[PATCH] RTC subsystem: sysfs interface
This patch adds the sysfs interface to the RTC subsystem.
Each RTC client will have his own entry under /sys/classs/rtc/rtcN .
Within this entry some attributes are exported by the subsystem, like date and
time.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
new file mode 100644
index 0000000..7c1f3d2
--- /dev/null
+++ b/drivers/rtc/rtc-sysfs.c
@@ -0,0 +1,124 @@
+/*
+ * RTC subsystem, sysfs interface
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+/* device attributes */
+
+static ssize_t rtc_sysfs_show_name(struct class_device *dev, 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)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(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)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(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)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(dev, &tm);
+ if (retval == 0) {
+ unsigned long time;
+ rtc_tm_to_time(&tm, &time);
+ retval = sprintf(buf, "%lu\n", 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 int __devinit rtc_sysfs_add_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ int err;
+
+ dev_info(class_dev->dev, "rtc intf: sysfs\n");
+
+ err = sysfs_create_group(&class_dev->kobj, &rtc_attr_group);
+ if (err)
+ dev_err(class_dev->dev,
+ "failed to create sysfs attributes\n");
+
+ return err;
+}
+
+static void rtc_sysfs_remove_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ sysfs_remove_group(&class_dev->kobj, &rtc_attr_group);
+}
+
+/* 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)
+{
+ return rtc_interface_register(&rtc_sysfs_interface);
+}
+
+static void __exit rtc_sysfs_exit(void)
+{
+ class_interface_unregister(&rtc_sysfs_interface);
+}
+
+module_init(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");