PM / devfreq: map devfreq drivers to governor using name
Allow devfreq drivers to register a preferred governor name
and when the devfreq governor loads itself at a later point
required drivers are managed appropriately, at the time of
unload of a devfreq governor, stop managing those drivers
as well.
Since the governor structures do not need to be exposed
anymore, remove the definitions and make them static
NOTE: devfreq_list_lock is now used to protect governor
start and stop - as this allows us to protect governors and
devfreq with the proper dependencies as needed.
As part of this change, change the registration of exynos
bus driver to request for ondemand using the governor name.
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kevin Hilman <khilman@ti.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Nishanth Menon <nm@ti.com>
[Merge conflict resolved by MyungJoo Ham]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 679ac42..0d7be03d 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -159,6 +159,9 @@
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 @@
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 @@
* 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 @@
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 @@
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 @@
if (!devfreq)
return -EINVAL;
+ if (!devfreq->governor)
+ return 0;
+
return devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_SUSPEND, NULL);
}
@@ -538,6 +551,9 @@
if (!devfreq)
return -EINVAL;
+ if (!devfreq->governor)
+ return 0;
+
return devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_RESUME, NULL);
}
@@ -550,6 +566,7 @@
int devfreq_add_governor(struct devfreq_governor *governor)
{
struct devfreq_governor *g;
+ struct devfreq *devfreq;
int err = 0;
if (!governor) {
@@ -568,6 +585,38 @@
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 @@
int devfreq_remove_governor(struct devfreq_governor *governor)
{
struct devfreq_governor *g;
+ struct devfreq *devfreq;
int err = 0;
if (!governor) {
@@ -597,6 +647,29 @@
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 @@
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 @@
unsigned int value;
int ret;
+ if (!df->governor)
+ return -EINVAL;
+
ret = sscanf(buf, "%u", &value);
if (ret != 1)
return -EINVAL;
