]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/rtc/rtc-sysfs.c
Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6-omap-h63xx.git] / drivers / rtc / rtc-sysfs.c
index 625637b84d33424be18af05530db5293b11fd3ea..69df94b4484169d0a61b5c08f32f3e0e6133f716 100644 (file)
 #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)
+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);
@@ -33,14 +39,15 @@ static ssize_t rtc_sysfs_show_date(struct class_device *dev, char *buf)
 
        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);
@@ -48,14 +55,15 @@ static ssize_t rtc_sysfs_show_time(struct class_device *dev, char *buf)
 
        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);
@@ -64,61 +72,123 @@ static ssize_t rtc_sysfs_show_since_epoch(struct class_device *dev, char *buf)
 
        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 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),
+       { },
 };
 
-static int __devinit rtc_sysfs_add_device(struct class_device *class_dev,
-                                       struct class_interface *class_intf)
+static ssize_t
+rtc_sysfs_show_wakealarm(struct device *dev, struct device_attribute *attr,
+               char *buf)
 {
-       int err;
+       ssize_t retval;
+       unsigned long alarm;
+       struct rtc_wkalrm alm;
+
+       /* Don't show disabled alarms; but the RTC could leave the
+        * alarm enabled after it's already triggered.  Alarms are
+        * conceptually one-shot, even though some common hardware
+        * (PCs) doesn't actually work that way.
+        *
+        * REVISIT maybe we should require RTC implementations to
+        * disable the RTC alarm after it triggers, for uniformity.
+        */
+       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);
+       }
 
-       dev_info(class_dev->dev, "rtc intf: sysfs\n");
+       return retval;
+}
 
-       err = sysfs_create_group(&class_dev->kobj, &rtc_attr_group);
-       if (err)
-               dev_err(class_dev->dev,
-                       "failed to create sysfs attributes\n");
+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);
+
+       /* 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);
+
+       alarm = simple_strtoul(buf, NULL, 0);
+       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);
 
-       return err;
+       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 void rtc_sysfs_remove_device(struct class_device *class_dev,
-                               struct class_interface *class_intf)
+/* 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)
 {
-       sysfs_remove_group(&class_dev->kobj, &rtc_attr_group);
+       if (!device_can_wakeup(rtc->dev.parent))
+               return 0;
+       return rtc->ops->set_alarm != NULL;
 }
 
-/* interface registration */
-
-static struct class_interface rtc_sysfs_interface = {
-       .add = &rtc_sysfs_add_device,
-       .remove = &rtc_sysfs_remove_device,
-};
 
-static int __init rtc_sysfs_init(void)
+void rtc_sysfs_add_device(struct rtc_device *rtc)
 {
-       return rtc_interface_register(&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",
+                               err);
 }
 
-static void __exit rtc_sysfs_exit(void)
+void rtc_sysfs_del_device(struct rtc_device *rtc)
 {
-       class_interface_unregister(&rtc_sysfs_interface);
+       /* REVISIT did we add it successfully? */
+       if (rtc_does_wakealarm(rtc))
+               device_remove_file(&rtc->dev, &dev_attr_wakealarm);
 }
 
-subsys_initcall(rtc_sysfs_init);
-module_exit(rtc_sysfs_exit);
-
-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;
+}