From 83f8ca45afbf041e312909f442128b99657d90b7 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 5 Dec 2018 12:05:53 +0100 Subject: PM / devfreq: add support for suspend/resume of a devfreq device The patch prepares devfreq device for handling suspend/resume functionality. The new fields will store needed information during this process. Devfreq framework handles opp-suspend DT entry and there is no need of modyfications in the drivers code. It uses atomic variables to make sure no race condition affects the process. Suggested-by: Tobias Jakobi Suggested-by: Chanwoo Choi Signed-off-by: Lukasz Luba Reviewed-by: Chanwoo Choi Signed-off-by: MyungJoo Ham --- include/linux/devfreq.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/devfreq.h') diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index e4963b0f45da..d98519996927 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -131,6 +131,9 @@ struct devfreq_dev_profile { * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. + * @suspend_freq: frequency of a device set during suspend phase. + * @resume_freq: frequency of a device set in resume phase. + * @suspend_count: suspend requests counter for a device. * @total_trans: Number of devfreq transitions * @trans_table: Statistics of devfreq transitions * @time_in_state: Statistics of devfreq states @@ -167,6 +170,10 @@ struct devfreq { unsigned long scaling_max_freq; bool stop_polling; + unsigned long suspend_freq; + unsigned long resume_freq; + atomic_t suspend_count; + /* information for device frequency transition */ unsigned int total_trans; unsigned int *trans_table; -- cgit From 5903195605287681f55094bbcdf8711ea109969b Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 5 Dec 2018 12:05:54 +0100 Subject: PM / devfreq: add devfreq_suspend/resume() functions This patch adds implementation for global suspend/resume for devfreq framework. System suspend will next use these functions. Suggested-by: Tobias Jakobi Suggested-by: Chanwoo Choi Signed-off-by: Lukasz Luba Reviewed-by: Chanwoo Choi Signed-off-by: MyungJoo Ham --- drivers/devfreq/devfreq.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/devfreq.h | 6 ++++++ 2 files changed, 50 insertions(+) (limited to 'include/linux/devfreq.h') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 46517b61b3a2..0ae3de76833b 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -934,6 +934,50 @@ int devfreq_resume_device(struct devfreq *devfreq) } EXPORT_SYMBOL(devfreq_resume_device); +/** + * devfreq_suspend() - Suspend devfreq governors and devices + * + * Called during system wide Suspend/Hibernate cycles for suspending governors + * and devices preserving the state for resume. On some platforms the devfreq + * device must have precise state (frequency) after resume in order to provide + * fully operating setup. + */ +void devfreq_suspend(void) +{ + struct devfreq *devfreq; + int ret; + + mutex_lock(&devfreq_list_lock); + list_for_each_entry(devfreq, &devfreq_list, node) { + ret = devfreq_suspend_device(devfreq); + if (ret) + dev_err(&devfreq->dev, + "failed to suspend devfreq device\n"); + } + mutex_unlock(&devfreq_list_lock); +} + +/** + * devfreq_resume() - Resume devfreq governors and devices + * + * Called during system wide Suspend/Hibernate cycle for resuming governors and + * devices that are suspended with devfreq_suspend(). + */ +void devfreq_resume(void) +{ + struct devfreq *devfreq; + int ret; + + mutex_lock(&devfreq_list_lock); + list_for_each_entry(devfreq, &devfreq_list, node) { + ret = devfreq_resume_device(devfreq); + if (ret) + dev_warn(&devfreq->dev, + "failed to resume devfreq device\n"); + } + mutex_unlock(&devfreq_list_lock); +} + /** * devfreq_add_governor() - Add devfreq governor * @governor: the devfreq governor to be added diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index d98519996927..fbffa74bfc1b 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -205,6 +205,9 @@ extern void devm_devfreq_remove_device(struct device *dev, extern int devfreq_suspend_device(struct devfreq *devfreq); extern int devfreq_resume_device(struct devfreq *devfreq); +extern void devfreq_suspend(void); +extern void devfreq_resume(void); + /** * update_devfreq() - Reevaluate the device and configure frequency * @devfreq: the devfreq device @@ -331,6 +334,9 @@ static inline int devfreq_resume_device(struct devfreq *devfreq) return 0; } +static inline void devfreq_suspend(void) {} +static inline void devfreq_resume(void) {} + static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, u32 flags) { -- cgit