path: root/drivers/hwmon/acpi_power_meter.c

/*
 * A hwmon driver for ACPI 4.0 power meters
 * Copyright (C) 2009 IBM
 *
 * Author: Darrick J. Wong <djwong@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/kdev_t.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>

#define ACPI_POWER_METER_NAME		"power_meter"
ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
#define ACPI_POWER_METER_DEVICE_NAME	"Power Meter"
#define ACPI_POWER_METER_CLASS		"pwr_meter_resource"

#define NUM_SENSORS			17

#define POWER_METER_CAN_MEASURE	(1 << 0)
#define POWER_METER_CAN_TRIP	(1 << 1)
#define POWER_METER_CAN_CAP	(1 << 2)
#define POWER_METER_CAN_NOTIFY	(1 << 3)
#define POWER_METER_IS_BATTERY	(1 << 8)
#define UNKNOWN_HYSTERESIS	0xFFFFFFFF

#define METER_NOTIFY_CONFIG	0x80
#define METER_NOTIFY_TRIP	0x81
#define METER_NOTIFY_CAP	0x82
#define METER_NOTIFY_CAPPING	0x83
#define METER_NOTIFY_INTERVAL	0x84

#define POWER_AVERAGE_NAME	"power1_average"
#define POWER_CAP_NAME		"power1_cap"
#define POWER_AVG_INTERVAL_NAME	"power1_average_interval"
#define POWER_ALARM_NAME	"power1_alarm"

static int cap_in_hardware;
static bool force_cap_on;

static int can_cap_in_hardware(void)
{
	return force_cap_on || cap_in_hardware;
}

static const struct acpi_device_id power_meter_ids[] = {
	{"ACPI000D", 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, power_meter_ids);

struct acpi_power_meter_capabilities {
	u64		flags;
	u64		units;
	u64		type;
	u64		accuracy;
	u64		sampling_time;
	u64		min_avg_interval;
	u64		max_avg_interval;
	u64		hysteresis;
	u64		configurable_cap;
	u64		min_cap;
	u64		max_cap;
};

struct acpi_power_meter_resource {
	struct acpi_device	*acpi_dev;
	acpi_bus_id		name;
	struct mutex		lock;
	struct device		*hwmon_dev;
	struct acpi_power_meter_capabilities	caps;
	acpi_string		model_number;
	acpi_string		serial_number;
	acpi_string		oem_info;
	u64		power;
	u64		cap;
	u64		avg_interval;
	int			sensors_valid;
	unsigned long		sensors_last_updated;
	struct sensor_device_attribute	sensors[NUM_SENSORS];
	int			num_sensors;
	int			trip[2];
	int			num_domain_devices;
	struct acpi_device	**domain_devices;
	struct kobject		*holders_dir;
};

struct ro_sensor_template {
	char *label;
	ssize_t (*show)(struct device *dev,
			struct device_attribute *devattr,
			char *buf);
	int index;
};

struct rw_sensor_template {
	char *label;
	ssize_t (*show)(struct device *dev,
			struct device_attribute *devattr,
			char *buf);
	ssize_t (*set)(struct device *dev,
		       struct device_attribute *devattr,
		       const char *buf, size_t count);
	int index;
};

/* Averaging interval */
static int update_avg_interval(struct acpi_power_meter_resource *resource)
{
	unsigned long long data;
	acpi_status status;

	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
				       NULL, &data);
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
		return -ENODEV;
	}

	resource->avg_interval = data;
	return 0;
}

static ssize_t show_avg_interval(struct device *dev,
				 struct device_attribute *devattr,
				 char *buf)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;

	mutex_lock(&resource->lock);
	update_avg_interval(resource);
	mutex_unlock(&resource->lock);

	return sprintf(buf, "%llu\n", resource->avg_interval);
}

static ssize_t set_avg_interval(struct device *dev,
				struct device_attribute *devattr,
				const char *buf, size_t count)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
	struct acpi_object_list args = { 1, &arg0 };
	int res;
	unsigned lon