1. System-wide sysfs interface
- tickle_all R: number of tickle_all execution
W: tickle all devfreq devices
- min_interval R: devfreq monitoring base interval in ms
- monitoring R: shows whether devfreq monitoring is active or
not.
2. Device specific sysfs interface
- tickle R: number of tickle execution for the device
W: tickle the device
Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
--
Changed from v2
- add ABI entries for devfreq sysfs interface
---
Documentation/ABI/testing/sysfs-devices-devfreq | 21 ++++
Documentation/ABI/testing/sysfs-power | 43 ++++++++
drivers/base/power/devfreq.c | 133 ++++++++++++++++++++++-
include/linux/devfreq.h | 3 +
4 files changed, 199 insertions(+), 1 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-devfreq
diff --git a/Documentation/ABI/testing/sysfs-devices-devfreq b/Documentation/ABI/testing/sysfs-devices-devfreq
new file mode 100644
index 0000000..7f35a64
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-devfreq
@@ -0,0 +1,21 @@
+What: /sys/devices/.../devfreq/
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/device/.../devfreq directory will contain files
+ that provide interfaces to DEVFREQ for a specific device.
+
+What: /sys/devices/.../devfreq/tickle
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/devices/.../devfreq/tickle file allows user space
+ to force the corresponding device to operate at its maximum
+ operable frequency instaneously and temporarily. After a
+ designated duration has passed, the operating frequency returns
+ to normal. When a user reads the tickle entry, it returns
+ the number of tickle executions for the device. When a user
+ writes to the tickle entry with the tickle duration in ms,
+ the effect of device tickling is held for the designated
+ duration. Note that the duration is rounded-up by
+ the value DEVFREQ_INTERVAL defined in devfreq.c
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index b464d12..4d8434b 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -172,3 +172,46 @@ Description:
Reading from this file will display the current value, which is
set to 1 MB by default.
+
+What: /sys/power/devfreq/
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/power/devfreq directory will contain files that will
+ provide a unified interface to the DEVFREQ, a generic DVFS
+ (dynamic voltage and frequency scaling) framework.
+
+What: /sys/power/devfreq/tickle_all
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/power/devfreq/tickle_all file allows user space to
+ force every device with DEVFREQ to operate at the maximum
+ frequency of the device instaneously and temporarily. After
+ a designated delay has passed, the operating frequency returns
+ to normal. If a user reads the tickle_all entry, it returns
+ the number of tickle_all executions. When writing to the
+ tickle_all entry, the user should supply with the duration of
+ tickle in ms (the "designated delay" mentioned before). Then,
+ the effect of tickle_all will hold for the denoted duration.
+ Note that the duration is rounded by the monitoring period
+ defined by DEVFREQ_INTERVAL in /drivers/base/power/devfreq.c.
+
+What: /sys/power/devfreq/min_interval
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/power/devfreq/min_interval file shows the monitoring
+ period defined by DEVFREQ_INTERVAL in
+ /drivers/base/power/devfreq.c. The duration of device tickling
+ is rounded-up by DEVFREQ_INTERVAL.
+
+What: /sys/power/devfreq/monitoring
+Date: May 2011
+Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+Description:
+ The /sys/power/devfreq/monitoring file shows whether DEVFREQ
+ is periodically monitoring. Periodic monitoring is activated
+ if there is a device that wants periodic monitoring for DVFS or
+ there is a device that is tickled (and the tickling duration is
+ not yet expired).
diff --git a/drivers/base/power/devfreq.c b/drivers/base/power/devfreq.c
index 7648a94..709c138 100644
--- a/drivers/base/power/devfreq.c
+++ b/drivers/base/power/devfreq.c
@@ -40,6 +40,9 @@ static LIST_HEAD(devfreq_list);
/* Exclusive access to devfreq_list and its elements */
static DEFINE_MUTEX(devfreq_list_lock);
+static struct kobject *devfreq_kobj;
+static struct attribute_group dev_attr_group;
+
/**
* find_device_devfreq() - find devfreq struct using device pointer
* @dev: device pointer used to lookup device DEVFREQ.
@@ -237,6 +240,8 @@ int devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile,
queue_delayed_work(devfreq_wq, &devfreq_work,
msecs_to_jiffies(DEVFREQ_INTERVAL));
}
+
+ sysfs_update_group(&dev->kobj, &dev_attr_group);
out:
mutex_unlock(&devfreq_list_lock);
@@ -263,6 +268,8 @@ int devfreq_remove_device(struct device *dev)
return -EINVAL;
}
+ sysfs_remove_group(&dev->kobj, &dev_attr_group);
+
list_del(&devfreq->node);
kfree(devfreq);
@@ -344,7 +351,7 @@ static int _devfreq_tickle_device(struct devfreq *df, unsigned long delay)
if (devfreq_wq && !polling) {
polling = true;
queue_delayed_work(devfreq_wq, &devfreq_work,
- msecs_to_jiffies(DEVFREQ_INTERVAL));
+ msecs_to_jiffies(DEVFREQ_INTERVAL));
}
return err;
@@ -382,6 +389,116 @@ int devfreq_tickle_device(struct device *dev, unsigned long duration_ms)
return err;
}
+static int num_tickle_all;
+static ssize_t tickle_all(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int duration = 0;
+ struct devfreq *tmp;
+ unsigned long delay;
+
+ sscanf(buf, "%d", &duration);
+ if (duration < DEVFREQ_INTERVAL)
+ duration = DEVFREQ_INTERVAL;
+
+ if (unlikely(IS_ERR_OR_NULL(dev))) {
+ pr_err("%s: Invalid parameters\n", __func__);
+ return -EINVAL;
+ }
+
+ delay = DIV_ROUND_UP(duration, DEVFREQ_INTERVAL);
+
+ mutex_lock(&devfreq_list_lock);
+ list_for_each_entry(tmp, &devfreq_list, node) {
+ _devfreq_tickle_device(tmp, delay);
+ }
+ mutex_unlock(&devfreq_list_lock);
+
+ num_tickle_all++;
+ return count;
+}
+
+static ssize_t show_num_tickle_all(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", num_tickle_all);
+}
+
+static ssize_t show_min_interval(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", DEVFREQ_INTERVAL);
+}
+
+static ssize_t show_monitoring(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", monitoring ? 1 : 0);
+}
+
+static DEVICE_ATTR(tickle_all, 0644, show_num_tickle_all, tickle_all);
+static DEVICE_ATTR(min_interval, 0444, show_min_interval, NULL);
+static DEVICE_ATTR(monitoring, 0444, show_monitoring, NULL);
+static struct attribute *devfreq_entries[] = {
+ &dev_attr_tickle_all.attr,
+ &dev_attr_min_interval.attr,
+ &dev_attr_monitoring.attr,
+ NULL,
+};
+static struct attribute_group devfreq_attr_group = {
+ .name = NULL,
+ .attrs = devfreq_entries,
+};
+
+static ssize_t tickle(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int duration;
+ struct devfreq *df;
+ unsigned long delay;
+
+ sscanf(buf, "%d", &duration);
+ if (duration < DEVFREQ_INTERVAL)
+ duration = DEVFREQ_INTERVAL;
+
+ if (unlikely(IS_ERR_OR_NULL(dev))) {
+ pr_err("%s: Invalid parameters\n", __func__);
+ return -EINVAL;
+ }
+
+ delay = DIV_ROUND_UP(duration, DEVFREQ_INTERVAL);
+
+ mutex_lock(&devfreq_list_lock);
+ df = find_device_devfreq(dev);
+ _devfreq_tickle_device(df, delay);
+ mutex_unlock(&devfreq_list_lock);
+
+ return count;
+}
+
+static ssize_t show_num_tickle(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct devfreq *df;
+
+ df = find_device_devfreq(dev);
+
+ if (!IS_ERR(df))
+ return sprintf(buf, "%d\n", df->num_tickle);
+
+ return PTR_ERR(df);
+}
+
+static DEVICE_ATTR(tickle, 0644, show_num_tickle, tickle);
+static struct attribute *dev_entries[] = {
+ &dev_attr_tickle.attr,
+ NULL,
+};
+static struct attribute_group dev_attr_group = {
+ .name = "devfreq",
+ .attrs = dev_entries,
+};
+
static int __init devfreq_init(void)
{
mutex_lock(&devfreq_list_lock);
@@ -389,6 +506,20 @@ static int __init devfreq_init(void)
polling = false;
devfreq_wq = create_freezable_workqueue("devfreq_wq");
INIT_DELAYED_WORK_DEFERRABLE(&devfreq_work, devfreq_monitor);
+
+#ifdef CONFIG_PM
+ /* Create sysfs */
+ devfreq_kobj = kobject_create_and_add("devfreq", power_kobj);
+ if (!devfreq_kobj) {
+ pr_err("Unable to create DEVFREQ kobject.\n");
+ goto out;
+ }
+ if (sysfs_create_group(devfreq_kobj, &devfreq_attr_group)) {
+ pr_err("Unable to create DEVFREQ sysfs entries.\n");
+ goto out;
+ }
+#endif
+out:
mutex_unlock(&devfreq_list_lock);
devfreq_monitor(&devfreq_work.work);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 1ec9a40..69334e7 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -59,6 +59,7 @@ struct devfreq_governor {
* at each executino of devfreq_monitor, tickle is decremented.
* User may tickle a device-devfreq in order to set maximum
* frequency instaneously with some guaranteed duration.
+ * @num_tickle number of tickle calls.
*
* This structure stores the DEVFREQ information for a give device.
*/
@@ -72,6 +73,8 @@ struct devfreq {
unsigned long previous_freq;
unsigned int next_polling;
unsigned int tickle;
+
+ unsigned int num_tickle;
};
#if defined(CONFIG_PM_DEVFREQ)
--
1.7.4.1
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