diff options
Diffstat (limited to 'drivers/base/power/opp.c')
| -rw-r--r-- | drivers/base/power/opp.c | 268 |
1 files changed, 159 insertions, 109 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 2bb9b4cf59d..89ced955faf 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -14,13 +14,14 @@ #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/pm_opp.h> +#include <linux/of.h> +#include <linux/export.h> /* * Internal data structure organization with the OPP layer library is as @@ -39,7 +40,7 @@ */ /** - * struct opp - Generic OPP description structure + * struct dev_pm_opp - Generic OPP description structure * @node: opp list node. The nodes are maintained throughout the lifetime * of boot. It is expected only an optimal set of OPPs are * added to the library by the SoC framework. @@ -52,10 +53,11 @@ * @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 dev_pm_opp { struct list_head node; bool available; @@ -63,6 +65,7 @@ struct opp { unsigned long u_volt; struct device_opp *dev_opp; + struct rcu_head head; }; /** @@ -73,6 +76,7 @@ struct opp { * 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 @@ -83,6 +87,7 @@ struct device_opp { struct list_head node; struct device *dev; + struct srcu_notifier_head head; struct list_head opp_list; }; @@ -129,7 +134,7 @@ static struct device_opp *find_device_opp(struct device *dev) } /** - * opp_get_voltage() - Gets the voltage corresponding to an available opp + * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an available opp * @opp: opp for which voltage has to be returned for * * Return voltage in micro volt corresponding to the opp, else @@ -143,9 +148,9 @@ static struct device_opp *find_device_opp(struct device *dev) * prior to unlocking with rcu_read_unlock() to maintain the integrity of the * pointer. */ -unsigned long opp_get_voltage(struct opp *opp) +unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) { - struct opp *tmp_opp; + struct dev_pm_opp *tmp_opp; unsigned long v = 0; tmp_opp = rcu_dereference(opp); @@ -156,9 +161,10 @@ unsigned long opp_get_voltage(struct opp *opp) return v; } +EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage); /** - * opp_get_freq() - Gets the frequency corresponding to an available opp + * 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 @@ -172,9 +178,9 @@ unsigned long opp_get_voltage(struct opp *opp) * prior to unlocking with rcu_read_unlock() to maintain the integrity of the * pointer. */ -unsigned long opp_get_freq(struct opp *opp) +unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) { - struct opp *tmp_opp; + struct dev_pm_opp *tmp_opp; unsigned long f = 0; tmp_opp = rcu_dereference(opp); @@ -185,9 +191,10 @@ unsigned long opp_get_freq(struct opp *opp) return f; } +EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq); /** - * opp_get_opp_count() - Get number of opps available in the opp list + * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list * @dev: device for which we do this operation * * This function returns the number of available opps if there are any, @@ -197,10 +204,10 @@ unsigned long opp_get_freq(struct opp *opp) * 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) +int dev_pm_opp_get_opp_count(struct device *dev) { struct device_opp *dev_opp; - struct opp *temp_opp; + struct dev_pm_opp *temp_opp; int count = 0; dev_opp = find_device_opp(dev); @@ -217,16 +224,20 @@ int opp_get_opp_count(struct device *dev) return count; } +EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count); /** - * opp_find_freq_exact() - search for an exact frequency + * dev_pm_opp_find_freq_exact() - search for an exact frequency * @dev: device for which we do this operation * @freq: frequency to search for - * @is_available: true/false - match for available opp + * @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. + * 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 @@ -241,11 +252,12 @@ int opp_get_opp_count(struct device *dev) * 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 dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, + unsigned long freq, + bool available) { struct device_opp *dev_opp; - struct opp *temp_opp, *opp = ERR_PTR(-ENODEV); + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); dev_opp = find_device_opp(dev); if (IS_ERR(dev_opp)) { @@ -264,9 +276,10 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq, return opp; } +EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); /** - * opp_find_freq_ceil() - Search for an rounded ceil freq + * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq * @dev: device for which we do this operation * @freq: Start frequency * @@ -274,7 +287,11 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long 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. + * 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 @@ -282,10 +299,11 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq, * 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 dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, + unsigned long *freq) { struct device_opp *dev_opp; - struct opp *temp_opp, *opp = ERR_PTR(-ENODEV); + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); if (!dev || !freq) { dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); @@ -294,7 +312,7 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq) dev_opp = find_device_opp(dev); if (IS_ERR(dev_opp)) - return 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) { @@ -306,9 +324,10 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq) return opp; } +EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil); /** - * opp_find_freq_floor() - Search for a rounded floor freq + * dev_pm_opp_find_freq_floor() - Search for a rounded floor freq * @dev: device for which we do this operation * @freq: Start frequency * @@ -316,7 +335,11 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *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. + * 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 @@ -324,10 +347,11 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq) * 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 dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, + unsigned long *freq) { struct device_opp *dev_opp; - struct opp *temp_opp, *opp = ERR_PTR(-ENODEV); + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); if (!dev || !freq) { dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq); @@ -336,7 +360,7 @@ struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq) dev_opp = find_device_opp(dev); if (IS_ERR(dev_opp)) - return opp; + return ERR_CAST(dev_opp); list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) { if (temp_opp->available) { @@ -352,31 +376,39 @@ struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq) return opp; } +EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); /** - * opp_add() - Add an OPP table from a table definitions + * 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 - * opp_enable/disable functions. + * 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 opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) +int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) { struct device_opp *dev_opp = NULL; - struct opp *opp, *new_opp; + struct dev_pm_opp *opp, *new_opp; struct list_head *head; /* allocate new OPP node */ - new_opp = kzalloc(sizeof(struct opp), GFP_KERNEL); + new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL); if (!new_opp) { dev_warn(dev, "%s: Unable to create new OPP node\n", __func__); return -ENOMEM; @@ -404,6 +436,7 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) } dev_opp->dev = dev; + srcu_init_notifier_head(&dev_opp->head); INIT_LIST_HEAD(&dev_opp->opp_list); /* Secure the device list modification */ @@ -416,20 +449,42 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) new_opp->u_volt = u_volt; new_opp->available = true; - /* Insert new OPP in order of increasing frequency */ + /* + * Insert new OPP in order of increasing frequency + * and discard if already present + */ head = &dev_opp->opp_list; list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { - if (new_opp->rate < opp->rate) + if (new_opp->rate <= opp->rate) break; else head = &opp->node; } + /* Duplicate OPPs ? */ + if (new_opp->rate == opp->rate) { + int ret = opp->available && new_opp->u_volt == opp->u_volt ? + 0 : -EEXIST; + + dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", + __func__, opp->rate, opp->u_volt, opp->available, + new_opp->rate, new_opp->u_volt, new_opp->available); + mutex_unlock(&dev_opp_list_lock); + kfree(new_opp); + return ret; + } + 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; } +EXPORT_SYMBOL_GPL(dev_pm_opp_add); /** * opp_set_availability() - helper to set the availability of an opp @@ -453,12 +508,12 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) static int opp_set_availability(struct device *dev, unsigned long freq, bool availability_req) { - struct device_opp *tmp_dev_opp, *dev_opp = NULL; - struct opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); + struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV); + struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); int r = 0; /* keep the node allocated */ - new_opp = kmalloc(sizeof(struct opp), GFP_KERNEL); + new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL); if (!new_opp) { dev_warn(dev, "%s: Unable to create OPP\n", __func__); return -ENOMEM; @@ -502,27 +557,32 @@ static int opp_set_availability(struct device *dev, unsigned long freq, list_replace_rcu(&opp->node, &new_opp->node); mutex_unlock(&dev_opp_list_lock); - synchronize_rcu(); + kfree_rcu(opp, head); - /* clean up old opp */ - new_opp = opp; - goto out; + /* 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); -out: kfree(new_opp); return r; } /** - * opp_enable() - Enable a specific OPP + * 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 opp_disable. + * 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 @@ -530,20 +590,21 @@ out: * 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) +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); /** - * opp_disable() - Disable a specific OPP + * 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 opp_enable). + * 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 @@ -551,78 +612,67 @@ int opp_enable(struct device *dev, unsigned long freq) * 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) +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); -#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. + * dev_pm_opp_get_notifier() - find notifier_head of the device with opp + * @dev: device pointer used to lookup device OPPs. */ -int opp_init_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table) +struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) { - 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); + struct device_opp *dev_opp = find_device_opp(dev); - 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; - } + if (IS_ERR(dev_opp)) + return ERR_CAST(dev_opp); /* matching type */ - 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; - } + return &dev_opp->head; +} - list_for_each_entry(opp, &dev_opp->opp_list, node) { - if (opp->available) { - freq_table[i].index = i; - freq_table[i].frequency = opp->rate / 1000; - i++; - } +#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; } - mutex_unlock(&dev_opp_list_lock); - freq_table[i].index = i; - freq_table[i].frequency = CPUFREQ_TABLE_END; + val = prop->value; + while (nr) { + unsigned long freq = be32_to_cpup(val++) * 1000; + unsigned long volt = be32_to_cpup(val++); - *table = &freq_table[0]; + if (dev_pm_opp_add(dev, freq, volt)) + dev_warn(dev, "%s: Failed to add OPP %ld\n", + __func__, freq); + nr -= 2; + } return 0; } -#endif /* CONFIG_CPU_FREQ */ +EXPORT_SYMBOL_GPL(of_init_opp_table); +#endif |