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 <[email protected]>
--
drivers/rtc/Kconfig | 11 ++++
drivers/rtc/Makefile | 2
drivers/rtc/rtc-sysfs.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 141 insertions(+), 1 deletion(-)
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-nslu2/drivers/rtc/rtc-sysfs.c 2006-01-08 17:07:57.000000000 +0100
@@ -0,0 +1,129 @@
+/*
+ * RTC subsystem, sysfs interface
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+*/
+
+#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 = -ENODEV;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ struct rtc_time tm;
+
+ if ((retval = down_interruptible(&rtc->ops_lock)))
+ return retval;
+
+ if (rtc->ops && ((retval = rtc_read_time(dev, &tm)) == 0)) {
+ retval = sprintf(buf, "%04d-%02d-%02d\n",
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+ }
+
+ up(&rtc->ops_lock);
+
+ 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 = -ENODEV;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ struct rtc_time tm;
+
+ if ((retval = down_interruptible(&rtc->ops_lock)))
+ return retval;
+
+
+ if (rtc->ops && ((retval = rtc_read_time(dev, &tm)) == 0)) {
+ retval = sprintf(buf, "%02d:%02d:%02d\n",
+ tm.tm_hour, tm.tm_min, tm.tm_sec);
+ }
+
+ up(&rtc->ops_lock);
+
+ 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 = -ENODEV;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ struct rtc_time tm;
+
+ if ((retval = down_interruptible(&rtc->ops_lock)))
+ return retval;
+
+ if (rtc->ops && ((retval = rtc_read_time(dev, &tm)) == 0)) {
+ unsigned long time;
+ rtc_tm_to_time(&tm, &time);
+ retval = sprintf(buf, "%lu\n", time);
+ }
+
+ up(&rtc->ops_lock);
+
+ return retval;
+}
+static CLASS_DEVICE_ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL);
+
+/* insertion/removal hooks */
+
+static int __devinit rtc_sysfs_add_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ class_device_create_file(class_dev, &class_device_attr_name);
+ class_device_create_file(class_dev, &class_device_attr_date);
+ class_device_create_file(class_dev, &class_device_attr_time);
+ class_device_create_file(class_dev, &class_device_attr_since_epoch);
+ dev_info(class_dev->dev, "rtc intf: sysfs\n");
+ return 0;
+}
+
+static void rtc_sysfs_remove_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ class_device_remove_file(class_dev, &class_device_attr_name);
+ class_device_remove_file(class_dev, &class_device_attr_date);
+ class_device_remove_file(class_dev, &class_device_attr_time);
+ class_device_remove_file(class_dev, &class_device_attr_since_epoch);
+}
+
+/* interface registration */
+
+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 <[email protected]>");
+MODULE_DESCRIPTION("RTC class sysfs interface");
+MODULE_LICENSE("GPL");
--- linux-nslu2.orig/drivers/rtc/Kconfig 2006-01-08 17:02:53.000000000 +0100
+++ linux-nslu2/drivers/rtc/Kconfig 2006-01-08 18:54:50.000000000 +0100
@@ -19,6 +19,17 @@ config RTC_CLASS
comment "RTC interfaces"
depends on RTC_CLASS
+config RTC_INTF_SYSFS
+ tristate "sysfs"
+ depends on RTC_CLASS && SYSFS
+ default RTC_CLASS
+ help
+ Say yes here if you want to use your RTC using the sysfs
+ interface, /sys/class/rtc/rtcX .
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-sysfs.
+
comment "RTC drivers"
depends on RTC_CLASS
--- linux-nslu2.orig/drivers/rtc/Makefile 2006-01-08 17:02:53.000000000 +0100
+++ linux-nslu2/drivers/rtc/Makefile 2006-01-08 18:54:50.000000000 +0100
@@ -5,4 +5,4 @@
obj-y += utils.o
obj-$(CONFIG_RTC_CLASS) += rtc-core.o
rtc-core-y := class.o interface.o
-
+obj-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
--
On Sun, 8 Jan 2006 21:02:40 -0500
Dmitry Torokhov <[email protected]> wrote:
> On Sunday 08 January 2006 18:12, Alessandro Zummo wrote:
> > +static ssize_t rtc_sysfs_show_date(struct class_device *dev, char *buf)
> > +{
> > +???????ssize_t retval = -ENODEV;
> > +???????struct rtc_device *rtc = to_rtc_device(dev);
> > +???????struct rtc_time tm;
[...]
> ops locking is a mess here. Half of the code accesses it under protection
> of ops_lock while other half is unlocked. I think it would be better if
> that lock was taken in rtc_read_time and friends.
Good point. I'll move them, thanks.
--
Best regards,
Alessandro Zummo,
Tower Technologies - Turin, Italy
http://www.towertech.it