[RFC][PATCH 1/7] RTC subsystem, class

From: Alessandro Zummo
Date: Mon Dec 26 2005 - 14:20:37 EST




This patch adds the basic RTC subsytem infrastructure
to the kernel.

rtc/class.c - registration facilities for RTC drivers
rtc/interface.c - kernel/rtc interface functions
rtc/utils.c - misc rtc-related utility functions

Signed-off-by: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
--
drivers/Kconfig | 2
drivers/Makefile | 1
drivers/rtc/Kconfig | 25 +++++++++
drivers/rtc/Makefile | 8 +++
drivers/rtc/class.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/rtc/interface.c | 78 +++++++++++++++++++++++++++++
drivers/rtc/utils.c | 96 ++++++++++++++++++++++++++++++++++++
include/linux/rtc.h | 66 ++++++++++++++++++++++++
8 files changed, 403 insertions(+)

--- linux.orig/include/linux/rtc.h 2005-12-26 19:13:47.000000000 +0100
+++ linux/include/linux/rtc.h 2005-12-26 19:14:29.000000000 +0100
@@ -91,8 +91,74 @@
#define RTC_PLL_GET _IOR('p', 0x11, struct rtc_pll_info) /* Get PLL correction */
#define RTC_PLL_SET _IOW('p', 0x12, struct rtc_pll_info) /* Set PLL correction */

+/* interrupt flags */
+#define RTC_IRQF 0x80 /* any of the following is active */
+#define RTC_PF 0x40
+#define RTC_AF 0x20
+#define RTC_UF 0x10
+
#ifdef __KERNEL__

+#include <linux/device.h>
+#include <linux/seq_file.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+
+struct rtc_class_ops {
+ struct module *owner;
+ int (*open)(struct device *);
+ void (*release)(struct device *);
+ int (*ioctl)(struct device *, unsigned int, unsigned long);
+ int (*read_time)(struct device *, struct rtc_time *);
+ int (*set_time)(struct device *, struct rtc_time *);
+ int (*read_alarm)(struct device *, struct rtc_wkalrm *);
+ int (*set_alarm)(struct device *, struct rtc_wkalrm *);
+ int (*proc)(struct device *, struct seq_file *);
+ int (*set_mmss)(struct device *, unsigned long secs);
+};
+
+struct rtc_device
+{
+ int id;
+ struct class_device class_dev;
+ struct rtc_class_ops *ops;
+
+ struct cdev char_dev;
+ struct semaphore char_sem;
+
+ unsigned long irq_data;
+ struct semaphore irq_lock;
+ wait_queue_head_t irq_queue;
+ struct fasync_struct *async_queue;
+};
+#define to_rtc_device(d) container_of(d, struct rtc_device, class_dev)
+
+static inline struct rtc_class_ops *rtc_get_ops(struct class_device *class_dev)
+{
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+ return rtc->ops;
+}
+
+extern int rtc_interface_register(struct class_interface *intf);
+extern struct rtc_device *rtc_device_register(struct device *dev,
+ struct rtc_class_ops *ops);
+extern void rtc_device_unregister(struct rtc_device *rdev);
+
+
+extern int rtc_month_days(unsigned int month, unsigned int year);
+extern int rtc_valid_tm(struct rtc_time *tm);
+extern void rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
+extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
+
+extern int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm);
+extern int rtc_set_time(struct class_device *class_dev, struct rtc_time *tm);
+extern int rtc_read_alarm(struct class_device *class_dev,
+ struct rtc_wkalrm *alrm);
+extern int rtc_set_alarm(struct class_device *class_dev,
+ struct rtc_wkalrm *alrm);
+extern void rtc_update_irq(struct class_device *class_dev,
+ unsigned long num, unsigned long events);
+
typedef struct rtc_task {
void (*func)(void *private_data);
void *private_data;
--- linux.orig/drivers/Kconfig 2005-12-26 19:13:47.000000000 +0100
+++ linux/drivers/Kconfig 2005-12-26 19:14:29.000000000 +0100
@@ -66,4 +66,6 @@

source "drivers/sn/Kconfig"

+source "drivers/rtc/Kconfig"
+
endmenu
--- linux.orig/drivers/Makefile 2005-12-26 19:13:47.000000000 +0100
+++ linux/drivers/Makefile 2005-12-26 19:21:04.000000000 +0100
@@ -54,6 +54,7 @@
obj-$(CONFIG_GAMEPORT) += input/gameport/
obj-$(CONFIG_INPUT) += input/
obj-$(CONFIG_I2O) += message/
+obj-y += rtc/
obj-$(CONFIG_I2C) += i2c/
obj-$(CONFIG_W1) += w1/
obj-$(CONFIG_HWMON) += hwmon/
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/rtc/class.c 2005-12-26 19:14:29.000000000 +0100
@@ -0,0 +1,127 @@
+/*
+ * RTC subsystem, base class
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
+ *
+ * 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 as published by
+ * the Free Software Foundation; version 2 of the License.
+*/
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/kdev_t.h>
+#include <linux/idr.h>
+
+static DEFINE_IDR(rtc_idr);
+static struct class *rtc_class;
+
+static void rtc_device_release(struct class_device *class_dev)
+{
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+ idr_remove(&rtc_idr, rtc->id);
+ 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(struct device *dev,
+ struct rtc_class_ops *ops)
+{
+ struct rtc_device *rtc;
+ int id, err;
+
+ if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ /* XXX spinlock here? */
+ if ((err = idr_get_new(&rtc_idr, NULL, &id)) < 0)
+ goto exit;
+
+ id = id & MAX_ID_MASK;
+
+ if ((rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL)) == NULL) {
+ err = -ENOMEM;
+ goto exit_idr;
+ }
+
+ rtc->id = id;
+ rtc->ops = ops;
+ rtc->class_dev.dev = dev;
+ rtc->class_dev.class = rtc_class;
+ rtc->class_dev.release = rtc_device_release;
+
+ snprintf(rtc->class_dev.class_id, BUS_ID_SIZE, "rtc%d", id);
+
+ class_set_devdata(&rtc->class_dev, rtc);
+
+ if ((err = class_device_register(&rtc->class_dev)))
+ goto exit_kfree;
+
+ dev_info(dev, "rtc core: registered %s\n", 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)
+{
+ 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@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("RTC class support");
+MODULE_LICENSE("GPL");
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/rtc/Kconfig 2005-12-26 19:35:41.000000000 +0100
@@ -0,0 +1,25 @@
+#
+# RTC class/drivers configuration
+#
+
+menu "Real Time Clock"
+
+config RTC_CLASS
+ tristate "RTC class"
+ depends on EXPERIMENTAL
+ default y
+ help
+ Generic RTC class support. If you say yes here, you will
+ be allowed to plug one or more RTCs to your system. You will
+ probably want to enable one of more of the interfaces below.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-class.
+
+comment "RTC interfaces"
+ depends on RTC_CLASS
+
+comment "RTC drivers"
+ depends on RTC_CLASS
+
+endmenu
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/rtc/Makefile 2005-12-26 19:35:41.000000000 +0100
@@ -0,0 +1,8 @@
+#
+# Makefile for RTC class/drivers.
+#
+
+obj-y += utils.o
+obj-$(CONFIG_RTC_CLASS) += rtc-core.o
+rtc-core-y := class.o interface.o
+
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/rtc/interface.c 2005-12-26 19:14:29.000000000 +0100
@@ -0,0 +1,78 @@
+/*
+ * RTC subsystem, interface functions
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
+ *
+ * based on arch/arm/common/rtctime.c
+ *
+ * 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/rtc.h>
+
+int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm)
+{
+ int err = -EINVAL;
+ struct rtc_class_ops *ops = rtc_get_ops(class_dev);
+
+ if (ops->read_time) {
+ memset(tm, 0, sizeof(struct rtc_time));
+ err = ops->read_time(class_dev->dev, tm);
+ }
+ return err;
+}
+EXPORT_SYMBOL(rtc_read_time);
+
+int rtc_set_time(struct class_device *class_dev, struct rtc_time *tm)
+{
+ int err = -EINVAL;
+ struct rtc_class_ops *ops = class_get_devdata(class_dev);
+
+ err = rtc_valid_tm(tm);
+ if (err == 0 && ops->set_time)
+ err = ops->set_time(class_dev->dev, tm);
+
+ return err;
+}
+EXPORT_SYMBOL(rtc_set_time);
+
+int rtc_read_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
+{
+ struct rtc_class_ops *ops = rtc_get_ops(class_dev);
+ int err = -EINVAL;
+
+ if (ops->read_alarm) {
+ memset(alarm, 0, sizeof(struct rtc_wkalrm));
+ err = ops->read_alarm(class_dev->dev, alarm);
+ }
+ return err;
+}
+EXPORT_SYMBOL(rtc_read_alarm);
+
+int rtc_set_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
+{
+ int err = -EINVAL;
+ struct rtc_class_ops *ops = rtc_get_ops(class_dev);
+
+ if (ops->set_alarm)
+ err = ops->set_alarm(class_dev->dev, alarm);
+ return err;
+}
+EXPORT_SYMBOL(rtc_set_alarm);
+
+void rtc_update_irq(struct class_device *class_dev,
+ unsigned long num, unsigned long events)
+{
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ spin_lock(&rtc->irq_lock);
+ rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
+ spin_unlock(&rtc->irq_lock);
+
+ wake_up_interruptible(&rtc->irq_queue);
+ kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
+}
+EXPORT_SYMBOL(rtc_update_irq);
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/rtc/utils.c 2005-12-26 19:14:29.000000000 +0100
@@ -0,0 +1,96 @@
+/*
+ * RTC subsystem, utility functions
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
+ *
+ * based on arch/arm/common/rtctime.c
+ *
+ * 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/rtc.h>
+
+static const unsigned char rtc_days_in_month[] = {
+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
+#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
+
+int rtc_month_days(unsigned int month, unsigned int year)
+{
+ return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
+}
+EXPORT_SYMBOL(rtc_month_days);
+
+/*
+ * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
+ */
+void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
+{
+ int days, month, year;
+
+ days = time / 86400;
+ time -= days * 86400;
+
+ tm->tm_wday = (days + 4) % 7;
+
+ year = 1970 + days / 365;
+ days -= (year - 1970) * 365
+ + LEAPS_THRU_END_OF(year - 1)
+ - LEAPS_THRU_END_OF(1970 - 1);
+ if (days < 0) {
+ year -= 1;
+ days += 365 + LEAP_YEAR(year);
+ }
+ tm->tm_year = year - 1900;
+ tm->tm_yday = days + 1;
+
+ for (month = 0; month < 11; month++) {
+ int newdays;
+
+ newdays = days - rtc_month_days(month, year);
+ if (newdays < 0)
+ break;
+ days = newdays;
+ }
+ tm->tm_mon = month;
+ tm->tm_mday = days + 1;
+
+ tm->tm_hour = time / 3600;
+ time -= tm->tm_hour * 3600;
+ tm->tm_min = time / 60;
+ tm->tm_sec = time - tm->tm_min * 60;
+}
+EXPORT_SYMBOL(rtc_time_to_tm);
+
+/*
+ * Does the rtc_time represent a valid date/time?
+ */
+int rtc_valid_tm(struct rtc_time *tm)
+{
+ if (tm->tm_year < 70 ||
+ tm->tm_mon >= 12 ||
+ tm->tm_mday < 1 ||
+ tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900) ||
+ tm->tm_hour >= 24 ||
+ tm->tm_min >= 60 ||
+ tm->tm_sec >= 60)
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL(rtc_valid_tm);
+
+/*
+ * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
+ */
+void rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
+{
+ *time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+}
+EXPORT_SYMBOL(rtc_tm_to_time);

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