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
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 <[email protected]>
--
drivers/Kconfig | 2
drivers/Makefile | 1
drivers/rtc/Kconfig | 42 +++++++
drivers/rtc/Makefile | 9 +
drivers/rtc/class.c | 143 +++++++++++++++++++++++++
drivers/rtc/hctosys.c | 67 +++++++++++
drivers/rtc/interface.c | 274 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/rtc/utils.c | 97 ++++++++++++++++
include/linux/rtc.h | 89 +++++++++++++++
9 files changed, 724 insertions(+)
--- linux-rtc.orig/include/linux/rtc.h 2006-02-15 03:24:36.000000000 +0100
+++ linux-rtc/include/linux/rtc.h 2006-02-15 04:13:58.000000000 +0100
@@ -93,8 +93,97 @@ struct rtc_pll_info {
#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>
+#include <linux/mutex.h>
+
+struct rtc_class_ops {
+ 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);
+ int (*irq_set_state)(struct device *, int enabled);
+ int (*irq_set_freq)(struct device *, int freq);
+ int (*read_callback)(struct device *, int data);
+};
+
+#define RTC_DEVICE_NAME_SIZE 20
+struct rtc_task;
+
+struct rtc_device
+{
+ struct class_device class_dev;
+ struct module *owner;
+
+ int id;
+ char name[RTC_DEVICE_NAME_SIZE];
+
+ struct rtc_class_ops *ops;
+ struct mutex ops_lock;
+
+ struct cdev char_dev;
+ struct mutex char_lock;
+
+ unsigned long irq_data;
+ spinlock_t irq_lock;
+ wait_queue_head_t irq_queue;
+ struct fasync_struct *async_queue;
+
+ struct rtc_task *irq_task;
+ spinlock_t irq_task_lock;
+ int irq_freq;
+};
+#define to_rtc_device(d) container_of(d, struct rtc_device, class_dev)
+
+extern struct rtc_device *rtc_device_register(const char *name,
+ struct device *dev,
+ struct rtc_class_ops *ops,
+ struct module *owner);
+extern void rtc_device_unregister(struct rtc_device *rdev);
+extern int rtc_interface_register(struct class_interface *intf);
+
+extern int rtc_month_days(unsigned int month, unsigned int year);
+extern int rtc_valid_tm(struct rtc_time *tm);
+extern int 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_set_mmss(struct class_device *class_dev, unsigned long secs);
+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);
+
+extern struct class_device *rtc_class_open(char *name);
+extern void rtc_class_close(struct class_device *class_dev);
+
+extern int rtc_irq_register(struct class_device *class_dev,
+ struct rtc_task *task);
+extern void rtc_irq_unregister(struct class_device *class_dev,
+ struct rtc_task *task);
+extern int rtc_irq_set_state(struct class_device *class_dev,
+ struct rtc_task *task, int enabled);
+extern int rtc_irq_set_freq(struct class_device *class_dev,
+ struct rtc_task *task, int freq);
+
typedef struct rtc_task {
void (*func)(void *private_data);
void *private_data;
--- linux-rtc.orig/drivers/Kconfig 2006-02-15 03:24:36.000000000 +0100
+++ linux-rtc/drivers/Kconfig 2006-02-15 03:24:47.000000000 +0100
@@ -70,4 +70,6 @@ source "drivers/sn/Kconfig"
source "drivers/edac/Kconfig"
+source "drivers/rtc/Kconfig"
+
endmenu
--- linux-rtc.orig/drivers/Makefile 2006-02-15 03:24:36.000000000 +0100
+++ linux-rtc/drivers/Makefile 2006-02-15 03:24:47.000000000 +0100
@@ -56,6 +56,7 @@ obj-$(CONFIG_USB_GADGET) += usb/gadget/
obj-$(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-rtc/drivers/rtc/class.c 2006-02-15 03:25:54.000000000 +0100
@@ -0,0 +1,143 @@
+/*
+ * RTC subsystem, base class
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <[email protected]>
+ *
+ * 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 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;
+
+ if ((rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL)) == 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);
+
+ if ((err = class_device_register(&rtc->class_dev)))
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("RTC class support");
+MODULE_LICENSE("GPL");
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-rtc/drivers/rtc/Kconfig 2006-02-19 23:33:06.000000000 +0100
@@ -0,0 +1,42 @@
+#
+# 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.
+
+config RTC_HCTOSYS
+ bool "Set system time from RTC on startup"
+ depends on RTC_CLASS = y
+ default y
+ help
+ If you say yes here, the system time will be set using
+ the value read from the specified RTC device. This is useful
+ in order to avoid unnecessary fschk runs.
+
+config RTC_HCTOSYS_DEVICE
+ string "The RTC to read the time from"
+ depends on RTC_HCTOSYS = y
+ default "rtc0"
+ help
+ The RTC device that will be used as the source for
+ the system time, usually rtc0.
+
+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-rtc/drivers/rtc/Makefile 2006-02-19 23:33:06.000000000 +0100
@@ -0,0 +1,9 @@
+#
+# Makefile for RTC class/drivers.
+#
+
+obj-y += utils.o
+obj-$(CONFIG_RTC_HCTOSYS) += hctosys.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-rtc/drivers/rtc/interface.c 2006-02-15 04:13:37.000000000 +0100
@@ -0,0 +1,274 @@
+/*
+ * RTC subsystem, interface functions
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <[email protected]>
+ *
+ * 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>
+
+extern struct class *rtc_class;
+
+int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm)
+{
+ int err;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if ((err = mutex_lock_interruptible(&rtc->ops_lock)))
+ return err;
+
+ if (!rtc->ops)
+ err = -ENODEV;
+ else if (!rtc->ops->read_time)
+ err = -EINVAL;
+ else {
+ memset(tm, 0, sizeof(struct rtc_time));
+ err = rtc->ops->read_time(class_dev->dev, tm);
+ }
+
+ mutex_unlock(&rtc->ops_lock);
+ return err;
+}
+EXPORT_SYMBOL(rtc_read_time);
+
+int rtc_set_time(struct class_device *class_dev, struct rtc_time *tm)
+{
+ int err;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if ((err = rtc_valid_tm(tm)) != 0)
+ return err;
+
+ if ((err = mutex_lock_interruptible(&rtc->ops_lock)))
+ return err;
+
+ if (!rtc->ops)
+ err = -ENODEV;
+ else if (!rtc->ops->set_time)
+ err = -EINVAL;
+ else
+ err = rtc->ops->set_time(class_dev->dev, tm);
+
+ mutex_unlock(&rtc->ops_lock);
+ return err;
+}
+EXPORT_SYMBOL(rtc_set_time);
+
+int rtc_set_mmss(struct class_device *class_dev, unsigned long secs)
+{
+ int err;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if ((err = mutex_lock_interruptible(&rtc->ops_lock)))
+ return err;
+
+ if (!rtc->ops)
+ err = -ENODEV;
+ else if (!rtc->ops->set_mmss) {
+ if (rtc->ops->read_time && rtc->ops->set_time) {
+ struct rtc_time new, old;
+
+ new.tm_sec = secs % 60;
+ secs /= 60;
+ new.tm_min = secs % 60;
+ secs /= 60;
+ new.tm_hour = secs % 24;
+
+ /*
+ * avoid writing when we're going to change the day
+ * of the month. We will retry in the next minute.
+ * This basically means that if the RTC must not drift
+ * by more than 1 minute in 11 minutes.
+ */
+ if (!((old.tm_hour == 23 && old.tm_min == 59) ||
+ (new.tm_hour == 23 && new.tm_min == 59)))
+ err = rtc->ops->set_time(class_dev->dev, &new);
+ }
+ else
+ err = -EINVAL;
+ }
+ else
+ err = rtc->ops->set_mmss(class_dev->dev, secs);
+
+ mutex_unlock(&rtc->ops_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(rtc_set_mmss);
+
+int rtc_read_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
+{
+ int err;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if ((err = mutex_lock_interruptible(&rtc->ops_lock)))
+ return err;
+
+ if (rtc->ops == NULL)
+ err = -ENODEV;
+ else if (!rtc->ops->read_alarm)
+ err = -EINVAL;
+ else {
+ memset(alarm, 0, sizeof(struct rtc_wkalrm));
+ err = rtc->ops->read_alarm(class_dev->dev, alarm);
+ }
+
+ mutex_unlock(&rtc->ops_lock);
+ return err;
+}
+EXPORT_SYMBOL(rtc_read_alarm);
+
+int rtc_set_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm)
+{
+ int err;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if ((err = mutex_lock_interruptible(&rtc->ops_lock)))
+ return err;
+
+ if (!rtc->ops)
+ err = -ENODEV;
+ else if (!rtc->ops->set_alarm)
+ err = -EINVAL;
+ else
+ err = rtc->ops->set_alarm(class_dev->dev, alarm);
+
+ mutex_unlock(&rtc->ops_lock);
+ 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);
+
+ spin_lock(&rtc->irq_task_lock);
+ if (rtc->irq_task)
+ rtc->irq_task->func(rtc->irq_task->private_data);
+ spin_unlock(&rtc->irq_task_lock);
+
+ wake_up_interruptible(&rtc->irq_queue);
+ kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
+}
+EXPORT_SYMBOL(rtc_update_irq);
+
+struct class_device *rtc_class_open(char *name)
+{
+ struct class_device *class_dev = NULL,
+ *class_dev_tmp;
+
+ down(&rtc_class->sem);
+ list_for_each_entry(class_dev_tmp, &rtc_class->children, node) {
+ if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) {
+ class_dev = class_dev_tmp;
+ break;
+ }
+ }
+
+ if (class_dev) {
+ if (!try_module_get(to_rtc_device(class_dev)->owner))
+ class_dev = NULL;
+ }
+ up(&rtc_class->sem);
+
+ return class_dev;
+}
+EXPORT_SYMBOL(rtc_class_open);
+
+void rtc_class_close(struct class_device *class_dev)
+{
+ module_put(to_rtc_device(class_dev)->owner);
+}
+EXPORT_SYMBOL(rtc_class_close);
+
+int rtc_irq_register(struct class_device *class_dev, struct rtc_task *task)
+{
+ int retval = -EBUSY;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ if (task == NULL || task->func == NULL)
+ return -EINVAL;
+
+ spin_lock(&rtc->irq_task_lock);
+ if (rtc->irq_task == NULL) {
+ rtc->irq_task = task;
+ retval = 0;
+ }
+ spin_unlock(&rtc->irq_task_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(rtc_irq_register);
+
+void rtc_irq_unregister(struct class_device *class_dev, struct rtc_task *task)
+{
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ spin_lock(&rtc->irq_task_lock);
+ if (rtc->irq_task == task)
+ rtc->irq_task = NULL;
+ spin_unlock(&rtc->irq_task_lock);
+}
+EXPORT_SYMBOL(rtc_irq_unregister);
+
+int rtc_irq_set_state(struct class_device *class_dev, struct rtc_task *task, int enabled)
+{
+ int err = 0;
+ unsigned long flags;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ spin_lock_irqsave(&rtc->irq_task_lock, flags);
+ if (rtc->irq_task != task)
+ err = -ENXIO;
+ spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+
+ if (err == 0)
+ err = rtc->ops->irq_set_state(class_dev->dev, enabled);
+
+ return err;
+}
+EXPORT_SYMBOL(rtc_irq_set_state);
+
+int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq)
+{
+ int err = 0, tmp = 0;
+ unsigned long flags;
+ struct rtc_device *rtc = to_rtc_device(class_dev);
+
+ /* allowed range is 2-8192 */
+ if (freq < 2 || freq > 8192)
+ return -EINVAL;
+
+/* if ((freq > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
+ return -EACCES;
+*/
+ /* check if freq is a power of 2 */
+ while (freq > (1 << tmp))
+ tmp++;
+
+ if (freq != (1 << tmp))
+ return -EINVAL;
+
+ spin_lock_irqsave(&rtc->irq_task_lock, flags);
+ if (rtc->irq_task != task)
+ err = -ENXIO;
+ spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+
+ if (err == 0) {
+ if ((err = rtc->ops->irq_set_freq(class_dev->dev, freq)) == 0)
+ rtc->irq_freq = freq;
+ }
+ return err;
+
+}
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-rtc/drivers/rtc/utils.c 2006-02-15 03:24:47.000000000 +0100
@@ -0,0 +1,97 @@
+/*
+ * RTC subsystem, utility functions
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <[email protected]>
+ *
+ * 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.
+ */
+int 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);
+ return 0;
+}
+EXPORT_SYMBOL(rtc_tm_to_time);
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-rtc/drivers/rtc/hctosys.c 2006-02-15 03:24:47.000000000 +0100
@@ -0,0 +1,67 @@
+/*
+ * RTC subsystem, initialize system time on startup
+ *
+ * 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/rtc.h>
+
+/* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
+ * whether it stores the most close value or the value with partial
+ * seconds truncated. However, it is important that we use it to store
+ * the truncated value. This is because otherwise it is necessary,
+ * in an rtc sync function, to read both xtime.tv_sec and
+ * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
+ * of >32bits is not possible. So storing the most close value would
+ * slow down the sync API. So here we have the truncated value and
+ * the best guess is to add 0.5s.
+ */
+
+static int __init rtc_hctosys(void)
+{
+ int err;
+ struct rtc_time tm;
+ struct class_device *class_dev = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
+
+ if (class_dev == NULL) {
+ printk("%s: unable to open rtc device (%s)\n",
+ __FILE__, CONFIG_RTC_HCTOSYS_DEVICE);
+ return -ENODEV;
+ }
+
+ if ((err = rtc_read_time(class_dev, &tm)) == 0) {
+ if (rtc_valid_tm(&tm)) {
+ struct timespec tv;
+
+ tv.tv_nsec = NSEC_PER_SEC >> 1;
+
+ rtc_tm_to_time(&tm, &tv.tv_sec);
+
+ do_settimeofday(&tv);
+
+ dev_info(class_dev->dev,
+ "setting the system clock to "
+ "%d-%02d-%02d %02d:%02d:%02d (%u)\n",
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+ tm.tm_hour, tm.tm_min, tm.tm_sec,
+ (unsigned int) tv.tv_sec);
+ }
+ else
+ dev_err(class_dev->dev,
+ "hctosys: invalid date/time\n");
+ }
+ else
+ dev_err(class_dev->dev,
+ "hctosys: unable to read the hardware clock\n");
+
+ rtc_class_close(class_dev);
+
+ return 0;
+}
+
+late_initcall(rtc_hctosys);
--
Alessandro Zummo <[email protected]> wrote:
>
> 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
> rtc/hctosys.c - snippet of code that copies hw clock to sw clock
> at bootup, if configured to do so.
Couple of questions.
a) Is all this code 100% compatible with existing kernel interfaces? No
userspace-visible breakage? Right down the all the same -EFOO return
codes for all the same errors?
b) Will the kernel compile and run at each stage of your patch series?
I hit a nasty no-compile half an hour through a git-bisect session
yesterday and it's still smarting.
Code looks nice and clean.
> + 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);
Oh the IDR API does suck. Not your fault though.
> + if ((rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL)) == NULL) {
You do a lot of
if ((lhs = rhs) == something)
But preferred kernel style is
lhs = rhs;
if (lhs == something)
Generally, kernel style is to keep things as utterly simple as they can be.
+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.
> +
> +config RTC_HCTOSYS
> + bool "Set system time from RTC on startup"
> + depends on RTC_CLASS = y
> + default y
> + help
> + If you say yes here, the system time will be set using
> + the value read from the specified RTC device. This is useful
> + in order to avoid unnecessary fschk runs.
> +
> +config RTC_HCTOSYS_DEVICE
> + string "The RTC to read the time from"
> + depends on RTC_HCTOSYS = y
> + default "rtc0"
> + help
> + The RTC device that will be used as the source for
> + the system time, usually rtc0.
hm. Doesn't the above disable RTC_HCTOSYS and RTC_HCTOSYS_DEVICE if
RTC_CLASS=m?
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ linux-rtc/drivers/rtc/interface.c 2006-02-15 04:13:37.000000000 +0100
> @@ -0,0 +1,274 @@
> +/*
> + * RTC subsystem, interface functions
> + *
> + * Copyright (C) 2005 Tower Technologies
> + * Author: Alessandro Zummo <[email protected]>
> + *
> + * 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>
> +
> +extern struct class *rtc_class;
Please always put extern declarations in a header file.
> +}
> +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);
> +
> + spin_lock(&rtc->irq_task_lock);
> + if (rtc->irq_task)
> + rtc->irq_task->func(rtc->irq_task->private_data);
> + spin_unlock(&rtc->irq_task_lock);
> +
> + wake_up_interruptible(&rtc->irq_queue);
> + kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
> +}
> +EXPORT_SYMBOL(rtc_update_irq);
I don't know what this does.
Please document all non-static functions. Preferably with kernel-doc
format. Feel free to document static functions too..
> +int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq)
> +{
> + int err = 0, tmp = 0;
> + unsigned long flags;
> + struct rtc_device *rtc = to_rtc_device(class_dev);
> +
> + /* allowed range is 2-8192 */
> + if (freq < 2 || freq > 8192)
> + return -EINVAL;
> +
> +/* if ((freq > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
> + return -EACCES;
> +*/
What happened to rtc_max_user_freq?
On Wed, 22 Feb 2006 14:15:54 -0800
Andrew Morton <[email protected]> wrote:
> Couple of questions.
>
> a) Is all this code 100% compatible with existing kernel interfaces? No
> userspace-visible breakage? Right down the all the same -EFOO return
> codes for all the same errors?
this new class works only in places of the kernel were there were no
RTCs before.. basically, I haven't touched the x86 or any other platform clock
and focused only on i2c clocks which were actually not used.
From the userspace point of view, the interface is the same. I noticed
that hwclock does not like things like time that is not changing or
an -EINVAL on a read, which can instead happen when you use
i2c clocks. However, that is not an issue yet because hwclock has
not been used on those i2c clocks until now.
>
> b) Will the kernel compile and run at each stage of your patch series?
> I hit a nasty no-compile half an hour through a git-bisect session
> yesterday and it's still smarting.
I' haven't tested it.. I think there may be problems because at some
points some functions in the kernel needs to be renamed and/or
changed.. i would say the first two patches should be applied
together.
> Code looks nice and clean.
thanks.
> > + if ((rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL)) == NULL) {
>
> You do a lot of
>
> if ((lhs = rhs) == something)
>
> But preferred kernel style is
>
> lhs = rhs;
> if (lhs == something)
good to know, that is also my preferred style. I will happily change
this, I just thought the kernel style was the other one :)
> Generally, kernel style is to keep things as utterly simple as they can be.
[..]
> > +config RTC_HCTOSYS_DEVICE
> > + string "The RTC to read the time from"
> > + depends on RTC_HCTOSYS = y
> > + default "rtc0"
> > + help
> > + The RTC device that will be used as the source for
> > + the system time, usually rtc0.
>
> hm. Doesn't the above disable RTC_HCTOSYS and RTC_HCTOSYS_DEVICE if
> RTC_CLASS=m?
yes. I can't remember if it is intended, but the point of having
hctosys was to copy the time early in the bootup process.
> > +
> > +extern struct class *rtc_class;
>
> Please always put extern declarations in a header file.
ack.
> > +EXPORT_SYMBOL(rtc_update_irq);
>
> I don't know what this does.
>
> Please document all non-static functions. Preferably with kernel-doc
> format. Feel free to document static functions too..
will do.
> > +int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq)
> > +{
> > + int err = 0, tmp = 0;
> > + unsigned long flags;
> > + struct rtc_device *rtc = to_rtc_device(class_dev);
> > +
> > + /* allowed range is 2-8192 */
> > + if (freq < 2 || freq > 8192)
> > + return -EINVAL;
> > +
> > +/* if ((freq > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
> > + return -EACCES;
> > +*/
>
> What happened to rtc_max_user_freq?
not implemented yet, I need to handle it in a different way. rtc_irq_set_freq
is the kernel interface, I must move this check in the /dev/rtc code.
How can I handle further updates, just repost the whole patchset
to lkml ?
thanks for you review!
--
Best regards,
Alessandro Zummo,
Tower Technologies - Turin, Italy
http://www.towertech.it
Alessandro Zummo <[email protected]> wrote:
>
> How can I handle further updates, just repost the whole patchset
> to lkml ?
Yes, that would be best. Once the patches are settled down I prefer
incremental updates so we can see what changed, but at this stage in
proceedings a wholesale replacement is OK.
It would be good if you can arrange it so there are no build-breaks
anywhere in the series.