diff options
| -rw-r--r-- | Documentation/cpu-freq/core.txt | 29 | ||||
| -rw-r--r-- | Documentation/power/opp.txt | 40 | ||||
| -rw-r--r-- | drivers/base/power/opp.c | 92 | ||||
| -rw-r--r-- | drivers/cpufreq/Makefile | 2 | ||||
| -rw-r--r-- | drivers/cpufreq/cpufreq_opp.c | 110 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 21 | ||||
| -rw-r--r-- | include/linux/pm_opp.h | 20 |
7 files changed, 167 insertions, 147 deletions
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt index 0060d76..70933ea 100644 --- a/Documentation/cpu-freq/core.txt +++ b/Documentation/cpu-freq/core.txt @@ -20,6 +20,7 @@ Contents: --------- 1. CPUFreq core and interfaces 2. CPUFreq notifiers +3. CPUFreq Table Generation with Operating Performance Point (OPP) 1. General Information ======================= @@ -92,3 +93,31 @@ values: cpu - number of the affected CPU old - old frequency new - new frequency + +3. CPUFreq Table Generation with Operating Performance Point (OPP) +================================================================== +For details about OPP, see Documentation/power/opp.txt + +dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with + cpufreq_frequency_table_cpuinfo which is provided with the list of + frequencies that are available for operation. This function provides + a ready to use conversion routine to translate the OPP layer's internal + information about the available frequencies into a format readily + providable to cpufreq. + + WARNING: Do not use this function in interrupt context. + + Example: + soc_pm_init() + { + /* Do things */ + r = dev_pm_opp_init_cpufreq_table(dev, &freq_table); + if (!r) + cpufreq_frequency_table_cpuinfo(policy, freq_table); + /* Do other things */ + } + + NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in + addition to CONFIG_PM_OPP. + +dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt index b8a907d..a9adad8 100644 --- a/Documentation/power/opp.txt +++ b/Documentation/power/opp.txt @@ -10,8 +10,7 @@ Contents 3. OPP Search Functions 4. OPP Availability Control Functions 5. OPP Data Retrieval Functions -6. Cpufreq Table Generation -7. Data Structures +6. Data Structures 1. Introduction =============== @@ -72,7 +71,6 @@ operations until that OPP could be re-enabled if possible. OPP library facilitates this concept in it's implementation. The following operational functions operate only on available opps: opp_find_freq_{ceil, floor}, dev_pm_opp_get_voltage, dev_pm_opp_get_freq, dev_pm_opp_get_opp_count -and dev_pm_opp_init_cpufreq_table dev_pm_opp_find_freq_exact is meant to be used to find the opp pointer which can then be used for dev_pm_opp_enable/disable functions to make an opp available as required. @@ -96,10 +94,9 @@ using RCU read locks. The opp_find_freq_{exact,ceil,floor}, opp_get_{voltage, freq, opp_count} fall into this category. opp_{add,enable,disable} are updaters which use mutex and implement it's own -RCU locking mechanisms. dev_pm_opp_init_cpufreq_table acts as an updater and uses -mutex to implment RCU updater strategy. These functions should *NOT* be called -under RCU locks and other contexts that prevent blocking functions in RCU or -mutex operations from working. +RCU locking mechanisms. These functions should *NOT* be called under RCU locks +and other contexts that prevent blocking functions in RCU or mutex operations +from working. 2. Initial OPP List Registration ================================ @@ -311,34 +308,7 @@ dev_pm_opp_get_opp_count - Retrieve the number of available opps for a device /* Do other things */ } -6. Cpufreq Table Generation -=========================== -dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with - cpufreq_frequency_table_cpuinfo which is provided with the list of - frequencies that are available for operation. This function provides - a ready to use conversion routine to translate the OPP layer's internal - information about the available frequencies into a format readily - providable to cpufreq. - - WARNING: Do not use this function in interrupt context. - - Example: - soc_pm_init() - { - /* Do things */ - r = dev_pm_opp_init_cpufreq_table(dev, &freq_table); - if (!r) - cpufreq_frequency_table_cpuinfo(policy, freq_table); - /* Do other things */ - } - - NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in - addition to CONFIG_PM as power management feature is required to - dynamically scale voltage and frequency in a system. - -dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table - -7. Data Structures +6. Data Structures ================== Typically an SoC contains multiple voltage domains which are variable. Each domain is represented by a device pointer. The relationship to OPP can be diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 38b43bb..d9e376a 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -15,7 +15,6 @@ #include <linux/errno.h> #include <linux/err.h> #include <linux/slab.h> -#include <linux/cpufreq.h> #include <linux/device.h> #include <linux/list.h> #include <linux/rculist.h> @@ -596,97 +595,6 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) } EXPORT_SYMBOL_GPL(dev_pm_opp_disable); -#ifdef CONFIG_CPU_FREQ -/** - * dev_pm_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. - * Since we just use the regular accessor functions to access the internal data - * structures, we use RCU read lock inside this function. As a result, users of - * this function DONOT need to use explicit locks for invoking. - */ -int dev_pm_opp_init_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table) -{ - struct dev_pm_opp *opp; - struct cpufreq_frequency_table *freq_table = NULL; - int i, max_opps, ret = 0; - unsigned long rate; - - rcu_read_lock(); - - max_opps = dev_pm_opp_get_opp_count(dev); - if (max_opps <= 0) { - ret = max_opps ? max_opps : -ENODATA; - goto out; - } - - freq_table = kzalloc(sizeof(*freq_table) * (max_opps + 1), GFP_KERNEL); - if (!freq_table) { - ret = -ENOMEM; - goto out; - } - - for (i = 0, rate = 0; i < max_opps; i++, rate++) { - /* find next rate */ - opp = dev_pm_opp_find_freq_ceil(dev, &rate); - if (IS_ERR(opp)) { - ret = PTR_ERR(opp); - goto out; - } - freq_table[i].driver_data = i; - freq_table[i].frequency = rate / 1000; - } - - freq_table[i].driver_data = i; - freq_table[i].frequency = CPUFREQ_TABLE_END; - - *table = &freq_table[0]; - -out: - rcu_read_unlock(); - if (ret) - kfree(freq_table); - - return ret; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table); - -/** - * dev_pm_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 dev_pm_opp_init_cpufreq_table - */ -void dev_pm_opp_free_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table) -{ - if (!table) - return; - - kfree(*table); - *table = NULL; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table); -#endif /* CONFIG_CPU_FREQ */ - /** * dev_pm_opp_get_notifier() - find notifier_head of the device with opp * @dev: device pointer used to lookup device OPPs. diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 0dbb963c..738c8b7 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -1,5 +1,7 @@ # CPUfreq core obj-$(CONFIG_CPU_FREQ) += cpufreq.o freq_table.o +obj-$(CONFIG_PM_OPP) += cpufreq_opp.o + # CPUfreq stats obj-$(CONFIG_CPU_FREQ_STAT) += cpufreq_stats.o diff --git a/drivers/cpufreq/cpufreq_opp.c b/drivers/cpufreq/cpufreq_opp.c new file mode 100644 index 0000000..c0c6f4a --- /dev/null +++ b/drivers/cpufreq/cpufreq_opp.c @@ -0,0 +1,110 @@ +/* + * Generic OPP helper interface for CPUFreq drivers + * + * Copyright (C) 2009-2014 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/cpufreq.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/pm_opp.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> + +/** + * dev_pm_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. + * Since we just use the regular accessor functions to access the internal data + * structures, we use RCU read lock inside this function. As a result, users of + * this function DONOT need to use explicit locks for invoking. + */ +int dev_pm_opp_init_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table) +{ + struct dev_pm_opp *opp; + struct cpufreq_frequency_table *freq_table = NULL; + int i, max_opps, ret = 0; + unsigned long rate; + + rcu_read_lock(); + + max_opps = dev_pm_opp_get_opp_count(dev); + if (max_opps <= 0) { + ret = max_opps ? max_opps : -ENODATA; + goto out; + } + + freq_table = kzalloc(sizeof(*freq_table) * (max_opps + 1), GFP_KERNEL); + if (!freq_table) { + ret = -ENOMEM; + goto out; + } + + for (i = 0, rate = 0; i < max_opps; i++, rate++) { + /* find next rate */ + opp = dev_pm_opp_find_freq_ceil(dev, &rate); + if (IS_ERR(opp)) { + ret = PTR_ERR(opp); + goto out; + } + freq_table[i].driver_data = i; + freq_table[i].frequency = rate / 1000; + } + + freq_table[i].driver_data = i; + freq_table[i].frequency = CPUFREQ_TABLE_END; + + *table = &freq_table[0]; + +out: + rcu_read_unlock(); + if (ret) + kfree(freq_table); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table); + +/** + * dev_pm_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 dev_pm_opp_init_cpufreq_table + */ +void dev_pm_opp_free_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table) +{ + if (!table) + return; + + kfree(*table); + *table = NULL; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index f3822f8..9d803b5 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -469,6 +469,27 @@ struct cpufreq_frequency_table { * order */ }; +#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP) +int dev_pm_opp_init_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table); +void dev_pm_opp_free_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table); +#else +static inline int dev_pm_opp_init_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table + **table) +{ + return -EINVAL; +} + +static inline void dev_pm_opp_free_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table + **table) +{ +} +#endif + + bool cpufreq_next_valid(struct cpufreq_frequency_table **pos); /* diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 5151b00..0330217 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -15,7 +15,6 @@ #define __LINUX_OPP_H__ #include <linux/err.h> -#include <linux/cpufreq.h> #include <linux/notifier.h> struct dev_pm_opp; @@ -117,23 +116,4 @@ static inline int of_init_opp_table(struct device *dev) } #endif -#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP) -int dev_pm_opp_init_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table); -void dev_pm_opp_free_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table); -#else -static inline int dev_pm_opp_init_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table) -{ - return -EINVAL; -} - -static inline -void dev_pm_opp_free_cpufreq_table(struct device *dev, - struct cpufreq_frequency_table **table) -{ -} -#endif /* CONFIG_CPU_FREQ */ - #endif /* __LINUX_OPP_H__ */ |
