[PATCH] RTC subsystem: class

Add the basic RTC subsystem infrastructure to the kernel.

rtc/class.c - registration facilities for RTC drivers
rtc/interface.c - kernel/rtc interface functions
rtc/hctosys.c - snippet of code that copies hw clock to sw clock
		at bootup, if configured to do so.

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>

1 files changed, 145 insertions, 0 deletions

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
new file mode 100644
index 000000000000..8533936d50d8
--- /dev/null
+++ b/drivers/rtc/class.c
@@ -0,0 +1,145 @@
+/*
+ * RTC subsystem, base class
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * class skeleton from drivers/hwmon/hwmon.c
+ *
+ * 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>
+#include <linux/kdev_t.h>
+#include <linux/idr.h>
+
+static DEFINE_IDR(rtc_idr);
+static DEFINE_MUTEX(idr_lock);
+struct class *rtc_class;
+
+static void rtc_device_release(struct class_device *class_dev)
+{
+	struct rtc_device *rtc = to_rtc_device(class_dev);
+	mutex_lock(&idr_lock);
+	idr_remove(&rtc_idr, rtc->id);
+	mutex_unlock(&idr_lock);
+	kfree(rtc);
+}
+
+/**
+ * rtc_device_register - register w/ RTC class
+ * @dev: the device to register
+ *
+ * rtc_device_unregister() must be called when the class device is no
+ * longer needed.
+ *
+ * Returns the pointer to the new struct class device.
+ */
+struct rtc_device *rtc_device_register(const char *name, struct device *dev,
+					struct rtc_class_ops *ops,
+					struct module *owner)
+{
+	struct rtc_device *rtc;
+	int id, err;
+
+	if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+
+	mutex_lock(&idr_lock);
+	err = idr_get_new(&rtc_idr, NULL, &id);
+	mutex_unlock(&idr_lock);
+
+	if (err < 0)
+		goto exit;
+
+	id = id & MAX_ID_MASK;
+
+	rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
+	if (rtc == NULL) {
+		err = -ENOMEM;
+		goto exit_idr;
+	}
+
+	rtc->id = id;
+	rtc->ops = ops;
+	rtc->owner = owner;
+	rtc->class_dev.dev = dev;
+	rtc->class_dev.class = rtc_class;
+	rtc->class_dev.release = rtc_device_release;
+
+	mutex_init(&rtc->ops_lock);
+	spin_lock_init(&rtc->irq_lock);
+	spin_lock_init(&rtc->irq_task_lock);
+
+	strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
+	snprintf(rtc->class_dev.class_id, BUS_ID_SIZE, "rtc%d", id);
+
+	err = class_device_register(&rtc->class_dev);
+	if (err)
+		goto exit_kfree;
+
+	dev_info(dev, "rtc core: registered %s as %s\n",
+			rtc->name, rtc->class_dev.class_id);
+
+	return rtc;
+
+exit_kfree:
+	kfree(rtc);
+
+exit_idr:
+	idr_remove(&rtc_idr, id);
+
+exit:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(rtc_device_register);
+
+
+/**
+ * rtc_device_unregister - removes the previously registered RTC class device
+ *
+ * @rtc: the RTC class device to destroy
+ */
+void rtc_device_unregister(struct rtc_device *rtc)
+{
+	mutex_lock(&rtc->ops_lock);
+	rtc->ops = NULL;
+	mutex_unlock(&rtc->ops_lock);
+	class_device_unregister(&rtc->class_dev);
+}
+EXPORT_SYMBOL_GPL(rtc_device_unregister);
+
+int rtc_interface_register(struct class_interface *intf)
+{
+	intf->class = rtc_class;
+	return class_interface_register(intf);
+}
+EXPORT_SYMBOL_GPL(rtc_interface_register);
+
+static int __init rtc_init(void)
+{
+	rtc_class = class_create(THIS_MODULE, "rtc");
+	if (IS_ERR(rtc_class)) {
+		printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
+		return PTR_ERR(rtc_class);
+	}
+	return 0;
+}
+
+static void __exit rtc_exit(void)
+{
+	class_destroy(rtc_class);
+}
+
+module_init(rtc_init);
+module_exit(rtc_exit);
+
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towerteh.it>");
+MODULE_DESCRIPTION("RTC class support");
+MODULE_LICENSE("GPL");