#include <linux/module.h>
#include <linux/rtc.h>
+#include "rtc-core.h"
+
+
/* device attributes */
-static ssize_t rtc_sysfs_show_name(struct class_device *dev, char *buf)
+/*
+ * NOTE: RTC times displayed in sysfs use the RTC's timezone. That's
+ * ideally UTC. However, PCs that also boot to MS-Windows normally use
+ * the local time and change to match daylight savings time. That affects
+ * attributes including date, time, since_epoch, and wakealarm.
+ */
+
+static ssize_t
+rtc_sysfs_show_name(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
return sprintf(buf, "%s\n", to_rtc_device(dev)->name);
}
-static CLASS_DEVICE_ATTR(name, S_IRUGO, rtc_sysfs_show_name, NULL);
-static ssize_t rtc_sysfs_show_date(struct class_device *dev, char *buf)
+static ssize_t
+rtc_sysfs_show_date(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
ssize_t retval;
struct rtc_time tm;
- retval = rtc_read_time(dev, &tm);
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
if (retval == 0) {
retval = sprintf(buf, "%04d-%02d-%02d\n",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
return retval;
}
-static CLASS_DEVICE_ATTR(date, S_IRUGO, rtc_sysfs_show_date, NULL);
-static ssize_t rtc_sysfs_show_time(struct class_device *dev, char *buf)
+static ssize_t
+rtc_sysfs_show_time(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
ssize_t retval;
struct rtc_time tm;
- retval = rtc_read_time(dev, &tm);
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
if (retval == 0) {
retval = sprintf(buf, "%02d:%02d:%02d\n",
tm.tm_hour, tm.tm_min, tm.tm_sec);
return retval;
}
-static CLASS_DEVICE_ATTR(time, S_IRUGO, rtc_sysfs_show_time, NULL);
-static ssize_t rtc_sysfs_show_since_epoch(struct class_device *dev, char *buf)
+static ssize_t
+rtc_sysfs_show_since_epoch(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
ssize_t retval;
struct rtc_time tm;
- retval = rtc_read_time(dev, &tm);
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
if (retval == 0) {
unsigned long time;
rtc_tm_to_time(&tm, &time);
return retval;
}
-static CLASS_DEVICE_ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL);
-
-static struct attribute *rtc_attrs[] = {
- &class_device_attr_name.attr,
- &class_device_attr_date.attr,
- &class_device_attr_time.attr,
- &class_device_attr_since_epoch.attr,
- NULL,
-};
-static struct attribute_group rtc_attr_group = {
- .attrs = rtc_attrs,
-};
+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 int __devinit rtc_sysfs_add_device(struct class_device *class_dev,
- struct class_interface *class_intf)
+static ssize_t
+rtc_sysfs_set_max_user_freq(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t n)
{
- int err;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ unsigned long val = simple_strtoul(buf, NULL, 0);
- dev_info(class_dev->dev, "rtc intf: sysfs\n");
+ if (val >= 4096 || val == 0)
+ return -EINVAL;
- err = sysfs_create_group(&class_dev->kobj, &rtc_attr_group);
- if (err)
- dev_err(class_dev->dev,
- "failed to create sysfs attributes\n");
+ rtc->max_user_freq = (int)val;
- return err;
+ return n;
}
-static void rtc_sysfs_remove_device(struct class_device *class_dev,
- struct class_interface *class_intf)
+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),
+ { },
+};
+
+static ssize_t
+rtc_sysfs_show_wakealarm(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
- sysfs_remove_group(&class_dev->kobj, &rtc_attr_group);
+ ssize_t retval;
+ unsigned long alarm;
+ struct rtc_wkalrm alm;
+
+ /* Don't show disabled alarms. For uniformity, RTC alarms are
+ * conceptually one-shot, even though some common RTCs (on PCs)
+ * don't actually work that way.
+ *
+ * NOTE: RTC implementations where the alarm doesn't match an
+ * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC
+ * alarms after they trigger, to ensure one-shot semantics.
+ */
+ retval = rtc_read_alarm(to_rtc_device(dev), &alm);
+ if (retval == 0 && alm.enabled) {
+ rtc_tm_to_time(&alm.time, &alarm);
+ retval = sprintf(buf, "%lu\n", alarm);
+ }
+
+ return retval;
}
-/* interface registration */
+static ssize_t
+rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t n)
+{
+ ssize_t retval;
+ unsigned long now, alarm;
+ struct rtc_wkalrm alm;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ char *buf_ptr;
+ int adjust = 0;
+
+ /* Only request alarms that trigger in the future. Disable them
+ * by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
+ */
+ retval = rtc_read_time(rtc, &alm.time);
+ if (retval < 0)
+ return retval;
+ rtc_tm_to_time(&alm.time, &now);
+
+ buf_ptr = (char *)buf;
+ if (*buf_ptr == '+') {
+ buf_ptr++;
+ adjust = 1;
+ }
+ alarm = simple_strtoul(buf_ptr, NULL, 0);
+ if (adjust) {
+ alarm += now;
+ }
+ if (alarm > now) {
+ /* Avoid accidentally clobbering active alarms; we can't
+ * entirely prevent that here, without even the minimal
+ * locking from the /dev/rtcN api.
+ */
+ retval = rtc_read_alarm(rtc, &alm);
+ if (retval < 0)
+ return retval;
+ if (alm.enabled)
+ return -EBUSY;
+
+ alm.enabled = 1;
+ } else {
+ alm.enabled = 0;
+
+ /* Provide a valid future alarm time. Linux isn't EFI,
+ * this time won't be ignored when disabling the alarm.
+ */
+ alarm = now + 300;
+ }
+ rtc_time_to_tm(alarm, &alm.time);
+
+ retval = rtc_set_alarm(rtc, &alm);
+ return (retval < 0) ? retval : n;
+}
+static DEVICE_ATTR(wakealarm, S_IRUGO | S_IWUSR,
+ rtc_sysfs_show_wakealarm, rtc_sysfs_set_wakealarm);
-static struct class_interface rtc_sysfs_interface = {
- .add = &rtc_sysfs_add_device,
- .remove = &rtc_sysfs_remove_device,
-};
-static int __init rtc_sysfs_init(void)
+/* The reason to trigger an alarm with no process watching it (via sysfs)
+ * is its side effect: waking from a system state like suspend-to-RAM or
+ * suspend-to-disk. So: no attribute unless that side effect is possible.
+ * (Userspace may disable that mechanism later.)
+ */
+static inline int rtc_does_wakealarm(struct rtc_device *rtc)
{
- return rtc_interface_register(&rtc_sysfs_interface);
+ if (!device_can_wakeup(rtc->dev.parent))
+ return 0;
+ return rtc->ops->set_alarm != NULL;
}
-static void __exit rtc_sysfs_exit(void)
+
+void rtc_sysfs_add_device(struct rtc_device *rtc)
{
- class_interface_unregister(&rtc_sysfs_interface);
+ int err;
+
+ /* not all RTCs support both alarms and wakeup */
+ if (!rtc_does_wakealarm(rtc))
+ return;
+
+ err = device_create_file(&rtc->dev, &dev_attr_wakealarm);
+ if (err)
+ dev_err(rtc->dev.parent,
+ "failed to create alarm attribute, %d\n", err);
}
-module_init(rtc_sysfs_init);
-module_exit(rtc_sysfs_exit);
+void rtc_sysfs_del_device(struct rtc_device *rtc)
+{
+ /* REVISIT did we add it successfully? */
+ if (rtc_does_wakealarm(rtc))
+ device_remove_file(&rtc->dev, &dev_attr_wakealarm);
+}
-MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
-MODULE_DESCRIPTION("RTC class sysfs interface");
-MODULE_LICENSE("GPL");
+void __init rtc_sysfs_init(struct class *rtc_class)
+{
+ rtc_class->dev_attrs = rtc_attrs;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff