/*
 * Copyright 2015 Martin Peres
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Martin Peres
 */
#include "priv.h"

#include <subdev/bios.h>
#include <subdev/bios/extdev.h>
#include <subdev/bios/iccsense.h>
#include <subdev/bios/power_budget.h>
#include <subdev/i2c.h>

static bool
nvkm_iccsense_validate_device(struct i2c_adapter *i2c, u8 addr,
                              enum nvbios_extdev_type type)
{
        switch (type) {
        case NVBIOS_EXTDEV_INA209:
        case NVBIOS_EXTDEV_INA219:
                return nv_rd16i2cr(i2c, addr, 0x0) >= 0;
        case NVBIOS_EXTDEV_INA3221:
                return nv_rd16i2cr(i2c, addr, 0xff) == 0x3220 &&
                       nv_rd16i2cr(i2c, addr, 0xfe) == 0x5449;
        default:
                return false;
        }
}

static int
nvkm_iccsense_poll_lane(struct i2c_adapter *i2c, u8 addr, u8 shunt_reg,
                        u8 shunt_shift, u8 bus_reg, u8 bus_shift, u8 shunt,
                        u16 lsb)
{
        int vshunt = nv_rd16i2cr(i2c, addr, shunt_reg);
        int vbus = nv_rd16i2cr(i2c, addr, bus_reg);

        if (vshunt < 0 || vbus < 0)
                return -EINVAL;

        vshunt >>= shunt_shift;
        vbus >>= bus_shift;

        return vbus * vshunt * lsb / shunt;
}

static int
nvkm_iccsense_ina2x9_read(struct nvkm_iccsense *iccsense,
                          struct nvkm_iccsense_rail *rail,
                          u8 shunt_reg, u8 bus_reg)
{
        return nvkm_iccsense_poll_lane(rail->sensor->i2c, rail->sensor->addr,
                                       shunt_reg, 0, bus_reg, 3, rail->mohm,
                                       10 * 4);
}

static int
nvkm_iccsense_ina209_read(struct nvkm_iccsense *iccsense,
                          struct nvkm_iccsense_rail *rail)
{
        return nvkm_iccsense_ina2x9_read(iccsense, rail, 3, 4);
}

static int
nvkm_iccsense_ina219_read(struct nvkm_iccsense *iccsense,
                          struct nvkm_iccsense_rail *rail)
{
        return nvkm_iccsense_ina2x9_read(iccsense, rail, 1, 2);
}

static int
nvkm_iccsense_ina3221_read(struct nvkm_iccsense *iccsense,
                           struct nvkm_iccsense_rail *rail)
{
        return nvkm_iccsense_poll_lane(rail->sensor->i2c, rail->sensor->addr,
                                       1 + (rail->idx * 2), 3,
                                       2 + (rail->idx * 2), 3, rail->mohm,
                                       40 * 8);
}

static void
nvkm_iccsense_sensor_config(struct nvkm_iccsense *iccsense,
                            struct nvkm_iccsense_sensor *sensor)
{
        struct nvkm_subdev *subdev = &iccsense->subdev;
        nvkm_trace(subdev, "write config of extdev %i: 0x%04x\n", sensor->id, sensor->config);
        nv_wr16i2cr(sensor->i2c, sensor->addr, 0x00, sensor->config);
}

int
nvkm_iccsense_read_all(struct nvkm_iccsense *iccsense)
{
        int result = 0;
        struct nvkm_iccsense_rail *rail;

        if (!iccsense)
                return -EINVAL;

        list_for_each_entry(rail, &iccsense->rails, head) {
                int res;
                if (!rail->read)
                        return -ENODEV;

                res = rail->read(iccsense, rail);
                if (res < 0)
                        return res;
                result += res;
        }
        return result;
}

static void *
nvkm_iccsense_dtor(struct nvkm_subdev *subdev)
{
        struct nvkm_iccsense *iccsense = nvkm_iccsense(subdev);
        struct nvkm_iccsense_sensor *sensor, *tmps;
        struct nvkm_iccsense_rail *rail, *tmpr;

        list_for_each_entry_safe(sensor, tmps, &iccsense->sensors, head) {
                list_del(&sensor->head);
                kfree(sensor);
        }
        list_for_each_entry_safe(rail, tmpr, &iccsense->rails, head) {
                list_del(&rail->head);
                kfree(rail);
        }

        return iccsense;
}

static struct nvkm_iccsense_sensor*
nvkm_iccsense_create_sensor(struct nvkm_iccsense *iccsense, u8 id)
{
        struct nvkm_subdev *subdev = &iccsense->subdev;
        struct nvkm_bios *bios = subdev->device->bios;
        struct nvkm_i2c *i2c = subdev->device->i2c;
        struct nvbios_extdev_func extdev;
        struct nvkm_i2c_bus *i2c_bus;
        struct nvkm_iccsense_sensor *sensor;
        u8 addr;

        if (!i2c || !bios || nvbios_extdev_parse(bios, id, &extdev))
                return NULL;

        if (extdev.type == 0xff)
                return NULL;

        if (extdev.type != NVBIOS_EXTDEV_INA209 &&
            extdev.type != NVBIOS_EXTDEV_INA219 &&
            extdev.type != NVBIOS_EXTDEV_INA3221) {
                iccsense->data_valid = false;
                nvkm_error(subdev, "Unknown sensor type %x, power reading "
                           "disabled\n", extdev.type);
                return NULL;
        }

        if (extdev.bus)
                i2c_bus = nvkm_i2c_bus_find(i2c, NVKM_I2C_BUS_SEC);
        else
                i2c_bus = nvkm_i2c_bus_find(i2c, NVKM_I2C_BUS_PRI);
        if (!i2c_bus)
                return NULL;

        addr = extdev.addr >> 1;
        if (!nvkm_iccsense_validate_device(&i2c_bus->i2c, addr,
                                           extdev.type)) {
                iccsense->data_valid = false;
                nvkm_warn(subdev, "found invalid sensor id: %i, power reading"
                          "might be invalid\n", id);
                return NULL;
        }

        sensor = kmalloc_obj(*sensor);
        if (!sensor)
                return NULL;

        list_add_tail(&sensor->head, &iccsense->sensors);
        sensor->id = id;
        sensor->type = extdev.type;
        sensor->i2c = &i2c_bus->i2c;
        sensor->addr = addr;
        sensor->config = 0x0;
        return sensor;
}

static struct nvkm_iccsense_sensor*
nvkm_iccsense_get_sensor(struct nvkm_iccsense *iccsense, u8 id)
{
        struct nvkm_iccsense_sensor *sensor;
        list_for_each_entry(sensor, &iccsense->sensors, head) {
                if (sensor->id == id)
                        return sensor;
        }
        return nvkm_iccsense_create_sensor(iccsense, id);
}

static int
nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
{
        struct nvkm_iccsense *iccsense = nvkm_iccsense(subdev);
        struct nvkm_bios *bios = subdev->device->bios;
        struct nvbios_power_budget budget;
        struct nvbios_iccsense stbl;
        int i, ret;

        if (!bios)
                return 0;

        ret = nvbios_power_budget_header(bios, &budget);
        if (!ret && budget.cap_entry != 0xff) {
                struct nvbios_power_budget_entry entry;
                ret = nvbios_power_budget_entry(bios, &budget,
                                                budget.cap_entry, &entry);
                if (!ret) {
                        iccsense->power_w_max  = entry.avg_w;
                        iccsense->power_w_crit = entry.max_w;
                }
        }

        if (nvbios_iccsense_parse(bios, &stbl) || !stbl.nr_entry)
                return 0;

        iccsense->data_valid = true;
        for (i = 0; i < stbl.nr_entry; ++i) {
                struct pwr_rail_t *pwr_rail = &stbl.rail[i];
                struct nvkm_iccsense_sensor *sensor;
                int r;

                if (pwr_rail->mode != 1 || !pwr_rail->resistor_count)
                        continue;

                sensor = nvkm_iccsense_get_sensor(iccsense, pwr_rail->extdev_id);
                if (!sensor)
                        continue;

                if (!sensor->config)
                        sensor->config = pwr_rail->config;
                else if (sensor->config != pwr_rail->config)
                        nvkm_error(subdev, "config mismatch found for extdev %i\n", pwr_rail->extdev_id);

                for (r = 0; r < pwr_rail->resistor_count; ++r) {
                        struct nvkm_iccsense_rail *rail;
                        struct pwr_rail_resistor_t *res = &pwr_rail->resistors[r];
                        int (*read)(struct nvkm_iccsense *,
                                    struct nvkm_iccsense_rail *);

                        if (!res->mohm || !res->enabled)
                                continue;

                        switch (sensor->type) {
                        case NVBIOS_EXTDEV_INA209:
                                read = nvkm_iccsense_ina209_read;
                                break;
                        case NVBIOS_EXTDEV_INA219:
                                read = nvkm_iccsense_ina219_read;
                                break;
                        case NVBIOS_EXTDEV_INA3221:
                                read = nvkm_iccsense_ina3221_read;
                                break;
                        default:
                                continue;
                        }

                        rail = kmalloc_obj(*rail);
                        if (!rail)
                                return -ENOMEM;

                        rail->read = read;
                        rail->sensor = sensor;
                        rail->idx = r;
                        rail->mohm = res->mohm;
                        nvkm_debug(subdev, "create rail for extdev %i: { idx: %i, mohm: %i }\n", pwr_rail->extdev_id, r, rail->mohm);
                        list_add_tail(&rail->head, &iccsense->rails);
                }
        }
        return 0;
}

static int
nvkm_iccsense_init(struct nvkm_subdev *subdev)
{
        struct nvkm_iccsense *iccsense = nvkm_iccsense(subdev);
        struct nvkm_iccsense_sensor *sensor;
        list_for_each_entry(sensor, &iccsense->sensors, head)
                nvkm_iccsense_sensor_config(iccsense, sensor);
        return 0;
}

static const struct nvkm_subdev_func
iccsense_func = {
        .oneinit = nvkm_iccsense_oneinit,
        .init = nvkm_iccsense_init,
        .dtor = nvkm_iccsense_dtor,
};

void
nvkm_iccsense_ctor(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
                   struct nvkm_iccsense *iccsense)
{
        nvkm_subdev_ctor(&iccsense_func, device, type, inst, &iccsense->subdev);
}

int
nvkm_iccsense_new_(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
                   struct nvkm_iccsense **iccsense)
{
        if (!(*iccsense = kzalloc_obj(**iccsense)))
                return -ENOMEM;
        INIT_LIST_HEAD(&(*iccsense)->sensors);
        INIT_LIST_HEAD(&(*iccsense)->rails);
        nvkm_iccsense_ctor(device, type, inst, *iccsense);
        return 0;
}