diff options
Diffstat (limited to 'drivers/base/power/qos.c')
| -rw-r--r-- | drivers/base/power/qos.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index c5d35883746..71855570922 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -41,6 +41,7 @@ #include <linux/mutex.h> #include <linux/export.h> +#include "power.h" static DEFINE_MUTEX(dev_pm_qos_mtx); @@ -166,6 +167,12 @@ void dev_pm_qos_constraints_destroy(struct device *dev) struct dev_pm_qos_request *req, *tmp; struct pm_qos_constraints *c; + /* + * If the device's PM QoS resume latency limit has been exposed to user + * space, it has to be hidden at this point. + */ + dev_pm_qos_hide_latency_limit(dev); + mutex_lock(&dev_pm_qos_mtx); dev->power.power_state = PMSG_INVALID; @@ -445,3 +452,57 @@ int dev_pm_qos_add_ancestor_request(struct device *dev, return error; } EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request); + +#ifdef CONFIG_PM_RUNTIME +static void __dev_pm_qos_drop_user_request(struct device *dev) +{ + dev_pm_qos_remove_request(dev->power.pq_req); + dev->power.pq_req = 0; +} + +/** + * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. + * @dev: Device whose PM QoS latency limit is to be exposed to user space. + * @value: Initial value of the latency limit. + */ +int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) +{ + struct dev_pm_qos_request *req; + int ret; + + if (!device_is_registered(dev) || value < 0) + return -EINVAL; + + if (dev->power.pq_req) + return -EEXIST; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + ret = dev_pm_qos_add_request(dev, req, value); + if (ret < 0) + return ret; + + dev->power.pq_req = req; + ret = pm_qos_sysfs_add(dev); + if (ret) + __dev_pm_qos_drop_user_request(dev); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); + +/** + * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space. + * @dev: Device whose PM QoS latency limit is to be hidden from user space. + */ +void dev_pm_qos_hide_latency_limit(struct device *dev) +{ + if (dev->power.pq_req) { + pm_qos_sysfs_remove(dev); + __dev_pm_qos_drop_user_request(dev); + } +} +EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); +#endif /* CONFIG_PM_RUNTIME */ |