Commit de9c739435b47e7d39e448b2cc4c8154cabc9e5a
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smarc-imx_3.14.28_1.0.0_ga
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PM / devfreq: add comments and Documentation
- Added missing ABI documents - Added comments to clarify the objectives of functions Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Acked-by: Nishanth Menon <nm@ti.com> Acked-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Showing 3 changed files with 32 additions and 0 deletions Side-by-side Diff
Documentation/ABI/testing/sysfs-class-devfreq
| ... | ... | @@ -78,4 +78,24 @@ |
| 78 | 78 | Description: |
| 79 | 79 | The /sys/class/devfreq/.../available_governors shows |
| 80 | 80 | currently available governors in the system. |
| 81 | + | |
| 82 | +What: /sys/class/devfreq/.../min_freq | |
| 83 | +Date: January 2013 | |
| 84 | +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> | |
| 85 | +Description: | |
| 86 | + The /sys/class/devfreq/.../min_freq shows and stores | |
| 87 | + the minimum frequency requested by users. It is 0 if | |
| 88 | + the user does not care. min_freq overrides the | |
| 89 | + frequency requested by governors. | |
| 90 | + | |
| 91 | +What: /sys/class/devfreq/.../max_freq | |
| 92 | +Date: January 2013 | |
| 93 | +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> | |
| 94 | +Description: | |
| 95 | + The /sys/class/devfreq/.../max_freq shows and stores | |
| 96 | + the maximum frequency requested by users. It is 0 if | |
| 97 | + the user does not care. max_freq overrides the | |
| 98 | + frequency requested by governors and min_freq. | |
| 99 | + The max_freq overrides min_freq because max_freq may be | |
| 100 | + used to throttle devices to avoid overheating. |
drivers/devfreq/devfreq.c
| ... | ... | @@ -527,6 +527,8 @@ |
| 527 | 527 | /** |
| 528 | 528 | * devfreq_remove_device() - Remove devfreq feature from a device. |
| 529 | 529 | * @devfreq: the devfreq instance to be removed |
| 530 | + * | |
| 531 | + * The opposite of devfreq_add_device(). | |
| 530 | 532 | */ |
| 531 | 533 | int devfreq_remove_device(struct devfreq *devfreq) |
| 532 | 534 | { |
| ... | ... | @@ -542,6 +544,10 @@ |
| 542 | 544 | /** |
| 543 | 545 | * devfreq_suspend_device() - Suspend devfreq of a device. |
| 544 | 546 | * @devfreq: the devfreq instance to be suspended |
| 547 | + * | |
| 548 | + * This function is intended to be called by the pm callbacks | |
| 549 | + * (e.g., runtime_suspend, suspend) of the device driver that | |
| 550 | + * holds the devfreq. | |
| 545 | 551 | */ |
| 546 | 552 | int devfreq_suspend_device(struct devfreq *devfreq) |
| 547 | 553 | { |
| ... | ... | @@ -559,6 +565,10 @@ |
| 559 | 565 | /** |
| 560 | 566 | * devfreq_resume_device() - Resume devfreq of a device. |
| 561 | 567 | * @devfreq: the devfreq instance to be resumed |
| 568 | + * | |
| 569 | + * This function is intended to be called by the pm callbacks | |
| 570 | + * (e.g., runtime_resume, resume) of the device driver that | |
| 571 | + * holds the devfreq. | |
| 562 | 572 | */ |
| 563 | 573 | int devfreq_resume_device(struct devfreq *devfreq) |
| 564 | 574 | { |
include/linux/devfreq.h
| ... | ... | @@ -181,6 +181,8 @@ |
| 181 | 181 | const char *governor_name, |
| 182 | 182 | void *data); |
| 183 | 183 | extern int devfreq_remove_device(struct devfreq *devfreq); |
| 184 | + | |
| 185 | +/* Supposed to be called by PM_SLEEP/PM_RUNTIME callbacks */ | |
| 184 | 186 | extern int devfreq_suspend_device(struct devfreq *devfreq); |
| 185 | 187 | extern int devfreq_resume_device(struct devfreq *devfreq); |
| 186 | 188 |