rtc: rename core files

Rename core files so there is a clearer separation between the RTC core and
the RTC drivers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

1 files changed, 483 insertions, 0 deletions

diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
new file mode 100644
index 000000000000..43d962a9c210
--- /dev/null
+++ b/drivers/rtc/dev.c
@@ -0,0 +1,483 @@
+/*
+ * RTC subsystem, dev interface
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * 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 version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/sched/signal.h>
+#include "rtc-core.h"
+
+static dev_t rtc_devt;
+
+#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
+
+static int rtc_dev_open(struct inode *inode, struct file *file)
+{
+        struct rtc_device *rtc = container_of(inode->i_cdev,
+                                        struct rtc_device, char_dev);
+
+        if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
+                return -EBUSY;
+
+        file->private_data = rtc;
+
+        spin_lock_irq(&rtc->irq_lock);
+        rtc->irq_data = 0;
+        spin_unlock_irq(&rtc->irq_lock);
+
+        return 0;
+}
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+/*
+ * Routine to poll RTC seconds field for change as often as possible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+static void rtc_uie_task(struct work_struct *work)
+{
+        struct rtc_device *rtc =
+                container_of(work, struct rtc_device, uie_task);
+        struct rtc_time tm;
+        int num = 0;
+        int err;
+
+        err = rtc_read_time(rtc, &tm);
+
+        spin_lock_irq(&rtc->irq_lock);
+        if (rtc->stop_uie_polling || err) {
+                rtc->uie_task_active = 0;
+        } else if (rtc->oldsecs != tm.tm_sec) {
+                num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
+                rtc->oldsecs = tm.tm_sec;
+                rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
+                rtc->uie_timer_active = 1;
+                rtc->uie_task_active = 0;
+                add_timer(&rtc->uie_timer);
+        } else if (schedule_work(&rtc->uie_task) == 0) {
+                rtc->uie_task_active = 0;
+        }
+        spin_unlock_irq(&rtc->irq_lock);
+        if (num)
+                rtc_handle_legacy_irq(rtc, num, RTC_UF);
+}
+static void rtc_uie_timer(struct timer_list *t)
+{
+        struct rtc_device *rtc = from_timer(rtc, t, uie_timer);
+        unsigned long flags;
+
+        spin_lock_irqsave(&rtc->irq_lock, flags);
+        rtc->uie_timer_active = 0;
+        rtc->uie_task_active = 1;
+        if ((schedule_work(&rtc->uie_task) == 0))
+                rtc->uie_task_active = 0;
+        spin_unlock_irqrestore(&rtc->irq_lock, flags);
+}
+
+static int clear_uie(struct rtc_device *rtc)
+{
+        spin_lock_irq(&rtc->irq_lock);
+        if (rtc->uie_irq_active) {
+                rtc->stop_uie_polling = 1;
+                if (rtc->uie_timer_active) {
+                        spin_unlock_irq(&rtc->irq_lock);
+                        del_timer_sync(&rtc->uie_timer);
+                        spin_lock_irq(&rtc->irq_lock);
+                        rtc->uie_timer_active = 0;
+                }
+                if (rtc->uie_task_active) {
+                        spin_unlock_irq(&rtc->irq_lock);
+                        flush_scheduled_work();
+                        spin_lock_irq(&rtc->irq_lock);
+                }
+                rtc->uie_irq_active = 0;
+        }
+        spin_unlock_irq(&rtc->irq_lock);
+        return 0;
+}
+
+static int set_uie(struct rtc_device *rtc)
+{
+        struct rtc_time tm;
+        int err;
+
+        err = rtc_read_time(rtc, &tm);
+        if (err)
+                return err;
+        spin_lock_irq(&rtc->irq_lock);
+        if (!rtc->uie_irq_active) {
+                rtc->uie_irq_active = 1;
+                rtc->stop_uie_polling = 0;
+                rtc->oldsecs = tm.tm_sec;
+                rtc->uie_task_active = 1;
+                if (schedule_work(&rtc->uie_task) == 0)
+                        rtc->uie_task_active = 0;
+        }
+        rtc->irq_data = 0;
+        spin_unlock_irq(&rtc->irq_lock);
+        return 0;
+}
+
+int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
+{
+        if (enabled)
+                return set_uie(rtc);
+        else
+                return clear_uie(rtc);
+}
+EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
+
+#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
+
+static ssize_t
+rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+        struct rtc_device *rtc = file->private_data;
+
+        DECLARE_WAITQUEUE(wait, current);
+        unsigned long data;
+        ssize_t ret;
+
+        if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
+                return -EINVAL;
+
+        add_wait_queue(&rtc->irq_queue, &wait);
+        do {
+                __set_current_state(TASK_INTERRUPTIBLE);
+
+                spin_lock_irq(&rtc->irq_lock);
+                data = rtc->irq_data;
+                rtc->irq_data = 0;
+                spin_unlock_irq(&rtc->irq_lock);
+
+                if (data != 0) {
+                        ret = 0;
+                        break;
+                }
+                if (file->f_flags & O_NONBLOCK) {
+                        ret = -EAGAIN;
+                        break;
+                }
+                if (signal_pending(current)) {
+                        ret = -ERESTARTSYS;
+                        break;
+                }
+                schedule();
+        } while (1);
+        set_current_state(TASK_RUNNING);
+        remove_wait_queue(&rtc->irq_queue, &wait);
+
+        if (ret == 0) {
+                /* Check for any data updates */
+                if (rtc->ops->read_callback)
+                        data = rtc->ops->read_callback(rtc->dev.parent,
+                                                       data);
+
+                if (sizeof(int) != sizeof(long) &&
+                    count == sizeof(unsigned int))
+                        ret = put_user(data, (unsigned int __user *)buf) ?:
+                                sizeof(unsigned int);
+                else
+                        ret = put_user(data, (unsigned long __user *)buf) ?:
+                                sizeof(unsigned long);
+        }
+        return ret;
+}
+
+static __poll_t rtc_dev_poll(struct file *file, poll_table *wait)
+{
+        struct rtc_device *rtc = file->private_data;
+        unsigned long data;
+
+        poll_wait(file, &rtc->irq_queue, wait);
+
+        data = rtc->irq_data;
+
+        return (data != 0) ? (EPOLLIN | EPOLLRDNORM) : 0;
+}
+
+static long rtc_dev_ioctl(struct file *file,
+                unsigned int cmd, unsigned long arg)
+{
+        int err = 0;
+        struct rtc_device *rtc = file->private_data;
+        const struct rtc_class_ops *ops = rtc->ops;
+        struct rtc_time tm;
+        struct rtc_wkalrm alarm;
+        void __user *uarg = (void __user *) arg;
+
+        err = mutex_lock_interruptible(&rtc->ops_lock);
+        if (err)
+                return err;
+
+        /* check that the calling task has appropriate permissions
+         * for certain ioctls. doing this check here is useful
+         * to avoid duplicate code in each driver.
+         */
+        switch (cmd) {
+        case RTC_EPOCH_SET:
+        case RTC_SET_TIME:
+                if (!capable(CAP_SYS_TIME))
+                        err = -EACCES;
+                break;
+
+        case RTC_IRQP_SET:
+                if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
+                        err = -EACCES;
+                break;
+
+        case RTC_PIE_ON:
+                if (rtc->irq_freq > rtc->max_user_freq &&
+                                !capable(CAP_SYS_RESOURCE))
+                        err = -EACCES;
+                break;
+        }
+
+        if (err)
+                goto done;
+
+        /*
+         * Drivers *SHOULD NOT* provide ioctl implementations
+         * for these requests.  Instead, provide methods to
+         * support the following code, so that the RTC's main
+         * features are accessible without using ioctls.
+         *
+         * RTC and alarm times will be in UTC, by preference,
+         * but dual-booting with MS-Windows implies RTCs must
+         * use the local wall clock time.
+         */
+
+        switch (cmd) {
+        case RTC_ALM_READ:
+                mutex_unlock(&rtc->ops_lock);
+
+                err = rtc_read_alarm(rtc, &alarm);
+                if (err < 0)
+                        return err;
+
+                if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
+                        err = -EFAULT;
+                return err;
+
+        case RTC_ALM_SET:
+                mutex_unlock(&rtc->ops_lock);
+
+                if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
+                        return -EFAULT;
+
+                alarm.enabled = 0;
+                alarm.pending = 0;
+                alarm.time.tm_wday = -1;
+                alarm.time.tm_yday = -1;
+                alarm.time.tm_isdst = -1;
+
+                /* RTC_ALM_SET alarms may be up to 24 hours in the future.
+                 * Rather than expecting every RTC to implement "don't care"
+                 * for day/month/year fields, just force the alarm to have
+                 * the right values for those fields.
+                 *
+                 * RTC_WKALM_SET should be used instead.  Not only does it
+                 * eliminate the need for a separate RTC_AIE_ON call, it
+                 * doesn't have the "alarm 23:59:59 in the future" race.
+                 *
+                 * NOTE:  some legacy code may have used invalid fields as
+                 * wildcards, exposing hardware "periodic alarm" capabilities.
+                 * Not supported here.
+                 */
+                {
+                        time64_t now, then;
+
+                        err = rtc_read_time(rtc, &tm);
+                        if (err < 0)
+                                return err;
+                        now = rtc_tm_to_time64(&tm);
+
+                        alarm.time.tm_mday = tm.tm_mday;
+                        alarm.time.tm_mon = tm.tm_mon;
+                        alarm.time.tm_year = tm.tm_year;
+                        err  = rtc_valid_tm(&alarm.time);
+                        if (err < 0)
+                                return err;
+                        then = rtc_tm_to_time64(&alarm.time);
+
+                        /* alarm may need to wrap into tomorrow */
+                        if (then < now) {
+                                rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
+                                alarm.time.tm_mday = tm.tm_mday;
+                                alarm.time.tm_mon = tm.tm_mon;
+                                alarm.time.tm_year = tm.tm_year;
+                        }
+                }
+
+                return rtc_set_alarm(rtc, &alarm);
+
+        case RTC_RD_TIME:
+                mutex_unlock(&rtc->ops_lock);
+
+                err = rtc_read_time(rtc, &tm);
+                if (err < 0)
+                        return err;
+
+                if (copy_to_user(uarg, &tm, sizeof(tm)))
+                        err = -EFAULT;
+                return err;
+
+        case RTC_SET_TIME:
+                mutex_unlock(&rtc->ops_lock);
+
+                if (copy_from_user(&tm, uarg, sizeof(tm)))
+                        return -EFAULT;
+
+                return rtc_set_time(rtc, &tm);
+
+        case RTC_PIE_ON:
+                err = rtc_irq_set_state(rtc, 1);
+                break;
+
+        case RTC_PIE_OFF:
+                err = rtc_irq_set_state(rtc, 0);
+                break;
+
+        case RTC_AIE_ON:
+                mutex_unlock(&rtc->ops_lock);
+                return rtc_alarm_irq_enable(rtc, 1);
+
+        case RTC_AIE_OFF:
+                mutex_unlock(&rtc->ops_lock);
+                return rtc_alarm_irq_enable(rtc, 0);
+
+        case RTC_UIE_ON:
+                mutex_unlock(&rtc->ops_lock);
+                return rtc_update_irq_enable(rtc, 1);
+
+        case RTC_UIE_OFF:
+                mutex_unlock(&rtc->ops_lock);
+                return rtc_update_irq_enable(rtc, 0);
+
+        case RTC_IRQP_SET:
+                err = rtc_irq_set_freq(rtc, arg);
+                break;
+
+        case RTC_IRQP_READ:
+                err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
+                break;
+
+        case RTC_WKALM_SET:
+                mutex_unlock(&rtc->ops_lock);
+                if (copy_from_user(&alarm, uarg, sizeof(alarm)))
+                        return -EFAULT;
+
+                return rtc_set_alarm(rtc, &alarm);
+
+        case RTC_WKALM_RD:
+                mutex_unlock(&rtc->ops_lock);
+                err = rtc_read_alarm(rtc, &alarm);
+                if (err < 0)
+                        return err;
+
+                if (copy_to_user(uarg, &alarm, sizeof(alarm)))
+                        err = -EFAULT;
+                return err;
+
+        default:
+                /* Finally try the driver's ioctl interface */
+                if (ops->ioctl) {
+                        err = ops->ioctl(rtc->dev.parent, cmd, arg);
+                        if (err == -ENOIOCTLCMD)
+                                err = -ENOTTY;
+                } else
+                        err = -ENOTTY;
+                break;
+        }
+
+done:
+        mutex_unlock(&rtc->ops_lock);
+        return err;
+}
+
+static int rtc_dev_fasync(int fd, struct file *file, int on)
+{
+        struct rtc_device *rtc = file->private_data;
+        return fasync_helper(fd, file, on, &rtc->async_queue);
+}
+
+static int rtc_dev_release(struct inode *inode, struct file *file)
+{
+        struct rtc_device *rtc = file->private_data;
+
+        /* We shut down the repeating IRQs that userspace enabled,
+         * since nothing is listening to them.
+         *  - Update (UIE) ... currently only managed through ioctls
+         *  - Periodic (PIE) ... also used through rtc_*() interface calls
+         *
+         * Leave the alarm alone; it may be set to trigger a system wakeup
+         * later, or be used by kernel code, and is a one-shot event anyway.
+         */
+
+        /* Keep ioctl until all drivers are converted */
+        rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
+        rtc_update_irq_enable(rtc, 0);
+        rtc_irq_set_state(rtc, 0);
+
+        clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
+        return 0;
+}
+
+static const struct file_operations rtc_dev_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .read           = rtc_dev_read,
+        .poll           = rtc_dev_poll,
+        .unlocked_ioctl = rtc_dev_ioctl,
+        .open           = rtc_dev_open,
+        .release        = rtc_dev_release,
+        .fasync         = rtc_dev_fasync,
+};
+
+/* insertion/removal hooks */
+
+void rtc_dev_prepare(struct rtc_device *rtc)
+{
+        if (!rtc_devt)
+                return;
+
+        if (rtc->id >= RTC_DEV_MAX) {
+                dev_dbg(&rtc->dev, "too many RTC devices\n");
+                return;
+        }
+
+        rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+        INIT_WORK(&rtc->uie_task, rtc_uie_task);
+        timer_setup(&rtc->uie_timer, rtc_uie_timer, 0);
+#endif
+
+        cdev_init(&rtc->char_dev, &rtc_dev_fops);
+        rtc->char_dev.owner = rtc->owner;
+}
+
+void __init rtc_dev_init(void)
+{
+        int err;
+
+        err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
+        if (err < 0)
+                pr_err("failed to allocate char dev region\n");
+}
+
+void __exit rtc_dev_exit(void)
+{
+        if (rtc_devt)
+                unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
+}