omap-thermal-common.c

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/*
 * OMAP thermal driver interface
 *
 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
 * Contact:
 *   Eduardo Valentin <[email protected]>
 *
 * 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/cpu_cooling.h>

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

/* common data structures */
struct omap_thermal_data {
    struct thermal_zone_device *omap_thermal;
    struct thermal_cooling_device *cool_dev;
    struct omap_bandgap *bg_ptr;
    enum thermal_device_mode mode;
    struct work_struct thermal_wq;
    int sensor_id;
};

static void omap_thermal_work(struct work_struct *work)
{
    struct omap_thermal_data *data = container_of(work,
                    struct omap_thermal_data, thermal_wq);

    thermal_zone_device_update(data->omap_thermal);

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

static inline int omap_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 omap_thermal_get_temp(struct thermal_zone_device *thermal,
                     unsigned long *temp)
{
    struct omap_thermal_data *data = thermal->devdata;
    struct omap_bandgap *bg_ptr;
    struct omap_temp_sensor *s;
    int ret, tmp, pcb_temp, slope, constant;

    if (!data)
        return 0;

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

    ret = omap_bandgap_read_temperature(bg_ptr, 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 = omap_thermal_hotspot_temperature(tmp, slope, constant);

    return ret;
}

/* Bind callback functions for thermal zone */
static int omap_thermal_bind(struct thermal_zone_device *thermal,
                  struct thermal_cooling_device *cdev)
{
    struct omap_thermal_data *data = thermal->devdata;
    int max, 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;
    max = data->bg_ptr->conf->sensors[id].cooling_data.freq_clip_count;

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

/* Unbind callback functions for thermal zone */
static int omap_thermal_unbind(struct thermal_zone_device *thermal,
                struct thermal_cooling_device *cdev)
{
    struct omap_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 omap_thermal_get_mode(struct thermal_zone_device *thermal,
                  enum thermal_device_mode *mode)
{
    struct omap_thermal_data *data = thermal->devdata;

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

    return 0;
}

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

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

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

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

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

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

    return 0;
}

/* Get trip type callback functions for thermal zone */
static int omap_thermal_get_trip_type(struct thermal_zone_device *thermal,
                       int trip, enum thermal_trip_type *type)
{
    if (!omap_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 omap_thermal_get_trip_temp(struct thermal_zone_device *thermal,
                       int trip, unsigned long *temp)
{
    if (!omap_thermal_is_valid_trip(trip))
        return -EINVAL;

    *temp = omap_thermal_get_trip_value(trip);

    return 0;
}

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

static struct thermal_zone_device_ops omap_thermal_ops = {
    .get_temp = omap_thermal_get_temp,
    /* TODO: add .get_trend */
    .bind = omap_thermal_bind,
    .unbind = omap_thermal_unbind,
    .get_mode = omap_thermal_get_mode,
    .set_mode = omap_thermal_set_mode,
    .get_trip_type = omap_thermal_get_trip_type,
    .get_trip_temp = omap_thermal_get_trip_temp,
    .get_crit_temp = omap_thermal_get_crit_temp,
};

static struct omap_thermal_data
*omap_thermal_build_data(struct omap_bandgap *bg_ptr, int id)
{
    struct omap_thermal_data *data;

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

    return data;
}

int omap_thermal_expose_sensor(struct omap_bandgap *bg_ptr, int id,
                   char *domain)
{
    struct omap_thermal_pdata pdata;

    data = omap_bandgap_get_sensor_data(bg_ptr, id);

    if (!data)
        data = omap_thermal_build_pdata(bg_ptr, id);

    if (!data)
        return -EINVAL;

    /* TODO: remove TC1 TC2 */
    /* Create thermal zone */
    data->omap_thermal = thermal_zone_device_register(domain,
                OMAP_TRIP_NUMBER, 0, data, &omap_thermal_ops,
                FAST_TEMP_MONITORING_RATE,
                FAST_TEMP_MONITORING_RATE);
    if (IS_ERR_OR_NULL(data->omap_thermal)) {
        dev_err(bg_ptr->dev, "thermal zone device is NULL\n");
        return PTR_ERR(data->omap_thermal);
    }
    data->omap_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
    omap_bandgap_set_sensor_data(bg_ptr, id, data);

    return 0;
}

int omap_thermal_remove_sensor(struct omap_bandgap *bg_ptr, int id)
{
    struct omap_thermal_data *data;

    data = omap_bandgap_get_sensor_data(bg_ptr, id);

    thermal_zone_device_unregister(data->omap_thermal);

    return 0;
}

int omap_thermal_report_sensor_temperature(struct omap_bandgap *bg_ptr, int id)
{
    struct omap_thermal_data *data;

    data = omap_bandgap_get_sensor_data(bg_ptr, id);

    schedule_work(&data->thermal_wq);

    return 0;
}

static int omap_thermal_build_cpufreq_clip(struct omap_bandgap *bg_ptr,
                       struct freq_clip_table **tab_ptr,
                       int *tab_size)
{
    struct cpufreq_frequency_table *freq_table;
    struct freq_clip_table *tab;
    int i, count = 0;

    freq_table = cpufreq_frequency_get_table(0);
    if (IS_ERR_OR_NULL(freq_table)) {
        dev_err(bg_ptr->dev,
            "%s: failed to get cpufreq table (%p)\n",
            __func__, freq_table);
        return -EINVAL;
    }

    for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
        unsigned int freq = freq_table[i].frequency;
        if (freq == CPUFREQ_ENTRY_INVALID)
            continue;
        count++;
    }

    tab = devm_kzalloc(bg_ptr->dev, sizeof(*tab) * count, GFP_KERNEL);
    if (!tab) {
        dev_err(bg_ptr->dev,
            "%s: no memory available\n", __func__);
        return -ENOMEM;
    }

    for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
        unsigned int freq = freq_table[i].frequency;

        if (freq == CPUFREQ_ENTRY_INVALID)
            continue;

        tab[count - i - 1].freq_clip_max = freq;
        tab[count - i - 1].temp_level = OMAP_TRIP_HOT;
        tab[count - i - 1].mask_val = cpumask_of(0);
    }

    *tab_ptr = tab;
    *tab_size = count;

    return 0;
}

int omap_thermal_register_cpu_cooling(struct omap_bandgap *bg_ptr, int id)
{
    struct omap_thermal_data *data;
    struct freq_clip_table *tab_ptr;
    int tab_size, ret;

    data = omap_bandgap_get_sensor_data(bg_ptr, id);
    if (!data)
        data = omap_thermal_build_pdata(bg_ptr, id);

    if (!data)
        return -EINVAL;

    ret = omap_thermal_build_cpufreq_clip(bg_ptr, &tab_ptr, &tab_size);
    if (ret < 0) {
        dev_err(bg_ptr->dev,
            "%s: failed to build cpufreq clip table\n", __func__);
        return ret;
    }

    /* Register cooling device */
    data->cool_dev = cpufreq_cooling_register(tab_ptr, tab_size);
    if (IS_ERR_OR_NULL(data->cool_dev)) {
        dev_err(bg_ptr->dev,
            "Failed to register cpufreq cooling device\n");
        return PTR_ERR(data->cool_dev);
    }
    bg_ptr->conf->sensors[id].cooling_data.freq_clip_count = tab_size;
    omap_bandgap_set_sensor_data(bg_ptr, id, data);

    return 0;
}

int omap_thermal_unregister_cpu_cooling(struct omap_bandgap *bg_ptr, int id)
{
    struct omap_thermal_data *data;

    data = omap_bandgap_get_sensor_data(bg_ptr, id);
    cpufreq_cooling_unregister(data->cool_dev);

    return 0;
}