From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/rtc/dev.c | 568 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 568 insertions(+) create mode 100644 drivers/rtc/dev.c (limited to 'drivers/rtc/dev.c') diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c new file mode 100644 index 0000000000..4aad9bb998 --- /dev/null +++ b/drivers/rtc/dev.c @@ -0,0 +1,568 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC subsystem, dev interface + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * based on arch/arm/common/rtctime.c + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#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_work(&rtc->uie_task); + 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) { + 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; + struct rtc_param param; + 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: + case RTC_PARAM_SET: + 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; + + case RTC_PARAM_GET: + if (copy_from_user(¶m, uarg, sizeof(param))) { + mutex_unlock(&rtc->ops_lock); + return -EFAULT; + } + + switch(param.param) { + case RTC_PARAM_FEATURES: + if (param.index != 0) + err = -EINVAL; + param.uvalue = rtc->features[0]; + break; + + case RTC_PARAM_CORRECTION: { + long offset; + mutex_unlock(&rtc->ops_lock); + if (param.index != 0) + return -EINVAL; + err = rtc_read_offset(rtc, &offset); + mutex_lock(&rtc->ops_lock); + if (err == 0) + param.svalue = offset; + break; + } + default: + if (rtc->ops->param_get) + err = rtc->ops->param_get(rtc->dev.parent, ¶m); + else + err = -EINVAL; + } + + if (!err) + if (copy_to_user(uarg, ¶m, sizeof(param))) + err = -EFAULT; + + break; + + case RTC_PARAM_SET: + if (copy_from_user(¶m, uarg, sizeof(param))) { + mutex_unlock(&rtc->ops_lock); + return -EFAULT; + } + + switch(param.param) { + case RTC_PARAM_FEATURES: + err = -EINVAL; + break; + + case RTC_PARAM_CORRECTION: + mutex_unlock(&rtc->ops_lock); + if (param.index != 0) + return -EINVAL; + return rtc_set_offset(rtc, param.svalue); + + default: + if (rtc->ops->param_set) + err = rtc->ops->param_set(rtc->dev.parent, ¶m); + else + err = -EINVAL; + } + + break; + + 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; +} + +#ifdef CONFIG_COMPAT +#define RTC_IRQP_SET32 _IOW('p', 0x0c, __u32) +#define RTC_IRQP_READ32 _IOR('p', 0x0b, __u32) +#define RTC_EPOCH_SET32 _IOW('p', 0x0e, __u32) + +static long rtc_dev_compat_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct rtc_device *rtc = file->private_data; + void __user *uarg = compat_ptr(arg); + + switch (cmd) { + case RTC_IRQP_READ32: + return put_user(rtc->irq_freq, (__u32 __user *)uarg); + + case RTC_IRQP_SET32: + /* arg is a plain integer, not pointer */ + return rtc_dev_ioctl(file, RTC_IRQP_SET, arg); + + case RTC_EPOCH_SET32: + /* arg is a plain integer, not pointer */ + return rtc_dev_ioctl(file, RTC_EPOCH_SET, arg); + } + + return rtc_dev_ioctl(file, cmd, (unsigned long)uarg); +} +#endif + +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, +#ifdef CONFIG_COMPAT + .compat_ioctl = rtc_dev_compat_ioctl, +#endif + .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"); +} -- cgit v1.2.3