root/drivers/thermal/tegra/tegra-bpmp-thermal.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015-2017, NVIDIA CORPORATION.  All rights reserved.
 *
 * Author:
 *      Mikko Perttunen <mperttunen@nvidia.com>
 *      Aapo Vienamo    <avienamo@nvidia.com>
 */

#include <linux/err.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>
#include <linux/workqueue.h>

#include <soc/tegra/bpmp.h>
#include <soc/tegra/bpmp-abi.h>

struct tegra_bpmp_thermal_zone {
        struct tegra_bpmp_thermal *tegra;
        struct thermal_zone_device *tzd;
        struct work_struct tz_device_update_work;
        unsigned int idx;
};

struct tegra_bpmp_thermal {
        struct device *dev;
        struct tegra_bpmp *bpmp;
        unsigned int num_zones;
        struct tegra_bpmp_thermal_zone **zones;
};

static int __tegra_bpmp_thermal_get_temp(struct tegra_bpmp_thermal_zone *zone,
                                         int *out_temp)
{
        struct mrq_thermal_host_to_bpmp_request req;
        union mrq_thermal_bpmp_to_host_response reply;
        struct tegra_bpmp_message msg;
        int err;

        memset(&req, 0, sizeof(req));
        req.type = CMD_THERMAL_GET_TEMP;
        req.get_temp.zone = zone->idx;

        memset(&msg, 0, sizeof(msg));
        msg.mrq = MRQ_THERMAL;
        msg.tx.data = &req;
        msg.tx.size = sizeof(req);
        msg.rx.data = &reply;
        msg.rx.size = sizeof(reply);

        err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
        if (err)
                return err;
        if (msg.rx.ret == -BPMP_EFAULT)
                return -EAGAIN;
        if (msg.rx.ret)
                return -EINVAL;

        *out_temp = reply.get_temp.temp;

        return 0;
}

static int tegra_bpmp_thermal_get_temp(struct thermal_zone_device *tz, int *out_temp)
{
        struct tegra_bpmp_thermal_zone *zone = thermal_zone_device_priv(tz);

        return __tegra_bpmp_thermal_get_temp(zone, out_temp);
}

static int tegra_bpmp_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
{
        struct tegra_bpmp_thermal_zone *zone = thermal_zone_device_priv(tz);
        struct mrq_thermal_host_to_bpmp_request req;
        struct tegra_bpmp_message msg;
        int err;

        memset(&req, 0, sizeof(req));
        req.type = CMD_THERMAL_SET_TRIP;
        req.set_trip.zone = zone->idx;
        req.set_trip.enabled = true;
        req.set_trip.low = low;
        req.set_trip.high = high;

        memset(&msg, 0, sizeof(msg));
        msg.mrq = MRQ_THERMAL;
        msg.tx.data = &req;
        msg.tx.size = sizeof(req);

        err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
        if (err)
                return err;
        if (msg.rx.ret)
                return -EINVAL;

        return 0;
}

static void tz_device_update_work_fn(struct work_struct *work)
{
        struct tegra_bpmp_thermal_zone *zone;

        zone = container_of(work, struct tegra_bpmp_thermal_zone,
                            tz_device_update_work);

        thermal_zone_device_update(zone->tzd, THERMAL_TRIP_VIOLATED);
}

static void bpmp_mrq_thermal(unsigned int mrq, struct tegra_bpmp_channel *ch,
                             void *data)
{
        struct mrq_thermal_bpmp_to_host_request req;
        struct tegra_bpmp_thermal *tegra = data;
        size_t offset;
        int i;

        offset = offsetof(struct tegra_bpmp_mb_data, data);
        iosys_map_memcpy_from(&req, &ch->ib, offset, sizeof(req));

        if (req.type != CMD_THERMAL_HOST_TRIP_REACHED) {
                dev_err(tegra->dev, "%s: invalid request type: %d\n", __func__, req.type);
                tegra_bpmp_mrq_return(ch, -EINVAL, NULL, 0);
                return;
        }

        for (i = 0; i < tegra->num_zones; ++i) {
                if (tegra->zones[i]->idx != req.host_trip_reached.zone)
                        continue;

                schedule_work(&tegra->zones[i]->tz_device_update_work);
                tegra_bpmp_mrq_return(ch, 0, NULL, 0);
                return;
        }

        dev_err(tegra->dev, "%s: invalid thermal zone: %d\n", __func__,
                req.host_trip_reached.zone);
        tegra_bpmp_mrq_return(ch, -EINVAL, NULL, 0);
}

static int tegra_bpmp_thermal_get_num_zones(struct tegra_bpmp *bpmp,
                                            int *num_zones)
{
        struct mrq_thermal_host_to_bpmp_request req;
        union mrq_thermal_bpmp_to_host_response reply;
        struct tegra_bpmp_message msg;
        int err;

        memset(&req, 0, sizeof(req));
        req.type = CMD_THERMAL_GET_NUM_ZONES;

        memset(&msg, 0, sizeof(msg));
        msg.mrq = MRQ_THERMAL;
        msg.tx.data = &req;
        msg.tx.size = sizeof(req);
        msg.rx.data = &reply;
        msg.rx.size = sizeof(reply);

        err = tegra_bpmp_transfer(bpmp, &msg);
        if (err)
                return err;
        if (msg.rx.ret)
                return -EINVAL;

        *num_zones = reply.get_num_zones.num;

        return 0;
}

static int tegra_bpmp_thermal_trips_supported(struct tegra_bpmp *bpmp, bool *supported)
{
        struct mrq_thermal_host_to_bpmp_request req;
        union mrq_thermal_bpmp_to_host_response reply;
        struct tegra_bpmp_message msg;
        int err;

        memset(&req, 0, sizeof(req));
        req.type = CMD_THERMAL_QUERY_ABI;
        req.query_abi.type = CMD_THERMAL_SET_TRIP;

        memset(&msg, 0, sizeof(msg));
        msg.mrq = MRQ_THERMAL;
        msg.tx.data = &req;
        msg.tx.size = sizeof(req);
        msg.rx.data = &reply;
        msg.rx.size = sizeof(reply);

        err = tegra_bpmp_transfer(bpmp, &msg);
        if (err)
                return err;

        if (msg.rx.ret == 0) {
                *supported = true;
                return 0;
        } else if (msg.rx.ret == -BPMP_ENODEV) {
                *supported = false;
                return 0;
        } else {
                return -EINVAL;
        }
}

static const struct thermal_zone_device_ops tegra_bpmp_of_thermal_ops = {
        .get_temp = tegra_bpmp_thermal_get_temp,
        .set_trips = tegra_bpmp_thermal_set_trips,
};

static const struct thermal_zone_device_ops tegra_bpmp_of_thermal_ops_notrips = {
        .get_temp = tegra_bpmp_thermal_get_temp,
};

static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
{
        struct tegra_bpmp *bpmp = dev_get_drvdata(pdev->dev.parent);
        const struct thermal_zone_device_ops *thermal_ops;
        struct tegra_bpmp_thermal *tegra;
        struct thermal_zone_device *tzd;
        unsigned int i, max_num_zones;
        bool supported;
        int err;

        err = tegra_bpmp_thermal_trips_supported(bpmp, &supported);
        if (err) {
                dev_err(&pdev->dev, "failed to determine if trip points are supported\n");
                return err;
        }

        if (supported)
                thermal_ops = &tegra_bpmp_of_thermal_ops;
        else
                thermal_ops = &tegra_bpmp_of_thermal_ops_notrips;

        tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
        if (!tegra)
                return -ENOMEM;

        tegra->dev = &pdev->dev;
        tegra->bpmp = bpmp;

        err = tegra_bpmp_thermal_get_num_zones(bpmp, &max_num_zones);
        if (err) {
                dev_err(&pdev->dev, "failed to get the number of zones: %d\n",
                        err);
                return err;
        }

        tegra->zones = devm_kcalloc(&pdev->dev, max_num_zones,
                                    sizeof(*tegra->zones), GFP_KERNEL);
        if (!tegra->zones)
                return -ENOMEM;

        for (i = 0; i < max_num_zones; ++i) {
                struct tegra_bpmp_thermal_zone *zone;
                int temp;

                zone = devm_kzalloc(&pdev->dev, sizeof(*zone), GFP_KERNEL);
                if (!zone)
                        return -ENOMEM;

                zone->idx = i;
                zone->tegra = tegra;

                err = __tegra_bpmp_thermal_get_temp(zone, &temp);

                /*
                 * Sensors in powergated domains may temporarily fail to be read
                 * (-EAGAIN), but will become accessible when the domain is powered on.
                 */
                if (err < 0 && err != -EAGAIN) {
                        devm_kfree(&pdev->dev, zone);
                        continue;
                }

                tzd = devm_thermal_of_zone_register(
                        &pdev->dev, i, zone, thermal_ops);
                if (IS_ERR(tzd)) {
                        if (PTR_ERR(tzd) == -EPROBE_DEFER)
                                return -EPROBE_DEFER;
                        devm_kfree(&pdev->dev, zone);
                        continue;
                }

                zone->tzd = tzd;
                INIT_WORK(&zone->tz_device_update_work,
                          tz_device_update_work_fn);

                tegra->zones[tegra->num_zones++] = zone;
        }

        err = tegra_bpmp_request_mrq(bpmp, MRQ_THERMAL, bpmp_mrq_thermal,
                                     tegra);
        if (err) {
                dev_err(&pdev->dev, "failed to register mrq handler: %d\n",
                        err);
                return err;
        }

        platform_set_drvdata(pdev, tegra);

        return 0;
}

static void tegra_bpmp_thermal_remove(struct platform_device *pdev)
{
        struct tegra_bpmp_thermal *tegra = platform_get_drvdata(pdev);

        tegra_bpmp_free_mrq(tegra->bpmp, MRQ_THERMAL, tegra);
}

static const struct of_device_id tegra_bpmp_thermal_of_match[] = {
        { .compatible = "nvidia,tegra186-bpmp-thermal" },
        { },
};
MODULE_DEVICE_TABLE(of, tegra_bpmp_thermal_of_match);

static struct platform_driver tegra_bpmp_thermal_driver = {
        .probe = tegra_bpmp_thermal_probe,
        .remove = tegra_bpmp_thermal_remove,
        .driver = {
                .name = "tegra-bpmp-thermal",
                .of_match_table = tegra_bpmp_thermal_of_match,
        },
};
module_platform_driver(tegra_bpmp_thermal_driver);

MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
MODULE_DESCRIPTION("NVIDIA Tegra BPMP thermal sensor driver");
MODULE_LICENSE("GPL v2");