// SPDX-License-Identifier: GPL-2.0+
/*
 * Hardware monitoring driver for Renesas Digital Multiphase Voltage Regulators
 *
 * Copyright (c) 2017 Google Inc
 * Copyright (c) 2020 Renesas Electronics America
 *
 */

#include <linux/err.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/string.h>
#include <linux/sysfs.h>

#include "pmbus.h"

#define ISL68137_VOUT_AVS       0x30
#define RAA_DMPVR2_READ_VMON    0xc8
#define MAX_CHANNELS            4

enum variants {
        raa_dmpvr1_2rail,
        raa_dmpvr2_1rail,
        raa_dmpvr2_2rail,
        raa_dmpvr2_2rail_nontc,
        raa_dmpvr2_2rail_pmbus,
        raa_dmpvr2_3rail,
        raa_dmpvr2_hv,
};

struct isl68137_channel {
        u32 vout_voltage_divider[2];
};

struct isl68137_data {
        struct pmbus_driver_info info;
        struct isl68137_channel channel[MAX_CHANNELS];
};

#define to_isl68137_data(x)     container_of(x, struct isl68137_data, info)

static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client,
                                             int page,
                                             char *buf)
{
        int val;

        val = pmbus_lock_interruptible(client);
        if (val)
                return val;

        val = pmbus_read_byte_data(client, page, PMBUS_OPERATION);

        pmbus_unlock(client);

        if (val < 0)
                return val;

        return sysfs_emit(buf, "%d\n",
                           (val & ISL68137_VOUT_AVS) == ISL68137_VOUT_AVS);
}

static ssize_t isl68137_avs_enable_store_page(struct i2c_client *client,
                                              int page,
                                              const char *buf, size_t count)
{
        int rc, op_val;
        bool result;

        rc = kstrtobool(buf, &result);
        if (rc)
                return rc;

        op_val = result ? ISL68137_VOUT_AVS : 0;

        rc = pmbus_lock_interruptible(client);
        if (rc)
                return rc;

        /*
         * Writes to VOUT setpoint over AVSBus will persist after the VRM is
         * switched to PMBus control. Switching back to AVSBus control
         * restores this persisted setpoint rather than re-initializing to
         * PMBus VOUT_COMMAND. Writing VOUT_COMMAND first over PMBus before
         * enabling AVS control is the workaround.
         */
        if (op_val == ISL68137_VOUT_AVS) {
                rc = pmbus_read_word_data(client, page, 0xff,
                                          PMBUS_VOUT_COMMAND);
                if (rc < 0)
                        goto unlock;

                rc = pmbus_write_word_data(client, page, PMBUS_VOUT_COMMAND,
                                           rc);
                if (rc < 0)
                        goto unlock;
        }

        rc = pmbus_update_byte_data(client, page, PMBUS_OPERATION,
                                    ISL68137_VOUT_AVS, op_val);

unlock:
        pmbus_unlock(client);

        return (rc < 0) ? rc : count;
}

static ssize_t isl68137_avs_enable_show(struct device *dev,
                                        struct device_attribute *devattr,
                                        char *buf)
{
        struct i2c_client *client = to_i2c_client(dev->parent);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

        return isl68137_avs_enable_show_page(client, attr->index, buf);
}

static ssize_t isl68137_avs_enable_store(struct device *dev,
                                struct device_attribute *devattr,
                                const char *buf, size_t count)
{
        struct i2c_client *client = to_i2c_client(dev->parent);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

        return isl68137_avs_enable_store_page(client, attr->index, buf, count);
}

static SENSOR_DEVICE_ATTR_RW(avs0_enable, isl68137_avs_enable, 0);
static SENSOR_DEVICE_ATTR_RW(avs1_enable, isl68137_avs_enable, 1);

static struct attribute *enable_attrs[] = {
        &sensor_dev_attr_avs0_enable.dev_attr.attr,
        &sensor_dev_attr_avs1_enable.dev_attr.attr,
        NULL,
};

static const struct attribute_group enable_group = {
        .attrs = enable_attrs,
};

static const struct attribute_group *isl68137_attribute_groups[] = {
        &enable_group,
        NULL,
};

static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page,
                                     int phase, int reg)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        const struct isl68137_data *data = to_isl68137_data(info);
        int ret;
        u64 temp;

        switch (reg) {
        case PMBUS_VIRT_READ_VMON:
                ret = pmbus_read_word_data(client, page, phase,
                                           RAA_DMPVR2_READ_VMON);
                break;
        case PMBUS_READ_POUT:
        case PMBUS_READ_VOUT:
                /*
                 * In cases where a voltage divider is attached to the target
                 * rail between Vout and the Vsense pin, both Vout and Pout
                 * should be scaled by the voltage divider scaling factor.
                 * I.e. Vout = Vsense * Rtotal / Rout
                 */
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret > 0) {
                        temp = DIV_U64_ROUND_CLOSEST((u64)ret *
                                data->channel[page].vout_voltage_divider[1],
                                data->channel[page].vout_voltage_divider[0]);
                        ret = clamp_val(temp, 0, 0xffff);
                }
                break;
        default:
                ret = -ENODATA;
                break;
        }

        return ret;
}

static int raa_dmpvr2_write_word_data(struct i2c_client *client, int page,
                                      int reg, u16 word)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        const struct isl68137_data *data = to_isl68137_data(info);
        int ret;
        u64 temp;

        switch (reg) {
        case PMBUS_VOUT_MAX:
        case PMBUS_VOUT_MARGIN_HIGH:
        case PMBUS_VOUT_MARGIN_LOW:
        case PMBUS_VOUT_OV_FAULT_LIMIT:
        case PMBUS_VOUT_UV_FAULT_LIMIT:
        case PMBUS_VOUT_COMMAND:
                /*
                 * In cases where a voltage divider is attached to the target
                 * rail between Vout and the Vsense pin, Vout related PMBus
                 * commands should be scaled based on the expected voltage
                 * at the Vsense pin.
                 * I.e. Vsense = Vout * Rout / Rtotal
                 */
                temp = DIV_U64_ROUND_CLOSEST((u64)word *
                                data->channel[page].vout_voltage_divider[0],
                                data->channel[page].vout_voltage_divider[1]);
                ret = clamp_val(temp, 0, 0xffff);
                break;
        default:
                ret = -ENODATA;
                break;
        }
        return ret;
}

static struct pmbus_driver_info raa_dmpvr_info = {
        .pages = 3,
        .format[PSC_VOLTAGE_IN] = direct,
        .format[PSC_VOLTAGE_OUT] = direct,
        .format[PSC_CURRENT_IN] = direct,
        .format[PSC_CURRENT_OUT] = direct,
        .format[PSC_POWER] = direct,
        .format[PSC_TEMPERATURE] = direct,
        .m[PSC_VOLTAGE_IN] = 1,
        .b[PSC_VOLTAGE_IN] = 0,
        .R[PSC_VOLTAGE_IN] = 2,
        .m[PSC_VOLTAGE_OUT] = 1,
        .b[PSC_VOLTAGE_OUT] = 0,
        .R[PSC_VOLTAGE_OUT] = 3,
        .m[PSC_CURRENT_IN] = 1,
        .b[PSC_CURRENT_IN] = 0,
        .R[PSC_CURRENT_IN] = 2,
        .m[PSC_CURRENT_OUT] = 1,
        .b[PSC_CURRENT_OUT] = 0,
        .R[PSC_CURRENT_OUT] = 1,
        .m[PSC_POWER] = 1,
        .b[PSC_POWER] = 0,
        .R[PSC_POWER] = 0,
        .m[PSC_TEMPERATURE] = 1,
        .b[PSC_TEMPERATURE] = 0,
        .R[PSC_TEMPERATURE] = 0,
        .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
            | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
            | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_TEMP
            | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
            | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT
                | PMBUS_HAVE_VMON,
        .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT
            | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_TEMP
            | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT
            | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
        .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT
            | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_TEMP
            | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT
            | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
};

static int isl68137_probe_child_from_dt(struct device *dev,
                                        struct device_node *child,
                                        struct isl68137_data *data)
{
        u32 channel, rout, rtotal;
        int err;

        err = of_property_read_u32(child, "reg", &channel);
        if (err) {
                dev_err(dev, "missing reg property of %pOFn\n", child);
                return err;
        }
        if (channel >= data->info.pages) {
                dev_err(dev, "invalid reg %d of %pOFn\n", channel, child);
                return -EINVAL;
        }

        err = of_property_read_u32_array(child, "vout-voltage-divider",
                                         data->channel[channel].vout_voltage_divider,
                                         ARRAY_SIZE(data->channel[channel].vout_voltage_divider));
        if (err && err != -EINVAL) {
                dev_err(dev,
                        "malformed vout-voltage-divider value for channel %d\n",
                        channel);
                return err;
        }

        rout = data->channel[channel].vout_voltage_divider[0];
        rtotal = data->channel[channel].vout_voltage_divider[1];
        if (rout == 0) {
                dev_err(dev,
                        "Voltage divider output resistance must be greater than 0\n");
                return -EINVAL;
        }
        if (rtotal < rout) {
                dev_err(dev,
                        "Voltage divider total resistance is less than output resistance\n");
                return -EINVAL;
        }

        return 0;
}

static int isl68137_probe_from_dt(struct device *dev,
                                  struct isl68137_data *data)
{
        const struct device_node *np = dev->of_node;
        int err;

        for_each_child_of_node_scoped(np, child) {
                if (strcmp(child->name, "channel"))
                        continue;

                err = isl68137_probe_child_from_dt(dev, child, data);
                if (err)
                        return err;
        }

        return 0;
}

static int isl68137_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct pmbus_driver_info *info;
        struct isl68137_data *data;
        int i, err;

        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        /*
         * Initialize all voltage dividers to Rout=1 and Rtotal=1 to simplify
         * logic in PMBus word read/write functions
         */
        for (i = 0; i < MAX_CHANNELS; i++)
                memset(data->channel[i].vout_voltage_divider,
                       1,
                       sizeof(data->channel[i].vout_voltage_divider));

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

        switch ((uintptr_t)i2c_get_match_data(client)) {
        case raa_dmpvr1_2rail:
                info->pages = 2;
                info->R[PSC_VOLTAGE_IN] = 3;
                info->func[0] &= ~PMBUS_HAVE_VMON;
                info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
                    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
                    | PMBUS_HAVE_POUT;
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                info->groups = isl68137_attribute_groups;
                break;
        case raa_dmpvr2_1rail:
                info->pages = 1;
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                break;
        case raa_dmpvr2_2rail_nontc:
                info->func[0] &= ~PMBUS_HAVE_TEMP3;
                info->func[1] &= ~PMBUS_HAVE_TEMP3;
                fallthrough;
        case raa_dmpvr2_2rail:
                info->pages = 2;
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                break;
        case raa_dmpvr2_2rail_pmbus:
                info->format[PSC_VOLTAGE_IN] = linear,
                info->format[PSC_VOLTAGE_OUT] = linear,
                info->format[PSC_CURRENT_IN] = linear;
                info->format[PSC_CURRENT_OUT] = linear;
                info->format[PSC_POWER] = linear;
                info->format[PSC_TEMPERATURE] = linear;
                info->pages = 2;
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                break;
        case raa_dmpvr2_3rail:
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                break;
        case raa_dmpvr2_hv:
                info->pages = 1;
                info->R[PSC_VOLTAGE_IN] = 1;
                info->m[PSC_VOLTAGE_OUT] = 2;
                info->R[PSC_VOLTAGE_OUT] = 2;
                info->m[PSC_CURRENT_IN] = 2;
                info->m[PSC_POWER] = 2;
                info->R[PSC_POWER] = -1;
                info->read_word_data = raa_dmpvr2_read_word_data;
                info->write_word_data = raa_dmpvr2_write_word_data;
                break;
        default:
                return -ENODEV;
        }

        err = isl68137_probe_from_dt(dev, data);
        if (err)
                return err;

        return pmbus_do_probe(client, info);
}

static const struct i2c_device_id raa_dmpvr_id[] = {
        { .name = "isl68137", .driver_data = raa_dmpvr1_2rail },
        { .name = "isl68220", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl68221", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl68222", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl68223", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl68224", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl68225", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl68226", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl68227", .driver_data = raa_dmpvr2_1rail },
        { .name = "isl68229", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl68233", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl68239", .driver_data = raa_dmpvr2_3rail },

        { .name = "isl69222", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69223", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl69224", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69225", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69227", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl69228", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl69234", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69236", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69239", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl69242", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69243", .driver_data = raa_dmpvr2_1rail },
        { .name = "isl69247", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69248", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69254", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69255", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69256", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69259", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69260", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69268", .driver_data = raa_dmpvr2_2rail },
        { .name = "isl69269", .driver_data = raa_dmpvr2_3rail },
        { .name = "isl69298", .driver_data = raa_dmpvr2_2rail },

        { .name = "raa228000", .driver_data = raa_dmpvr2_hv },
        { .name = "raa228004", .driver_data = raa_dmpvr2_hv },
        { .name = "raa228006", .driver_data = raa_dmpvr2_hv },
        { .name = "raa228228", .driver_data = raa_dmpvr2_2rail_nontc },
        { .name = "raa228244", .driver_data = raa_dmpvr2_2rail_nontc },
        { .name = "raa228246", .driver_data = raa_dmpvr2_2rail_nontc },
        { .name = "raa228942", .driver_data = raa_dmpvr2_2rail_nontc },
        { .name = "raa228943", .driver_data = raa_dmpvr2_2rail_nontc },
        { .name = "raa229001", .driver_data = raa_dmpvr2_2rail },
        { .name = "raa229004", .driver_data = raa_dmpvr2_2rail },
        { .name = "raa229141", .driver_data = raa_dmpvr2_2rail_pmbus },
        { .name = "raa229621", .driver_data = raa_dmpvr2_2rail },
        { }
};

MODULE_DEVICE_TABLE(i2c, raa_dmpvr_id);

static const struct of_device_id isl68137_of_match[] = {
        { .compatible = "isil,isl68137", .data = (void *)raa_dmpvr1_2rail },
        { .compatible = "renesas,isl68220", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl68221", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl68222", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl68223", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl68224", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl68225", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl68226", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl68227", .data = (void *)raa_dmpvr2_1rail },
        { .compatible = "renesas,isl68229", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl68233", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl68239", .data = (void *)raa_dmpvr2_3rail },

        { .compatible = "renesas,isl69222", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69223", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl69224", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69225", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69227", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl69228", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl69234", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69236", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69239", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl69242", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69243", .data = (void *)raa_dmpvr2_1rail },
        { .compatible = "renesas,isl69247", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69248", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69254", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69255", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69256", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69259", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "isil,isl69260", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,isl69268", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "isil,isl69269", .data = (void *)raa_dmpvr2_3rail },
        { .compatible = "renesas,isl69298", .data = (void *)raa_dmpvr2_2rail },

        { .compatible = "renesas,raa228000", .data = (void *)raa_dmpvr2_hv },
        { .compatible = "renesas,raa228004", .data = (void *)raa_dmpvr2_hv },
        { .compatible = "renesas,raa228006", .data = (void *)raa_dmpvr2_hv },
        { .compatible = "renesas,raa228228", .data = (void *)raa_dmpvr2_2rail_nontc },
        { .compatible = "renesas,raa228244", .data = (void *)raa_dmpvr2_2rail_nontc },
        { .compatible = "renesas,raa228246", .data = (void *)raa_dmpvr2_2rail_nontc },
        { .compatible = "renesas,raa229001", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,raa229004", .data = (void *)raa_dmpvr2_2rail },
        { .compatible = "renesas,raa229621", .data = (void *)raa_dmpvr2_2rail },
        { },
};

MODULE_DEVICE_TABLE(of, isl68137_of_match);

/* This is the driver that will be inserted */
static struct i2c_driver isl68137_driver = {
        .driver = {
                .name = "isl68137",
                .of_match_table = isl68137_of_match,
        },
        .probe = isl68137_probe,
        .id_table = raa_dmpvr_id,
};

module_i2c_driver(isl68137_driver);

MODULE_AUTHOR("Maxim Sloyko <maxims@google.com>");
MODULE_DESCRIPTION("PMBus driver for Renesas digital multiphase voltage regulators");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");