup_mode_read(bdreg, &mode);
        if (ret)
                return ret;

        mode &= ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK;
        if (bdreg->bkup_mode_enabled)
                mode |= bdreg->bkup_mode_cnt_keepon;

        ret = bd9571mwv_bkup_mode_write(bdreg, mode);
        if (ret)
                return ret;

        return count;
}

static DEVICE_ATTR_RW(backup_mode);

static int bd9571mwv_suspend(struct device *dev)
{
        struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
        unsigned int mode;
        int ret;

        if (!bdreg->bkup_mode_enabled)
                return 0;

        /* Save DDR Backup Mode */
        ret = bd9571mwv_bkup_mode_read(bdreg, &mode);
        if (ret)
                return ret;

        bdreg->bkup_mode_cnt_saved = mode;

        if (!bdreg->rstbmode_pulse)
                return 0;

        /* Enable DDR Backup Mode */
        mode &= ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK;
        mode |= bdreg->bkup_mode_cnt_keepon;

        if (mode != bdreg->bkup_mode_cnt_saved)
                return bd9571mwv_bkup_mode_write(bdreg, mode);

        return 0;
}

static int bd9571mwv_resume(struct device *dev)
{
        struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);

        if (!bdreg->bkup_mode_enabled)
                return 0;

        /* Restore DDR Backup Mode */
        return bd9571mwv_bkup_mode_write(bdreg, bdreg->bkup_mode_cnt_saved);
}

static const struct dev_pm_ops bd9571mwv_pm  = {
        SET_SYSTEM_SLEEP_PM_OPS(bd9571mwv_suspend, bd9571mwv_resume)
};

static void bd9571mwv_regulator_remove(struct platform_device *pdev)
{
        device_remove_file(&pdev->dev, &dev_attr_backup_mode);
}
#define DEV_PM_OPS      &bd9571mwv_pm
#else
#define DEV_PM_OPS      NULL
#define bd9571mwv_regulator_remove      NULL
#endif /* CONFIG_PM_SLEEP */

static int bd9571mwv_regulator_probe(struct platform_device *pdev)
{
        struct regulator_config config = { };
        struct bd9571mwv_reg *bdreg;
        struct regulator_dev *rdev;
        unsigned int val;
        int i;
        enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;

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

        bdreg->regmap = dev_get_regmap(pdev->dev.parent, NULL);

        platform_set_drvdata(pdev, bdreg);

        config.dev = &pdev->dev;
        config.dev->of_node = pdev->dev.parent->of_node;
        config.driver_data = bdreg;
        config.regmap = bdreg->regmap;

        for (i = 0; i < ARRAY_SIZE(regulators); i++) {
                /* BD9574MWF supports DVFS only */
                if (chip == ROHM_CHIP_TYPE_BD9574 && regulators[i].id != DVFS)
                        continue;
                rdev = devm_regulator_register(&pdev->dev, &regulators[i],
                                               &config);
                if (IS_ERR(rdev)) {
                        dev_err(&pdev->dev, "failed to register %s regulator\n",
                                regulators[i].name);
                        return PTR_ERR(rdev);
                }
        }

        val = 0;
        of_property_read_u32(config.dev->of_node, "rohm,ddr-backup-power", &val);
        if (val & ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK) {
                dev_err(&pdev->dev, "invalid %s mode %u\n",
                        "rohm,ddr-backup-power", val);
                return -EINVAL;
        }
        bdreg->bkup_mode_cnt_keepon = val;

        bdreg->rstbmode_level = of_property_read_bool(config.dev->of_node,
                                                      "rohm,rstbmode-level");
        bdreg->rstbmode_pulse = of_property_read_bool(config.dev->of_node,
                                                      "rohm,rstbmode-pulse");
        if (bdreg->rstbmode_level && bdreg->rstbmode_pulse) {
                dev_err(&pdev->dev, "only one rohm,rstbmode-* may be specified");
                return -EINVAL;
        }

#ifdef CONFIG_PM_SLEEP
        if (bdreg->bkup_mode_cnt_keepon) {
                int ret;

                /*
                 * Backup mode is enabled by default in pulse mode, but needs
                 * explicit user setup in level mode.
                 */
                bdreg->bkup_mode_enabled = bdreg->rstbmode_pulse;

                ret = device_create_file(&pdev->dev, &dev_attr_backup_mode);
                if (ret)
                        return ret;
        }
#endif /* CONFIG_PM_SLEEP */

        return 0;
}

static const struct platform_device_id bd9571mwv_regulator_id_table[] = {
        { "bd9571mwv-regulator", ROHM_CHIP_TYPE_BD9571 },
        { "bd9574mwf-regulator", ROHM_CHIP_TYPE_BD9574 },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, bd9571mwv_regulator_id_table);

static struct platform_driver bd9571mwv_regulator_driver = {
        .driver = {
                .name = "bd9571mwv-regulator",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .pm = DEV_PM_OPS,
        },
        .probe = bd9571mwv_regulator_probe,
        .remove = bd9571mwv_regulator_remove,
        .id_table = bd9571mwv_regulator_id_table,
};
module_platform_driver(bd9571mwv_regulator_driver);

MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
MODULE_DESCRIPTION("BD9571MWV Regulator driver");
MODULE_LICENSE("GPL v2");