/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2020 Oxide Computer Company
 */

#include <mlxcx.h>
#include <sys/sensors.h>

/*
 * The PRM indicates that the temperature is measured in 1/8th degrees.
 */
#define MLXCX_TEMP_GRAN 8

/*
 * Read a single temperature sensor entry. The ksensor framework guarantees that
 * it will only call this once for a given sensor at any time, though multiple
 * sensors can be in parallel.
 */
static int
mlxcx_temperature_read(void *arg, sensor_ioctl_scalar_t *scalar)
{
        boolean_t ok;
        uint16_t tmp;
        mlxcx_register_data_t data;
        mlxcx_temp_sensor_t *sensor = arg;
        mlxcx_t *mlxp = sensor->mlts_mlx;

        bzero(&data, sizeof (data));
        data.mlrd_mtmp.mlrd_mtmp_sensor_index = to_be16(sensor->mlts_index);
        ok = mlxcx_cmd_access_register(mlxp, MLXCX_CMD_ACCESS_REGISTER_READ,
            MLXCX_REG_MTMP, &data);
        if (!ok) {
                return (EIO);
        }

        tmp = from_be16(data.mlrd_mtmp.mlrd_mtmp_temperature);
        sensor->mlts_value = (int16_t)tmp;
        tmp = from_be16(data.mlrd_mtmp.mlrd_mtmp_max_temperature);
        sensor->mlts_max_value = (int16_t)tmp;
        bcopy(data.mlrd_mtmp.mlrd_mtmp_name, sensor->mlts_name,
            sizeof (sensor->mlts_name));

        scalar->sis_unit = SENSOR_UNIT_CELSIUS;
        scalar->sis_gran = MLXCX_TEMP_GRAN;
        scalar->sis_prec = 0;
        scalar->sis_value = (int64_t)sensor->mlts_value;

        return (0);
}

static const ksensor_ops_t mlxcx_temp_ops = {
        .kso_kind = ksensor_kind_temperature,
        .kso_scalar = mlxcx_temperature_read
};

void
mlxcx_teardown_sensors(mlxcx_t *mlxp)
{
        if (mlxp->mlx_temp_nsensors == 0)
                return;
        (void) ksensor_remove(mlxp->mlx_dip, KSENSOR_ALL_IDS);
        kmem_free(mlxp->mlx_temp_sensors, sizeof (mlxcx_temp_sensor_t) *
            mlxp->mlx_temp_nsensors);
}

boolean_t
mlxcx_setup_sensors(mlxcx_t *mlxp)
{
        mlxcx_register_data_t data;
        boolean_t ok;

        mlxp->mlx_temp_nsensors = 0;
        bzero(&data, sizeof (data));
        ok = mlxcx_cmd_access_register(mlxp, MLXCX_CMD_ACCESS_REGISTER_READ,
            MLXCX_REG_MTCAP, &data);
        if (!ok) {
                return (B_FALSE);
        }

        if (data.mlrd_mtcap.mlrd_mtcap_sensor_count == 0) {
                return (B_TRUE);
        }

        mlxp->mlx_temp_nsensors = data.mlrd_mtcap.mlrd_mtcap_sensor_count;
        mlxp->mlx_temp_sensors = kmem_zalloc(sizeof (mlxcx_temp_sensor_t) *
            mlxp->mlx_temp_nsensors, KM_SLEEP);

        for (uint8_t i = 0; i < mlxp->mlx_temp_nsensors; i++) {
                char buf[32];
                int ret;

                if (snprintf(buf, sizeof (buf), "temp%u", i) >= sizeof (buf)) {
                        mlxcx_warn(mlxp, "sensor name %u would overflow "
                            "internal buffer");
                        goto err;
                }

                mlxp->mlx_temp_sensors[i].mlts_mlx = mlxp;
                mlxp->mlx_temp_sensors[i].mlts_index = i;

                ret = ksensor_create_scalar_pcidev(mlxp->mlx_dip,
                    SENSOR_KIND_TEMPERATURE, &mlxcx_temp_ops,
                    &mlxp->mlx_temp_sensors[i], buf,
                    &mlxp->mlx_temp_sensors[i].mlts_ksensor);
                if (ret != 0) {
                        mlxcx_warn(mlxp, "failed to create temp sensor %s: %d",
                            buf, ret);
                        goto err;
                }
        }

        return (B_TRUE);
err:
        mlxcx_teardown_sensors(mlxp);
        return (B_FALSE);
}