--- /dev/null
+/*
+ * 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 <linux/errno.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/export.h>
+
+#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)
+{
+ 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;
+
+ 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);
+
+ 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;
+
+ 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);
+ 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;
+
+ /*
+ * 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);
+
+ 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;
+}
+
+/**
+ * _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;
+ }
+
+ /*
+ * 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
+ 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 <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_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
Code Review / kvmfornfv.git / blobdiff