diff options
| author | MyungJoo Ham <myungjoo.ham@samsung.com> | 2011-11-14 17:31:35 -0500 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-11-14 17:31:35 -0500 |
| commit | 6c81f90588972b8631bda4d538ffd0199a3e1b41 (patch) | |
| tree | ccf3fb4b293ac0416423566f07812050220388f6 | |
| parent | 9f3bdd4f937a75c4589a867dc1f8fefe09c1a618 (diff) | |
PM / devfreq: correct Kconfig dependency
Devfreq does not depend on OPP. The dependency is removed.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| -rw-r--r-- | drivers/devfreq/Kconfig | 41 |
1 files changed, 17 insertions, 24 deletions
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 643b055ed3cd..8f0491037080 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig | |||
| @@ -1,36 +1,29 @@ | |||
| 1 | config ARCH_HAS_DEVFREQ | ||
| 2 | bool | ||
| 3 | depends on ARCH_HAS_OPP | ||
| 4 | help | ||
| 5 | Denotes that the architecture supports DEVFREQ. If the architecture | ||
| 6 | supports multiple OPP entries per device and the frequency of the | ||
| 7 | devices with OPPs may be altered dynamically, the architecture | ||
| 8 | supports DEVFREQ. | ||
| 9 | |||
| 10 | menuconfig PM_DEVFREQ | 1 | menuconfig PM_DEVFREQ |
| 11 | bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" | 2 | bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" |
| 12 | depends on PM_OPP && ARCH_HAS_DEVFREQ | ||
| 13 | help | 3 | help |
| 14 | With OPP support, a device may have a list of frequencies and | 4 | A device may have a list of frequencies and voltages available. |
| 15 | voltages available. DEVFREQ, a generic DVFS framework can be | 5 | devfreq, a generic DVFS framework can be registered for a device |
| 16 | registered for a device with OPP support in order to let the | 6 | in order to let the governor provided to devfreq choose an |
| 17 | governor provided to DEVFREQ choose an operating frequency | 7 | operating frequency based on the device driver's policy. |
| 18 | based on the OPP's list and the policy given with DEVFREQ. | ||
| 19 | 8 | ||
| 20 | Each device may have its own governor and policy. DEVFREQ can | 9 | Each device may have its own governor and policy. Devfreq can |
| 21 | reevaluate the device state periodically and/or based on the | 10 | reevaluate the device state periodically and/or based on the |
| 22 | OPP list changes (each frequency/voltage pair in OPP may be | 11 | notification to "nb", a notifier block, of devfreq. |
| 23 | disabled or enabled). | ||
| 24 | 12 | ||
| 25 | Like some CPUs with CPUFREQ, a device may have multiple clocks. | 13 | Like some CPUs with CPUfreq, a device may have multiple clocks. |
| 26 | However, because the clock frequencies of a single device are | 14 | However, because the clock frequencies of a single device are |
| 27 | determined by the single device's state, an instance of DEVFREQ | 15 | determined by the single device's state, an instance of devfreq |
| 28 | is attached to a single device and returns a "representative" | 16 | is attached to a single device and returns a "representative" |
| 29 | clock frequency from the OPP of the device, which is also attached | 17 | clock frequency of the device, which is also attached |
| 30 | to a device by 1-to-1. The device registering DEVFREQ takes the | 18 | to a device by 1-to-1. The device registering devfreq takes the |
| 31 | responsiblity to "interpret" the frequency listed in OPP and | 19 | responsiblity to "interpret" the representative frequency and |
| 32 | to set its every clock accordingly with the "target" callback | 20 | to set its every clock accordingly with the "target" callback |
| 33 | given to DEVFREQ. | 21 | given to devfreq. |
| 22 | |||
| 23 | When OPP is used with the devfreq device, it is recommended to | ||
| 24 | register devfreq's nb to the OPP's notifier head. If OPP is | ||
| 25 | used with the devfreq device, you may use OPP helper | ||
| 26 | functions defined in devfreq.h. | ||
| 34 | 27 | ||
| 35 | if PM_DEVFREQ | 28 | if PM_DEVFREQ |
| 36 | 29 | ||
