diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 69df94b44841..6cad0841f3c4 100644 --- a/drivers/rtc/rtc-sysfs.c +++ b/drivers/rtc/rtc-sysfs.c @@ -73,11 +73,35 @@ rtc_sysfs_show_since_epoch(struct device *dev, struct device_attribute *attr, return retval; } +static ssize_t +rtc_sysfs_show_max_user_freq(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", to_rtc_device(dev)->max_user_freq); +} + +static ssize_t +rtc_sysfs_set_max_user_freq(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + struct rtc_device *rtc = to_rtc_device(dev); + unsigned long val = simple_strtoul(buf, NULL, 0); + + if (val >= 4096 || val == 0) + return -EINVAL; + + rtc->max_user_freq = (int)val; + + return n; +} + static struct device_attribute rtc_attrs[] = { __ATTR(name, S_IRUGO, rtc_sysfs_show_name, NULL), __ATTR(date, S_IRUGO, rtc_sysfs_show_date, NULL), __ATTR(time, S_IRUGO, rtc_sysfs_show_time, NULL), __ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL), + __ATTR(max_user_freq, S_IRUGO | S_IWUSR, rtc_sysfs_show_max_user_freq, + rtc_sysfs_set_max_user_freq), { }, };