PowerCap: Add class driver
The power capping framework providing a consistent interface between the
kernel and user space that allows power capping drivers to expose their
settings to user space in a uniform way.
The overall design of the framework is described in the documentation
added by the previous patch in this series.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
new file mode 100644
index 0000000..c22fa4c
--- /dev/null
+++ b/drivers/powercap/powercap_sys.c
@@ -0,0 +1,683 @@
+/*
+ * Power capping class
+ * 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.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/powercap.h>
+
+#define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
+#define to_powercap_control_type(n) \
+ container_of(n, struct powercap_control_type, dev)
+
+/* Power zone show function */
+#define define_power_zone_show(_attr) \
+static ssize_t _attr##_show(struct device *dev, \
+ struct device_attribute *dev_attr,\
+ char *buf) \
+{ \
+ u64 value; \
+ ssize_t len = -EINVAL; \
+ struct powercap_zone *power_zone = to_powercap_zone(dev); \
+ \
+ if (power_zone->ops->get_##_attr) { \
+ if (!power_zone->ops->get_##_attr(power_zone, &value)) \
+ len = sprintf(buf, "%lld\n", value); \
+ } \
+ \
+ return len; \
+}
+
+/* The only meaningful input is 0 (reset), others are silently ignored */
+#define define_power_zone_store(_attr) \
+static ssize_t _attr##_store(struct device *dev,\
+ struct device_attribute *dev_attr, \
+ const char *buf, size_t count) \
+{ \
+ int err; \
+ struct powercap_zone *power_zone = to_powercap_zone(dev); \
+ u64 value; \
+ \
+ err = kstrtoull(buf, 10, &value); \
+ if (err) \
+ return -EINVAL; \
+ if (value) \
+ return count; \
+ if (power_zone->ops->reset_##_attr) { \
+ if (!power_zone->ops->reset_##_attr(power_zone)) \
+ return count; \
+ } \
+ \
+ return -EINVAL; \
+}
+
+/* Power zone constraint show function */
+#define define_power_zone_constraint_show(_attr) \
+static ssize_t show_constraint_##_attr(struct device *dev, \
+ struct device_attribute *dev_attr,\
+ char *buf) \
+{ \
+ u64 value; \
+ ssize_t len = -ENODATA; \
+ struct powercap_zone *power_zone = to_powercap_zone(dev); \
+ int id; \
+ struct powercap_zone_constraint *pconst;\
+ \
+ if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
+ return -EINVAL; \
+ if (id >= power_zone->const_id_cnt) \
+ return -EINVAL; \
+ pconst = &power_zone->constraints[id]; \
+ if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
+ if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
+ len = sprintf(buf, "%lld\n", value); \
+ } \
+ \
+ return len; \
+}
+
+/* Power zone constraint store function */
+#define define_power_zone_constraint_store(_attr) \
+static ssize_t store_constraint_##_attr(struct device *dev,\
+ struct device_attribute *dev_attr, \
+ const char *buf, size_t count) \
+{ \
+ int err; \
+ u64 value; \
+ struct powercap_zone *power_zone = to_powercap_zone(dev); \
+ int id; \
+ struct powercap_zone_constraint *pconst;\
+ \
+ if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
+ return -EINVAL; \
+ if (id >= power_zone->const_id_cnt) \
+ return -EINVAL; \
+ pconst = &power_zone->constraints[id]; \
+ err = kstrtoull(buf, 10, &value); \
+ if (err) \
+ return -EINVAL; \
+ if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
+ if (!pconst->ops->set_##_attr(power_zone, id, value)) \
+ return count; \
+ } \
+ \
+ return -ENODATA; \
+}
+
+/* Power zone information callbacks */
+define_power_zone_show(power_uw);
+define_power_zone_show(max_power_range_uw);
+define_power_zone_show(energy_uj);
+define_power_zone_store(energy_uj);
+define_power_zone_show(max_energy_range_uj);
+
+/* Power zone attributes */
+static DEVICE_ATTR_RO(max_power_range_uw);
+static DEVICE_ATTR_RO(power_uw);
+static DEVICE_ATTR_RO(max_energy_range_uj);
+static DEVICE_ATTR_RW(energy_uj);
+
+/* Power zone constraint attributes callbacks */
+define_power_zone_constraint_show(power_limit_uw);
+define_power_zone_constraint_store(power_limit_uw);
+define_power_zone_constraint_show(time_window_us);
+define_power_zone_constraint_store(time_window_us);
+define_power_zone_constraint_show(max_power_uw);
+define_power_zone_constraint_show(min_power_uw);
+define_power_zone_constraint_show(max_time_window_us);
+define_power_zone_constraint_show(min_time_window_us);
+
+/* For one time seeding of constraint device attributes */
+struct powercap_constraint_attr {
+ struct device_attribute power_limit_attr;
+ struct device_attribute time_window_attr;
+ struct device_attribute max_power_attr;
+ struct device_attribute min_power_attr;
+ struct device_attribute max_time_window_attr;
+ struct device_attribute min_time_window_attr;
+ struct device_attribute name_attr;
+};
+
+static struct powercap_constraint_attr
+ constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
+
+/* A list of powercap control_types */
+static LIST_HEAD(powercap_cntrl_list);
+/* Mutex to protect list of powercap control_types */
+static DEFINE_MUTEX(powercap_cntrl_list_lock);
+
+#define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
+static ssize_t show_constraint_name(struct device *dev,
+ struct device_attribute *dev_attr,
+ char *buf)
+{
+ const char *name;
+ struct powercap_zone *power_zone = to_powercap_zone(dev);
+ int id;
+ ssize_t len = -ENODATA;
+ struct powercap_zone_constraint *pconst;
+
+ if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
+ return -EINVAL;
+ if (id >= power_zone->const_id_cnt)
+ return -EINVAL;
+ pconst = &power_zone->constraints[id];
+
+ if (pconst && pconst->ops && pconst->ops->get_name) {
+ name = pconst->ops->get_name(power_zone, id);
+ if (name) {
+ snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN,
+ "%s\n", name);
+ buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0';
+ len = strlen(buf);
+ }
+ }
+
+ return len;
+}
+
+static int create_constraint_attribute(int id, const char *name,
+ int mode,
+ struct device_attribute *dev_attr,
+ ssize_t (*show)(struct device *,
+ struct device_attribute *, char *),
+ ssize_t (*store)(struct device *,
+ struct device_attribute *,
+ const char *, size_t)
+ )
+{
+
+ dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
+ id, name);
+ if (!dev_attr->attr.name)
+ return -ENOMEM;
+ dev_attr->attr.mode = mode;
+ dev_attr->show = show;
+ dev_attr->store = store;
+
+ return 0;
+}
+
+static void free_constraint_attributes(void)
+{
+ int i;
+
+ for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
+ kfree(constraint_attrs[i].power_limit_attr.attr.name);
+ kfree(constraint_attrs[i].time_window_attr.attr.name);
+ kfree(constraint_attrs[i].name_attr.attr.name);
+ kfree(constraint_attrs[i].max_power_attr.attr.name);
+ kfree(constraint_attrs[i].min_power_attr.attr.name);
+ kfree(constraint_attrs[i].max_time_window_attr.attr.name);
+ kfree(constraint_attrs[i].min_time_window_attr.attr.name);
+ }
+}
+
+static int seed_constraint_attributes(void)
+{
+ int i;
+ int ret;
+
+ for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
+ ret = create_constraint_attribute(i, "power_limit_uw",
+ S_IWUSR | S_IRUGO,
+ &constraint_attrs[i].power_limit_attr,
+ show_constraint_power_limit_uw,
+ store_constraint_power_limit_uw);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "time_window_us",
+ S_IWUSR | S_IRUGO,
+ &constraint_attrs[i].time_window_attr,
+ show_constraint_time_window_us,
+ store_constraint_time_window_us);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "name", S_IRUGO,
+ &constraint_attrs[i].name_attr,
+ show_constraint_name,
+ NULL);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
+ &constraint_attrs[i].max_power_attr,
+ show_constraint_max_power_uw,
+ NULL);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
+ &constraint_attrs[i].min_power_attr,
+ show_constraint_min_power_uw,
+ NULL);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "max_time_window_us",
+ S_IRUGO,
+ &constraint_attrs[i].max_time_window_attr,
+ show_constraint_max_time_window_us,
+ NULL);
+ if (ret)
+ goto err_alloc;
+ ret = create_constraint_attribute(i, "min_time_window_us",
+ S_IRUGO,
+ &constraint_attrs[i].min_time_window_attr,
+ show_constraint_min_time_window_us,
+ NULL);
+ if (ret)
+ goto err_alloc;
+
+ }
+
+ return 0;
+
+err_alloc:
+ free_constraint_attributes();
+
+ return ret;
+}
+
+static int create_constraints(struct powercap_zone *power_zone,
+ int nr_constraints,
+ struct powercap_zone_constraint_ops *const_ops)
+{
+ int i;
+ int ret = 0;
+ int count;
+ struct powercap_zone_constraint *pconst;
+
+ if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
+ !const_ops->set_power_limit_uw ||
+ !const_ops->get_time_window_us ||
+ !const_ops->set_time_window_us)
+ return -EINVAL;
+
+ count = power_zone->zone_attr_count;
+ for (i = 0; i < nr_constraints; ++i) {
+ pconst = &power_zone->constraints[i];
+ pconst->ops = const_ops;
+ pconst->id = power_zone->const_id_cnt;
+ power_zone->const_id_cnt++;
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].power_limit_attr.attr;
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].time_window_attr.attr;
+ if (pconst->ops->get_name)
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].name_attr.attr;
+ if (pconst->ops->get_max_power_uw)
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].max_power_attr.attr;
+ if (pconst->ops->get_min_power_uw)
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].min_power_attr.attr;
+ if (pconst->ops->get_max_time_window_us)
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].max_time_window_attr.attr;
+ if (pconst->ops->get_min_time_window_us)
+ power_zone->zone_dev_attrs[count++] =
+ &constraint_attrs[i].min_time_window_attr.attr;
+ }
+ power_zone->zone_attr_count = count;
+
+ return ret;
+}
+
+static bool control_type_valid(void *control_type)
+{
+ struct powercap_control_type *pos = NULL;
+ bool found = false;
+
+ mutex_lock(&powercap_cntrl_list_lock);
+
+ list_for_each_entry(pos, &powercap_cntrl_list, node) {
+ if (pos == control_type) {
+ found = true;
+ break;
+ }
+ }
+ mutex_unlock(&powercap_cntrl_list_lock);
+
+ return found;
+}
+
+static ssize_t name_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct powercap_zone *power_zone = to_powercap_zone(dev);
+
+ return sprintf(buf, "%s\n", power_zone->name);
+}
+
+static DEVICE_ATTR_RO(name);
+
+/* Create zone and attributes in sysfs */
+static void create_power_zone_common_attributes(
+ struct powercap_zone *power_zone)
+{
+ int count = 0;
+
+ power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
+ if (power_zone->ops->get_max_energy_range_uj)
+ power_zone->zone_dev_attrs[count++] =
+ &dev_attr_max_energy_range_uj.attr;
+ if (power_zone->ops->get_energy_uj)
+ power_zone->zone_dev_attrs[count++] =
+ &dev_attr_energy_uj.attr;
+ if (power_zone->ops->get_power_uw)
+ power_zone->zone_dev_attrs[count++] =
+ &dev_attr_power_uw.attr;
+ if (power_zone->ops->get_max_power_range_uw)
+ power_zone->zone_dev_attrs[count++] =
+ &dev_attr_max_power_range_uw.attr;
+ power_zone->zone_dev_attrs[count] = NULL;
+ power_zone->zone_attr_count = count;
+}
+
+static void powercap_release(struct device *dev)
+{
+ bool allocated;
+
+ if (dev->parent) {
+ struct powercap_zone *power_zone = to_powercap_zone(dev);
+
+ /* Store flag as the release() may free memory */
+ allocated = power_zone->allocated;
+ /* Remove id from parent idr struct */
+ idr_remove(power_zone->parent_idr, power_zone->id);
+ /* Destroy idrs allocated for this zone */
+ idr_destroy(&power_zone->idr);
+ kfree(power_zone->name);
+ kfree(power_zone->zone_dev_attrs);
+ kfree(power_zone->constraints);
+ if (power_zone->ops->release)
+ power_zone->ops->release(power_zone);
+ if (allocated)
+ kfree(power_zone);
+ } else {
+ struct powercap_control_type *control_type =
+ to_powercap_control_type(dev);
+
+ /* Store flag as the release() may free memory */
+ allocated = control_type->allocated;
+ idr_destroy(&control_type->idr);
+ mutex_destroy(&control_type->lock);
+ if (control_type->ops && control_type->ops->release)
+ control_type->ops->release(control_type);
+ if (allocated)
+ kfree(control_type);
+ }
+}
+
+static ssize_t enabled_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ bool mode = true;
+
+ /* Default is enabled */
+ if (dev->parent) {
+ struct powercap_zone *power_zone = to_powercap_zone(dev);
+ if (power_zone->ops->get_enable)
+ if (power_zone->ops->get_enable(power_zone, &mode))
+ mode = false;
+ } else {
+ struct powercap_control_type *control_type =
+ to_powercap_control_type(dev);
+ if (control_type->ops && control_type->ops->get_enable)
+ if (control_type->ops->get_enable(control_type, &mode))
+ mode = false;
+ }
+
+ return sprintf(buf, "%d\n", mode);
+}
+
+static ssize_t enabled_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ bool mode;
+
+ if (strtobool(buf, &mode))
+ return -EINVAL;
+ if (dev->parent) {
+ struct powercap_zone *power_zone = to_powercap_zone(dev);
+ if (power_zone->ops->set_enable)
+ if (!power_zone->ops->set_enable(power_zone, mode))
+ return len;
+ } else {
+ struct powercap_control_type *control_type =
+ to_powercap_control_type(dev);
+ if (control_type->ops && control_type->ops->set_enable)
+ if (!control_type->ops->set_enable(control_type, mode))
+ return len;
+ }
+
+ return -ENOSYS;
+}
+
+static struct device_attribute powercap_def_attrs[] = {
+ __ATTR(enabled, S_IWUSR | S_IRUGO, enabled_show,
+ enabled_store),
+ __ATTR_NULL
+};
+
+static struct class powercap_class = {
+ .name = "powercap",
+ .dev_release = powercap_release,
+ .dev_attrs = powercap_def_attrs,
+};
+
+struct powercap_zone *powercap_register_zone(
+ struct powercap_zone *power_zone,
+ struct powercap_control_type *control_type,
+ const char *name,
+ struct powercap_zone *parent,
+ const struct powercap_zone_ops *ops,
+ int nr_constraints,
+ struct powercap_zone_constraint_ops *const_ops)
+{
+ int result;
+ int nr_attrs;
+
+ if (!name || !control_type || !ops ||
+ nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
+ (!ops->get_energy_uj && !ops->get_power_uw) ||
+ !control_type_valid(control_type))
+ return ERR_PTR(-EINVAL);
+
+ if (power_zone) {
+ if (!ops->release)
+ return ERR_PTR(-EINVAL);
+ memset(power_zone, 0, sizeof(*power_zone));
+ } else {
+ power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
+ if (!power_zone)
+ return ERR_PTR(-ENOMEM);
+ power_zone->allocated = true;
+ }
+ power_zone->ops = ops;
+ power_zone->control_type_inst = control_type;
+ if (!parent) {
+ power_zone->dev.parent = &control_type->dev;
+ power_zone->parent_idr = &control_type->idr;
+ } else {
+ power_zone->dev.parent = &parent->dev;
+ power_zone->parent_idr = &parent->idr;
+ }
+ power_zone->dev.class = &powercap_class;
+
+ mutex_lock(&control_type->lock);
+ /* Using idr to get the unique id */
+ result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
+ if (result < 0)
+ goto err_idr_alloc;
+
+ power_zone->id = result;
+ idr_init(&power_zone->idr);
+ power_zone->name = kstrdup(name, GFP_KERNEL);
+ if (!power_zone->name)
+ goto err_name_alloc;
+ dev_set_name(&power_zone->dev, "%s:%x",
+ dev_name(power_zone->dev.parent),
+ power_zone->id);
+ power_zone->constraints = kzalloc(sizeof(*power_zone->constraints) *
+ nr_constraints, GFP_KERNEL);
+ if (!power_zone->constraints)
+ goto err_const_alloc;
+
+ nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
+ POWERCAP_ZONE_MAX_ATTRS + 1;
+ power_zone->zone_dev_attrs = kzalloc(sizeof(void *) *
+ nr_attrs, GFP_KERNEL);
+ if (!power_zone->zone_dev_attrs)
+ goto err_attr_alloc;
+ create_power_zone_common_attributes(power_zone);
+ result = create_constraints(power_zone, nr_constraints, const_ops);
+ if (result)
+ goto err_dev_ret;
+
+ power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
+ power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
+ power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
+ power_zone->dev_attr_groups[1] = NULL;
+ power_zone->dev.groups = power_zone->dev_attr_groups;
+ result = device_register(&power_zone->dev);
+ if (result)
+ goto err_dev_ret;
+
+ control_type->nr_zones++;
+ mutex_unlock(&control_type->lock);
+
+ return power_zone;
+
+err_dev_ret:
+ kfree(power_zone->zone_dev_attrs);
+err_attr_alloc:
+ kfree(power_zone->constraints);
+err_const_alloc:
+ kfree(power_zone->name);
+err_name_alloc:
+ idr_remove(power_zone->parent_idr, power_zone->id);
+err_idr_alloc:
+ if (power_zone->allocated)
+ kfree(power_zone);
+ mutex_unlock(&control_type->lock);
+
+ return ERR_PTR(result);
+}
+EXPORT_SYMBOL_GPL(powercap_register_zone);
+
+int powercap_unregister_zone(struct powercap_control_type *control_type,
+ struct powercap_zone *power_zone)
+{
+ if (!power_zone || !control_type)
+ return -EINVAL;
+
+ mutex_lock(&control_type->lock);
+ control_type->nr_zones--;
+ mutex_unlock(&control_type->lock);
+
+ device_unregister(&power_zone->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(powercap_unregister_zone);
+
+struct powercap_control_type *powercap_register_control_type(
+ struct powercap_control_type *control_type,
+ const char *name,
+ const struct powercap_control_type_ops *ops)
+{
+ int result;
+
+ if (!name)
+ return ERR_PTR(-EINVAL);
+ if (control_type) {
+ if (!ops || !ops->release)
+ return ERR_PTR(-EINVAL);
+ memset(control_type, 0, sizeof(*control_type));
+ } else {
+ control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
+ if (!control_type)
+ return ERR_PTR(-ENOMEM);
+ control_type->allocated = true;
+ }
+ mutex_init(&control_type->lock);
+ control_type->ops = ops;
+ INIT_LIST_HEAD(&control_type->node);
+ control_type->dev.class = &powercap_class;
+ dev_set_name(&control_type->dev, name);
+ result = device_register(&control_type->dev);
+ if (result) {
+ if (control_type->allocated)
+ kfree(control_type);
+ return ERR_PTR(result);
+ }
+ idr_init(&control_type->idr);
+
+ mutex_lock(&powercap_cntrl_list_lock);
+ list_add_tail(&control_type->node, &powercap_cntrl_list);
+ mutex_unlock(&powercap_cntrl_list_lock);
+
+ return control_type;
+}
+EXPORT_SYMBOL_GPL(powercap_register_control_type);
+
+int powercap_unregister_control_type(struct powercap_control_type *control_type)
+{
+ struct powercap_control_type *pos = NULL;
+
+ if (control_type->nr_zones) {
+ dev_err(&control_type->dev, "Zones of this type still not freed\n");
+ return -EINVAL;
+ }
+ mutex_lock(&powercap_cntrl_list_lock);
+ list_for_each_entry(pos, &powercap_cntrl_list, node) {
+ if (pos == control_type) {
+ list_del(&control_type->node);
+ mutex_unlock(&powercap_cntrl_list_lock);
+ device_unregister(&control_type->dev);
+ return 0;
+ }
+ }
+ mutex_unlock(&powercap_cntrl_list_lock);
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
+
+static int __init powercap_init(void)
+{
+ int result = 0;
+
+ result = seed_constraint_attributes();
+ if (result)
+ return result;
+
+ result = class_register(&powercap_class);
+
+ return result;
+}
+
+device_initcall(powercap_init);
+
+MODULE_DESCRIPTION("PowerCap sysfs Driver");
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL v2");