PM / OPP: Update kernel documentation (984f16c8) · Commits · e / devices / android_kernel_teracube_emerald

drivers/base/power/opp.c

+114 −13

Original line number	Diff line number	Diff line
		@@ -123,7 +123,7 @@ do { \
		* Search list of device OPPs for one containing matching device. Does a RCU
		* reader operation to grab the pointer needed.
		*
		* Returns pointer to 'struct device_opp' if found, otherwise -ENODEV or
		* Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or
		* -EINVAL based on type of error.
		*
		* Locking: This function must be called under rcu_read_lock(). device_opp
		@@ -153,7 +153,7 @@ static struct device_opp _find_device_opp(struct device dev)
		* dev_pm_opp_get_voltage() - Gets the voltage corresponding to an available opp
		* @opp: opp for which voltage has to be returned for
		*
		* Return voltage in micro volt corresponding to the opp, else
		* Return: voltage in micro volt corresponding to the opp, else
		* return 0
		*
		* Locking: This function must be called under rcu_read_lock(). opp is a rcu
		@@ -183,7 +183,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
		* dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
		* @opp: opp for which frequency has to be returned for
		*
		* Return frequency in hertz corresponding to the opp, else
		* Return: frequency in hertz corresponding to the opp, else
		* return 0
		*
		* Locking: This function must be called under rcu_read_lock(). opp is a rcu
		@@ -213,7 +213,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
		* dev_pm_opp_get_opp_count() - Get number of opps available in the opp list
		* @dev: device for which we do this operation
		*
		* This function returns the number of available opps if there are any,
		* Return: This function returns the number of available opps if there are any,
		* else returns 0 if none or the corresponding error value.
		*
		* Locking: This function takes rcu_read_lock().
		@@ -251,9 +251,9 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
		* @freq: frequency to search for
		* @available: true/false - match for available opp
		*
		* Searches for exact match in the opp list and returns pointer to the matching
		* opp if found, else returns ERR_PTR in case of error and should be handled
		* using IS_ERR. Error return values can be:
		* Return: Searches for exact match in the opp list and returns pointer to the
		* matching opp if found, else returns ERR_PTR in case of error and should
		* be handled using IS_ERR. Error return values can be:
		* EINVAL: for bad pointer
		* ERANGE: no match found for search
		* ENODEV: if device not found in list of registered devices
		@@ -307,7 +307,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
		* Search for the matching ceil available OPP from a starting freq
		* for a device.
		*
		* Returns matching opp and refreshes freq accordingly, else returns
		* Return: matching opp and refreshes freq accordingly, else returns
		* ERR_PTR in case of error and should be handled using IS_ERR. Error return
		* values can be:
		* EINVAL: for bad pointer
		@@ -357,7 +357,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
		* Search for the matching floor available OPP from a starting freq
		* for a device.
		*
		* Returns matching opp and refreshes freq accordingly, else returns
		* Return: matching opp and refreshes freq accordingly, else returns
		* ERR_PTR in case of error and should be handled using IS_ERR. Error return
		* values can be:
		* EINVAL: for bad pointer
		@@ -403,6 +403,15 @@ struct dev_pm_opp dev_pm_opp_find_freq_floor(struct device dev,
		}
		EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);

		/**
		* _add_device_opp() - Allocate a new device OPP table
		* @dev: device for which we do this operation
		*
		* New device node which uses OPPs - used when multiple devices with OPP tables
		* are maintained.
		*
		* Return: valid device_opp pointer if success, else NULL.
		*/
		static struct device_opp _add_device_opp(struct device dev)
		{
		struct device_opp *dev_opp;
		@@ -424,6 +433,33 @@ static struct device_opp _add_device_opp(struct device dev)
		return dev_opp;
		}

		/**
		* _opp_add_dynamic() - Allocate a dynamic OPP.
		* @dev: device for which we do this operation
		* @freq: Frequency in Hz for this OPP
		* @u_volt: Voltage in uVolts for this OPP
		* @dynamic: Dynamically added OPPs.
		*
		* This function adds an opp definition to the opp list and returns status.
		* The opp is made available by default and it can be controlled using
		* dev_pm_opp_enable/disable functions and may be removed by dev_pm_opp_remove.
		*
		* NOTE: "dynamic" parameter impacts OPPs added by the of_init_opp_table and
		* freed by of_free_opp_table.
		*
		* Locking: The internal device_opp and opp structures are RCU protected.
		* Hence this function internally uses RCU updater strategy with mutex locks
		* to keep the integrity of the internal data structures. Callers should ensure
		* that this function is NOT called under RCU protection or in contexts where
		* mutex cannot be locked.
		*
		* Return:
		* 0 On success OR
		* Duplicate OPPs (both freq and volt are same) and opp->available
		* -EEXIST Freq are same and volt are different OR
		* Duplicate OPPs (both freq and volt are same) and !opp->available
		* -ENOMEM Memory allocation failure
		*/
		static int _opp_add_dynamic(struct device *dev, unsigned long freq,
		long u_volt, bool dynamic)
		{
		@@ -519,11 +555,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
		* mutex cannot be locked.
		*
		* Return:
		* 0: On success OR
		* 0 On success OR
		* Duplicate OPPs (both freq and volt are same) and opp->available
		* -EEXIST: Freq are same and volt are different OR
		* -EEXIST Freq are same and volt are different OR
		* Duplicate OPPs (both freq and volt are same) and !opp->available
		* -ENOMEM: Memory allocation failure
		* -ENOMEM Memory allocation failure
		*/
		int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
		{
		@@ -531,6 +567,10 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
		}
		EXPORT_SYMBOL_GPL(dev_pm_opp_add);

		/**
		* _kfree_opp_rcu() - Free OPP RCU handler
		* @head: RCU head
		*/
		static void _kfree_opp_rcu(struct rcu_head *head)
		{
		struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
		@@ -538,6 +578,10 @@ static void _kfree_opp_rcu(struct rcu_head *head)
		kfree_rcu(opp, rcu_head);
		}

		/**
		* _kfree_device_rcu() - Free device_opp RCU handler
		* @head: RCU head
		*/
		static void _kfree_device_rcu(struct rcu_head *head)
		{
		struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
		@@ -545,6 +589,17 @@ static void _kfree_device_rcu(struct rcu_head *head)
		kfree_rcu(device_opp, rcu_head);
		}

		/**
		* _opp_remove() - Remove an OPP from a table definition
		* @dev_opp: points back to the device_opp struct this opp belongs to
		* @opp: pointer to the OPP to remove
		*
		* This function removes an opp definition from the opp list.
		*
		* Locking: The internal device_opp and opp structures are RCU protected.
		* It is assumed that the caller holds required mutex for an RCU updater
		* strategy.
		*/
		static void _opp_remove(struct device_opp *dev_opp,
		struct dev_pm_opp *opp)
		{
		@@ -569,6 +624,12 @@ static void _opp_remove(struct device_opp *dev_opp,
		* @freq: OPP to remove with matching 'freq'
		*
		* This function removes an opp from the opp list.
		*
		* Locking: The internal device_opp and opp structures are RCU protected.
		* Hence this function internally uses RCU updater strategy with mutex locks
		* to keep the integrity of the internal data structures. Callers should ensure
		* that this function is NOT called under RCU protection or in contexts where
		* mutex cannot be locked.
		*/
		void dev_pm_opp_remove(struct device *dev, unsigned long freq)
		{
		@@ -611,7 +672,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
		* Set the availability of an OPP with an RCU operation, opp_{enable,disable}
		* share a common logic which is isolated here.
		*
		* Returns -EINVAL for bad pointers, -ENOMEM if no memory available for the
		* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
		* copy operation, returns 0 if no modifcation was done OR modification was
		* successful.
		*
		@@ -700,6 +761,10 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
		* integrity of the internal data structures. Callers should ensure that
		* this function is NOT called under RCU protection or in contexts where
		* mutex locking or synchronize_rcu() blocking calls cannot be used.
		*
		* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
		* copy operation, returns 0 if no modifcation was done OR modification was
		* successful.
		*/
		int dev_pm_opp_enable(struct device *dev, unsigned long freq)
		{
		@@ -722,6 +787,10 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_enable);
		* integrity of the internal data structures. Callers should ensure that
		* this function is NOT called under RCU protection or in contexts where
		* mutex locking or synchronize_rcu() blocking calls cannot be used.
		*
		* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
		* copy operation, returns 0 if no modifcation was done OR modification was
		* successful.
		*/
		int dev_pm_opp_disable(struct device *dev, unsigned long freq)
		{
		@@ -732,6 +801,16 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_disable);
		/**
		* dev_pm_opp_get_notifier() - find notifier_head of the device with opp
		* @dev: device pointer used to lookup device OPPs.
		*
		* Return: pointer to notifier head if found, otherwise -ENODEV or
		* -EINVAL based on type of error casted as pointer. value must be checked
		* with IS_ERR to determine valid pointer or error result.
		*
		* Locking: This function must be called under rcu_read_lock(). dev_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.
		*/
		struct srcu_notifier_head dev_pm_opp_get_notifier(struct device dev)
		{
		@@ -750,6 +829,22 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);
		* @dev: device pointer used to lookup device OPPs.
		*
		* Register the initial OPP table with the OPP library for given device.
		*
		* Locking: The internal device_opp and opp structures are RCU protected.
		* Hence this function indirectly uses RCU updater strategy with mutex locks
		* to keep the integrity of the internal data structures. Callers should ensure
		* that this function is NOT called under RCU protection or in contexts where
		* mutex cannot be locked.
		*
		* Return:
		* 0 On success OR
		* Duplicate OPPs (both freq and volt are same) and opp->available
		* -EEXIST Freq are same and volt are different OR
		* Duplicate OPPs (both freq and volt are same) and !opp->available
		* -ENOMEM Memory allocation failure
		* -ENODEV when 'operating-points' property is not found or is invalid data
		* in device node.
		* -ENODATA when empty 'operating-points' property is found
		*/
		int of_init_opp_table(struct device *dev)
		{
		@@ -793,6 +888,12 @@ EXPORT_SYMBOL_GPL(of_init_opp_table);
		* @dev: device pointer used to lookup device OPPs.
		*
		* Free OPPs created using static entries present in DT.
		*
		* Locking: The internal device_opp and opp structures are RCU protected.
		* Hence this function indirectly uses RCU updater strategy with mutex locks
		* to keep the integrity of the internal data structures. Callers should ensure
		* that this function is NOT called under RCU protection or in contexts where
		* mutex cannot be locked.
		*/
		void of_free_opp_table(struct device *dev)
		{