| /* |
| * 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/init.h> |
| #include <linux/slab.h> |
| #include <linux/cpufreq.h> |
| #include <linux/device.h> |
| #include <linux/list.h> |
| #include <linux/rculist.h> |
| #include <linux/rcupdate.h> |
| #include <linux/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 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. |
| * @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 |
| * @head: RCU callback head used for deferred freeing |
| * |
| * This structure stores the OPP information for a given device. |
| */ |
| struct opp { |
| struct list_head node; |
| |
| bool available; |
| unsigned long rate; |
| unsigned long u_volt; |
| |
| struct device_opp *dev_opp; |
| struct rcu_head 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 |
| * @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 |
| * a device. This structure is not meant to be shared to users as it is |
| * meant for book keeping and private to OPP library |
| */ |
| struct device_opp { |
| struct list_head node; |
| |
| struct device *dev; |
| struct srcu_notifier_head 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); |
| |
| /** |
| * 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. |
| * |
| * Returns 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; |
| } |
| |
| /** |
| * 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 opp_get_voltage(struct opp *opp) |
| { |
| struct opp *tmp_opp; |
| unsigned long v = 0; |
| |
| 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(opp_get_voltage); |
| |
| /** |
| * 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 opp_get_freq(struct opp *opp) |
| { |
| struct opp *tmp_opp; |
| unsigned long f = 0; |
| |
| 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(opp_get_freq); |
| |
| /** |
| * 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, |
| * else returns 0 if none or the corresponding error value. |
| * |
| * Locking: This function must be called under rcu_read_lock(). This function |
| * internally references two RCU protected structures: device_opp and opp which |
| * are safe as long as we are under a common RCU locked section. |
| */ |
| int opp_get_opp_count(struct device *dev) |
| { |
| struct device_opp *dev_opp; |
| struct opp *temp_opp; |
| int count = 0; |
| |
| 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 r; |
| } |
| |
| list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { |
| if (temp_opp->available) |
| count++; |
| } |
| |
| return count; |
| } |
| EXPORT_SYMBOL_GPL(opp_get_opp_count); |
| |
| /** |
| * 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 |
| * |
| * 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 opp *opp_find_freq_exact(struct device *dev, unsigned long freq, |
| bool available) |
| { |
| struct device_opp *dev_opp; |
| struct opp *temp_opp, *opp = ERR_PTR(-ERANGE); |
| |
| 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(opp_find_freq_exact); |
| |
| /** |
| * 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. |
| * |
| * Returns 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 opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq) |
| { |
| struct device_opp *dev_opp; |
| struct opp *temp_opp, *opp = ERR_PTR(-ERANGE); |
| |
| 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(opp_find_freq_ceil); |
| |
| /** |
| * 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. |
| * |
| * Returns 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 opp *opp_find_freq_floor(struct device *dev, unsigned long *freq) |
| { |
| struct device_opp *dev_opp; |
| struct opp *temp_opp, *opp = ERR_PTR(-ERANGE); |
| |
| 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(opp_find_freq_floor); |
| |
| /** |
| * 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 |
| * 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. |
| */ |
| int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) |
| { |
| struct device_opp *dev_opp = NULL; |
| struct opp *opp, *new_opp; |
| struct list_head *head; |
| |
| /* allocate new OPP node */ |
| new_opp = kzalloc(sizeof(struct opp), GFP_KERNEL); |
| if (!new_opp) { |
| dev_warn(dev, "%s: Unable to create new OPP node\n", __func__); |
| return -ENOMEM; |
| } |
| |
| /* 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)) { |
| /* |
| * 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(struct device_opp), GFP_KERNEL); |
| if (!dev_opp) { |
| mutex_unlock(&dev_opp_list_lock); |
| kfree(new_opp); |
| dev_warn(dev, |
| "%s: Unable to create device OPP structure\n", |
| __func__); |
| return -ENOMEM; |
| } |
| |
| dev_opp->dev = dev; |
| srcu_init_notifier_head(&dev_opp->head); |
| INIT_LIST_HEAD(&dev_opp->opp_list); |
| |
| /* Secure the device list modification */ |
| list_add_rcu(&dev_opp->node, &dev_opp_list); |
| } |
| |
| /* populate the opp table */ |
| new_opp->dev_opp = dev_opp; |
| new_opp->rate = freq; |
| new_opp->u_volt = u_volt; |
| new_opp->available = true; |
| |
| /* Insert new OPP in order of increasing frequency */ |
| 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; |
| } |
| |
| 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; |
| } |
| |
| /** |
| * 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. |
| * |
| * Returns -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 *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV); |
| struct opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); |
| int r = 0; |
| |
| /* keep the node allocated */ |
| new_opp = kmalloc(sizeof(struct opp), GFP_KERNEL); |
| if (!new_opp) { |
| dev_warn(dev, "%s: Unable to create OPP\n", __func__); |
| return -ENOMEM; |
| } |
| |
| mutex_lock(&dev_opp_list_lock); |
| |
| /* Find the device_opp */ |
| list_for_each_entry(tmp_dev_opp, &dev_opp_list, node) { |
| if (dev == tmp_dev_opp->dev) { |
| dev_opp = tmp_dev_opp; |
| break; |
| } |
| } |
| 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); |
| kfree_rcu(opp, head); |
| |
| /* 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); |
| |
| return 0; |
| |
| unlock: |
| mutex_unlock(&dev_opp_list_lock); |
| kfree(new_opp); |
| return r; |
| } |
| |
| /** |
| * 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 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. |
| */ |
| int opp_enable(struct device *dev, unsigned long freq) |
| { |
| return opp_set_availability(dev, freq, true); |
| } |
| EXPORT_SYMBOL_GPL(opp_enable); |
| |
| /** |
| * 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 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. |
| */ |
| int opp_disable(struct device *dev, unsigned long freq) |
| { |
| return opp_set_availability(dev, freq, false); |
| } |
| EXPORT_SYMBOL_GPL(opp_disable); |
| |
| #ifdef CONFIG_CPU_FREQ |
| /** |
| * opp_init_cpufreq_table() - create a cpufreq table for a device |
| * @dev: device for which we do this operation |
| * @table: Cpufreq table returned back to caller |
| * |
| * Generate a cpufreq table for a provided device- this assumes that the |
| * opp list is already initialized and ready for usage. |
| * |
| * This function allocates required memory for the cpufreq table. It is |
| * expected that the caller does the required maintenance such as freeing |
| * the table as required. |
| * |
| * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM |
| * if no memory available for the operation (table is not populated), returns 0 |
| * if successful and table is populated. |
| * |
| * WARNING: It is important for the callers to ensure refreshing their copy of |
| * the table if any of the mentioned functions have been invoked in the interim. |
| * |
| * Locking: The internal device_opp and opp structures are RCU protected. |
| * To simplify the logic, we pretend we are updater and hold relevant mutex here |
| * Callers should ensure that this function is *NOT* called under RCU protection |
| * or in contexts where mutex locking cannot be used. |
| */ |
| int opp_init_cpufreq_table(struct device *dev, |
| struct cpufreq_frequency_table **table) |
| { |
| struct device_opp *dev_opp; |
| struct opp *opp; |
| struct cpufreq_frequency_table *freq_table; |
| int i = 0; |
| |
| /* Pretend as if I am an updater */ |
| mutex_lock(&dev_opp_list_lock); |
| |
| dev_opp = find_device_opp(dev); |
| if (IS_ERR(dev_opp)) { |
| int r = PTR_ERR(dev_opp); |
| mutex_unlock(&dev_opp_list_lock); |
| dev_err(dev, "%s: Device OPP not found (%d)\n", __func__, r); |
| return r; |
| } |
| |
| freq_table = kzalloc(sizeof(struct cpufreq_frequency_table) * |
| (opp_get_opp_count(dev) + 1), GFP_KERNEL); |
| if (!freq_table) { |
| mutex_unlock(&dev_opp_list_lock); |
| dev_warn(dev, "%s: Unable to allocate frequency table\n", |
| __func__); |
| return -ENOMEM; |
| } |
| |
| list_for_each_entry(opp, &dev_opp->opp_list, node) { |
| if (opp->available) { |
| freq_table[i].driver_data = i; |
| freq_table[i].frequency = opp->rate / 1000; |
| i++; |
| } |
| } |
| mutex_unlock(&dev_opp_list_lock); |
| |
| freq_table[i].driver_data = i; |
| freq_table[i].frequency = CPUFREQ_TABLE_END; |
| |
| *table = &freq_table[0]; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(opp_init_cpufreq_table); |
| |
| /** |
| * opp_free_cpufreq_table() - free the cpufreq table |
| * @dev: device for which we do this operation |
| * @table: table to free |
| * |
| * Free up the table allocated by opp_init_cpufreq_table |
| */ |
| void opp_free_cpufreq_table(struct device *dev, |
| struct cpufreq_frequency_table **table) |
| { |
| if (!table) |
| return; |
| |
| kfree(*table); |
| *table = NULL; |
| } |
| EXPORT_SYMBOL_GPL(opp_free_cpufreq_table); |
| #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_CAST(dev_opp); /* matching type */ |
| |
| return &dev_opp->head; |
| } |
| |
| #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. |
| */ |
| 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(dev, freq, volt)) { |
| dev_warn(dev, "%s: Failed to add OPP %ld\n", |
| __func__, freq); |
| continue; |
| } |
| nr -= 2; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(of_init_opp_table); |
| #endif |