summaryrefslogtreecommitdiffstats
path: root/drivers/devfreq/devfreq.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c116
1 files changed, 53 insertions, 63 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 47206a21bb90..dea04871b50d 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -111,18 +111,16 @@ static void devfreq_set_freq_table(struct devfreq *devfreq)
return;
}
- rcu_read_lock();
for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
if (IS_ERR(opp)) {
devm_kfree(devfreq->dev.parent, profile->freq_table);
profile->max_state = 0;
- rcu_read_unlock();
return;
}
+ dev_pm_opp_put(opp);
profile->freq_table[i] = freq;
}
- rcu_read_unlock();
}
/**
@@ -130,7 +128,7 @@ static void devfreq_set_freq_table(struct devfreq *devfreq)
* @devfreq: the devfreq instance
* @freq: the update target frequency
*/
-static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
+int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
{
int lev, prev_lev, ret = 0;
unsigned long cur_time;
@@ -166,6 +164,7 @@ out:
devfreq->last_stat_updated = cur_time;
return ret;
}
+EXPORT_SYMBOL(devfreq_update_status);
/**
* find_devfreq_governor() - find devfreq governor from name
@@ -474,11 +473,15 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
}
/**
- * _remove_devfreq() - Remove devfreq from the list and release its resources.
- * @devfreq: the devfreq struct
+ * devfreq_dev_release() - Callback for struct device to release the device.
+ * @dev: the devfreq device
+ *
+ * Remove devfreq from the list and release its resources.
*/
-static void _remove_devfreq(struct devfreq *devfreq)
+static void devfreq_dev_release(struct device *dev)
{
+ struct devfreq *devfreq = to_devfreq(dev);
+
mutex_lock(&devfreq_list_lock);
if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
mutex_unlock(&devfreq_list_lock);
@@ -500,19 +503,6 @@ static void _remove_devfreq(struct devfreq *devfreq)
}
/**
- * devfreq_dev_release() - Callback for struct device to release the device.
- * @dev: the devfreq device
- *
- * This calls _remove_devfreq() if _remove_devfreq() is not called.
- */
-static void devfreq_dev_release(struct device *dev)
-{
- struct devfreq *devfreq = to_devfreq(dev);
-
- _remove_devfreq(devfreq);
-}
-
-/**
* devfreq_add_device() - Add devfreq feature to the device
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
@@ -527,6 +517,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
{
struct devfreq *devfreq;
struct devfreq_governor *governor;
+ static atomic_t devfreq_no = ATOMIC_INIT(-1);
int err = 0;
if (!dev || !profile || !governor_name) {
@@ -538,15 +529,14 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq = find_device_devfreq(dev);
mutex_unlock(&devfreq_list_lock);
if (!IS_ERR(devfreq)) {
- dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
+ dev_err(dev, "%s: Unable to create devfreq for the device.\n",
+ __func__);
err = -EINVAL;
goto err_out;
}
devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
if (!devfreq) {
- dev_err(dev, "%s: Unable to create devfreq for the device\n",
- __func__);
err = -ENOMEM;
goto err_out;
}
@@ -569,18 +559,21 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_lock(&devfreq->lock);
}
- dev_set_name(&devfreq->dev, "%s", dev_name(dev));
+ dev_set_name(&devfreq->dev, "devfreq%d",
+ atomic_inc_return(&devfreq_no));
err = device_register(&devfreq->dev);
if (err) {
mutex_unlock(&devfreq->lock);
goto err_out;
}
- devfreq->trans_table = devm_kzalloc(&devfreq->dev, sizeof(unsigned int) *
+ devfreq->trans_table = devm_kzalloc(&devfreq->dev,
+ sizeof(unsigned int) *
devfreq->profile->max_state *
devfreq->profile->max_state,
GFP_KERNEL);
- devfreq->time_in_state = devm_kzalloc(&devfreq->dev, sizeof(unsigned long) *
+ devfreq->time_in_state = devm_kzalloc(&devfreq->dev,
+ sizeof(unsigned long) *
devfreq->profile->max_state,
GFP_KERNEL);
devfreq->last_stat_updated = jiffies;
@@ -939,6 +932,9 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
if (df->governor == governor) {
ret = 0;
goto out;
+ } else if (df->governor->immutable || governor->immutable) {
+ ret = -EINVAL;
+ goto out;
}
if (df->governor) {
@@ -968,13 +964,33 @@ static ssize_t available_governors_show(struct device *d,
struct device_attribute *attr,
char *buf)
{
- struct devfreq_governor *tmp_governor;
+ struct devfreq *df = to_devfreq(d);
ssize_t count = 0;
mutex_lock(&devfreq_list_lock);
- list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
- count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
- "%s ", tmp_governor->name);
+
+ /*
+ * The devfreq with immutable governor (e.g., passive) shows
+ * only own governor.
+ */
+ if (df->governor->immutable) {
+ count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
+ "%s ", df->governor_name);
+ /*
+ * The devfreq device shows the registered governor except for
+ * immutable governors such as passive governor .
+ */
+ } else {
+ struct devfreq_governor *governor;
+
+ list_for_each_entry(governor, &devfreq_governor_list, node) {
+ if (governor->immutable)
+ continue;
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%s ", governor->name);
+ }
+ }
+
mutex_unlock(&devfreq_list_lock);
/* Truncate the trailing space */
@@ -995,7 +1011,7 @@ static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
if (devfreq->profile->get_cur_freq &&
!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
- return sprintf(buf, "%lu\n", freq);
+ return sprintf(buf, "%lu\n", freq);
return sprintf(buf, "%lu\n", devfreq->previous_freq);
}
@@ -1112,17 +1128,16 @@ static ssize_t available_frequencies_show(struct device *d,
ssize_t count = 0;
unsigned long freq = 0;
- rcu_read_lock();
do {
opp = dev_pm_opp_find_freq_ceil(dev, &freq);
if (IS_ERR(opp))
break;
+ dev_pm_opp_put(opp);
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
"%lu ", freq);
freq++;
} while (1);
- rcu_read_unlock();
/* Truncate the trailing space */
if (count)
@@ -1213,7 +1228,7 @@ static int __init devfreq_init(void)
subsys_initcall(devfreq_init);
/*
- * The followings are helper functions for devfreq user device drivers with
+ * The following are helper functions for devfreq user device drivers with
* OPP framework.
*/
@@ -1224,11 +1239,8 @@ subsys_initcall(devfreq_init);
* @freq: The frequency given to target function
* @flags: Flags handed from devfreq framework.
*
- * Locking: This function must be called under rcu_read_lock(). opp is a rcu
- * protected pointer. The reason for the same is that the opp pointer which is
- * returned will remain valid for use with opp_get_{voltage, freq} only while
- * under the locked area. The pointer returned must be used prior to unlocking
- * with rcu_read_unlock() to maintain the integrity of the pointer.
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
*/
struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
unsigned long *freq,
@@ -1265,18 +1277,7 @@ EXPORT_SYMBOL(devfreq_recommended_opp);
*/
int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
{
- struct srcu_notifier_head *nh;
- int ret = 0;
-
- rcu_read_lock();
- nh = dev_pm_opp_get_notifier(dev);
- if (IS_ERR(nh))
- ret = PTR_ERR(nh);
- rcu_read_unlock();
- if (!ret)
- ret = srcu_notifier_chain_register(nh, &devfreq->nb);
-
- return ret;
+ return dev_pm_opp_register_notifier(dev, &devfreq->nb);
}
EXPORT_SYMBOL(devfreq_register_opp_notifier);
@@ -1292,18 +1293,7 @@ EXPORT_SYMBOL(devfreq_register_opp_notifier);
*/
int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
{
- struct srcu_notifier_head *nh;
- int ret = 0;
-
- rcu_read_lock();
- nh = dev_pm_opp_get_notifier(dev);
- if (IS_ERR(nh))
- ret = PTR_ERR(nh);
- rcu_read_unlock();
- if (!ret)
- ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
-
- return ret;
+ return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
}
EXPORT_SYMBOL(devfreq_unregister_opp_notifier);