/*
 * OMAP thermal driver interface
 *
 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
 * Contact:
 *   Eduardo Valentin <eduardo.valentin@ti.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/thermal.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/cpu_cooling.h>

#include "ti-thermal.h"
#include "ti-bandgap.h"

/* common data structures */
struct ti_thermal_data {
        struct thermal_zone_device *ti_thermal;
        struct thermal_cooling_device *cool_dev;
        struct ti_bandgap *bgp;
        enum thermal_device_mode mode;
        struct work_struct thermal_wq;
        int sensor_id;
};

static void ti_thermal_work(struct work_struct *work)
{
        struct ti_thermal_data *data = container_of(work,
                                        struct ti_thermal_data, thermal_wq);

        thermal_zone_device_update(data->ti_thermal);

        dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
                data->ti_thermal->type);
}

/**
 * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
 * @t:  omap sensor temperature
 * @s:  omap sensor slope value
 * @c:  omap sensor const value
 */
static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
{
        int delta = t * s / 1000 + c;

        if (delta < 0)
                delta = 0;

        return t + delta;
}

/* thermal zone ops */
/* Get temperature callback function for thermal zone*/
static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
                                      unsigned long *temp)
{
        struct ti_thermal_data *data = thermal->devdata;
        struct ti_bandgap *bgp;
        const struct ti_temp_sensor *s;
        int ret, tmp, pcb_temp, slope, constant;

        if (!data)
                return 0;

        bgp = data->bgp;
        s = &bgp->conf->sensors[data->sensor_id];

        ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
        if (ret)
                return ret;

        pcb_temp = 0;
        /* TODO: Introduce pcb temperature lookup */
        /* In case pcb zone is available, use the extrapolation rule with it */
        if (pcb_temp) {
                tmp -= pcb_temp;
                slope = s->slope_pcb;
                constant = s->constant_pcb;
        } else {
                slope = s->slope;
                constant = s->constant;
        }
        *temp = ti_thermal_hotspot_temperature(tmp, slope, constant);

        return ret;
}

/* Bind callback functions for thermal zone */
static int ti_thermal_bind(struct thermal_zone_device *thermal,
                           struct thermal_cooling_device *cdev)
{
        struct ti_thermal_data *data = thermal->devdata;
        int id;

        if (IS_ERR_OR_NULL(data))
                return -ENODEV;

        /* check if this is the cooling device we registered */
        if (data->cool_dev != cdev)
                return 0;

        id = data->sensor_id;

        /* Simple thing, two trips, one passive another critical */
        return thermal_zone_bind_cooling_device(thermal, 0, cdev,
        /* bind with min and max states defined by cpu_cooling */
                                                THERMAL_NO_LIMIT,
                                                THERMAL_NO_LIMIT);
}

/* Unbind callback functions for thermal zone */
static int ti_thermal_unbind(struct thermal_zone_device *thermal,
                             struct thermal_cooling_device *cdev)
{
        struct ti_thermal_data *data = thermal->devdata;

        if (IS_ERR_OR_NULL(data))
                return -ENODEV;

        /* check if this is the cooling device we registered */
        if (data->cool_dev != cdev)
                return 0;

        /* Simple thing, two trips, one passive another critical */
        return thermal_zone_unbind_cooling_device(thermal, 0, cdev);
}

/* Get mode callback functions for thermal zone */
static int ti_thermal_get_mode(struct thermal_zone_device *thermal,
                               enum thermal_device_mode *mode)
{
        struct ti_thermal_data *data = thermal->devdata;

        if (data)
                *mode = data->mode;

        return 0;
}

/* Set mode callback functions for thermal zone */
static int ti_thermal_set_mode(struct thermal_zone_device *thermal,
                               enum thermal_device_mode mode)
{
        struct ti_thermal_data *data = thermal->devdata;

        if (!data->ti_thermal) {
                dev_notice(&thermal->device, "thermal zone not registered\n");
                return 0;
        }

        mutex_lock(&data->ti_thermal->lock);

        if (mode == THERMAL_DEVICE_ENABLED)
                data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
        else
                data->ti_thermal->polling_delay = 0;

        mutex_unlock(&data->ti_thermal->lock);

        data->mode = mode;
        thermal_zone_device_update(data->ti_thermal);
        dev_dbg(&thermal->device, "thermal polling set for duration=%d msec\n",
                data->ti_thermal->polling_delay);

        return 0;
}

/* Get trip type callback functions for thermal zone */
static int ti_thermal_get_trip_type(struct thermal_zone_device *thermal,
                                    int trip, enum thermal_trip_type *type)
{
        if (!ti_thermal_is_valid_trip(trip))
                return -EINVAL;

        if (trip + 1 == OMAP_TRIP_NUMBER)
                *type = THERMAL_TRIP_CRITICAL;
        else
                *type = THERMAL_TRIP_PASSIVE;

        return 0;
}

/* Get trip temperature callback functions for thermal zone */
static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
                                    int trip, unsigned long *temp)
{
        if (!ti_thermal_is_valid_trip(trip))
                return -EINVAL;

        *temp = ti_thermal_get_trip_value(trip);

        return 0;
}

/* Get the temperature trend callback functions for thermal zone */
static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
                                int trip, enum thermal_trend *trend)
{
        struct ti_thermal_data *data = thermal->devdata;
        struct ti_bandgap *bgp;
        int id, tr, ret = 0;

        bgp = data->bgp;
        id = data->sensor_id;

        ret = ti_bandgap_get_trend(bgp, id, &tr);
        if (ret)
                return ret;

        if (tr > 0)
                *trend = THERMAL_TREND_RAISING;
        else if (tr < 0)
                *trend = THERMAL_TREND_DROPPING;
        else
                *trend = THERMAL_TREND_STABLE;

        return 0;
}

/* Get critical temperature callback functions for thermal zone */
static int ti_thermal_get_crit_temp(struct thermal_zone_device *thermal,
                                    unsigned long *temp)
{
        /* shutdown zone */
        return ti_thermal_get_trip_temp(thermal, OMAP_TRIP_NUMBER - 1, temp);
}

static struct thermal_zone_device_ops ti_thermal_ops = {
        .get_temp = ti_thermal_get_temp,
        .get_trend = ti_thermal_get_trend,
        .bind = ti_thermal_bind,
        .unbind = ti_thermal_unbind,
        .get_mode = ti_thermal_get_mode,
        .set_mode = ti_thermal_set_mode,
        .get_trip_type = ti_thermal_get_trip_type,
        .get_trip_temp = ti_thermal_get_trip_temp,
        .get_crit_temp = ti_thermal_get_crit_temp,
};

static struct ti_thermal_data
*ti_thermal_build_data(struct ti_bandgap *bgp, int id)
{
        struct ti_thermal_data *data;

        data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
        if (!data) {
                dev_err(bgp->dev, "kzalloc fail\n");
                return NULL;
        }
        data->sensor_id = id;
        data->bgp = bgp;
        data->mode = THERMAL_DEVICE_ENABLED;
        INIT_WORK(&data->thermal_wq, ti_thermal_work);

        return data;
}

int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
                             char *domain)
{
        struct ti_thermal_data *data;

        data = ti_bandgap_get_sensor_data(bgp, id);

        if (IS_ERR_OR_NULL(data))
                data = ti_thermal_build_data(bgp, id);

        if (!data)
                return -EINVAL;

        /* Create thermal zone */
        data->ti_thermal = thermal_zone_device_register(domain,
                                OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,
                                NULL, FAST_TEMP_MONITORING_RATE,
                                FAST_TEMP_MONITORING_RATE);
        if (IS_ERR_OR_NULL(data->ti_thermal)) {
                dev_err(bgp->dev, "thermal zone device is NULL\n");
                return PTR_ERR(data->ti_thermal);
        }
        data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
        ti_bandgap_set_sensor_data(bgp, id, data);

        return 0;
}

int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
{
        struct ti_thermal_data *data;

        data = ti_bandgap_get_sensor_data(bgp, id);

        thermal_zone_device_unregister(data->ti_thermal);

        return 0;
}

int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
{
        struct ti_thermal_data *data;

        data = ti_bandgap_get_sensor_data(bgp, id);

        schedule_work(&data->thermal_wq);

        return 0;
}

int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
{
        struct ti_thermal_data *data;

        data = ti_bandgap_get_sensor_data(bgp, id);
        if (IS_ERR_OR_NULL(data))
                data = ti_thermal_build_data(bgp, id);

        if (!data)
                return -EINVAL;

        if (!cpufreq_get_current_driver()) {
                dev_dbg(bgp->dev, "no cpufreq driver yet\n");
                return -EPROBE_DEFER;
        }

        /* Register cooling device */
        data->cool_dev = cpufreq_cooling_register(cpu_present_mask);
        if (IS_ERR_OR_NULL(data->cool_dev)) {
                dev_err(bgp->dev,
                        "Failed to register cpufreq cooling device\n");
                return PTR_ERR(data->cool_dev);
        }
        ti_bandgap_set_sensor_data(bgp, id, data);

        return 0;
}

int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
{
        struct ti_thermal_data *data;

        data = ti_bandgap_get_sensor_data(bgp, id);
        cpufreq_cooling_unregister(data->cool_dev);

        return 0;
}