diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 44 | ||||
| -rw-r--r-- | drivers/devfreq/devfreq.c | 69 |
2 files changed, 113 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq new file mode 100644 index 00000000000..0ec855f479c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -0,0 +1,44 @@ +What: /sys/class/devfreq/.../ +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + Provide a place in sysfs for the devfreq objects. + This allows accessing various devfreq specific variables. + The name of devfreq object denoted as ... is same as the + name of device using devfreq. + +What: /sys/class/devfreq/.../governor +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../governor shows the name of the + governor used by the corresponding devfreq object. + +What: /sys/class/devfreq/.../cur_freq +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../cur_freq shows the current + frequency of the corresponding devfreq object. + +What: /sys/class/devfreq/.../central_polling +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../central_polling shows whether + the devfreq ojbect is using devfreq-provided central + polling mechanism or not. + +What: /sys/class/devfreq/.../polling_interval +Date: September 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + The /sys/class/devfreq/.../polling_interval shows and sets + the requested polling interval of the corresponding devfreq + object. The values are represented in ms. If the value is + less than 1 jiffy, it is considered to be 0, which means + no polling. This value is meaningless if the governor is + not polling; thus. If the governor is not using + devfreq-provided central polling + (/sys/class/devfreq/.../central_polling is 0), this value + may be useless. diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index f3100b19f79..5d15b812377 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -437,6 +437,74 @@ int devfreq_remove_device(struct devfreq *devfreq) return 0; } +static ssize_t show_governor(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); +} + +static ssize_t show_freq(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); +} + +static ssize_t show_polling_interval(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); +} + +static ssize_t store_polling_interval(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct devfreq *df = to_devfreq(dev); + unsigned int value; + int ret; + + ret = sscanf(buf, "%u", &value); + if (ret != 1) + goto out; + + mutex_lock(&df->lock); + df->profile->polling_ms = value; + df->next_polling = df->polling_jiffies + = msecs_to_jiffies(value); + mutex_unlock(&df->lock); + + ret = count; + + if (df->governor->no_central_polling) + goto out; + + mutex_lock(&devfreq_list_lock); + if (df->next_polling > 0 && !polling) { + polling = true; + queue_delayed_work(devfreq_wq, &devfreq_work, + df->next_polling); + } + mutex_unlock(&devfreq_list_lock); +out: + return ret; +} + +static ssize_t show_central_polling(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", + !to_devfreq(dev)->governor->no_central_polling); +} + +static struct device_attribute devfreq_attrs[] = { + __ATTR(governor, S_IRUGO, show_governor, NULL), + __ATTR(cur_freq, S_IRUGO, show_freq, NULL), + __ATTR(central_polling, S_IRUGO, show_central_polling, NULL), + __ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval, + store_polling_interval), + { }, +}; + /** * devfreq_start_polling() - Initialize data structure for devfreq framework and * start polling registered devfreq devices. @@ -461,6 +529,7 @@ static int __init devfreq_init(void) pr_err("%s: couldn't create class\n", __FILE__); return PTR_ERR(devfreq_class); } + devfreq_class->dev_attrs = devfreq_attrs; return 0; } subsys_initcall(devfreq_init); |