// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for Texas Instruments TPS53679
 *
 * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com>
 */

#include <linux/bits.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include "pmbus.h"

enum chips {
        tps53647, tps53667, tps53676, tps53679, tps53681, tps53685, tps53688
};

#define TPS53647_PAGE_NUM               1

#define TPS53676_USER_DATA_03           0xb3
#define TPS53676_MAX_PHASES             7

#define TPS53679_PROT_VR12_5MV          0x01 /* VR12.0 mode, 5-mV DAC */
#define TPS53679_PROT_VR12_5_10MV       0x02 /* VR12.5 mode, 10-mV DAC */
#define TPS53679_PROT_VR13_10MV         0x04 /* VR13.0 mode, 10-mV DAC */
#define TPS53679_PROT_IMVP8_5MV         0x05 /* IMVP8 mode, 5-mV DAC */
#define TPS53679_PROT_VR13_5MV          0x07 /* VR13.0 mode, 5-mV DAC */
#define TPS53679_PAGE_NUM               2

#define TPS53681_DEVICE_ID     "\x81"
#define TPS53685_DEVICE_ID     "TIShP"

#define TPS53681_PMBUS_REVISION         0x33

#define TPS53681_MFR_SPECIFIC_20        0xe4    /* Number of phases, per page */

static const struct i2c_device_id tps53679_id[];

static int tps53679_identify_mode(struct i2c_client *client,
                                  struct pmbus_driver_info *info)
{
        u8 vout_params;
        int i, ret;

        for (i = 0; i < info->pages; i++) {
                /* Read the register with VOUT scaling value.*/
                ret = pmbus_read_byte_data(client, i, PMBUS_VOUT_MODE);
                if (ret < 0)
                        return ret;

                vout_params = ret & GENMASK(4, 0);

                switch (vout_params) {
                case TPS53679_PROT_VR13_10MV:
                case TPS53679_PROT_VR12_5_10MV:
                        info->vrm_version[i] = vr13;
                        break;
                case TPS53679_PROT_VR13_5MV:
                case TPS53679_PROT_VR12_5MV:
                case TPS53679_PROT_IMVP8_5MV:
                        info->vrm_version[i] = vr12;
                        break;
                default:
                        return -EINVAL;
                }
        }

        return 0;
}

static int tps53679_identify_phases(struct i2c_client *client,
                                    struct pmbus_driver_info *info)
{
        int ret;

        /* On TPS53681, only channel A provides per-phase output current */
        ret = pmbus_read_byte_data(client, 0, TPS53681_MFR_SPECIFIC_20);
        if (ret < 0)
                return ret;
        info->phases[0] = (ret & 0x07) + 1;

        return 0;
}

static int tps53679_identify_chip(struct i2c_client *client,
                                  u8 revision, char *id)
{
        u8 buf[I2C_SMBUS_BLOCK_MAX];
        int ret;
        int buf_len;
        int id_len;

        ret = pmbus_read_byte_data(client, 0, PMBUS_REVISION);
        if (ret < 0)
                return ret;
        if (ret != revision) {
                dev_err(&client->dev, "Unexpected PMBus revision 0x%x\n", ret);
                return -ENODEV;
        }

        ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
        if (ret <= 0)
                return ret < 0 ? ret : -EIO;

        /* Adjust length if null terminator is present */
        buf_len = (buf[ret - 1] != '\x00' ? ret : ret - 1);

        id_len = strlen(id);

        if (buf_len != id_len || strncmp(id, buf, id_len)) {
                dev_err(&client->dev, "Unexpected device ID: %*ph\n", ret, buf);
                return -ENODEV;
        }
        return 0;
}

/*
 * Common identification function for chips with multi-phase support.
 * Since those chips have special configuration registers, we want to have
 * some level of reassurance that we are really talking with the chip
 * being probed. Check PMBus revision and chip ID.
 */
static int tps53679_identify_multiphase(struct i2c_client *client,
                                        struct pmbus_driver_info *info,
                                        int pmbus_rev, char *device_id)
{
        int ret;

        ret = tps53679_identify_chip(client, pmbus_rev, device_id);
        if (ret < 0)
                return ret;

        ret = tps53679_identify_mode(client, info);
        if (ret < 0)
                return ret;

        return tps53679_identify_phases(client, info);
}

static int tps53679_identify(struct i2c_client *client,
                             struct pmbus_driver_info *info)
{
        return tps53679_identify_mode(client, info);
}

static int tps53685_identify(struct i2c_client *client,
                             struct pmbus_driver_info *info)
{
        info->func[1] |= PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
                         PMBUS_HAVE_STATUS_INPUT;
        info->format[PSC_VOLTAGE_OUT] = linear;
        return tps53679_identify_chip(client, TPS53681_PMBUS_REVISION,
                                           TPS53685_DEVICE_ID);
}

static int tps53681_identify(struct i2c_client *client,
                             struct pmbus_driver_info *info)
{
        return tps53679_identify_multiphase(client, info,
                                            TPS53681_PMBUS_REVISION,
                                            TPS53681_DEVICE_ID);
}

static int tps53676_identify(struct i2c_client *client,
                             struct pmbus_driver_info *info)
{
        u8 buf[I2C_SMBUS_BLOCK_MAX];
        int phases_a = 0, phases_b = 0;
        int i, ret;

        ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
        if (ret < 0)
                return ret;
        if (ret != 6 || memcmp(buf, "TI\x53\x67\x60\x00", 6)) {
                dev_err(&client->dev, "Unexpected device ID: %*ph\n", ret, buf);
                return -ENODEV;
        }

        ret = i2c_smbus_read_block_data(client, TPS53676_USER_DATA_03, buf);
        if (ret < 0)
                return ret;
        if (ret != 24)
                return -EIO;
        for (i = 0; i < 2 * TPS53676_MAX_PHASES; i += 2) {
                if (buf[i + 1] & 0x80) {
                        if (buf[i] & 0x08)
                                phases_b++;
                        else
                                phases_a++;
                }
        }

        info->format[PSC_VOLTAGE_OUT] = linear;
        info->pages = 1;
        info->phases[0] = phases_a;
        if (phases_b > 0) {
                info->pages = 2;
                info->phases[1] = phases_b;
        }
        return 0;
}

static int tps53681_read_word_data(struct i2c_client *client, int page,
                                   int phase, int reg)
{
        /*
         * For reading the total output current (READ_IOUT) for all phases,
         * the chip datasheet is a bit vague. It says "PHASE must be set to
         * FFh to access all phases simultaneously. PHASE may also be set to
         * 80h readack (!) the total phase current".
         * Experiments show that the command does _not_ report the total
         * current for all phases if the phase is set to 0xff. Instead, it
         * appears to report the current of one of the phases. Override phase
         * parameter with 0x80 when reading the total output current on page 0.
         */
        if (reg == PMBUS_READ_IOUT && page == 0 && phase == 0xff)
                return pmbus_read_word_data(client, page, 0x80, reg);
        return -ENODATA;
}

static struct pmbus_driver_info tps53679_info = {
        .format[PSC_VOLTAGE_IN] = linear,
        .format[PSC_VOLTAGE_OUT] = vid,
        .format[PSC_TEMPERATURE] = linear,
        .format[PSC_CURRENT_OUT] = linear,
        .format[PSC_POWER] = linear,
        .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
                PMBUS_HAVE_STATUS_INPUT |
                PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
                PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
                PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
                PMBUS_HAVE_POUT,
        .func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
                PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
                PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
                PMBUS_HAVE_POUT,
        .pfunc[0] = PMBUS_HAVE_IOUT,
        .pfunc[1] = PMBUS_HAVE_IOUT,
        .pfunc[2] = PMBUS_HAVE_IOUT,
        .pfunc[3] = PMBUS_HAVE_IOUT,
        .pfunc[4] = PMBUS_HAVE_IOUT,
        .pfunc[5] = PMBUS_HAVE_IOUT,
        .pfunc[6] = PMBUS_HAVE_IOUT,
};

static int tps53679_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct pmbus_driver_info *info;
        enum chips chip_id;

        if (dev->of_node)
                chip_id = (uintptr_t)of_device_get_match_data(dev);
        else
                chip_id = i2c_match_id(tps53679_id, client)->driver_data;

        info = devm_kmemdup(dev, &tps53679_info, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        switch (chip_id) {
        case tps53647:
        case tps53667:
                info->pages = TPS53647_PAGE_NUM;
                info->identify = tps53679_identify;
                break;
        case tps53676:
                info->identify = tps53676_identify;
                break;
        case tps53679:
        case tps53688:
                info->pages = TPS53679_PAGE_NUM;
                info->identify = tps53679_identify;
                break;
        case tps53681:
                info->pages = TPS53679_PAGE_NUM;
                info->phases[0] = 6;
                info->identify = tps53681_identify;
                info->read_word_data = tps53681_read_word_data;
                break;
        case tps53685:
                info->pages = TPS53679_PAGE_NUM;
                info->identify = tps53685_identify;
                break;
        default:
                return -ENODEV;
        }

        return pmbus_do_probe(client, info);
}

static const struct i2c_device_id tps53679_id[] = {
        {"bmr474", tps53676},
        {"tps53647", tps53647},
        {"tps53667", tps53667},
        {"tps53676", tps53676},
        {"tps53679", tps53679},
        {"tps53681", tps53681},
        {"tps53685", tps53685},
        {"tps53688", tps53688},
        {}
};

MODULE_DEVICE_TABLE(i2c, tps53679_id);

static const struct of_device_id __maybe_unused tps53679_of_match[] = {
        {.compatible = "ti,tps53647", .data = (void *)tps53647},
        {.compatible = "ti,tps53667", .data = (void *)tps53667},
        {.compatible = "ti,tps53676", .data = (void *)tps53676},
        {.compatible = "ti,tps53679", .data = (void *)tps53679},
        {.compatible = "ti,tps53681", .data = (void *)tps53681},
        {.compatible = "ti,tps53685", .data = (void *)tps53685},
        {.compatible = "ti,tps53688", .data = (void *)tps53688},
        {}
};
MODULE_DEVICE_TABLE(of, tps53679_of_match);

static struct i2c_driver tps53679_driver = {
        .driver = {
                .name = "tps53679",
                .of_match_table = of_match_ptr(tps53679_of_match),
        },
        .probe = tps53679_probe,
        .id_table = tps53679_id,
};

module_i2c_driver(tps53679_driver);

MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("PMBus driver for Texas Instruments TPS53679");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");