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authorBryan Kadzban <bryan@kdzbn.homelinux.net>2007-10-16 01:28:22 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:43:13 -0700
commit06c65eb45578c52d1bc69d044239646d4c90e7ea (patch)
tree50d136607746d1a885ed8bb3757a3850faa28dd6 /drivers/rtc
parent05440dfcfcabde6fcf7297dfa5a29f0355b78ffb (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>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-sysfs.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
index 69df94b4484..6cad0841f3c 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),
{ },
};