From: Alessandro Zummo This patch adds 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 Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton --- arch/arm/Kconfig | 2 drivers/Kconfig | 2 drivers/Makefile | 1 drivers/rtc/Kconfig | 42 +++++ drivers/rtc/Makefile | 8 + drivers/rtc/class.c | 145 +++++++++++++++++++ drivers/rtc/hctosys.c | 69 +++++++++ drivers/rtc/interface.c | 280 ++++++++++++++++++++++++++++++++++++++ include/linux/rtc.h | 92 ++++++++++++ 9 files changed, 641 insertions(+) diff -puN arch/arm/Kconfig~rtc-subsystem-class arch/arm/Kconfig --- devel/arch/arm/Kconfig~rtc-subsystem-class 2006-02-26 21:46:50.000000000 -0800 +++ devel-akpm/arch/arm/Kconfig 2006-02-26 21:46:50.000000000 -0800 @@ -823,6 +823,8 @@ source "drivers/usb/Kconfig" source "drivers/mmc/Kconfig" +source "drivers/rtc/Kconfig" + endmenu source "fs/Kconfig" diff -puN drivers/Kconfig~rtc-subsystem-class drivers/Kconfig --- devel/drivers/Kconfig~rtc-subsystem-class 2006-02-26 21:46:50.000000000 -0800 +++ devel-akpm/drivers/Kconfig 2006-02-26 21:46:50.000000000 -0800 @@ -74,4 +74,6 @@ source "drivers/edac/Kconfig" source "drivers/dlm/Kconfig" +source "drivers/rtc/Kconfig" + endmenu diff -puN drivers/Makefile~rtc-subsystem-class drivers/Makefile --- devel/drivers/Makefile~rtc-subsystem-class 2006-02-26 21:46:50.000000000 -0800 +++ devel-akpm/drivers/Makefile 2006-02-26 21:46:50.000000000 -0800 @@ -54,6 +54,7 @@ obj-$(CONFIG_SERIO) += input/serio/ obj-$(CONFIG_GAMEPORT) += input/gameport/ obj-$(CONFIG_INPUT) += input/ obj-$(CONFIG_I2O) += message/ +obj-$(CONFIG_RTC_CLASS) += rtc/ obj-$(CONFIG_I2C) += i2c/ obj-$(CONFIG_W1) += w1/ obj-$(CONFIG_HWMON) += hwmon/ diff -puN /dev/null drivers/rtc/class.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/rtc/class.c 2006-02-26 21:46:50.000000000 -0800 @@ -0,0 +1,145 @@ +/* + * RTC subsystem, base class + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * 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 +#include +#include +#include + +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 "); +MODULE_DESCRIPTION("RTC class support"); +MODULE_LICENSE("GPL"); diff -puN /dev/null drivers/rtc/hctosys.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/rtc/hctosys.c 2006-02-26 21:46:50.000000000 -0800 @@ -0,0 +1,69 @@ +/* + * RTC subsystem, initialize system time on startup + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * 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 + +/* 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; + } + + err = rtc_read_time(class_dev, &tm); + if (err == 0) { + err = rtc_valid_tm(&tm); + if (err == 0) { + 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); diff -puN /dev/null drivers/rtc/interface.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/rtc/interface.c 2006-02-26 21:46:50.000000000 -0800 @@ -0,0 +1,280 @@ +/* + * RTC subsystem, interface functions + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * 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 + +int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + 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_GPL(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); + + err = rtc_valid_tm(tm); + if (err != 0) + return err; + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + 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_GPL(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); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + 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_GPL(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); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + 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_GPL(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); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + 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_GPL(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_GPL(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_GPL(rtc_class_open); + +void rtc_class_close(struct class_device *class_dev) +{ + module_put(to_rtc_device(class_dev)->owner); +} +EXPORT_SYMBOL_GPL(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_GPL(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_GPL(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_GPL(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; +/* + FIXME: this does not belong here, will move where appropriate + at a later stage. It cannot hurt right now, trust me :) + 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) { + err = rtc->ops->irq_set_freq(class_dev->dev, freq); + if (err == 0) + rtc->irq_freq = freq; + } + return err; +} diff -puN /dev/null drivers/rtc/Kconfig --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/rtc/Kconfig 2006-02-26 21:46:50.000000000 -0800 @@ -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 diff -puN /dev/null drivers/rtc/Makefile --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/rtc/Makefile 2006-02-26 21:46:50.000000000 -0800 @@ -0,0 +1,8 @@ +# +# Makefile for RTC class/drivers. +# + +obj-$(CONFIG_RTC_HCTOSYS) += hctosys.o +obj-$(CONFIG_RTC_CLASS) += rtc-core.o +rtc-core-y := class.o interface.o + diff -puN include/linux/rtc.h~rtc-subsystem-class include/linux/rtc.h --- devel/include/linux/rtc.h~rtc-subsystem-class 2006-02-26 21:46:50.000000000 -0800 +++ devel-akpm/include/linux/rtc.h 2006-02-26 21:46:50.000000000 -0800 @@ -93,8 +93,100 @@ 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 +#include +#include +#include +#include + +extern struct class *rtc_class; + +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 class_device *rtc_dev; + 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; _