diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 12 | ||||
| -rw-r--r-- | drivers/devfreq/devfreq.c | 86 | ||||
| -rw-r--r-- | include/linux/devfreq.h | 9 |
3 files changed, 106 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 9758eb85ade3..deefffb3bbe4 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -108,3 +108,15 @@ Description: frequency requested by governors and min_freq. The max_freq overrides min_freq because max_freq may be used to throttle devices to avoid overheating. + +What: /sys/class/devfreq/.../timer +Date: July 2020 +Contact: Chanwoo Choi <cw00.choi@samsung.com> +Description: + This ABI shows and stores the kind of work timer by users. + This work timer is used by devfreq workqueue in order to + monitor the device status such as utilization. The user + can change the work timer on runtime according to their demand + as following: + echo deferrable > /sys/class/devfreq/.../timer + echo delayed > /sys/class/devfreq/.../timer diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 52b9c3e141f3..5320c3b37f35 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -49,6 +49,11 @@ static LIST_HEAD(devfreq_governor_list); static LIST_HEAD(devfreq_list); static DEFINE_MUTEX(devfreq_list_lock); +static const char timer_name[][DEVFREQ_NAME_LEN] = { + [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" }, + [DEVFREQ_TIMER_DELAYED] = { "delayed" }, +}; + /** * find_device_devfreq() - find devfreq struct using device pointer * @dev: device pointer used to lookup device devfreq. @@ -454,7 +459,17 @@ void devfreq_monitor_start(struct devfreq *devfreq) if (devfreq->governor->interrupt_driven) return; - INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); + switch (devfreq->profile->timer) { + case DEVFREQ_TIMER_DEFERRABLE: + INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); + break; + case DEVFREQ_TIMER_DELAYED: + INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor); + break; + default: + return; + } + if (devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); @@ -771,6 +786,11 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq->data = data; devfreq->nb.notifier_call = devfreq_notifier_call; + if (devfreq->profile->timer < 0 + || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) { + goto err_out; + } + if (!devfreq->profile->max_state && !devfreq->profile->freq_table) { mutex_unlock(&devfreq->lock); err = set_freq_table(devfreq); @@ -1625,6 +1645,69 @@ static ssize_t trans_stat_store(struct device *dev, } static DEVICE_ATTR_RW(trans_stat); +static ssize_t timer_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct devfreq *df = to_devfreq(dev); + + if (!df->profile) + return -EINVAL; + + return sprintf(buf, "%s\n", timer_name[df->profile->timer]); +} + +static ssize_t timer_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct devfreq *df = to_devfreq(dev); + char str_timer[DEVFREQ_NAME_LEN + 1]; + int timer = -1; + int ret = 0, i; + + if (!df->governor || !df->profile) + return -EINVAL; + + ret = sscanf(buf, "%16s", str_timer); + if (ret != 1) + return -EINVAL; + + for (i = 0; i < DEVFREQ_TIMER_NUM; i++) { + if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) { + timer = i; + break; + } + } + + if (timer < 0) { + ret = -EINVAL; + goto out; + } + + if (df->profile->timer == timer) { + ret = 0; + goto out; + } + + mutex_lock(&df->lock); + df->profile->timer = timer; + mutex_unlock(&df->lock); + + ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); + if (ret) { + dev_warn(dev, "%s: Governor %s not stopped(%d)\n", + __func__, df->governor->name, ret); + goto out; + } + + ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); + if (ret) + dev_warn(dev, "%s: Governor %s not started(%d)\n", + __func__, df->governor->name, ret); +out: + return ret ? ret : count; +} +static DEVICE_ATTR_RW(timer); + static struct attribute *devfreq_attrs[] = { &dev_attr_name.attr, &dev_attr_governor.attr, @@ -1636,6 +1719,7 @@ static struct attribute *devfreq_attrs[] = { &dev_attr_min_freq.attr, &dev_attr_max_freq.attr, &dev_attr_trans_stat.attr, + &dev_attr_timer.attr, NULL, }; ATTRIBUTE_GROUPS(devfreq); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 57e871a559a9..12782fbb4c25 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -31,6 +31,13 @@ #define DEVFREQ_PRECHANGE (0) #define DEVFREQ_POSTCHANGE (1) +/* DEVFREQ work timers */ +enum devfreq_timer { + DEVFREQ_TIMER_DEFERRABLE = 0, + DEVFREQ_TIMER_DELAYED, + DEVFREQ_TIMER_NUM, +}; + struct devfreq; struct devfreq_governor; @@ -70,6 +77,7 @@ struct devfreq_dev_status { * @initial_freq: The operating frequency when devfreq_add_device() is * called. * @polling_ms: The polling interval in ms. 0 disables polling. + * @timer: Timer type is either deferrable or delayed timer. * @target: The device should set its operating frequency at * freq or lowest-upper-than-freq value. If freq is * higher than any operable frequency, set maximum. @@ -96,6 +104,7 @@ struct devfreq_dev_status { struct devfreq_dev_profile { unsigned long initial_freq; unsigned int polling_ms; + enum devfreq_timer timer; int (*target)(struct device *dev, unsigned long *freq, u32 flags); int (*get_dev_status)(struct device *dev, |