Thermal: introduce INT3402 thermal driver

ACPI INT3402 device object could report temperature for the memory module.
To expose such information to user space, a thermal zone device is registered
for it so that the thermal sysfs interface can expose such information for
userspace to use.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/int340x_thermal/Makefile

 obj-$(CONFIG_INT340X_THERMAL)	+= int3400_thermal.o
+obj-$(CONFIG_INT340X_THERMAL)	+= int3402_thermal.o

drivers/thermal/int340x_thermal/int3402_thermal.c

+/*
+ * INT3402 thermal driver for memory temperature reporting
+ *
+ * Copyright (C) 2014, Intel Corporation
+ * Authors: Aaron Lu <aaron.lu@intel.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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/thermal.h>
+
+#define ACPI_ACTIVE_COOLING_MAX_NR 10
+
+struct active_trip {
+	unsigned long temp;
+	int id;
+	bool valid;
+};
+
+struct int3402_thermal_data {
+	unsigned long *aux_trips;
+	int aux_trip_nr;
+	unsigned long psv_temp;
+	int psv_trip_id;
+	unsigned long crt_temp;
+	int crt_trip_id;
+	unsigned long hot_temp;
+	int hot_trip_id;
+	struct active_trip act_trips[ACPI_ACTIVE_COOLING_MAX_NR];
+	acpi_handle *handle;
+};
+
+static int int3402_thermal_get_zone_temp(struct thermal_zone_device *zone,
+					 unsigned long *temp)
+{
+	struct int3402_thermal_data *d = zone->devdata;
+	unsigned long long tmp;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(d->handle, "_TMP", NULL, &tmp);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	/* _TMP returns the temperature in tenths of degrees Kelvin */
+	*temp = DECI_KELVIN_TO_MILLICELSIUS(tmp);
+
+	return 0;
+}
+
+static int int3402_thermal_get_trip_temp(struct thermal_zone_device *zone,
+					 int trip, unsigned long *temp)
+{
+	struct int3402_thermal_data *d = zone->devdata;
+	int i;
+
+	if (trip < d->aux_trip_nr)
+		*temp = d->aux_trips[trip];
+	else if (trip == d->crt_trip_id)
+		*temp = d->crt_temp;
+	else if (trip == d->psv_trip_id)
+		*temp = d->psv_temp;
+	else if (trip == d->hot_trip_id)
+		*temp = d->hot_temp;
+	else {
+		for (i = 0; i < ACPI_ACTIVE_COOLING_MAX_NR; i++) {
+			if (d->act_trips[i].valid &&
+			    d->act_trips[i].id == trip) {
+				*temp = d->act_trips[i].temp;
+				break;
+			}
+		}
+		if (i == ACPI_ACTIVE_COOLING_MAX_NR)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static int int3402_thermal_get_trip_type(struct thermal_zone_device *zone,
+					 int trip, enum thermal_trip_type *type)
+{
+	struct int3402_thermal_data *d = zone->devdata;
+	int i;
+
+	if (trip < d->aux_trip_nr)
+		*type = THERMAL_TRIP_PASSIVE;
+	else if (trip == d->crt_trip_id)
+		*type = THERMAL_TRIP_CRITICAL;
+	else if (trip == d->hot_trip_id)
+		*type = THERMAL_TRIP_HOT;
+	else if (trip == d->psv_trip_id)
+		*type = THERMAL_TRIP_PASSIVE;
+	else {
+		for (i = 0; i < ACPI_ACTIVE_COOLING_MAX_NR; i++) {
+			if (d->act_trips[i].valid &&
+			    d->act_trips[i].id == trip) {
+				*type = THERMAL_TRIP_ACTIVE;
+				break;
+			}
+		}
+		if (i == ACPI_ACTIVE_COOLING_MAX_NR)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static int int3402_thermal_set_trip_temp(struct thermal_zone_device *zone, int trip,
+				  unsigned long temp)
+{
+	struct int3402_thermal_data *d = zone->devdata;
+	acpi_status status;
+	char name[10];
+
+	snprintf(name, sizeof(name), "PAT%d", trip);
+	status = acpi_execute_simple_method(d->handle, name,
+			MILLICELSIUS_TO_DECI_KELVIN(temp));
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	d->aux_trips[trip] = temp;
+	return 0;
+}
+
+static struct thermal_zone_device_ops int3402_thermal_zone_ops = {
+	.get_temp       = int3402_thermal_get_zone_temp,
+	.get_trip_temp	= int3402_thermal_get_trip_temp,
+	.get_trip_type	= int3402_thermal_get_trip_type,
+	.set_trip_temp	= int3402_thermal_set_trip_temp,
+};
+
+static struct thermal_zone_params int3402_thermal_params = {
+	.governor_name = "user_space",
+	.no_hwmon = true,
+};
+
+static int int3402_thermal_get_temp(acpi_handle handle, char *name,
+				    unsigned long *temp)
+{
+	unsigned long long r;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(handle, name, NULL, &r);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	*temp = DECI_KELVIN_TO_MILLICELSIUS(r);
+	return 0;
+}
+
+static int int3402_thermal_probe(struct platform_device *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct int3402_thermal_data *d;
+	struct thermal_zone_device *zone;
+	acpi_status status;
+	unsigned long long trip_cnt;
+	int trip_mask = 0, i;
+
+	if (!acpi_has_method(adev->handle, "_TMP"))
+		return -ENODEV;
+
+	d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	status = acpi_evaluate_integer(adev->handle, "PATC", NULL, &trip_cnt);
+	if (ACPI_FAILURE(status))
+		trip_cnt = 0;
+	else {
+		d->aux_trips = devm_kzalloc(&pdev->dev,
+				sizeof(*d->aux_trips) * trip_cnt, GFP_KERNEL);
+		if (!d->aux_trips)
+			return -ENOMEM;
+		trip_mask = trip_cnt - 1;
+		d->handle = adev->handle;
+		d->aux_trip_nr = trip_cnt;
+	}
+
+	d->crt_trip_id = -1;
+	if (!int3402_thermal_get_temp(adev->handle, "_CRT", &d->crt_temp))
+		d->crt_trip_id = trip_cnt++;
+	d->hot_trip_id = -1;
+	if (!int3402_thermal_get_temp(adev->handle, "_HOT", &d->hot_temp))
+		d->hot_trip_id = trip_cnt++;
+	d->psv_trip_id = -1;
+	if (!int3402_thermal_get_temp(adev->handle, "_PSV", &d->psv_temp))
+		d->psv_trip_id = trip_cnt++;
+	for (i = 0; i < ACPI_ACTIVE_COOLING_MAX_NR; i++) {
+		char name[5] = { '_', 'A', 'C', '0' + i, '\0' };
+		if (int3402_thermal_get_temp(adev->handle, name,
+					     &d->act_trips[i].temp))
+			break;
+		d->act_trips[i].id = trip_cnt++;
+		d->act_trips[i].valid = true;
+	}
+
+	zone = thermal_zone_device_register(acpi_device_bid(adev), trip_cnt,
+					    trip_mask, d,
+					    &int3402_thermal_zone_ops,
+					    &int3402_thermal_params,
+					    0, 0);
+	if (IS_ERR(zone))
+		return PTR_ERR(zone);
+	platform_set_drvdata(pdev, zone);
+
+	return 0;
+}
+
+static int int3402_thermal_remove(struct platform_device *pdev)
+{
+	struct thermal_zone_device *zone = platform_get_drvdata(pdev);
+
+	thermal_zone_device_unregister(zone);
+	return 0;
+}
+
+static const struct acpi_device_id int3402_thermal_match[] = {
+	{"INT3402", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, int3402_thermal_match);
+
+static struct platform_driver int3402_thermal_driver = {
+	.probe = int3402_thermal_probe,
+	.remove = int3402_thermal_remove,
+	.driver = {
+		   .name = "int3402 thermal",
+		   .owner = THIS_MODULE,
+		   .acpi_match_table = int3402_thermal_match,
+		   },
+};
+
+module_platform_driver(int3402_thermal_driver);
+
+MODULE_DESCRIPTION("INT3402 Thermal driver");
+MODULE_LICENSE("GPL");

include/linux/thermal.h

@@ -46,6 +46,8 @@
 #define CELSIUS_TO_KELVIN(t)	((t)*10+2732)
 #define DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(t, off) (((t) - (off)) * 100)
 #define DECI_KELVIN_TO_MILLICELSIUS(t) DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(t, 2732)
+#define MILLICELSIUS_TO_DECI_KELVIN_WITH_OFFSET(t, off) (((t) / 100) + (off))
+#define MILLICELSIUS_TO_DECI_KELVIN(t) MILLICELSIUS_TO_DECI_KELVIN_WITH_OFFSET(t, 2732)
 
 /* Adding event notification support elements */
 #define THERMAL_GENL_FAMILY_NAME                "thermal_event"