// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP29502)
 */

#include <linux/bitfield.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include "pmbus.h"

#define MFR_VOUT_SCALE_LOOP     0x29
#define MFR_SVI3_IOUT_PRT       0x67
#define MFR_READ_PIN_EST        0x94
#define MFR_READ_IIN_EST        0x95
#define MFR_VOUT_PROT1  0x3D
#define MFR_VOUT_PROT2  0x51
#define MFR_SLOPE_CNT_SET       0xA8
#define MFR_TSNS_FLT_SET        0xBB

#define MP29502_VIN_OV_GAIN     4
#define MP29502_TEMP_LIMIT_OFFSET       40
#define MP29502_READ_VOUT_DIV   1024
#define MP29502_READ_IOUT_DIV   32
#define MP29502_IOUT_LIMIT_UINT 8
#define MP29502_OVUV_LIMIT_SCALE        10
#define MP28502_VOUT_OV_GAIN    512
#define MP28502_VOUT_OV_SCALE   40
#define MP29502_VOUT_UV_OFFSET  36
#define MP29502_PIN_GAIN        2
#define MP29502_IIN_DIV 2

#define MP29502_PAGE_NUM        1

#define MP29502_RAIL_FUNC       (PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | \
                                                        PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | \
                                                        PMBUS_HAVE_TEMP | PMBUS_HAVE_PIN | \
                                                        PMBUS_HAVE_IIN | \
                                                        PMBUS_HAVE_STATUS_VOUT | \
                                                        PMBUS_HAVE_STATUS_IOUT | \
                                                        PMBUS_HAVE_STATUS_TEMP | \
                                                        PMBUS_HAVE_STATUS_INPUT)

struct mp29502_data {
        struct pmbus_driver_info info;
        int vout_scale;
        int vout_bottom_div;
        int vout_top_div;
        int ovp_div;
        int iout_scale;
};

#define to_mp29502_data(x)      container_of(x, struct mp29502_data, info)

static u16 mp29502_reg2data_linear11(u16 word)
{
        s16 exponent;
        s32 mantissa;
        s64 val;

        exponent = ((s16)word) >> 11;
        mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
        val = mantissa;

        if (exponent >= 0)
                val <<= exponent;
        else
                val >>= -exponent;

        return val;
}

static int
mp29502_identify_vout_scale(struct i2c_client *client, struct pmbus_driver_info *info,
                            int page)
{
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_VOUT_SCALE_LOOP);
        if (ret < 0)
                return ret;

        switch (FIELD_GET(GENMASK(12, 10), ret)) {
        case 0:
                data->vout_scale = 6400;
                break;
        case 1:
                data->vout_scale = 5120;
                break;
        case 2:
                data->vout_scale = 2560;
                break;
        case 3:
                data->vout_scale = 2048;
                break;
        case 4:
                data->vout_scale = 1024;
                break;
        case 5:
                data->vout_scale = 4;
                break;
        case 6:
                data->vout_scale = 2;
                break;
        case 7:
                data->vout_scale = 1;
                break;
        default:
                data->vout_scale = 1;
                break;
        }

        return 0;
}

static int
mp29502_identify_vout_divider(struct i2c_client *client, struct pmbus_driver_info *info,
                              int page)
{
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_VOUT_PROT1);
        if (ret < 0)
                return ret;

        data->vout_bottom_div = FIELD_GET(GENMASK(11, 0), ret);

        ret = i2c_smbus_read_word_data(client, MFR_VOUT_PROT2);
        if (ret < 0)
                return ret;

        data->vout_top_div = FIELD_GET(GENMASK(14, 0), ret);

        return 0;
}

static int
mp29502_identify_ovp_divider(struct i2c_client *client, struct pmbus_driver_info *info,
                             int page)
{
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_SLOPE_CNT_SET);
        if (ret < 0)
                return ret;

        data->ovp_div = FIELD_GET(GENMASK(9, 0), ret);

        return 0;
}

static int
mp29502_identify_iout_scale(struct i2c_client *client, struct pmbus_driver_info *info,
                            int page)
{
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_SVI3_IOUT_PRT);
        if (ret < 0)
                return ret;

        switch (ret & GENMASK(2, 0)) {
        case 0:
        case 6:
                data->iout_scale = 32;
                break;
        case 1:
                data->iout_scale = 1;
                break;
        case 2:
                data->iout_scale = 2;
                break;
        case 3:
                data->iout_scale = 4;
                break;
        case 4:
                data->iout_scale = 8;
                break;
        case 5:
                data->iout_scale = 16;
                break;
        default:
                data->iout_scale = 64;
                break;
        }

        return 0;
}

static int mp29502_read_vout_ov_limit(struct i2c_client *client, struct mp29502_data *data)
{
        int ret;
        int ov_value;

        /*
         * This is because the vout ov fault limit value comes from
         * page1 MFR_TSNS_FLT_SET reg, and other telemetry and limit
         * value comes from page0 reg. So the page should be set to
         * 0 after the reading of vout ov limit.
         */
        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 1);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_TSNS_FLT_SET);
        if (ret < 0)
                return ret;

        ov_value = DIV_ROUND_CLOSEST(FIELD_GET(GENMASK(12, 7), ret) *
                                                   MP28502_VOUT_OV_GAIN * MP28502_VOUT_OV_SCALE,
                                                   data->ovp_div);

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
        if (ret < 0)
                return ret;

        return ov_value;
}

static int mp29502_write_vout_ov_limit(struct i2c_client *client, u16 word,
                                       struct mp29502_data *data)
{
        int ret;

        /*
         * This is because the vout ov fault limit value comes from
         * page1 MFR_TSNS_FLT_SET reg, and other telemetry and limit
         * value comes from page0 reg. So the page should be set to
         * 0 after the writing of vout ov limit.
         */
        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 1);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_read_word_data(client, MFR_TSNS_FLT_SET);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_word_data(client, MFR_TSNS_FLT_SET,
                                        (ret & ~GENMASK(12, 7)) |
                FIELD_PREP(GENMASK(12, 7),
                           DIV_ROUND_CLOSEST(word * data->ovp_div,
                                             MP28502_VOUT_OV_GAIN * MP28502_VOUT_OV_SCALE)));

        return i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
}

static int mp29502_read_byte_data(struct i2c_client *client, int page, int reg)
{
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
        if (ret < 0)
                return ret;

        switch (reg) {
        case PMBUS_VOUT_MODE:
                ret = PB_VOUT_MODE_DIRECT;
                break;
        default:
                ret = -ENODATA;
                break;
        }

        return ret;
}

static int mp29502_read_word_data(struct i2c_client *client, int page,
                                  int phase, int reg)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        switch (reg) {
        case PMBUS_STATUS_WORD:
                ret = -ENODATA;
                break;
        case PMBUS_READ_VIN:
                /*
                 * The MP29502 PMBUS_READ_VIN[10:0] is the vin value, the vin scale is
                 * 125mV/LSB. And the vin scale is set to 125mV/Lsb(using r/m/b scale)
                 * in MP29502 pmbus_driver_info struct, so the word data bit0-bit10 can
                 * be returned to pmbus core directly.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = FIELD_GET(GENMASK(10, 0), ret);
                break;
        case PMBUS_READ_VOUT:
                /*
                 * The MP29502 PMBUS_READ_VOUT[11:0] is the vout value, and vout
                 * value is calculated based on vout scale and vout divider.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST((ret &  GENMASK(11, 0)) *
                                                                data->vout_scale *
                                                                (data->vout_bottom_div +
                                                                4 * data->vout_top_div),
                                                                MP29502_READ_VOUT_DIV *
                                                                data->vout_bottom_div);
                break;
        case PMBUS_READ_IIN:
                /*
                 * The MP29502 MFR_READ_IIN_EST register is linear11 format, and the
                 * exponent is not a constant value. But the iin scale is set to
                 * 1A/Lsb(using r/m/b scale). As a result, the iin read from MP29502
                 * should be calculated to A, then return the result to pmbus core.
                 */
                ret = pmbus_read_word_data(client, page, phase, MFR_READ_IIN_EST);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST(mp29502_reg2data_linear11(ret),
                                        MP29502_IIN_DIV);
                break;
        case PMBUS_READ_PIN:
                /*
                 * The MP29502 MFR_READ_PIN_EST register is linear11 format, and the
                 * exponent is not a constant value. But the pin scale is set to
                 * 1W/Lsb(using r/m/b scale). As a result, the pout read from MP29502
                 * should be calculated to W, then return the result to pmbus core.
                 */
                ret = pmbus_read_word_data(client, page, phase, MFR_READ_PIN_EST);
                if (ret < 0)
                        return ret;

                ret = mp29502_reg2data_linear11(ret) * MP29502_PIN_GAIN;
                break;
        case PMBUS_READ_POUT:
                /*
                 * The MP29502 PMBUS_READ_POUT register is linear11 format, and the
                 * exponent is not a constant value. But the pout scale is set to
                 * 1W/Lsb(using r/m/b scale). As a result, the pout read from MP29502
                 * should be calculated to W, then return the result to pmbus core.
                 * And the pout is calculated based on vout divider.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST(mp29502_reg2data_linear11(ret) *
                                        (data->vout_bottom_div +
                                        4 * data->vout_top_div),
                                        data->vout_bottom_div);
                break;
        case PMBUS_READ_IOUT:
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST((ret & GENMASK(10, 0)) * data->iout_scale,
                                        MP29502_READ_IOUT_DIV);
                break;
        case PMBUS_READ_TEMPERATURE_1:
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = FIELD_GET(GENMASK(10, 0), ret);
                break;
        case PMBUS_VIN_OV_FAULT_LIMIT:
                /*
                 * The MP29502 PMBUS_VIN_OV_FAULT_LIMIT is 500mV/Lsb, but
                 * the vin  scale is set to 125mV/Lsb(using r/m/b scale),
                 * so the word data should multiply by 4.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = FIELD_GET(GENMASK(7, 0), ret) * MP29502_VIN_OV_GAIN;
                break;
        case PMBUS_VIN_UV_WARN_LIMIT:
        case PMBUS_VIN_UV_FAULT_LIMIT:
                /*
                 * The MP29502 PMBUS_VIN_UV_WARN_LIMIT and PMBUS_VIN_UV_FAULT_LIMIT
                 * scale is 125mV/Lsb, but the vin scale is set to 125mV/Lsb(using
                 * r/m/b scale), so the word data bit0-bit9 can be returned to pmbus
                 * core directly.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = FIELD_GET(GENMASK(9, 0), ret);
                break;
        case PMBUS_VOUT_OV_FAULT_LIMIT:
                /*
                 * The MP29502 vout ov fault limit value comes from
                 * page1 MFR_TSNS_FLT_SET[12:7].
                 */
                ret = mp29502_read_vout_ov_limit(client, data);
                if (ret < 0)
                        return ret;

                break;
        case PMBUS_VOUT_UV_FAULT_LIMIT:
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST((FIELD_GET(GENMASK(8, 0), ret) *
                                                                MP29502_OVUV_LIMIT_SCALE -
                                                                MP29502_VOUT_UV_OFFSET) *
                                                                (data->vout_bottom_div +
                                                                4 * data->vout_top_div),
                                                                data->vout_bottom_div);
                break;
        case PMBUS_IOUT_OC_FAULT_LIMIT:
        case PMBUS_IOUT_OC_WARN_LIMIT:
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = DIV_ROUND_CLOSEST((ret & GENMASK(7, 0)) *
                                                                data->iout_scale *
                                                                MP29502_IOUT_LIMIT_UINT,
                                                                MP29502_READ_IOUT_DIV);
                break;
        case PMBUS_OT_FAULT_LIMIT:
        case PMBUS_OT_WARN_LIMIT:
                /*
                 * The scale of MP29502 PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT
                 * is 1°C/LSB and they have 40°C offset.
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;

                ret = (ret & GENMASK(7, 0)) - MP29502_TEMP_LIMIT_OFFSET;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int mp29502_write_word_data(struct i2c_client *client, int page, int reg,
                                   u16 word)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        struct mp29502_data *data = to_mp29502_data(info);
        int ret;

        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
        if (ret < 0)
                return ret;

        switch (reg) {
        case PMBUS_VIN_OV_FAULT_LIMIT:
                /*
                 * The PMBUS_VIN_OV_FAULT_LIMIT[7:0] is the limit value,
                 * and bit8-bit15 should not be changed. The scale of
                 * PMBUS_VIN_OV_FAULT_LIMIT is 500mV/Lsb, but the vin
                 * scale is set to 125mV/Lsb(using r/m/b scale), so
                 * the word data should divide by 4.
                 */
                ret = pmbus_read_word_data(client, page, 0xff, reg);
                if (ret < 0)
                        return ret;

                ret = pmbus_write_word_data(client, page, reg,
                                            (ret & ~GENMASK(7, 0)) |
                                FIELD_PREP(GENMASK(7, 0),
                                           DIV_ROUND_CLOSEST(word,
                                                             MP29502_VIN_OV_GAIN)));
                break;
        case PMBUS_VIN_UV_WARN_LIMIT:
        case PMBUS_VIN_UV_FAULT_LIMIT:
                /*
                 * The PMBUS_VIN_UV_WARN_LIMIT[9:0] and PMBUS_VIN_UV_FAULT_LIMIT[9:0]
                 * are the limit value, and bit10-bit15 should not be changed.
                 */
                ret = pmbus_read_word_data(client, page, 0xff, reg);
                if (ret < 0)
                        return ret;

                ret = pmbus_write_word_data(client, page, reg,
                                            (ret & ~GENMASK(9, 0)) |
                                                        FIELD_PREP(GENMASK(9, 0),
                                                                   word));
                break;
        case PMBUS_VOUT_OV_FAULT_LIMIT:
                ret = mp29502_write_vout_ov_limit(client, word, data);
                if (ret < 0)
                        return ret;

                break;
        case PMBUS_VOUT_UV_FAULT_LIMIT:
                ret = pmbus_read_word_data(client, page, 0xff, reg);
                if (ret < 0)
                        return ret;

                ret = pmbus_write_word_data(client, page, reg,
                                            (ret & ~GENMASK(8, 0)) |
                                                FIELD_PREP(GENMASK(8, 0),
                                                           DIV_ROUND_CLOSEST(word *
                                                                        data->vout_bottom_div +
                                                                        MP29502_VOUT_UV_OFFSET *
                                                                        (data->vout_bottom_div +
                                                                        4 * data->vout_top_div),
                                                                        MP29502_OVUV_LIMIT_SCALE *
                                                                        (data->vout_bottom_div +
                                                                        4 * data->vout_top_div))));
                break;
        case PMBUS_IOUT_OC_FAULT_LIMIT:
        case PMBUS_IOUT_OC_WARN_LIMIT:
                ret = pmbus_write_word_data(client, page, reg,
                                            DIV_ROUND_CLOSEST(word *
                                                        MP29502_READ_IOUT_DIV,
                                                        MP29502_IOUT_LIMIT_UINT *
                                                        data->iout_scale));
                break;
        case PMBUS_OT_FAULT_LIMIT:
        case PMBUS_OT_WARN_LIMIT:
                /*
                 * The PMBUS_OT_FAULT_LIMIT[7:0] and PMBUS_OT_WARN_LIMIT[7:0]
                 * are the limit value, and bit8-bit15 should not be changed.
                 */
                ret = pmbus_read_word_data(client, page, 0xff, reg);
                if (ret < 0)
                        return ret;

                ret = pmbus_write_word_data(client, page, reg,
                                            (ret & ~GENMASK(7, 0)) |
                                        FIELD_PREP(GENMASK(7, 0),
                                                   word + MP29502_TEMP_LIMIT_OFFSET));
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int mp29502_identify(struct i2c_client *client, struct pmbus_driver_info *info)
{
        int ret;

        /* Identify vout scale */
        ret = mp29502_identify_vout_scale(client, info, 0);
        if (ret < 0)
                return ret;

        /* Identify vout divider. */
        ret = mp29502_identify_vout_divider(client, info, 1);
        if (ret < 0)
                return ret;

        /* Identify ovp divider. */
        ret = mp29502_identify_ovp_divider(client, info, 1);
        if (ret < 0)
                return ret;

        /* Identify iout scale */
        return mp29502_identify_iout_scale(client, info, 0);
}

static const struct pmbus_driver_info mp29502_info = {
        .pages = MP29502_PAGE_NUM,
        .format[PSC_VOLTAGE_IN] = direct,
        .format[PSC_TEMPERATURE] = direct,
        .format[PSC_CURRENT_IN] = direct,
        .format[PSC_CURRENT_OUT] = direct,
        .format[PSC_VOLTAGE_OUT] = direct,
        .format[PSC_POWER] = direct,

        .m[PSC_VOLTAGE_IN] = 8,
        .R[PSC_VOLTAGE_IN] = 0,
        .b[PSC_VOLTAGE_IN] = 0,

        .m[PSC_VOLTAGE_OUT] = 1,
        .R[PSC_VOLTAGE_OUT] = 3,
        .b[PSC_VOLTAGE_OUT] = 0,

        .m[PSC_TEMPERATURE] = 1,
        .R[PSC_TEMPERATURE] = 0,
        .b[PSC_TEMPERATURE] = 0,

        .m[PSC_CURRENT_IN] = 1,
        .R[PSC_CURRENT_IN] = 0,
        .b[PSC_CURRENT_IN] = 0,

        .m[PSC_CURRENT_OUT] = 1,
        .R[PSC_CURRENT_OUT] = 0,
        .b[PSC_CURRENT_OUT] = 0,

        .m[PSC_POWER] = 1,
        .R[PSC_POWER] = 0,
        .b[PSC_POWER] = 0,

        .func[0] = MP29502_RAIL_FUNC,
        .read_word_data = mp29502_read_word_data,
        .read_byte_data = mp29502_read_byte_data,
        .write_word_data = mp29502_write_word_data,
        .identify = mp29502_identify,
};

static int mp29502_probe(struct i2c_client *client)
{
        struct pmbus_driver_info *info;
        struct mp29502_data *data;

        data = devm_kzalloc(&client->dev, sizeof(struct mp29502_data),
                            GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        memcpy(&data->info, &mp29502_info, sizeof(*info));
        info = &data->info;

        return pmbus_do_probe(client, info);
}

static const struct i2c_device_id mp29502_id[] = {
        {"mp29502", 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, mp29502_id);

static const struct of_device_id __maybe_unused mp29502_of_match[] = {
        {.compatible = "mps,mp29502"},
        {}
};
MODULE_DEVICE_TABLE(of, mp29502_of_match);

static struct i2c_driver mp29502_driver = {
        .driver = {
                .name = "mp29502",
                .of_match_table = mp29502_of_match,
        },
        .probe = mp29502_probe,
        .id_table = mp29502_id,
};

module_i2c_driver(mp29502_driver);

MODULE_AUTHOR("Wensheng Wang <wenswang@yeah.net");
MODULE_DESCRIPTION("PMBus driver for MPS MP29502");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");