thermal: Add Tegra BPMP thermal sensor driver

On Tegra186, the BPMP (Boot and Power Management Processor) exposes an
interface to thermal sensors on the system-on-chip. This driver
implements access to the interface. It supports reading the
temperature, setting trip points and receiving notification of a
tripped trip point.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/thermal/Makefile

@@ -54,7 +54,7 @@ obj-$(CONFIG_INTEL_BXT_PMIC_THERMAL) += intel_bxt_pmic_thermal.o
 obj-$(CONFIG_INTEL_PCH_THERMAL)	+= intel_pch_thermal.o
 obj-$(CONFIG_ST_THERMAL)	+= st/
 obj-$(CONFIG_QCOM_TSENS)	+= qcom/
-obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra/
+obj-y				+= tegra/
 obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
 obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o

drivers/thermal/tegra/Kconfig

@@ -10,4 +10,11 @@ config TEGRA_SOCTHERM
 	  zones to manage temperatures. This option is also required for the
 	  emergency thermal reset (thermtrip) feature to function.
 
+config TEGRA_BPMP_THERMAL
+	tristate "Tegra BPMP thermal sensing"
+	depends on TEGRA_BPMP || COMPILE_TEST
+	help
+	 Enable this option for support for sensing system temperature of NVIDIA
+	 Tegra systems-on-chip with the BPMP coprocessor (Tegra186).
+
 endmenu

drivers/thermal/tegra/Makefile

-obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra-soctherm.o
+obj-$(CONFIG_TEGRA_SOCTHERM)		+= tegra-soctherm.o
+obj-$(CONFIG_TEGRA_BPMP_THERMAL)	+= tegra-bpmp-thermal.o
 
 tegra-soctherm-y				:= soctherm.o soctherm-fuse.o
 tegra-soctherm-$(CONFIG_ARCH_TEGRA_124_SOC)	+= tegra124-soctherm.o

drivers/thermal/tegra/tegra-bpmp-thermal.c

+/*
+ * Copyright (c) 2015-2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Author:
+ *	Mikko Perttunen <mperttunen@nvidia.com>
+ *	Aapo Vienamo	<avienamo@nvidia.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#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(void *data, int *out_temp)
+{
+	struct tegra_bpmp_thermal_zone *zone = data;
+	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;
+
+	*out_temp = reply.get_temp.temp;
+
+	return 0;
+}
+
+static int tegra_bpmp_thermal_set_trips(void *data, int low, int high)
+{
+	struct tegra_bpmp_thermal_zone *zone = data;
+	struct mrq_thermal_host_to_bpmp_request req;
+	struct tegra_bpmp_message msg;
+
+	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);
+
+	return tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
+}
+
+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;
+	int i;
+
+	req = (struct mrq_thermal_bpmp_to_host_request *)ch->ib->data;
+
+	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;
+
+	*num_zones = reply.get_num_zones.num;
+
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops tegra_bpmp_of_thermal_ops = {
+	.get_temp = tegra_bpmp_thermal_get_temp,
+	.set_trips = tegra_bpmp_thermal_set_trips,
+};
+
+static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
+{
+	struct tegra_bpmp *bpmp = dev_get_drvdata(pdev->dev.parent);
+	struct tegra_bpmp_thermal *tegra;
+	struct thermal_zone_device *tzd;
+	unsigned int i, max_num_zones;
+	int err;
+
+	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);
+		if (err < 0) {
+			devm_kfree(&pdev->dev, zone);
+			continue;
+		}
+
+		tzd = devm_thermal_zone_of_sensor_register(
+			&pdev->dev, i, zone, &tegra_bpmp_of_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 int 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);
+
+	return 0;
+}
+
+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");