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 0060d76b445f..70933eadc308 100644 --- a/Documentation/cpu-freq/core.txt +++ b/Documentation/cpu-freq/core.txt | |||
| @@ -20,6 +20,7 @@ Contents: | |||
| 20 | --------- | 20 | --------- |
| 21 | 1. CPUFreq core and interfaces | 21 | 1. CPUFreq core and interfaces |
| 22 | 2. CPUFreq notifiers | 22 | 2. CPUFreq notifiers |
| 23 | 3. CPUFreq Table Generation with Operating Performance Point (OPP) | ||
| 23 | 24 | ||
| 24 | 1. General Information | 25 | 1. General Information |
| 25 | ======================= | 26 | ======================= |
| @@ -92,3 +93,31 @@ values: | |||
| 92 | cpu - number of the affected CPU | 93 | cpu - number of the affected CPU |
| 93 | old - old frequency | 94 | old - old frequency |
| 94 | new - new frequency | 95 | new - new frequency |
| 96 | |||
| 97 | 3. CPUFreq Table Generation with Operating Performance Point (OPP) | ||
| 98 | ================================================================== | ||
| 99 | For details about OPP, see Documentation/power/opp.txt | ||
| 100 | |||
| 101 | dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with | ||
| 102 | cpufreq_frequency_table_cpuinfo which is provided with the list of | ||
| 103 | frequencies that are available for operation. This function provides | ||
| 104 | a ready to use conversion routine to translate the OPP layer's internal | ||
| 105 | information about the available frequencies into a format readily | ||
| 106 | providable to cpufreq. | ||
| 107 | |||
| 108 | WARNING: Do not use this function in interrupt context. | ||
| 109 | |||
| 110 | Example: | ||
| 111 | soc_pm_init() | ||
| 112 | { | ||
| 113 | /* Do things */ | ||
| 114 | r = dev_pm_opp_init_cpufreq_table(dev, &freq_table); | ||
| 115 | if (!r) | ||
| 116 | cpufreq_frequency_table_cpuinfo(policy, freq_table); | ||
| 117 | /* Do other things */ | ||
| 118 | } | ||
| 119 | |||
| 120 | NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in | ||
| 121 | addition to CONFIG_PM_OPP. | ||
| 122 | |||
| 123 | 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 b8a907dc0169..a9adad828cdc 100644 --- a/Documentation/power/opp.txt +++ b/Documentation/power/opp.txt | |||
| @@ -10,8 +10,7 @@ Contents | |||
| 10 | 3. OPP Search Functions | 10 | 3. OPP Search Functions |
| 11 | 4. OPP Availability Control Functions | 11 | 4. OPP Availability Control Functions |
| 12 | 5. OPP Data Retrieval Functions | 12 | 5. OPP Data Retrieval Functions |
| 13 | 6. Cpufreq Table Generation | 13 | 6. Data Structures |
| 14 | 7. Data Structures | ||
| 15 | 14 | ||
| 16 | 1. Introduction | 15 | 1. Introduction |
| 17 | =============== | 16 | =============== |
| @@ -72,7 +71,6 @@ operations until that OPP could be re-enabled if possible. | |||
| 72 | OPP library facilitates this concept in it's implementation. The following | 71 | OPP library facilitates this concept in it's implementation. The following |
| 73 | operational functions operate only on available opps: | 72 | operational functions operate only on available opps: |
| 74 | opp_find_freq_{ceil, floor}, dev_pm_opp_get_voltage, dev_pm_opp_get_freq, dev_pm_opp_get_opp_count | 73 | opp_find_freq_{ceil, floor}, dev_pm_opp_get_voltage, dev_pm_opp_get_freq, dev_pm_opp_get_opp_count |
| 75 | and dev_pm_opp_init_cpufreq_table | ||
| 76 | 74 | ||
| 77 | dev_pm_opp_find_freq_exact is meant to be used to find the opp pointer which can then | 75 | dev_pm_opp_find_freq_exact is meant to be used to find the opp pointer which can then |
| 78 | be used for dev_pm_opp_enable/disable functions to make an opp available as required. | 76 | 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}, | |||
| 96 | opp_get_{voltage, freq, opp_count} fall into this category. | 94 | opp_get_{voltage, freq, opp_count} fall into this category. |
| 97 | 95 | ||
| 98 | opp_{add,enable,disable} are updaters which use mutex and implement it's own | 96 | opp_{add,enable,disable} are updaters which use mutex and implement it's own |
| 99 | RCU locking mechanisms. dev_pm_opp_init_cpufreq_table acts as an updater and uses | 97 | RCU locking mechanisms. These functions should *NOT* be called under RCU locks |
| 100 | mutex to implment RCU updater strategy. These functions should *NOT* be called | 98 | and other contexts that prevent blocking functions in RCU or mutex operations |
| 101 | under RCU locks and other contexts that prevent blocking functions in RCU or | 99 | from working. |
| 102 | mutex operations from working. | ||
| 103 | 100 | ||
| 104 | 2. Initial OPP List Registration | 101 | 2. Initial OPP List Registration |
| 105 | ================================ | 102 | ================================ |
| @@ -311,34 +308,7 @@ dev_pm_opp_get_opp_count - Retrieve the number of available opps for a device | |||
| 311 | /* Do other things */ | 308 | /* Do other things */ |
| 312 | } | 309 | } |
| 313 | 310 | ||
| 314 | 6. Cpufreq Table Generation | 311 | 6. Data Structures |
| 315 | =========================== | ||
| 316 | dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with | ||
| 317 | cpufreq_frequency_table_cpuinfo which is provided with the list of | ||
| 318 | frequencies that are available for operation. This function provides | ||
| 319 | a ready to use conversion routine to translate the OPP layer's internal | ||
| 320 | information about the available frequencies into a format readily | ||
| 321 | providable to cpufreq. | ||
| 322 | |||
| 323 | WARNING: Do not use this function in interrupt context. | ||
| 324 | |||
| 325 | Example: | ||
| 326 | soc_pm_init() | ||
| 327 | { | ||
| 328 | /* Do things */ | ||
| 329 | r = dev_pm_opp_init_cpufreq_table(dev, &freq_table); | ||
| 330 | if (!r) | ||
| 331 | cpufreq_frequency_table_cpuinfo(policy, freq_table); | ||
| 332 | /* Do other things */ | ||
| 333 | } | ||
| 334 | |||
| 335 | NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in | ||
| 336 | addition to CONFIG_PM as power management feature is required to | ||
| 337 | dynamically scale voltage and frequency in a system. | ||
| 338 | |||
| 339 | dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table | ||
| 340 | |||
| 341 | 7. Data Structures | ||
| 342 | ================== | 312 | ================== |
| 343 | Typically an SoC contains multiple voltage domains which are variable. Each | 313 | Typically an SoC contains multiple voltage domains which are variable. Each |
| 344 | domain is represented by a device pointer. The relationship to OPP can be | 314 | 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 38b43bb20878..d9e376a6d19d 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c | |||
| @@ -15,7 +15,6 @@ | |||
| 15 | #include <linux/errno.h> | 15 | #include <linux/errno.h> |
| 16 | #include <linux/err.h> | 16 | #include <linux/err.h> |
| 17 | #include <linux/slab.h> | 17 | #include <linux/slab.h> |
| 18 | #include <linux/cpufreq.h> | ||
| 19 | #include <linux/device.h> | 18 | #include <linux/device.h> |
| 20 | #include <linux/list.h> | 19 | #include <linux/list.h> |
| 21 | #include <linux/rculist.h> | 20 | #include <linux/rculist.h> |
| @@ -596,97 +595,6 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) | |||
| 596 | } | 595 | } |
| 597 | EXPORT_SYMBOL_GPL(dev_pm_opp_disable); | 596 | EXPORT_SYMBOL_GPL(dev_pm_opp_disable); |
| 598 | 597 | ||
| 599 | #ifdef CONFIG_CPU_FREQ | ||
| 600 | /** | ||
| 601 | * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device | ||
| 602 | * @dev: device for which we do this operation | ||
| 603 | * @table: Cpufreq table returned back to caller | ||
| 604 | * | ||
| 605 | * Generate a cpufreq table for a provided device- this assumes that the | ||
| 606 | * opp list is already initialized and ready for usage. | ||
| 607 | * | ||
| 608 | * This function allocates required memory for the cpufreq table. It is | ||
| 609 | * expected that the caller does the required maintenance such as freeing | ||
| 610 | * the table as required. | ||
| 611 | * | ||
| 612 | * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM | ||
| 613 | * if no memory available for the operation (table is not populated), returns 0 | ||
| 614 | * if successful and table is populated. | ||
| 615 | * | ||
| 616 | * WARNING: It is important for the callers to ensure refreshing their copy of | ||
| 617 | * the table if any of the mentioned functions have been invoked in the interim. | ||
| 618 | * | ||
| 619 | * Locking: The internal device_opp and opp structures are RCU protected. | ||
| 620 | * Since we just use the regular accessor functions to access the internal data | ||
| 621 | * structures, we use RCU read lock inside this function. As a result, users of | ||
| 622 | * this function DONOT need to use explicit locks for invoking. | ||
| 623 | */ | ||
| 624 | int dev_pm_opp_init_cpufreq_table(struct device *dev, | ||
| 625 | struct cpufreq_frequency_table **table) | ||
| 626 | { | ||
| 627 | struct dev_pm_opp *opp; | ||
| 628 | struct cpufreq_frequency_table *freq_table = NULL; | ||
| 629 | int i, max_opps, ret = 0; | ||
| 630 | unsigned long rate; | ||
| 631 | |||
| 632 | rcu_read_lock(); | ||
| 633 | |||
| 634 | max_opps = dev_pm_opp_get_opp_count(dev); | ||
| 635 | if (max_opps <= 0) { | ||
| 636 | ret = max_opps ? max_opps : -ENODATA; | ||
| 637 | goto out; | ||
| 638 | } | ||
| 639 | |||
| 640 | freq_table = kzalloc(sizeof(*freq_table) * (max_opps + 1), GFP_KERNEL); | ||
| 641 | if (!freq_table) { | ||
| 642 | ret = -ENOMEM; | ||
| 643 | goto out; | ||
| 644 | } | ||
| 645 | |||
