From 06c65eb45578c52d1bc69d044239646d4c90e7ea Mon Sep 17 00:00:00 2001 From: Bryan Kadzban Date: Tue, 16 Oct 2007 01:28:22 -0700 Subject: [PATCH] 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 Acked-by: Alessandro Zummo Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-sysfs.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) 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), { }, }; -- 2.30.2