diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 679ac424472f..0d7be03d561f 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -159,6 +159,9 @@ int update_devfreq(struct devfreq *devfreq)
return -EINVAL;
}
+ if (!devfreq->governor)
+ return -EINVAL;
+
/* Reevaluate the proper frequency */
err = devfreq->governor->get_target_freq(devfreq, &freq);
if (err)
@@ -379,7 +382,9 @@ static void _remove_devfreq(struct devfreq *devfreq, bool skip)
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
- devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_STOP, NULL);
+ if (devfreq->governor)
+ devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
@@ -412,19 +417,20 @@ static void devfreq_dev_release(struct device *dev)
* devfreq_add_device() - Add devfreq feature to the device
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
- * @governor: the policy to choose frequency.
+ * @governor_name: name of the policy to choose frequency.
* @data: private data for the governor. The devfreq framework does not
* touch this value.
*/
struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
- const struct devfreq_governor *governor,
+ const char *governor_name,
void *data)
{
struct devfreq *devfreq;
+ struct devfreq_governor *governor;
int err = 0;
- if (!dev || !profile || !governor) {
+ if (!dev || !profile || !governor_name) {
dev_err(dev, "%s: Invalid parameters.\n", __func__);
return ERR_PTR(-EINVAL);
}
@@ -452,7 +458,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq->dev.class = devfreq_class;
devfreq->dev.release = devfreq_dev_release;
devfreq->profile = profile;
- devfreq->governor = governor;
+ strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
devfreq->previous_freq = profile->initial_freq;
devfreq->data = data;
devfreq->nb.notifier_call = devfreq_notifier_call;
@@ -478,10 +484,14 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_lock(&devfreq_list_lock);
list_add(&devfreq->node, &devfreq_list);
- mutex_unlock(&devfreq_list_lock);
- err = devfreq->governor->event_handler(devfreq,
- DEVFREQ_GOV_START, NULL);
+ governor = find_devfreq_governor(devfreq->governor_name);
+ if (!IS_ERR(governor))
+ devfreq->governor = governor;
+ if (devfreq->governor)
+ err = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_START, NULL);
+ mutex_unlock(&devfreq_list_lock);
if (err) {
dev_err(dev, "%s: Unable to start governor for the device\n",
__func__);
@@ -524,6 +534,9 @@ int devfreq_suspend_device(struct devfreq *devfreq)
if (!devfreq)
return -EINVAL;
+ if (!devfreq->governor)
+ return 0;
+
return devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_SUSPEND, NULL);
}
@@ -538,6 +551,9 @@ int devfreq_resume_device(struct devfreq *devfreq)
if (!devfreq)
return -EINVAL;
+ if (!devfreq->governor)
+ return 0;
+
return devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_RESUME, NULL);
}
@@ -550,6 +566,7 @@ EXPORT_SYMBOL(devfreq_resume_device);
int devfreq_add_governor(struct devfreq_governor *governor)
{
struct devfreq_governor *g;
+ struct devfreq *devfreq;
int err = 0;
if (!governor) {
@@ -568,6 +585,38 @@ int devfreq_add_governor(struct devfreq_governor *governor)
list_add(&governor->node, &devfreq_governor_list);
+ list_for_each_entry(devfreq, &devfreq_list, node) {
+ int ret = 0;
+ struct device *dev = devfreq->dev.parent;
+
+ if (!strncmp(devfreq->governor_name, governor->name,
+ DEVFREQ_NAME_LEN)) {
+ /* The following should never occur */
+ if (devfreq->governor) {
+ dev_warn(dev,
+ "%s: Governor %s already present\n",
+ __func__, devfreq->governor->name);
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
+ if (ret) {
+ dev_warn(dev,
+ "%s: Governor %s stop = %d\n",
+ __func__,
+ devfreq->governor->name, ret);
+ }
+ /* Fall through */
+ }
+ devfreq->governor = governor;
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_START, NULL);
+ if (ret) {
+ dev_warn(dev, "%s: Governor %s start=%d\n",
+ __func__, devfreq->governor->name,
+ ret);
+ }
+ }
+ }
+
err_out:
mutex_unlock(&devfreq_list_lock);
@@ -582,6 +631,7 @@ EXPORT_SYMBOL(devfreq_add_governor);
int devfreq_remove_governor(struct devfreq_governor *governor)
{
struct devfreq_governor *g;
+ struct devfreq *devfreq;
int err = 0;
if (!governor) {
@@ -597,6 +647,29 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
err = -EINVAL;
goto err_out;
}
+ list_for_each_entry(devfreq, &devfreq_list, node) {
+ int ret;
+ struct device *dev = devfreq->dev.parent;
+
+ if (!strncmp(devfreq->governor_name, governor->name,
+ DEVFREQ_NAME_LEN)) {
+ /* we should have a devfreq governor! */
+ if (!devfreq->governor) {
+ dev_warn(dev, "%s: Governor %s NOT present\n",
+ __func__, governor->name);
+ continue;
+ /* Fall through */
+ }
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
+ if (ret) {
+ dev_warn(dev, "%s: Governor %s stop=%d\n",
+ __func__, devfreq->governor->name,
+ ret);
+ }
+ devfreq->governor = NULL;
+ }
+ }
list_del(&governor->node);
err_out:
@@ -609,6 +682,9 @@ EXPORT_SYMBOL(devfreq_remove_governor);
static ssize_t show_governor(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ if (!to_devfreq(dev)->governor)
+ return -EINVAL;
+
return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
}
@@ -645,6 +721,9 @@ static ssize_t store_polling_interval(struct device *dev,
unsigned int value;
int ret;
+ if (!df->governor)
+ return -EINVAL;
+
ret = sscanf(buf, "%u", &value);
if (ret != 1)
return -EINVAL;
diff --git a/drivers/devfreq/exynos4_bus.c b/drivers/devfreq/exynos4_bus.c
index 68145316c49c..b8ac28497b37 100644
--- a/drivers/devfreq/exynos4_bus.c
+++ b/drivers/devfreq/exynos4_bus.c
@@ -1040,7 +1040,7 @@ static __devinit int exynos4_busfreq_probe(struct platform_device *pdev)
busfreq_mon_reset(data);
data->devfreq = devfreq_add_device(dev, &exynos4_devfreq_profile,
- &devfreq_simple_ondemand, NULL);
+ "simple_ondemand", NULL);
if (IS_ERR(data->devfreq))
return PTR_ERR(data->devfreq);
diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
index db8ff77dbed2..865a36956917 100644
--- a/drivers/devfreq/governor_performance.c
+++ b/drivers/devfreq/governor_performance.c
@@ -40,7 +40,7 @@ static int devfreq_performance_handler(struct devfreq *devfreq,
return ret;
}
-const struct devfreq_governor devfreq_performance = {
+static struct devfreq_governor devfreq_performance = {
.name = "performance",
.get_target_freq = devfreq_performance_func,
.event_handler = devfreq_performance_handler,
diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
index 30f0fca8d635..8612c0f96b79 100644
--- a/drivers/devfreq/governor_powersave.c
+++ b/drivers/devfreq/governor_powersave.c
@@ -37,7 +37,7 @@ static int devfreq_powersave_handler(struct devfreq *devfreq,
return ret;
}
-const struct devfreq_governor devfreq_powersave = {
+static struct devfreq_governor devfreq_powersave = {
.name = "powersave",
.get_target_freq = devfreq_powersave_func,
.event_handler = devfreq_powersave_handler,
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index 85f9ed531b1e..a870a24bb56b 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -120,7 +120,7 @@ static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
return 0;
}
-const struct devfreq_governor devfreq_simple_ondemand = {
+static struct devfreq_governor devfreq_simple_ondemand = {
.name = "simple_ondemand",
.get_target_freq = devfreq_simple_ondemand_func,
.event_handler = devfreq_simple_ondemand_handler,
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
index 110f178fec04..34fb80f50cf6 100644
--- a/drivers/devfreq/governor_userspace.c
+++ b/drivers/devfreq/governor_userspace.c
@@ -135,7 +135,7 @@ static int devfreq_userspace_handler(struct devfreq *devfreq,
return ret;
}
-const struct devfreq_governor devfreq_userspace = {
+static struct devfreq_governor devfreq_userspace = {
.name = "userspace",
.get_target_freq = devfreq_userspace_func,
.event_handler = devfreq_userspace_handler,
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 6484a3f8dda8..235248cb2c93 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -125,6 +125,7 @@ struct devfreq_governor {
* using devfreq.
* @profile: device-specific devfreq profile
* @governor: method how to choose frequency based on the usage.
+ * @governor_name: devfreq governor name for use with this devfreq
* @nb: notifier block used to notify devfreq object that it should
* reevaluate operable frequencies. Devfreq users may use
* devfreq.nb to the corresponding register notifier call chain.
@@ -155,6 +156,7 @@ struct devfreq {
struct device dev;
struct devfreq_dev_profile *profile;
const struct devfreq_governor *governor;
+ char governor_name[DEVFREQ_NAME_LEN];
struct notifier_block nb;
struct delayed_work work;
@@ -176,7 +178,7 @@ struct devfreq {
#if defined(CONFIG_PM_DEVFREQ)
extern struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
- const struct devfreq_governor *governor,
+ const char *governor_name,
void *data);
extern int devfreq_remove_device(struct devfreq *devfreq);
extern int devfreq_suspend_device(struct devfreq *devfreq);
@@ -190,17 +192,7 @@ extern int devfreq_register_opp_notifier(struct device *dev,
extern int devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq);
-#ifdef CONFIG_DEVFREQ_GOV_POWERSAVE
-extern const struct devfreq_governor devfreq_powersave;
-#endif
-#ifdef CONFIG_DEVFREQ_GOV_PERFORMANCE
-extern const struct devfreq_governor devfreq_performance;
-#endif
-#ifdef CONFIG_DEVFREQ_GOV_USERSPACE
-extern const struct devfreq_governor devfreq_userspace;
-#endif
#ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND
-extern const struct devfreq_governor devfreq_simple_ondemand;
/**
* struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
* and devfreq_add_device
@@ -223,7 +215,7 @@ struct devfreq_simple_ondemand_data {
#else /* !CONFIG_PM_DEVFREQ */
static struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
- struct devfreq_governor *governor,
+ const char *governor_name,
void *data)
{
return NULL;
@@ -262,11 +254,6 @@ static int devfreq_unregister_opp_notifier(struct device *dev,
return -EINVAL;
}
-#define devfreq_powersave NULL
-#define devfreq_performance NULL
-#define devfreq_userspace NULL
-#define devfreq_simple_ondemand NULL
-
#endif /* CONFIG_PM_DEVFREQ */
#endif /* __LINUX_DEVFREQ_H__ */