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 --- drivers/devfreq/devfreq.c | 47 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 6 deletions(-) (limited to 'drivers/devfreq') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index a9fd61bbacf1..46517b61b3a2 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -316,6 +316,10 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq, "Couldn't update frequency transition information.\n"); devfreq->previous_freq = new_freq; + + if (devfreq->suspend_freq) + devfreq->resume_freq = cur_freq; + return err; } @@ -667,6 +671,9 @@ struct devfreq *devfreq_add_device(struct device *dev, } devfreq->max_freq = devfreq->scaling_max_freq; + devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); + atomic_set(&devfreq->suspend_count, 0); + dev_set_name(&devfreq->dev, "devfreq%d", atomic_inc_return(&devfreq_no)); err = device_register(&devfreq->dev); @@ -867,14 +874,28 @@ EXPORT_SYMBOL(devm_devfreq_remove_device); */ int devfreq_suspend_device(struct devfreq *devfreq) { + int ret; + if (!devfreq) return -EINVAL; - if (!devfreq->governor) + if (atomic_inc_return(&devfreq->suspend_count) > 1) return 0; - return devfreq->governor->event_handler(devfreq, - DEVFREQ_GOV_SUSPEND, NULL); + if (devfreq->governor) { + ret = devfreq->governor->event_handler(devfreq, + DEVFREQ_GOV_SUSPEND, NULL); + if (ret) + return ret; + } + + if (devfreq->suspend_freq) { + ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0); + if (ret) + return ret; + } + + return 0; } EXPORT_SYMBOL(devfreq_suspend_device); @@ -888,14 +909,28 @@ EXPORT_SYMBOL(devfreq_suspend_device); */ int devfreq_resume_device(struct devfreq *devfreq) { + int ret; + if (!devfreq) return -EINVAL; - if (!devfreq->governor) + if (atomic_dec_return(&devfreq->suspend_count) >= 1) return 0; - return devfreq->governor->event_handler(devfreq, - DEVFREQ_GOV_RESUME, NULL); + if (devfreq->resume_freq) { + ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0); + if (ret) + return ret; + } + + if (devfreq->governor) { + ret = devfreq->governor->event_handler(devfreq, + DEVFREQ_GOV_RESUME, NULL); + if (ret) + return ret; + } + + return 0; } EXPORT_SYMBOL(devfreq_resume_device); -- cgit v1.2.3-55-g7522