diff options
Diffstat (limited to 'drivers/base/power/opp.c')
| -rw-r--r-- | drivers/base/power/opp.c | 927 |
1 files changed, 0 insertions, 927 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c deleted file mode 100644 index 677fb2843553..000000000000 --- a/drivers/base/power/opp.c +++ /dev/null @@ -1,927 +0,0 @@ -/* - * Generic OPP Interface - * - * Copyright (C) 2009-2010 Texas Instruments Incorporated. - * Nishanth Menon - * Romit Dasgupta - * Kevin Hilman - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/kernel.h> -#include <linux/errno.h> -#include <linux/err.h> -#include <linux/slab.h> -#include <linux/device.h> -#include <linux/list.h> -#include <linux/rculist.h> -#include <linux/rcupdate.h> -#include <linux/pm_opp.h> -#include <linux/of.h> -#include <linux/export.h> - -/* - * Internal data structure organization with the OPP layer library is as - * follows: - * dev_opp_list (root) - * |- device 1 (represents voltage domain 1) - * | |- opp 1 (availability, freq, voltage) - * | |- opp 2 .. - * ... ... - * | `- opp n .. - * |- device 2 (represents the next voltage domain) - * ... - * `- device m (represents mth voltage domain) - * device 1, 2.. are represented by dev_opp structure while each opp - * is represented by the opp structure. - */ - -/** - * struct dev_pm_opp - Generic OPP description structure - * @node: opp list node. The nodes are maintained throughout the lifetime - * of boot. It is expected only an optimal set of OPPs are - * added to the library by the SoC framework. - * RCU usage: opp list is traversed with RCU locks. node - * modification is possible realtime, hence the modifications - * are protected by the dev_opp_list_lock for integrity. - * IMPORTANT: the opp nodes should be maintained in increasing - * order. - * @dynamic: not-created from static DT entries. - * @available: true/false - marks if this OPP as available or not - * @rate: Frequency in hertz - * @u_volt: Nominal voltage in microvolts corresponding to this OPP - * @dev_opp: points back to the device_opp struct this opp belongs to - * @rcu_head: RCU callback head used for deferred freeing - * - * This structure stores the OPP information for a given device. - */ -struct dev_pm_opp { - struct list_head node; - - bool available; - bool dynamic; - unsigned long rate; - unsigned long u_volt; - - struct device_opp *dev_opp; - struct rcu_head rcu_head; -}; - -/** - * struct device_opp - Device opp structure - * @node: list node - contains the devices with OPPs that - * have been registered. Nodes once added are not modified in this - * list. - * 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 - * @srcu_head: notifier head to notify the OPP availability changes. - * @rcu_head: RCU callback head used for deferred freeing - * @opp_list: list of opps - * - * This is an internal data structure maintaining the link to opps attached to - * a device. This structure is not meant to be shared to users as it is - * meant for book keeping and private to OPP library. - * - * Because the opp structures can be used from both rcu and srcu readers, we - * need to wait for the grace period of both of them before freeing any - * resources. And so we have used kfree_rcu() from within call_srcu() handlers. - */ -struct device_opp { - struct list_head node; - - struct device *dev; - struct srcu_notifier_head srcu_head; - struct rcu_head rcu_head; - struct list_head opp_list; -}; - -/* - * The root of the list of all devices. All device_opp structures branch off - * from here, with each device_opp containing the list of opp it supports in - * various states of availability. - */ -static LIST_HEAD(dev_opp_list); -/* Lock to allow exclusive modification to the device and opp lists */ -static DEFINE_MUTEX(dev_opp_list_lock); - -#define opp_rcu_lockdep_assert() \ -do { \ - rcu_lockdep_assert(rcu_read_lock_held() || \ - lockdep_is_held(&dev_opp_list_lock), \ - "Missing rcu_read_lock() or " \ - "dev_opp_list_lock protection"); \ -} while (0) - -/** - * _find_device_opp() - find device_opp struct using device pointer - * @dev: device pointer used to lookup device OPPs - * - * Search list of device OPPs for one containing matching device. Does a RCU - * reader operation to grab the pointer needed. - * - * 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 - * is a RCU protected pointer. This means that device_opp is valid as long - * as we are under RCU lock. - */ -static struct device_opp *_find_device_opp(struct device *dev) -{ - struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV); - - if (unlikely(IS_ERR_OR_NULL(dev))) { - pr_err("%s: Invalid parameters\n", __func__); - return ERR_PTR(-EINVAL); - } - - list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) { - if (tmp_dev_opp->dev == dev) { - dev_opp = tmp_dev_opp; - break; - } - } - - return dev_opp; -} - -/** - * 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 0 - * - * Locking: This function must be called under rcu_read_lock(). opp is a rcu - * protected pointer. This means that opp which could have been fetched by - * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are - * under RCU lock. The pointer returned by the opp_find_freq family must be - * used in the same section as the usage of this function with the pointer - * prior to unlocking with rcu_read_unlock() to maintain the integrity of the - * pointer. - */ -unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) -{ - struct dev_pm_opp *tmp_opp; - unsigned long v = 0; - - opp_rcu_lockdep_assert(); - - tmp_opp = rcu_dereference(opp); - if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) - pr_err("%s: Invalid parameters\n", __func__); - else - v = tmp_opp->u_volt; - - return v; -} -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 0 - * - * Locking: This function must be called under rcu_read_lock(). opp is a rcu - * protected pointer. This means that opp which could have been fetched by - * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are - * under RCU lock. The pointer returned by the opp_find_freq family must be - * used in the same section as the usage of this function with the pointer - * prior to unlocking with rcu_read_unlock() to maintain the integrity of the - * pointer. - */ -unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) -{ - struct dev_pm_opp *tmp_opp; - unsigned long f = 0; - - opp_rcu_lockdep_assert(); - - tmp_opp = rcu_dereference(opp); - if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) - pr_err("%s: Invalid parameters\n", __func__); - else - f = tmp_opp->rate; - - return f; -} -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 - * - * 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(). - */ -int dev_pm_opp_get_opp_count(struct device *dev) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *temp_opp; - int count = 0; - - rcu_read_lock(); - - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - count = PTR_ERR(dev_opp); - dev_err(dev, "%s: device OPP not found (%d)\n", - __func__, count); - goto out_unlock; - } - - list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { - if (temp_opp->available) - count++; - } - -out_unlock: - rcu_read_unlock(); - return count; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count); - -/** - * dev_pm_opp_find_freq_exact() - search for an exact frequency - * @dev: device for which we do this operation - * @freq: frequency to search for - * @available: true/false - match for available opp - * - * 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 - * - * Note: available is a modifier for the search. if available=true, then the - * match is for exact matching frequency and is available in the stored OPP - * table. if false, the match is for exact frequency which is not available. - * - * This provides a mechanism to enable an opp which is not available currently - * or the opposite as well. - * - * Locking: This function must be called under rcu_read_lock(). 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 dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, - unsigned long freq, - bool available) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - - opp_rcu_lockdep_assert(); - - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - int r = PTR_ERR(dev_opp); - dev_err(dev, "%s: device OPP not found (%d)\n", __func__, r); - return ERR_PTR(r); - } - - list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { - if (temp_opp->available == available && - temp_opp->rate == freq) { - opp = temp_opp; - break; - } - } - - return opp; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); - -/** - * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq - * @dev: device for which we do this operation - * @freq: Start frequency - * - * Search for the matching ceil *available* OPP from a starting freq - * for a device. - * - * 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 - * ERANGE: no match found for search - * ENODEV: if device not found in list of registered devices - * - * Locking: This function must be called under rcu_read_lock(). 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 dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, - unsigned long *freq) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - - opp_rcu_lockdep_assert(); - - if (!dev || !freq) { - dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); - return ERR_PTR(-EINVAL); - } - - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) - return ERR_CAST(dev_opp); - - list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { - if (temp_opp->available && temp_opp->rate >= *freq) { - opp = temp_opp; - *freq = opp->rate; - break; - } - } - - return opp; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil); - -/** - * dev_pm_opp_find_freq_floor() - Search for a rounded floor freq - * @dev: device for which we do this operation - * @freq: Start frequency - * - * Search for the matching floor *available* OPP from a starting freq - * for a device. - * - * 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 - * ERANGE: no match found for search - * ENODEV: if device not found in list of registered devices - * - * Locking: This function must be called under rcu_read_lock(). 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 dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, - unsigned long *freq) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - - opp_rcu_lockdep_assert(); - - if (!dev || !freq) { - dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); - return ERR_PTR(-EINVAL); - } - - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) - return ERR_CAST(dev_opp); - - list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { - if (temp_opp->available) { - /* go to the next node, before choosing prev */ - if (temp_opp->rate > *freq) - break; - else - opp = temp_opp; - } - } - if (!IS_ERR(opp)) - *freq = opp->rate; - - return opp; -} -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; - - /* - * Allocate a new device OPP table. In the infrequent case where a new - * device is needed to be added, we pay this penalty. - */ - dev_opp = kzalloc(sizeof(*dev_opp), GFP_KERNEL); - if (!dev_opp) - return NULL; - - dev_opp->dev = dev; - srcu_init_notifier_head(&dev_opp->srcu_head); - INIT_LIST_HEAD(&dev_opp->opp_list); - - /* Secure the device list modification */ - list_add_rcu(&dev_opp->node, &dev_opp_list); - 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) -{ - struct device_opp *dev_opp = NULL; - struct dev_pm_opp *opp, *new_opp; - struct list_head *head; - int ret; - - /* allocate new OPP node */ - new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL); - if (!new_opp) - return -ENOMEM; - - /* Hold our list modification lock here */ - mutex_lock(&dev_opp_list_lock); - - /* populate the opp table */ - new_opp->rate = freq; - new_opp->u_volt = u_volt; - new_opp->available = true; - new_opp->dynamic = dynamic; - - /* Check for existing list for 'dev' */ - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - dev_opp = _add_device_opp(dev); - if (!dev_opp) { - ret = -ENOMEM; - goto free_opp; - } - - head = &dev_opp->opp_list; - goto list_add; - } - - /* - * Insert new OPP in order of increasing frequency - * and discard if already present - */ - head = &dev_opp->opp_list; - list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { - if (new_opp->rate <= opp->rate) - break; - else - head = &opp->node; - } - - /* Duplicate OPPs ? */ - if (new_opp->rate == opp->rate) { - ret = opp->available && new_opp->u_volt == opp->u_volt ? - 0 : -EEXIST; - - dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", - __func__, opp->rate, opp->u_volt, opp->available, - new_opp->rate, new_opp->u_volt, new_opp->available); - goto free_opp; - } - -list_add: - new_opp->dev_opp = dev_opp; - 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->srcu_head, OPP_EVENT_ADD, new_opp); - return 0; - -free_opp: - mutex_unlock(&dev_opp_list_lock); - kfree(new_opp); - return ret; -} - -/** - * dev_pm_opp_add() - Add an OPP table from a table definitions - * @dev: device for which we do this operation - * @freq: Frequency in Hz for this OPP - * @u_volt: Voltage in uVolts for this OPP - * - * 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. - * - * 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 - */ -int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) -{ - return _opp_add_dynamic(dev, freq, u_volt, true); -} -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); - - 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); - - 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) -{ - /* - * Notify the changes in the availability of the operable - * frequency/voltage list. - */ - srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp); - list_del_rcu(&opp->node); - call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu); - - if (list_empty(&dev_opp->opp_list)) { - list_del_rcu(&dev_opp->node); - call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head, - _kfree_device_rcu); - } -} - -/** - * dev_pm_opp_remove() - Remove an OPP from OPP list - * @dev: device for which we do this operation - * @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) -{ - struct dev_pm_opp *opp; - struct device_opp *dev_opp; - bool found = false; - - /* Hold our list modification lock here */ - mutex_lock(&dev_opp_list_lock); - - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) - goto unlock; - - list_for_each_entry(opp, &dev_opp->opp_list, node) { - if (opp->rate == freq) { - found = true; - break; - } - } - - if (!found) { - dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n", - __func__, freq); - goto unlock; - } - - _opp_remove(dev_opp, opp); -unlock: - mutex_unlock(&dev_opp_list_lock); -} -EXPORT_SYMBOL_GPL(dev_pm_opp_remove); - -/** - * _opp_set_availability() - helper to set the availability of an opp - * @dev: device for which we do this operation - * @freq: OPP frequency to modify availability - * @availability_req: availability status requested for this opp - * - * Set the availability of an OPP with an RCU operation, opp_{enable,disable} - * share a common logic which is isolated here. - * - * 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. - * - * 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 locking or synchronize_rcu() blocking calls cannot be used. - */ -static int _opp_set_availability(struct device *dev, unsigned long freq, - bool availability_req) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); - int r = 0; - - /* keep the node allocated */ - new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL); - if (!new_opp) - return -ENOMEM; - - mutex_lock(&dev_opp_list_lock); - - /* Find the device_opp */ - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - r = PTR_ERR(dev_opp); - dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r); - goto unlock; - } - - /* Do we have the frequency? */ - list_for_each_entry(tmp_opp, &dev_opp->opp_list, node) { - if (tmp_opp->rate == freq) { - opp = tmp_opp; - break; - } - } - if (IS_ERR(opp)) { - r = PTR_ERR(opp); - goto unlock; - } - - /* Is update really needed? */ - if (opp->available == availability_req) - goto unlock; - /* copy the old data over */ - *new_opp = *opp; - - /* plug in new node */ - new_opp->available = availability_req; - - list_replace_rcu(&opp->node, &new_opp->node); - mutex_unlock(&dev_opp_list_lock); - call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu); - - /* Notify the change of the OPP availability */ - if (availability_req) - srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ENABLE, - new_opp); - else - srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_DISABLE, - new_opp); - - return 0; - -unlock: - mutex_unlock(&dev_opp_list_lock); - kfree(new_opp); - return r; -} - -/** - * dev_pm_opp_enable() - Enable a specific OPP - * @dev: device for which we do this operation - * @freq: OPP frequency to enable - * - * Enables a provided opp. If the operation is valid, this returns 0, else the - * corresponding error value. It is meant to be used for users an OPP available - * after being temporarily made unavailable with dev_pm_opp_disable. - * - * Locking: The internal device_opp and opp structures are RCU protected. - * Hence this function indirectly uses RCU and 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 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) -{ - return _opp_set_availability(dev, freq, true); -} -EXPORT_SYMBOL_GPL(dev_pm_opp_enable); - -/** - * dev_pm_opp_disable() - Disable a specific OPP - * @dev: device for which we do this operation - * @freq: OPP frequency to disable - * - * Disables a provided opp. If the operation is valid, this returns - * 0, else the corresponding error value. It is meant to be a temporary - * control by users to make this OPP not available until the circumstances are - * right to make it available again (with a call to dev_pm_opp_enable). - * - * Locking: The internal device_opp and opp structures are RCU protected. - * Hence this function indirectly uses RCU and 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 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) -{ - return _opp_set_availability(dev, freq, false); -} -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) -{ - struct device_opp *dev_opp = _find_device_opp(dev); - - if (IS_ERR(dev_opp)) - return ERR_CAST(dev_opp); /* matching type */ - - return &dev_opp->srcu_head; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier); - -#ifdef CONFIG_OF -/** - * of_init_opp_table() - Initialize opp table from device tree - * @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) -{ - const struct property *prop; - const __be32 *val; - int nr; - - prop = of_find_property(dev->of_node, "operating-points", NULL); - if (!prop) - return -ENODEV; - if (!prop->value) - return -ENODATA; - - /* - * Each OPP is a set of tuples consisting of frequency and - * voltage like <freq-kHz vol-uV>. - */ - nr = prop->length / sizeof(u32); - if (nr % 2) { - dev_err(dev, "%s: Invalid OPP list\n", __func__); - return -EINVAL; - } - - val = prop->value; - while (nr) { - unsigned long freq = be32_to_cpup(val++) * 1000; - unsigned long volt = be32_to_cpup(val++); - - if (_opp_add_dynamic(dev, freq, volt, false)) - dev_warn(dev, "%s: Failed to add OPP %ld\n", - __func__, freq); - nr -= 2; - } - - return 0; -} -EXPORT_SYMBOL_GPL(of_init_opp_table); - -/** - * of_free_opp_table() - Free OPP table entries created from static DT entries - * @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) -{ - struct device_opp *dev_opp; - struct dev_pm_opp *opp, *tmp; - - /* Check for existing list for 'dev' */ - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - int error = PTR_ERR(dev_opp); - if (error != -ENODEV) - WARN(1, "%s: dev_opp: %d\n", - IS_ERR_OR_NULL(dev) ? - "Invalid device" : dev_name(dev), - error); - return; - } - - /* Hold our list modification lock here */ - mutex_lock(&dev_opp_list_lock); - - /* Free static OPPs */ - list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) { - if (!opp->dynamic) - _opp_remove(dev_opp, opp); - } - - mutex_unlock(&dev_opp_list_lock); -} -EXPORT_SYMBOL_GPL(of_free_opp_table); -#endif |