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-rw-r--r--drivers/hwmon/acpi_power_meter.c1011
1 files changed, 1011 insertions, 0 deletions
diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
new file mode 100644
index 0000000000..b772c076a5
--- /dev/null
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -0,0 +1,1011 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * A hwmon driver for ACPI 4.0 power meters
+ * Copyright (C) 2009 IBM
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+
+#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 <linux/err.h>
+#include <linux/acpi.h>
+
+#define ACPI_POWER_METER_NAME "power_meter"
+#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 UNKNOWN_POWER 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;
+ s64 trip[2];
+ int num_domain_devices;
+ struct acpi_device **domain_devices;
+ struct kobject *holders_dir;
+};
+
+struct 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_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
+ status);
+ 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 = kstrtoul(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_SUCCESS(status))
+ resource->avg_interval = temp;
+ mutex_unlock(&resource->lock);
+
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
+ status);
+ return -EINVAL;
+ }
+
+ /* _PAI returns 0 on success, nonzero otherwise */
+ 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_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
+ status);
+ 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 = kstrtoul(buf, 10, &temp);
+ if (res)
+ return res;
+
+ temp = DIV_ROUND_CLOSEST(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_SUCCESS(status))
+ resource->cap = temp;
+ mutex_unlock(&resource->lock);
+
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
+ status);
+ return -EINVAL;
+ }
+
+ /* _SHL returns 0 on success, nonzero otherwise */
+ 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_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
+ status);
+ return -EINVAL;
+ }
+
+ /* _PTP returns 0 on success, nonzero otherwise */
+ if (data)
+ return -EINVAL;
+
+ return 0;
+}
+
+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 = kstrtoul(buf, 10, &temp);
+ if (res)
+ return res;
+
+ temp = DIV_ROUND_CLOSEST(temp, 1000);
+
+ 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_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
+ status);
+ 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);
+
+ if (resource->power == UNKNOWN_POWER)
+ return -ENODATA;
+
+ return sprintf(buf, "%llu\n", resource->power * 1000);
+}
+
+/* Miscellaneous */
+static ssize_t show_str(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_string val;
+ int ret;
+
+ mutex_lock(&resource->lock);
+ switch (attr->index) {
+ case 0:
+ val = resource->model_number;
+ break;
+ case 1:
+ val = resource->serial_number;
+ break;
+ case 2:
+ val = resource->oem_info;
+ break;
+ default:
+ WARN(1, "Implementation error: unexpected attribute index %d\n",
+ attr->index);
+ val = "";
+ break;
+ }
+ ret = sprintf(buf, "%s\n", val);
+ mutex_unlock(&resource->lock);
+ return ret;
+}
+
+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;
+ u64 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:
+ WARN(1, "Implementation error: unexpected attribute index %d\n",
+ attr->index);
+ break;
+ }
+
+ 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);
+}
+
+#define RO_SENSOR_TEMPLATE(_label, _show, _index) \
+ { \
+ .label = _label, \
+ .show = _show, \
+ .index = _index, \
+ }
+
+#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
+ { \
+ .label = _label, \
+ .show = _show, \
+ .set = _set, \
+ .index = _index, \
+ }
+
+/* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */
+static struct sensor_template meter_attrs[] = {
+ RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
+ RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
+ RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
+ RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
+ RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
+ RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
+ set_avg_interval, 0),
+ {},
+};
+
+static struct sensor_template misc_cap_attrs[] = {
+ RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
+ RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
+ RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
+ RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
+ {},
+};
+
+static struct sensor_template ro_cap_attrs[] = {
+ RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
+ {},
+};
+
+static struct sensor_template rw_cap_attrs[] = {
+ RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
+ {},
+};
+
+static struct sensor_template trip_attrs[] = {
+ RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
+ RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
+ {},
+};
+
+static struct sensor_template misc_attrs[] = {
+ RO_SENSOR_TEMPLATE("name", show_name, 0),
+ RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
+ RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
+ RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
+ {},
+};
+
+#undef RO_SENSOR_TEMPLATE
+#undef RW_SENSOR_TEMPLATE
+
+/* Read power domain data */
+static void remove_domain_devices(struct acpi_power_meter_resource *resource)
+{
+ int i;
+
+ if (!resource->num_domain_devices)
+ return;
+
+ for (i = 0; i < resource->num_domain_devices; i++) {
+ struct acpi_device *obj = resource->domain_devices[i];
+
+ if (!obj)
+ continue;
+
+ sysfs_remove_link(resource->holders_dir,
+ kobject_name(&obj->dev.kobj));
+ acpi_dev_put(obj);
+ }
+
+ kfree(resource->domain_devices);
+ kobject_put(resource->holders_dir);
+ resource->num_domain_devices = 0;
+}
+
+static int read_domain_devices(struct acpi_power_meter_resource *resource)
+{
+ int res = 0;
+ int i;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *pss;
+ acpi_status status;
+
+ status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
+ &buffer);
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
+ status);
+ return -ENODEV;
+ }
+
+ pss = buffer.pointer;
+ if (!pss ||
+ pss->type != ACPI_TYPE_PACKAGE) {
+ dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
+ "Invalid _PMD data\n");
+ res = -EFAULT;
+ goto end;
+ }
+
+ if (!pss->package.count)
+ goto end;
+
+ resource->domain_devices = kcalloc(pss->package.count,
+ sizeof(struct acpi_device *),
+ GFP_KERNEL);
+ if (!resource->domain_devices) {
+ res = -ENOMEM;
+ goto end;
+ }
+
+ resource->holders_dir = kobject_create_and_add("measures",
+ &resource->acpi_dev->dev.kobj);
+ if (!resource->holders_dir) {
+ res = -ENOMEM;
+ goto exit_free;
+ }
+
+ resource->num_domain_devices = pss->package.count;
+
+ for (i = 0; i < pss->package.count; i++) {
+ struct acpi_device *obj;
+ union acpi_object *element = &pss->package.elements[i];
+
+ /* Refuse non-references */
+ if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
+ continue;
+
+ /* Create a symlink to domain objects */
+ obj = acpi_get_acpi_dev(element->reference.handle);
+ resource->domain_devices[i] = obj;
+ if (!obj)
+ continue;
+
+ res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
+ kobject_name(&obj->dev.kobj));
+ if (res) {
+ acpi_dev_put(obj);
+ resource->domain_devices[i] = NULL;
+ }
+ }
+
+ res = 0;
+ goto end;
+
+exit_free:
+ kfree(resource->domain_devices);
+end:
+ kfree(buffer.pointer);
+ return res;
+}
+
+/* Registration and deregistration */
+static int register_attrs(struct acpi_power_meter_resource *resource,
+ struct sensor_template *attrs)
+{
+ struct device *dev = &resource->acpi_dev->dev;
+ struct sensor_device_attribute *sensors =
+ &resource->sensors[resource->num_sensors];
+ int res = 0;
+
+ while (attrs->label) {
+ sensors->dev_attr.attr.name = attrs->label;
+ sensors->dev_attr.attr.mode = 0444;
+ sensors->dev_attr.show = attrs->show;
+ sensors->index = attrs->index;
+
+ if (attrs->set) {
+ sensors->dev_attr.attr.mode |= 0200;
+ sensors->dev_attr.store = attrs->set;
+ }
+
+ sysfs_attr_init(&sensors->dev_attr.attr);
+ res = device_create_file(dev, &sensors->dev_attr);
+ if (res) {
+ sensors->dev_attr.attr.name = NULL;
+ goto error;
+ }
+ sensors++;
+ resource->num_sensors++;
+ attrs++;
+ }
+
+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);
+ }
+
+ remove_domain_devices(resource);
+
+ resource->num_sensors = 0;
+}
+
+static int setup_attrs(struct acpi_power_meter_resource *resource)
+{
+ int res = 0;
+
+ res = read_domain_devices(resource);
+ if (res)
+ return res;
+
+ if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
+ res = register_attrs(resource, meter_attrs);
+ if (res)
+ goto error;
+ }
+
+ if (resource->caps.flags & POWER_METER_CAN_CAP) {
+ if (!can_cap_in_hardware()) {
+ dev_warn(&resource->acpi_dev->dev,
+ "Ignoring unsafe software power cap!\n");
+ goto skip_unsafe_cap;
+ }
+
+ if (resource->caps.configurable_cap)
+ res = register_attrs(resource, rw_cap_attrs);
+ else
+ res = register_attrs(resource, ro_cap_attrs);
+
+ if (res)
+ goto error;
+
+ res = register_attrs(resource, misc_cap_attrs);
+ if (res)
+ goto error;
+ }
+
+skip_unsafe_cap:
+ if (resource->caps.flags & POWER_METER_CAN_TRIP) {
+ res = register_attrs(resource, trip_attrs);
+ if (res)
+ goto error;
+ }
+
+ res = register_attrs(resource, misc_attrs);
+ if (res)
+ goto error;
+
+ return res;
+error:
+ remove_attrs(resource);
+ return res;
+}
+
+static void free_capabilities(struct acpi_power_meter_resource *resource)
+{
+ acpi_string *str;
+ int i;
+
+ str = &resource->model_number;
+ for (i = 0; i < 3; i++, str++) {
+ kfree(*str);
+ *str = NULL;
+ }
+}
+
+static int read_capabilities(struct acpi_power_meter_resource *resource)
+{
+ int res = 0;
+ int i;
+ 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_string *str;
+ acpi_status status;
+
+ status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
+ &buffer);
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
+ status);
+ return -ENODEV;
+ }
+
+ pss = buffer.pointer;
+ if (!pss ||
+ pss->type != ACPI_TYPE_PACKAGE ||
+ pss->package.count != 14) {
+ dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
+ "Invalid _PMC data\n");
+ res = -EFAULT;
+ goto end;
+ }
+
+ /* Grab all the integer data at once */
+ state.length = sizeof(struct acpi_power_meter_capabilities);
+ state.pointer = &resource->caps;
+
+ status = acpi_extract_package(pss, &format, &state);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
+ "_PMC package parsing failed: %s\n",
+ acpi_format_exception(status));
+ res = -EFAULT;
+ goto end;
+ }
+
+ if (resource->caps.units) {
+ dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
+ "Unknown units %llu.\n",
+ resource->caps.units);
+ res = -EINVAL;
+ goto end;
+ }
+
+ /* Grab the string data */
+ str = &resource->model_number;
+
+ for (i = 11; i < 14; i++) {
+ union acpi_object *element = &pss->package.elements[i];
+
+ if (element->type != ACPI_TYPE_STRING) {
+ res = -EINVAL;
+ goto error;
+ }
+
+ *str = kcalloc(element->string.length + 1, sizeof(u8),
+ GFP_KERNEL);
+ if (!*str) {
+ res = -ENOMEM;
+ goto error;
+ }
+
+ strncpy(*str, element->string.pointer, element->string.length);
+ str++;
+ }
+
+ dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
+ goto end;
+error:
+ free_capabilities(resource);
+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);
+
+ switch (event) {
+ case METER_NOTIFY_CONFIG:
+ mutex_lock(&resource->lock);
+ free_capabilities(resource);
+ res = read_capabilities(resource);
+ mutex_unlock(&resource->lock);
+ if (res)
+ break;
+
+ remove_attrs(resource);
+ setup_attrs(resource);
+ break;
+ case METER_NOTIFY_TRIP:
+ sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
+ break;
+ case METER_NOTIFY_CAP:
+ sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
+ break;
+ case METER_NOTIFY_INTERVAL:
+ sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
+ break;
+ case METER_NOTIFY_CAPPING:
+ sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
+ dev_info(&device->dev, "Capping in progress.\n");
+ break;
+ default:
+ WARN(1, "Unexpected event %d\n", event);
+ break;
+ }
+
+ acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
+ dev_name(&device->dev), event, 0);
+}
+
+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(*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] = -1;
+ resource->trip[1] = -1;
+
+ res = setup_attrs(resource);
+ if (res)
+ goto exit_free_capability;
+
+ 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_capability:
+ free_capabilities(resource);
+exit_free:
+ kfree(resource);
+exit:
+ return res;
+}
+
+static void acpi_power_meter_remove(struct acpi_device *device)
+{
+ struct acpi_power_meter_resource *resource;
+
+ if (!device || !acpi_driver_data(device))
+ return;
+
+ resource = acpi_driver_data(device);
+ hwmon_device_unregister(resource->hwmon_dev);
+
+ remove_attrs(resource);
+ free_capabilities(resource);
+
+ kfree(resource);
+}
+
+static int acpi_power_meter_resume(struct device *dev)
+{
+ struct acpi_power_meter_resource *resource;
+
+ if (!dev)
+ return -EINVAL;
+
+ resource = acpi_driver_data(to_acpi_device(dev));
+ if (!resource)
+ return -EINVAL;
+
+ free_capabilities(resource);
+ read_capabilities(resource);
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL,
+ acpi_power_meter_resume);
+
+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,
+ .notify = acpi_power_meter_notify,
+ },
+ .drv.pm = pm_sleep_ptr(&acpi_power_meter_pm),
+};
+
+/* Module init/exit routines */
+static int __init enable_cap_knobs(const struct dmi_system_id *d)
+{
+ cap_in_hardware = 1;
+ return 0;
+}
+
+static const struct dmi_system_id pm_dmi_table[] __initconst = {
+ {
+ enable_cap_knobs, "IBM Active Energy Manager",
+ {
+ DMI_MATCH(DMI_SYS_VENDOR, "IBM")
+ },
+ },
+ {}
+};
+
+static int __init acpi_power_meter_init(void)
+{
+ int result;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ dmi_check_system(pm_dmi_table);
+
+ result = acpi_bus_register_driver(&acpi_power_meter_driver);
+ if (result < 0)
+ return result;
+
+ return 0;
+}
+
+static void __exit acpi_power_meter_exit(void)
+{
+ acpi_bus_unregister_driver(&acpi_power_meter_driver);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
+MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
+MODULE_LICENSE("GPL");
+
+module_param(force_cap_on, bool, 0644);
+MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
+
+module_init(acpi_power_meter_init);
+module_exit(acpi_power_meter_exit);