/* * 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. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include "opp.h" /* * 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 */ DEFINE_MUTEX(dev_opp_list_lock); #define opp_rcu_lockdep_assert() \ do { \ RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&dev_opp_list_lock), \ "Missing rcu_read_lock() or " \ "dev_opp_list_lock protection"); \ } while (0) static struct device_list_opp *_find_list_dev(const struct device *dev, struct device_opp *dev_opp) { struct device_list_opp *list_dev; list_for_each_entry(list_dev, &dev_opp->dev_list, node) if (list_dev->dev == dev) return list_dev; return NULL; } static struct device_opp *_managed_opp(const struct device_node *np) { struct device_opp *dev_opp; list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) { if (dev_opp->np == np) { /* * Multiple devices can point to the same OPP table and * so will have same node-pointer, np. * * But the OPPs will be considered as shared only if the * OPP table contains a "opp-shared" property. */ return dev_opp->shared_opp ? dev_opp : NULL; } } return NULL; } /** * _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: For readers, this function must be called under rcu_read_lock(). * device_opp is a RCU protected pointer, which means that device_opp is valid * as long as we are under RCU lock. * * For Writers, this function must be called with dev_opp_list_lock held. */ struct device_opp *_find_device_opp(struct device *dev) { struct device_opp *dev_opp; opp_rcu_lockdep_assert(); if (IS_ERR_OR_NULL(dev)) { pr_err("%s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) if (_find_list_dev(dev, dev_opp)) return dev_opp; return ERR_PTR(-ENODEV); } /** * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an 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 (IS_ERR_OR_NULL(tmp_opp)) 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 (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_is_turbo() - Returns if opp is turbo OPP or not * @opp: opp for which turbo mode is being verified * * Turbo OPPs are not for normal use, and can be enabled (under certain * conditions) for short duration of times to finish high throughput work * quickly. Running on them for longer times may overheat the chip. * * Return: true if opp is turbo opp, else false. * * 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. */ bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp) { struct dev_pm_opp *tmp_opp; opp_rcu_lockdep_assert(); tmp_opp = rcu_dereference(opp); if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) { pr_err("%s: Invalid parameters\n", __func__); return false; } return tmp_opp->turbo; } EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo); /** * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds * @dev: device for which we do this operation * * Return: This function returns the max clock latency in nanoseconds. * * Locking: This function takes rcu_read_lock(). */ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev) { struct device_opp *dev_opp; unsigned long clock_latency_ns; rcu_read_lock(); dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) clock_latency_ns = 0; else clock_latency_ns = dev_opp->clock_latency_ns_max; rcu_read_unlock(); return clock_latency_ns; } EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency); /** * dev_pm_opp_get_suspend_opp() - Get suspend opp * @dev: device for which we do this operation * * Return: This function returns pointer to the suspend opp if it is * defined and available, otherwise it returns NULL. * * 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_get_suspend_opp(struct device *dev) { struct device_opp *dev_opp; opp_rcu_lockdep_assert(); dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp) || !dev_opp->suspend_opp || !dev_opp->suspend_opp->available) return NULL; return dev_opp->suspend_opp; } EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp); /** * 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); /* List-dev Helpers */ static void _kfree_list_dev_rcu(struct rcu_head *head) { struct device_list_opp *list_dev; list_dev = container_of(head, struct device_list_opp, rcu_head); kfree_rcu(list_dev, rcu_head); } static void _remove_list_dev(struct device_list_opp *list_dev, struct device_opp *dev_opp) { opp_debug_unregister(list_dev, dev_opp); list_del(&list_dev->node); call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head, _kfree_list_dev_rcu); } struct device_list_opp *_add_list_dev(const struct device *dev, struct device_opp *dev_opp) { struct device_list_opp *list_dev; int ret; list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL); if (!list_dev) return NULL; /* Initialize list-dev */ list_dev->dev = dev; list_add_rcu(&list_dev->node, &dev_opp->dev_list); /* Create debugfs entries for the dev_opp */ ret = opp_debug_register(list_dev, dev_opp); if (ret) dev_err(dev, "%s: Failed to register opp debugfs (%d)\n", __func__, ret); return list_dev; } /** * _add_device_opp() - Find device OPP table or allocate a new one * @dev: device for which we do this operation * * It tries to find an existing table first, if it couldn't find one, it * allocates a new OPP table and returns that. * * Return: valid device_opp pointer if success, else NULL. */ static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; struct device_list_opp *list_dev; /* Check for existing list for 'dev' first */ dev_opp = _find_device_opp(dev); if (!IS_ERR(dev_opp)) return 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; INIT_LIST_HEAD(&dev_opp->dev_list); list_dev = _add_list_dev(dev, dev_opp); if (!list_dev) { kfree(dev_opp); return NULL; } 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; } /** * _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); } /** * _remove_device_opp() - Removes a device OPP table * @dev_opp: device OPP table to be removed. * * Removes/frees device OPP table it it doesn't contain any OPPs. */ static void _remove_device_opp(struct device_opp *dev_opp) { struct device_list_opp *list_dev; if (!list_empty(&dev_opp->opp_list)) return; if (dev_opp->supported_hw) return; list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp, node); _remove_list_dev(list_dev, dev_opp); /* dev_list must be empty now */ WARN_ON(!list_empty(&dev_opp->dev_list)); list_del_rcu(&dev_opp->node); call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head, _kfree_device_rcu); } /** * _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); } /** * _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 * @notify: OPP_EVENT_REMOVE notification should be sent or not * * 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, bool notify) { /* * Notify the changes in the availability of the operable * frequency/voltage list. */ if (notify) srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp); opp_debug_remove_one(opp); list_del_rcu(&opp->node); call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu); _remove_device_opp(dev_opp); } /** * 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, true); unlock: mutex_unlock(&dev_opp_list_lock); } EXPORT_SYMBOL_GPL(dev_pm_opp_remove); static struct dev_pm_opp *_allocate_opp(struct device *dev, struct device_opp **dev_opp) { struct dev_pm_opp *opp; /* allocate new OPP node */ opp = kzalloc(sizeof(*opp), GFP_KERNEL); if (!opp) return NULL; INIT_LIST_HEAD(&opp->node); *dev_opp = _add_device_opp(dev); if (!*dev_opp) { kfree(opp); return NULL; } return opp; } static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct device_opp *dev_opp) { struct dev_pm_opp *opp; struct list_head *head = &dev_opp->opp_list; int ret; /* * Insert new OPP in order of increasing frequency and discard if * already present. * * Need to use &dev_opp->opp_list in the condition part of the 'for' * loop, don't replace it with head otherwise it will become an infinite * loop. */ list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { if (new_opp->rate > opp->rate) { head = &opp->node; continue; } if (new_opp->rate < opp->rate) break; /* Duplicate OPPs */ 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); return opp->available && new_opp->u_volt == opp->u_volt ? 0 : -EEXIST; } new_opp->dev_opp = dev_opp; list_add_rcu(&new_opp->node, head); ret = opp_debug_create_one(new_opp, dev_opp); if (ret) dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n", __func__, ret); return 0; } /** * _opp_add_v1() - Allocate a OPP based on v1 bindings. * @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 dev_pm_opp_of_add_table * and freed by dev_pm_opp_of_remove_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_v1(struct device *dev, unsigned long freq, long u_volt, bool dynamic) { struct device_opp *dev_opp; struct dev_pm_opp *new_opp; int ret; /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); new_opp = _allocate_opp(dev, &dev_opp); if (!new_opp) { ret = -ENOMEM; goto unlock; } /* populate the opp table */ new_opp->rate = freq; new_opp->u_volt = u_volt; new_opp->available = true; new_opp->dynamic = dynamic; ret = _opp_add(dev, new_opp, dev_opp); if (ret) goto free_opp; 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: _opp_remove(dev_opp, new_opp, false); unlock: mutex_unlock(&dev_opp_list_lock); return ret; } /* TODO: Support multiple regulators */ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev) { u32 microvolt[3] = {0}; u32 val; int count, ret; /* Missing property isn't a problem, but an invalid entry is */ if (!of_find_property(opp->np, "opp-microvolt", NULL)) return 0; count = of_property_count_u32_elems(opp->np, "opp-microvolt"); if (count < 0) { dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n", __func__, count); return count; } /* There can be one or three elements here */ if (count != 1 && count != 3) { dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n", __func__, count); return -EINVAL; } ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt, count); if (ret) { dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__, ret); return -EINVAL; } opp->u_volt = microvolt[0]; opp->u_volt_min = microvolt[1]; opp->u_volt_max = microvolt[2]; if (!of_property_read_u32(opp->np, "opp-microamp", &val)) opp->u_amp = val; return 0; } /** * dev_pm_opp_set_supported_hw() - Set supported platforms * @dev: Device for which supported-hw has to be set. * @versions: Array of hierarchy of versions to match. * @count: Number of elements in the array. * * This is required only for the V2 bindings, and it enables a platform to * specify the hierarchy of versions it supports. OPP layer will then enable * OPPs, which are available for those versions, based on its 'opp-supported-hw' * property. * * 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. */ int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, unsigned int count) { struct device_opp *dev_opp; int ret = 0; /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); dev_opp = _add_device_opp(dev); if (!dev_opp) { ret = -ENOMEM; goto unlock; } /* Make sure there are no concurrent readers while updating dev_opp */ WARN_ON(!list_empty(&dev_opp->opp_list)); /* Do we already have a version hierarchy associated with dev_opp? */ if (dev_opp->supported_hw) { dev_err(dev, "%s: Already have supported hardware list\n", __func__); ret = -EBUSY; goto err; } dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions), GFP_KERNEL); if (!dev_opp->supported_hw) { ret = -ENOMEM; goto err; } dev_opp->supported_hw_count = count; mutex_unlock(&dev_opp_list_lock); return 0; err: _remove_device_opp(dev_opp); unlock: mutex_unlock(&dev_opp_list_lock); return ret; } EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw); /** * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw * @dev: Device for which supported-hw has to be set. * * This is required only for the V2 bindings, and is called for a matching * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp structure * will not be freed. * * 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_put_supported_hw(struct device *dev) { struct device_opp *dev_opp; /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); /* Check for existing list for 'dev' first */ dev_opp = _find_device_opp(dev); if (IS_ERR(dev_opp)) { dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp)); goto unlock; } /* Make sure there are no concurrent readers while updating dev_opp */ WARN_ON(!list_empty(&dev_opp->opp_list)); if (!dev_opp->supported_hw) { dev_err(dev, "%s: Doesn't have supported hardware list\n", __func__); goto unlock; } kfree(dev_opp->supported_hw); dev_opp->supported_hw = NULL; dev_opp->supported_hw_count = 0; /* Try freeing device_opp if this was the last blocking resource */ _remove_device_opp(dev_opp); unlock: mutex_unlock(&dev_opp_list_lock); } EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw); static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp, struct device_node *np) { unsigned int count = dev_opp->supported_hw_count; u32 version; int ret; if (!dev_opp->supported_hw) return true; while (count--) { ret = of_property_read_u32_index(np, "opp-supported-hw", count, &version); if (ret) { dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n", __func__, count, ret); return false; } /* Both of these are bitwise masks of the versions */ if (!(version & dev_opp->supported_hw[count])) return false; } return true; } /** * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings) * @dev: device for which we do this operation * @np: device node * * This function adds an opp definition to the opp list and returns status. The * opp can be controlled using dev_pm_opp_enable/disable functions and may be * removed by dev_pm_opp_remove. * * 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 * -EINVAL Failed parsing the OPP node */ static int _opp_add_static_v2(struct device *dev, struct device_node *np) { struct device_opp *dev_opp; struct dev_pm_opp *new_opp; u64 rate; u32 val; int ret; /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); new_opp = _allocate_opp(dev, &dev_opp); if (!new_opp) { ret = -ENOMEM; goto unlock; } ret = of_property_read_u64(np, "opp-hz", &rate); if (ret < 0) { dev_err(dev, "%s: opp-hz not found\n", __func__); goto free_opp; } /* Check if the OPP supports hardware's hierarchy of versions or not */ if (!_opp_is_supported(dev, dev_opp, np)) { dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate); goto free_opp; } /* * Rate is defined as an unsigned long in clk API, and so casting * explicitly to its type. Must be fixed once rate is 64 bit * guaranteed in clk API. */ new_opp->rate = (unsigned long)rate; new_opp->turbo = of_property_read_bool(np, "turbo-mode"); new_opp->np = np; new_opp->dynamic = false; new_opp->available = true; if (!of_property_read_u32(np, "clock-latency-ns", &val)) new_opp->clock_latency_ns = val; ret = opp_parse_supplies(new_opp, dev); if (ret) goto free_opp; ret = _opp_add(dev, new_opp, dev_opp); if (ret) goto free_opp; /* OPP to select on device suspend */ if (of_property_read_bool(np, "opp-suspend")) { if (dev_opp->suspend_opp) { dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n", __func__, dev_opp->suspend_opp->rate, new_opp->rate); } else { new_opp->suspend = true; dev_opp->suspend_opp = new_opp; } } if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max) dev_opp->clock_latency_ns_max = new_opp->clock_latency_ns; mutex_unlock(&dev_opp_list_lock); pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n", __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt, new_opp->u_volt_min, new_opp->u_volt_max, new_opp->clock_latency_ns); /* * 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: _opp_remove(dev_opp, new_opp, false); unlock: mutex_unlock(&dev_opp_list_lock); 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_v1(dev, freq, u_volt, true); } EXPORT_SYMBOL_GPL(dev_pm_opp_add); /** * _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 modification 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 modification 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 modification 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 /** * dev_pm_opp_of_remove_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 dev_pm_opp_of_remove_table(struct device *dev) { struct device_opp *dev_opp; struct dev_pm_opp *opp, *tmp; /* Hold our list modification lock here */ mutex_lock(&dev_opp_list_lock); /* 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); goto unlock; } /* Find if dev_opp manages a single device */ if (list_is_singular(&dev_opp->dev_list)) { /* Free static OPPs */ list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) { if (!opp->dynamic) _opp_remove(dev_opp, opp, true); } } else { _remove_list_dev(_find_list_dev(dev, dev_opp), dev_opp); } unlock: mutex_unlock(&dev_opp_list_lock); } EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table); /* Returns opp descriptor node for a device, caller must do of_node_put() */ struct device_node *_of_get_opp_desc_node(struct device *dev) { /* * TODO: Support for multiple OPP tables. * * There should be only ONE phandle present in "operating-points-v2" * property. */ return of_parse_phandle(dev->of_node, "operating-points-v2", 0); } /* Initializes OPP tables based on new bindings */ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) { struct device_node *np; struct device_opp *dev_opp; int ret = 0, count = 0; mutex_lock(&dev_opp_list_lock); dev_opp = _managed_opp(opp_np); if (dev_opp) { /* OPPs are already managed */ if (!_add_list_dev(dev, dev_opp)) ret = -ENOMEM; mutex_unlock(&dev_opp_list_lock); return ret; } mutex_unlock(&dev_opp_list_lock); /* We have opp-list node now, iterate over it and add OPPs */ for_each_available_child_of_node(opp_np, np) { count++; ret = _opp_add_static_v2(dev, np); if (ret) { dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, ret); goto free_table; } } /* There should be one of more OPP defined */ if (WARN_ON(!count)) return -ENOENT; mutex_lock(&dev_opp_list_lock); dev_opp = _find_device_opp(dev); if (WARN_ON(IS_ERR(dev_opp))) { ret = PTR_ERR(dev_opp); mutex_unlock(&dev_opp_list_lock); goto free_table; } dev_opp->np = opp_np; dev_opp->shared_opp = of_property_read_bool(opp_np, "opp-shared"); mutex_unlock(&dev_opp_list_lock); return 0; free_table: dev_pm_opp_of_remove_table(dev); return ret; } /* Initializes OPP tables based on old-deprecated bindings */ static int _of_add_opp_table_v1(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 . */ 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_v1(dev, freq, volt, false)) dev_warn(dev, "%s: Failed to add OPP %ld\n", __func__, freq); nr -= 2; } return 0; } /** * dev_pm_opp_of_add_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 * -EINVAL when invalid entries are found in opp-v2 table */ int dev_pm_opp_of_add_table(struct device *dev) { struct device_node *opp_np; int ret; /* * OPPs have two version of bindings now. The older one is deprecated, * try for the new binding first. */ opp_np = _of_get_opp_desc_node(dev); if (!opp_np) { /* * Try old-deprecated bindings for backward compatibility with * older dtbs. */ return _of_add_opp_table_v1(dev); } ret = _of_add_opp_table_v2(dev, opp_np); of_node_put(opp_np); return ret; } EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table); #endif