/sys/class/rtc/rtcX/date and /sys/class/rtc/rtcX/time currently have
read-only access. This patch introduces write functionality which will
set the rtc time.
Usage: echo YYYY-MM-DD > /sys/class/rtc/rtcX/date
echo HH:MM:SS > /sys/class/rtc/rtcX/time
Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Matt Fleming <matt.fleming@xxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: linux-efi@xxxxxxxxxxxxxxx
---
drivers/rtc/rtc-sysfs.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 84 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
index b70e2bb..87d63d7 100644
--- a/drivers/rtc/rtc-sysfs.c
+++ b/drivers/rtc/rtc-sysfs.c
@@ -48,6 +48,46 @@ rtc_sysfs_show_date(struct device *dev, struct device_attribute *attr,
}
static ssize_t
+rtc_sysfs_store_date(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+ char tmp[11] = "\0", *tmpptr = tmp;
+ char *cyear, *cmonth, *cday;
+ int year, month, day;
+
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* from rtc_sysfs_show_date(): date string format is YYYY-MM-DD */
+ if (strlen(buf) != 11)
+ return -EINVAL;
+
+ strncpy(tmp, buf, 11);
+ cyear = strsep(&tmpptr, "-");
+ sscanf(cyear, "%i", &year);
+ cmonth = strsep(&tmpptr, "-");
+ sscanf(cmonth, "%i", &month);
+ cday = strsep(&tmpptr, "-");
+ sscanf(cday, "%i", &day);
+
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return -ENODEV;
+
+ tm.tm_year = year - 1900;
+ tm.tm_mon = month - 1;
+ tm.tm_mday = day;
+
+ retval = rtc_set_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return retval;
+
+ return count;
+}
+
+static ssize_t
rtc_sysfs_show_time(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -64,6 +104,46 @@ rtc_sysfs_show_time(struct device *dev, struct device_attribute *attr,
}
static ssize_t
+rtc_sysfs_store_time(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+ char tmp[9] = "\0", *tmpptr = tmp;
+ char *chour, *cmin, *csec;
+ int hour, min, sec;
+
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* from rtc_sysfs_show_time(): time string format is HH:MM:SS */
+ if (strlen(buf) != 9)
+ return -EINVAL;
+
+ strncpy(tmp, buf, 9);
+ chour = strsep(&tmpptr, ":");
+ sscanf(chour, "%i", &hour);
+ cmin = strsep(&tmpptr, ":");
+ sscanf(cmin, "%i", &min);
+ csec = strsep(&tmpptr, ":");
+ sscanf(csec, "%i", &sec);
+
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return -ENODEV;
+
+ tm.tm_hour = hour;
+ tm.tm_min = min;
+ tm.tm_sec = sec;
+
+ retval = rtc_set_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return retval;
+
+ return count;
+}
+
+static ssize_t
rtc_sysfs_show_since_epoch(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -124,8 +204,10 @@ rtc_sysfs_show_hctosys(struct device *dev, struct device_attribute *attr,
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(date, S_IRUGO | S_IWUGO, rtc_sysfs_show_date,
+ rtc_sysfs_store_date),
+ __ATTR(time, S_IRUGO | S_IWUGO, rtc_sysfs_show_time,
+ rtc_sysfs_store_time),
__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),
--
1.8.1.2
--
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