diff options
| author | Bryan Kadzban <bryan@kdzbn.homelinux.net> | 2007-10-16 01:28:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:43:13 -0700 |
| commit | 06c65eb45578c52d1bc69d044239646d4c90e7ea (patch) | |
| tree | 50d136607746d1a885ed8bb3757a3850faa28dd6 | |
| parent | 05440dfcfcabde6fcf7297dfa5a29f0355b78ffb (diff) | |
rtc: add max_user_freq to sysfs
drivers/char/rtc.c exposed a sysctl to change the maximum frequency at
which a non-root user could ask the RTC to generate interrupts (via the
RTC_IRQP_SET ioctl). This value is no longer available under the new RTC
subsystem, so add it to sysfs for each RTC device.
Works for me on x86_64 (both reads and writes), using rtc-cmos.
Signed-off-by: Bryan Kadzban <bryan@kdzbn.homelinux.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/rtc/rtc-sysfs.c | 24 |
1 files changed, 24 insertions, 0 deletions
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), { }, }; |