diff options
author | MyungJoo Ham <myungjoo.ham@samsung.com> | 2011-09-30 22:35:12 +0200 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-09-30 22:35:12 +0200 |
commit | 03ca370fbf7b76d6d002380dbdc2cdc2319f9c80 (patch) | |
tree | d6978f3139f109755e0b2966995527a44c2e4681 /drivers | |
parent | a102a9ece5489e1718cd7543aa079082450ac3a2 (diff) | |
download | linux-stable-03ca370fbf7b76d6d002380dbdc2cdc2319f9c80.tar.gz linux-stable-03ca370fbf7b76d6d002380dbdc2cdc2319f9c80.tar.bz2 linux-stable-03ca370fbf7b76d6d002380dbdc2cdc2319f9c80.zip |
PM / OPP: Add OPP availability change notifier.
The patch enables to register notifier_block for an OPP-device in order
to get notified for any changes in the availability of OPPs of the
device. For example, if a new OPP is inserted or enable/disable status
of an OPP is changed, the notifier is executed.
This enables the usage of opp_add, opp_enable, and opp_disable to
directly take effect with any connected entities such as cpufreq or
devfreq.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/base/power/opp.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index b23de185cb04..434a6c011675 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -73,6 +73,7 @@ struct opp { * RCU usage: nodes are not modified in the list of device_opp, * however addition is possible and is secured by dev_opp_list_lock * @dev: device pointer + * @head: notifier head to notify the OPP availability changes. * @opp_list: list of opps * * This is an internal data structure maintaining the link to opps attached to @@ -83,6 +84,7 @@ struct device_opp { struct list_head node; struct device *dev; + struct srcu_notifier_head head; struct list_head opp_list; }; @@ -404,6 +406,7 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) } dev_opp->dev = dev; + srcu_init_notifier_head(&dev_opp->head); INIT_LIST_HEAD(&dev_opp->opp_list); /* Secure the device list modification */ @@ -428,6 +431,11 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) list_add_rcu(&new_opp->node, head); mutex_unlock(&dev_opp_list_lock); + /* + * Notify the changes in the availability of the operable + * frequency/voltage list. + */ + srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp); return 0; } @@ -504,6 +512,14 @@ static int opp_set_availability(struct device *dev, unsigned long freq, mutex_unlock(&dev_opp_list_lock); synchronize_rcu(); + /* Notify the change of the OPP availability */ + if (availability_req) + srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE, + new_opp); + else + srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE, + new_opp); + /* clean up old opp */ new_opp = opp; goto out; @@ -643,3 +659,17 @@ void opp_free_cpufreq_table(struct device *dev, *table = NULL; } #endif /* CONFIG_CPU_FREQ */ + +/** + * opp_get_notifier() - find notifier_head of the device with opp + * @dev: device pointer used to lookup device OPPs. + */ +struct srcu_notifier_head *opp_get_notifier(struct device *dev) +{ + struct device_opp *dev_opp = find_device_opp(dev); + + if (IS_ERR(dev_opp)) + return ERR_PTR(PTR_ERR(dev_opp)); /* matching type */ + + return &dev_opp->head; +} |