/*
   * ACPI INT3403 thermal driver
   * Copyright (c) 2013, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope 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/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/types.h>
  #include <linux/acpi.h>
  #include <linux/thermal.h>
  
  #define INT3403_TYPE_SENSOR		0x03
  #define INT3403_PERF_CHANGED_EVENT	0x80
  #define INT3403_THERMAL_EVENT		0x90
  
  #define DECI_KELVIN_TO_MILLI_CELSIUS(t, off) (((t) - (off)) * 100)
  #define KELVIN_OFFSET	2732
  #define MILLI_CELSIUS_TO_DECI_KELVIN(t, off) (((t) / 100) + (off))
  
  #define ACPI_INT3403_CLASS		"int3403"
  #define ACPI_INT3403_FILE_STATE		"state"
  
  struct int3403_sensor {
  	struct thermal_zone_device *tzone;
  	unsigned long *thresholds;
  };
  
  static int sys_get_curr_temp(struct thermal_zone_device *tzone,
  				unsigned long *temp)
  {
  	struct acpi_device *device = tzone->devdata;
  	unsigned long long tmp;
  	acpi_status status;
  
  	status = acpi_evaluate_integer(device->handle, "_TMP", NULL, &tmp);
  	if (ACPI_FAILURE(status))
  		return -EIO;
  
  	*temp = DECI_KELVIN_TO_MILLI_CELSIUS(tmp, KELVIN_OFFSET);
  
  	return 0;
  }
  
  static int sys_get_trip_hyst(struct thermal_zone_device *tzone,
  		int trip, unsigned long *temp)
  {
  	struct acpi_device *device = tzone->devdata;
  	unsigned long long hyst;
  	acpi_status status;
  
  	status = acpi_evaluate_integer(device->handle, "GTSH", NULL, &hyst);
  	if (ACPI_FAILURE(status))
  		return -EIO;
  
  	*temp = DECI_KELVIN_TO_MILLI_CELSIUS(hyst, KELVIN_OFFSET);
  
  	return 0;
  }
  
  static int sys_get_trip_temp(struct thermal_zone_device *tzone,
  		int trip, unsigned long *temp)
  {
  	struct acpi_device *device = tzone->devdata;
  	struct int3403_sensor *obj = acpi_driver_data(device);
  
  	/*
  	 * get_trip_temp is a mandatory callback but
  	 * PATx method doesn't return any value, so return
  	 * cached value, which was last set from user space.
  	 */
  	*temp = obj->thresholds[trip];
  
  	return 0;
  }
  
  static int sys_get_trip_type(struct thermal_zone_device *thermal,
  		int trip, enum thermal_trip_type *type)
  {
  	/* Mandatory callback, may not mean much here */
  	*type = THERMAL_TRIP_PASSIVE;
  
  	return 0;
  }
  
  int sys_set_trip_temp(struct thermal_zone_device *tzone, int trip,
  							unsigned long temp)
  {
  	struct acpi_device *device = tzone->devdata;
  	acpi_status status;
  	char name[10];
  	int ret = 0;
  	struct int3403_sensor *obj = acpi_driver_data(device);
  
  	snprintf(name, sizeof(name), "PAT%d", trip);
  	if (acpi_has_method(device->handle, name)) {
  		status = acpi_execute_simple_method(device->handle, name,
  				MILLI_CELSIUS_TO_DECI_KELVIN(temp,
  							KELVIN_OFFSET));
  		if (ACPI_FAILURE(status))
  			ret = -EIO;
  		else
  			obj->thresholds[trip] = temp;
  	} else {
  		ret = -EIO;
  		dev_err(&device->dev, "sys_set_trip_temp: method not found
  ");
  	}
  
  	return ret;
  }
  
  static struct thermal_zone_device_ops tzone_ops = {
  	.get_temp = sys_get_curr_temp,
  	.get_trip_temp = sys_get_trip_temp,
  	.get_trip_type = sys_get_trip_type,
  	.set_trip_temp = sys_set_trip_temp,
  	.get_trip_hyst =  sys_get_trip_hyst,
  };
  
  static void acpi_thermal_notify(struct acpi_device *device, u32 event)
  {
  	struct int3403_sensor *obj;
  
  	if (!device)
  		return;
  
  	obj = acpi_driver_data(device);
  	if (!obj)
  		return;
  
  	switch (event) {
  	case INT3403_PERF_CHANGED_EVENT:
  		break;
  	case INT3403_THERMAL_EVENT:
  		thermal_zone_device_update(obj->tzone);
  		break;
  	default:
  		dev_err(&device->dev, "Unsupported event [0x%x]
  ", event);
  		break;
  	}
  }
  
  static int acpi_int3403_add(struct acpi_device *device)
  {
  	int result = 0;
  	unsigned long long ptyp;
  	acpi_status status;
  	struct int3403_sensor *obj;
  	unsigned long long trip_cnt;
  	int trip_mask = 0;
  
  	if (!device)
  		return -EINVAL;
  
  	status = acpi_evaluate_integer(device->handle, "PTYP", NULL, &ptyp);
  	if (ACPI_FAILURE(status))
  		return -EINVAL;
  
  	if (ptyp != INT3403_TYPE_SENSOR)
  		return -EINVAL;
  
  	obj = devm_kzalloc(&device->dev, sizeof(*obj), GFP_KERNEL);
  	if (!obj)
  		return -ENOMEM;
  
  	device->driver_data = obj;
  
  	status = acpi_evaluate_integer(device->handle, "PATC", NULL,
  						&trip_cnt);
  	if (ACPI_FAILURE(status))
  		trip_cnt = 0;
  
  	if (trip_cnt) {
  		/* We have to cache, thresholds can't be readback */
  		obj->thresholds = devm_kzalloc(&device->dev,
  					sizeof(*obj->thresholds) * trip_cnt,
  					GFP_KERNEL);
  		if (!obj->thresholds)
  			return -ENOMEM;
  		trip_mask = BIT(trip_cnt) - 1;
  	}
  	obj->tzone = thermal_zone_device_register(acpi_device_bid(device),
  				trip_cnt, trip_mask, device, &tzone_ops,
  				NULL, 0, 0);
  	if (IS_ERR(obj->tzone)) {
  		result = PTR_ERR(obj->tzone);
  		return result;
  	}
  
  	strcpy(acpi_device_name(device), "INT3403");
  	strcpy(acpi_device_class(device), ACPI_INT3403_CLASS);
  
  	return 0;
  }
  
  static int acpi_int3403_remove(struct acpi_device *device)
  {
  	struct int3403_sensor *obj;
  
  	obj = acpi_driver_data(device);
  	thermal_zone_device_unregister(obj->tzone);
  
  	return 0;
  }
  
  ACPI_MODULE_NAME("int3403");
  static const struct acpi_device_id int3403_device_ids[] = {
  	{"INT3403", 0},
  	{"", 0},
  };
  MODULE_DEVICE_TABLE(acpi, int3403_device_ids);
  
  static struct acpi_driver acpi_int3403_driver = {
  	.name = "INT3403",
  	.class = ACPI_INT3403_CLASS,
  	.ids = int3403_device_ids,
  	.ops = {
  		.add = acpi_int3403_add,
  		.remove = acpi_int3403_remove,
  		.notify = acpi_thermal_notify,
  		},
  };
  
  module_acpi_driver(acpi_int3403_driver);
  
  MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("ACPI INT3403 thermal driver");