[PATCH 2/2] acpi_power_meter: hwmon driver for ACPI 4.0 power meters

Darrick J. Wong
2009-07-25T00:36:11Z

This driver exposes ACPI 4.0 compliant power meters as hardware monitoring
devices.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
Documentation/hwmon/acpi_power_meter | 25 +
drivers/acpi/Kconfig | 12 +
drivers/acpi/Makefile | 1
drivers/acpi/power_meter.c | 776 ++++++++++++++++++++++++++++++++++
4 files changed, 814 insertions(+), 0 deletions(-)
create mode 100644 Documentation/hwmon/acpi_power_meter
create mode 100644 drivers/acpi/power_meter.c

diff --git a/Documentation/hwmon/acpi_power_meter b/Documentation/hwmon/acpi_power_meter
new file mode 100644
index 0000000..0af2e9a
--- /dev/null
+++ b/Documentation/hwmon/acpi_power_meter
@@ -0,0 +1,25 @@
+Kernel driver power_meter
+=========================
+
+This driver talks to ACPI 4.0 power meters.
+
+Supported systems:
+ * Any recent system with ACPI 4.0.
+ Prefix: 'power_meter'
+ Datasheet: http://acpi.info/, section 10.4.
+
+Author: Darrick J. Wong
+
+Description
+-----------
+
+This driver implements sensor reading support for the power meters exposed in
+the ACPI 4.0 spec (Chapter 10.4). These devices have a simple set of
+features--a power meter that returns average power use over a configurable
+interval, an optional capping mechanism, and a couple of trip points.
+
+Special Features
+----------------
+
+The power[1-*]_is_battery knob indicates if the power supply is a battery.
+Both power[1-*]_average_{min,max} must be set before the trip points will work.
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 7ec7d88..8ac801d 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -82,6 +82,18 @@ config ACPI_PROCFS_POWER

Say N to delete power /proc/acpi/ directories that have moved to /sys/

+config ACPI_POWER_METER
+ tristate "ACPI 4.0 power meter"
+ depends on HWMON
+ default m
+ help
+ This driver exposes ACPI 4.0 power meters as hardware monitoring
+ devices. Say Y (or M) if you have an Intel or AMD computer with
+ a power meter.
+
+ To compile this driver as a module, choose M here:
+ the module will be called power-meter.
+
config ACPI_SYSFS_POWER
bool "Future power /sys interface"
select POWER_SUPPLY
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 03a985b..82cd49d 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ACPI_HOTPLUG_MEMORY) += acpi_memhotplug.o
obj-$(CONFIG_ACPI_BATTERY) += battery.o
obj-$(CONFIG_ACPI_SBS) += sbshc.o
obj-$(CONFIG_ACPI_SBS) += sbs.o
+obj-$(CONFIG_ACPI_POWER_METER) += power_meter.o

# processor has its own "processor." module_param namespace
processor-y := processor_core.o processor_throttling.o
diff --git a/drivers/acpi/power_meter.c b/drivers/acpi/power_meter.c
new file mode 100644
index 0000000..9418bbd
--- /dev/null
+++ b/drivers/acpi/power_meter.c
@@ -0,0 +1,776 @@
+/*
+ * 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/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 "power_meter_resource"
+
+#define NUM_SENSORS 14
+
+#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
+
+static struct acpi_device_id power_meter_ids[] = {
+ {"ACPI000D", 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, power_meter_ids);
+
+struct acpi_power_meter_capabilities {
+ acpi_integer flags;
+ acpi_integer units;
+ acpi_integer type;
+ acpi_integer accuracy;
+ acpi_integer sampling_time;
+ acpi_integer min_avg_interval;
+ acpi_integer max_avg_interval;
+ acpi_integer hysteresis;
+ acpi_integer configurable_cap;
+ acpi_integer min_cap;
+ acpi_integer 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_integer power;
+ acpi_integer cap;
+ acpi_integer avg_interval;
+ int sensors_valid;
+ unsigned long sensors_last_updated;
+ struct sensor_device_attribute sensors[NUM_SENSORS];
+ int num_sensors;
+ int trip[2];
+};
+
+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 long temp;
+ unsigned long long data;
+ acpi_status status;
+
+ res = strict_strtoul(buf, 10, &temp);
+ if (res)
+ return res;
+
+ if (temp > resource->caps.max_avg_interval ||
+ temp < resource->caps.min_avg_interval)
+ return -EINVAL;
+ arg0.integer.value = temp;
+
+ mutex_lock(&resource->lock);
+ status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
+ &args, &data);
+ if (!ACPI_FAILURE(status))
+ resource->avg_interval = temp;
+ mutex_unlock(&resource->lock);
+
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
+ return -EINVAL;
+ }
+
+ if (data)
+ return -EINVAL;
+
+ return count;
+}
+
+/* Cap functions */
+static int update_cap(struct acpi_power_meter_resource *resource)
+{
+ unsigned long long data;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
+ NULL, &data);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
+ return -ENODEV;
+ }
+
+ resource->cap = data;
+ return 0;
+}
+
+static ssize_t show_cap(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_cap(resource);
+ mutex_unlock(&resource->lock);
+
+ return sprintf(buf, "%llu\n", resource->cap * 1000);
+}
+
+static ssize_t set_cap(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 long temp;
+ unsigned long long data;
+ acpi_status status;
+
+ res = strict_strtoul(buf, 10, &temp);
+ if (res)
+ return res;
+
+ temp /= 1000;
+ if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
+ return -EINVAL;
+ arg0.integer.value = temp;
+
+ mutex_lock(&resource->lock);
+ status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
+ &args, &data);
+ if (!ACPI_FAILURE(status))
+ resource->cap = temp;
+ mutex_unlock(&resource->lock);
+
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
+ return -EINVAL;
+ }
+
+ if (data)
+ return -EINVAL;
+
+ return count;
+}
+
+/* Power meter trip points */
+static int set_acpi_trip(struct acpi_power_meter_resource *resource)
+{
+ union acpi_object arg_objs[] = {
+ {ACPI_TYPE_INTEGER},
+ {ACPI_TYPE_INTEGER}
+ };
+ struct acpi_object_list args = { 2, arg_objs };
+ unsigned long long data;
+ acpi_status status;
+
+ /* Both trip levels must be set */
+ if (resource->trip[0] < 0 || resource->trip[1] < 0)
+ return 0;
+
+ /* This driver stores min, max; ACPI wants max, min. */
+ arg_objs[0].integer.value = resource->trip[1];
+ arg_objs[1].integer.value = resource->trip[0];
+
+ status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
+ &args, &data);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
+ return -EINVAL;
+ }
+
+ return data;
+}
+
+static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
+ int res;
+ unsigned long temp;
+
+ res = strict_strtoul(buf, 10, &temp);
+ if (res)
+ return res;
+
+ temp /= 1000;
+ if (temp < 0)
+ return -EINVAL;
+
+ mutex_lock(&resource->lock);
+ resource->trip[attr->index - 7] = temp;
+ res = set_acpi_trip(resource);
+ mutex_unlock(&resource->lock);
+
+ if (res)
+ return res;
+
+ return count;
+}
+
+/* Power meter */
+static int update_meter(struct acpi_power_meter_resource *resource)
+{
+ unsigned long long data;
+ acpi_status status;
+ unsigned long local_jiffies = jiffies;
+
+ if (time_before(local_jiffies, resource->sensors_last_updated +
+ msecs_to_jiffies(resource->caps.sampling_time)) &&
+ resource->sensors_valid)
+ return 0;
+
+ status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
+ NULL, &data);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
+ return -ENODEV;
+ }
+
+ resource->power = data;
+ resource->sensors_valid = 1;
+ resource->sensors_last_updated = jiffies;
+ return 0;
+}
+
+static ssize_t show_power(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_meter(resource);
+ mutex_unlock(&resource->lock);
+
+ return sprintf(buf, "%llu\n", resource->power * 1000);
+}
+
+/* Miscellaneous */
+static ssize_t show_val(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
+ acpi_integer val = 0;
+
+ switch (attr->index) {
+ case 0:
+ val = resource->caps.min_avg_interval;
+ break;
+ case 1:
+ val = resource->caps.max_avg_interval;
+ break;
+ case 2:
+ val = resource->caps.min_cap * 1000;
+ break;
+ case 3:
+ val = resource->caps.max_cap * 1000;
+ break;
+ case 4:
+ if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
+ return sprintf(buf, "unknown\n");
+
+ val = resource->caps.hysteresis * 1000;
+ break;
+ case 5:
+ if (resource->caps.flags & POWER_METER_IS_BATTERY)
+ val = 1;
+ else
+ val = 0;
+ break;
+ case 6:
+ if (resource->power > resource->cap)
+ val = 1;
+ else
+ val = 0;
+ break;
+ case 7:
+ case 8:
+ if (resource->trip[attr->index - 7] < 0)
+ return sprintf(buf, "unknown\n");
+
+ val = resource->trip[attr->index - 7] * 1000;
+ break;
+ default:
+ BUG();
+ }
+
+ return sprintf(buf, "%llu\n", val);
+}
+
+static ssize_t show_accuracy(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;
+ unsigned int acc = resource->caps.accuracy;
+
+ return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
+}
+
+static ssize_t show_name(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
+}
+
+/* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */
+static struct ro_sensor_template meter_ro_attrs[] = {
+{"power1_average", show_power, 0},
+{"power1_accuracy", show_accuracy, 0},
+{"power1_average_interval_min", show_val, 0},
+{"power1_average_interval_max", show_val, 1},
+{"power1_is_battery", show_val, 5},
+{NULL, NULL, 0},
+};
+
+static struct rw_sensor_template meter_rw_attrs[] = {
+{"power1_average_interval", show_avg_interval, set_avg_interval, 0},
+{NULL, NULL, NULL, 0},
+};
+
+static struct ro_sensor_template misc_cap_attrs[] = {
+{"power1_cap_min", show_val, 2},
+{"power1_cap_max", show_val, 3},
+{"power1_cap_hyst", show_val, 4},
+{"power1_alarm", show_val, 6},
+{NULL, NULL, 0},
+};
+
+static struct ro_sensor_template ro_cap_attrs[] = {
+{"power1_cap", show_cap, 0},
+{NULL, NULL, 0},
+};
+
+static struct rw_sensor_template rw_cap_attrs[] = {
+{"power1_cap", show_cap, set_cap, 0},
+{NULL, NULL, NULL, 0},
+};
+
+static struct rw_sensor_template trip_attrs[] = {
+{"power1_average_min", show_val, set_trip, 7},
+{"power1_average_max", show_val, set_trip, 8},
+{NULL, NULL, NULL, 0},
+};
+
+static struct ro_sensor_template misc_attrs[] = {
+{"name", show_name, 0},
+{NULL, NULL, 0},
+};
+
+/* Registration and deregistration */
+static int register_ro_attrs(struct acpi_power_meter_resource *resource,
+ struct ro_sensor_template *ro)
+{
+ struct device *dev = &resource->acpi_dev->dev;
+ struct sensor_device_attribute *sensors =
+ &resource->sensors[resource->num_sensors];
+ int res;
+
+ while (ro->label) {
+ sensors->dev_attr.attr.name = ro->label;
+ sensors->dev_attr.attr.mode = S_IRUGO;
+ sensors->dev_attr.show = ro->show;
+ sensors->index = ro->index;
+
+ res = device_create_file(dev, &sensors->dev_attr);
+ if (res) {
+ sensors->dev_attr.attr.name = NULL;
+ goto error;
+ }
+ sensors++;
+ resource->num_sensors++;
+ ro++;
+ }
+
+error:
+ return res;
+}
+
+static int register_rw_attrs(struct acpi_power_meter_resource *resource,
+ struct rw_sensor_template *rw)
+{
+ struct device *dev = &resource->acpi_dev->dev;
+ struct sensor_device_attribute *sensors =
+ &resource->sensors[resource->num_sensors];
+ int res;
+
+ while (rw->label) {
+ sensors->dev_attr.attr.name = rw->label;
+ sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
+ sensors->dev_attr.show = rw->show;
+ sensors->dev_attr.store = rw->set;
+ sensors->index = rw->index;
+
+ res = device_create_file(dev, &sensors->dev_attr);
+ if (res) {
+ sensors->dev_attr.attr.name = NULL;
+ goto error;
+ }
+ sensors++;
+ resource->num_sensors++;
+ rw++;
+ }
+
+error:
+ return res;
+}
+
+static void remove_attrs(struct acpi_power_meter_resource *resource)
+{
+ int i;
+
+ for (i = 0; i < resource->num_sensors; i++) {
+ if (!resource->sensors[i].dev_attr.attr.name)
+ continue;
+ device_remove_file(&resource->acpi_dev->dev,
+ &resource->sensors[i].dev_attr);
+ }
+
+ resource->num_sensors = 0;
+}
+
+static int setup_attrs(struct acpi_power_meter_resource *resource)
+{
+ int res = 0;
+
+ if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
+ res = register_ro_attrs(resource, meter_ro_attrs);
+ if (res)
+ goto error;
+ res = register_rw_attrs(resource, meter_rw_attrs);
+ if (res)
+ goto error;
+ }
+
+ if (resource->caps.flags & POWER_METER_CAN_CAP) {
+ if (resource->caps.configurable_cap) {
+ res = register_rw_attrs(resource, rw_cap_attrs);
+ if (res)
+ goto error;
+ } else {
+ res = register_ro_attrs(resource, ro_cap_attrs);
+ if (res)
+ goto error;
+ }
+ res = register_ro_attrs(resource, misc_cap_attrs);
+ if (res)
+ goto error;
+ }
+
+ if (resource->caps.flags & POWER_METER_CAN_TRIP) {
+ res = register_rw_attrs(resource, trip_attrs);
+ if (res)
+ goto error;
+ }
+
+ res = register_ro_attrs(resource, misc_attrs);
+ if (res)
+ goto error;
+
+ return res;
+error:
+ remove_attrs(resource);
+ return res;
+}
+
+static int read_capabilities(struct acpi_power_meter_resource *resource)
+{
+ int res = 0;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer state = { 0, NULL };
+ struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
+ union acpi_object *pss;
+ acpi_status status;
+
+ status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
+ &buffer);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
+ return -ENODEV;
+ }
+
+ pss = buffer.pointer;
+ if (!pss ||
+ pss->type != ACPI_TYPE_PACKAGE ||
+ pss->package.count != 14) {
+ dev_err(&resource->acpi_dev->dev, PREFIX "Invalid _PMC data\n");
+ res = -EFAULT;
+ goto end;
+ }
+
+ state.length = sizeof(struct acpi_power_meter_capabilities);
+ state.pointer = &resource->caps;
+
+ status = acpi_extract_package(pss, &format, &state);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
+ res = -EFAULT;
+ goto end;
+ }
+
+ if (resource->caps.units) {
+ dev_err(&resource->acpi_dev->dev, PREFIX "Unknown unit %llu.\n",
+ resource->caps.units);
+ res = -EINVAL;
+ goto end;
+ }
+
+ dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
+end:
+ kfree(buffer.pointer);
+ return res;
+}
+
+/* Handle ACPI event notifications */
+static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
+{
+ struct acpi_power_meter_resource *resource;
+ int res;
+
+ if (!device || !acpi_driver_data(device))
+ return;
+
+ resource = acpi_driver_data(device);
+
+ mutex_lock(&resource->lock);
+ switch (event) {
+ case METER_NOTIFY_CONFIG:
+ res = read_capabilities(resource);
+ if (res)
+ break;
+
+ remove_attrs(resource);
+ setup_attrs(resource);
+ break;
+ case METER_NOTIFY_TRIP:
+ update_meter(resource);
+ break;
+ case METER_NOTIFY_CAP:
+ update_cap(resource);
+ break;
+ case METER_NOTIFY_INTERVAL:
+ update_avg_interval(resource);
+ break;
+ case METER_NOTIFY_CAPPING:
+ dev_info(&device->dev, "Capping in progress.\n");
+ break;
+ default:
+ BUG();
+ }
+ mutex_unlock(&resource->lock);
+}
+
+static int acpi_power_meter_add(struct acpi_device *device)
+{
+ int res;
+ struct acpi_power_meter_resource *resource;
+
+ if (!device)
+ return -EINVAL;
+
+ resource = kzalloc(sizeof(struct acpi_power_meter_resource),
+ GFP_KERNEL);
+ if (!resource)
+ return -ENOMEM;
+
+ resource->sensors_valid = 0;
+ resource->acpi_dev = device;
+ mutex_init(&resource->lock);
+ strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
+ strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
+ device->driver_data = resource;
+
+ res = read_capabilities(resource);
+ if (res)
+ goto exit_free;
+
+ resource->trip[0] = resource->trip[1] = -1;
+
+ res = setup_attrs(resource);
+ if (res)
+ goto exit_free;
+
+ resource->hwmon_dev = hwmon_device_register(&device->dev);
+ if (IS_ERR(resource->hwmon_dev)) {
+ res = PTR_ERR(resource->hwmon_dev);
+ goto exit_remove;
+ }
+
+ res = 0;
+ goto exit;
+
+exit_remove:
+ remove_attrs(resource);
+exit_free:
+ kfree(resource);
+exit:
+ return res;
+}
+
+static int acpi_power_meter_remove(struct acpi_device *device, int type)
+{
+ struct acpi_power_meter_resource *resource;
+
+ if (!device || !acpi_driver_data(device))
+ return -EINVAL;
+
+ resource = acpi_driver_data(device);
+ hwmon_device_unregister(resource->hwmon_dev);
+
+ remove_attrs(resource);
+
+ kfree(resource);
+ return 0;
+}
+
+static int acpi_power_meter_resume(struct acpi_device *device)
+{
+ struct acpi_power_meter_resource *resource;
+
+ if (!device || !acpi_driver_data(device))
+ return -EINVAL;
+
+ resource = acpi_driver_data(device);
+ read_capabilities(resource);
+
+ return 0;
+}
+
+static struct acpi_driver acpi_power_meter_driver = {
+ .name = "power_meter",
+ .class = ACPI_POWER_METER_CLASS,
+ .ids = power_meter_ids,
+ .ops = {
+ .add = acpi_power_meter_add,
+ .remove = acpi_power_meter_remove,
+ .resume = acpi_power_meter_resume,
+ .notify = acpi_power_meter_notify,
+ },
+};
+
+/* Module init/exit routines */
+
+static int __init acpi_power_meter_init(void)
+{
+ int result;
+
+ result = acpi_bus_register_driver(&acpi_power_meter_driver);
+ if (result < 0)
+ return -ENODEV;
+
+ return 0;
+}
+
+static void __exit acpi_power_meter_exit(void)
+{
+ acpi_bus_unregister_driver(&acpi_power_meter_driver);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
+MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
+MODULE_LICENSE("GPL");
+
+module_init(acpi_power_meter_init);
+module_exit(acpi_power_meter_exit);