/*
* 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.
*/
#include <linux/module.h>
#include <linux/rtc.h>
static struct class *rtc_dev_class;
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)
{
int err;
struct rtc_device *rtc = container_of(inode->i_cdev,
struct rtc_device, char_dev);
struct rtc_class_ops *ops = rtc->ops;
/* We keep the lock as long as the device is in use
* and return immediately if busy
*/
if (!(mutex_trylock(&rtc->char_lock)))
return -EBUSY;
file->private_data = &rtc->class_dev;
err = ops->open ? ops->open(rtc->class_dev.dev) : 0;
if (err == 0) {
spin_lock_irq(&rtc->irq_lock);
rtc->irq_data = 0;
spin_unlock_irq(&rtc->irq_lock);
return 0;
}
/* something has gone wrong, release the lock */
mutex_unlock(&rtc->char_lock);
return err;
}
static ssize_t
rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
struct rtc_device *rtc = to_rtc_device(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->class_dev.dev,
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 unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
{
struct rtc_device *rtc = to_rtc_device(file->private_data);
unsigned long data;
poll_wait(file, &rtc->irq_queue, wait);
data = rtc->irq_data;
return (data != 0) ? (POLLIN | POLLRDNORM) : 0;
}
static int rtc_dev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int err = 0;
struct class_device *class_dev = file->private_data;
struct rtc_device *rtc = to_rtc_device(class_dev);
struct rtc_class_ops *ops = rtc->ops;
struct rtc_time tm;
struct rtc_wkalrm alarm;
void __user *uarg = (void __user *) arg;
/* avoid conflicting IRQ users */
if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
spin_lock(&rtc->irq_task_lock);
if (rtc->irq_task)
err = -EBUSY;
spin_unlock(&rtc->irq_task_lock);
if (err < 0)
return err;
}
/* try the driver's ioctl interface */
if (ops->ioctl) {
err = ops->ioctl(class_dev->dev, cmd, arg);
if (err != -EINVAL)
return err;
}
/* if the driver does not provide the ioctl interface
* or if that particular ioctl was not implemented
* (-EINVAL), we will try to emulate here.
*/
switch (cmd) {
case RTC_ALM_READ:
err = rtc_read_alarm(class_dev, &alarm);
if (err < 0)
return err;
if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
return -EFAULT;
break;
case RTC_ALM_SET:
if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
return -EFAULT;
alarm.enabled = 0;
alarm.pending = 0;
alarm.time.tm_mday = -1;
alarm.time.tm_mon = -1;
alarm.time.tm_year = -1;
alarm.time.tm_wday = -1;
alarm.time.tm_yday = -1;
alarm.time.tm_isdst = -1;
err = rtc_set_alarm(class_dev, &alarm);
break;
case RTC_RD_TIME:
err = rtc_read_time(class_dev, &tm);
if (err < 0)
return err;
if (copy_to_user(uarg, &tm, sizeof(tm)))
return -EFAULT;
break;
case RTC_SET_TIME:
if (!capable(CAP_SYS_TIME))
return -EACCES;
if (copy_from_user(&tm, uarg, sizeof(tm)))
return -EFAULT;
err = rtc_set_time(class_dev, &tm);
break;
#if 0
case RTC_EPOCH_SET:
#ifndef rtc_epoch
/*
* There were no RTC clocks before 1900.
*/
if (arg < 1900) {
err = -EINVAL;
break;
}
if (!capable(CAP_SYS_TIME)) {
err = -EACCES;
break;
}
rtc_epoch = arg;
err = 0;
#endif
break;
case RTC_EPOCH_READ:
err = put_user(rtc_epoch, (unsigned long __user *)uarg);
break;
#endif
case RTC_WKALM_SET:
if (copy_from_user(&alarm, uarg, sizeof(alarm)))
return -EFAULT;
err = rtc_set_alarm(class_dev, &alarm);
break;
case RTC_WKALM_RD:
err = rtc_read_alarm(class_dev, &alarm);
if (err < 0)
return err;
if (copy_to_user(uarg, &alarm, sizeof(alarm)))
return -EFAULT;
break;
default:
err = -EINVAL;
break;
}
return err;
}
static int rtc_dev_release(struct inode *inode, struct file *file)
{
struct rtc_device *rtc = to_rtc_device(file->private_data);
if (rtc->ops->release)
rtc->ops->release(rtc->class_dev.dev);
mutex_unlock(&rtc->char_lock);
return 0;
}
static int rtc_dev_fasync(int fd, struct file *file, int on)
{
struct rtc_device *rtc = to_rtc_device(file->private_data);
return fasync_helper(fd, file, on, &rtc->async_queue);
}
static struct file_operations rtc_dev_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = rtc_dev_read,
.poll = rtc_dev_poll,
.ioctl = rtc_dev_ioctl,
.open = rtc_dev_open,
.release = rtc_dev_release,
.fasync = rtc_dev_fasync,
};
/* insertion/removal hooks */
static int rtc_dev_add_device(struct class_device *class_dev,
struct class_interface *class_intf)
{
int err = 0;
struct rtc_device *rtc = to_rtc_device(class_dev);
if (rtc->id >= RTC_DEV_MAX) {
dev_err(class_dev->dev, "too many RTCs\n");
return -EINVAL;
}
mutex_init(&rtc->char_lock);
spin_lock_init(&rtc->irq_lock);
init_waitqueue_head(&rtc->irq_queue);
cdev_init(&rtc->char_dev, &rtc_dev_fops);
rtc->char_dev.owner = rtc->owner;
if (cdev_add(&rtc->char_dev, MKDEV(MAJOR(rtc_devt), rtc->id), 1)) {
cdev_del(&rtc->char_dev);
dev_err(class_dev->dev,
"failed to add char device %d:%d\n",
MAJOR(rtc_devt), rtc->id);
return -ENODEV;
}
rtc->rtc_dev = class_device_create(rtc_dev_class, NULL,
MKDEV(MAJOR(rtc_devt), rtc->id),
class_dev->dev, "rtc%d", rtc->id);
if (IS_ERR(rtc->rtc_dev)) {
dev_err(class_dev->dev, "cannot create rtc_dev device\n");
err = PTR_ERR(rtc->rtc_dev);
goto err_cdev_del;
}
dev_info(class_dev->dev, "rtc intf: dev (%d:%d)\n",
MAJOR(rtc->rtc_dev->devt),
MINOR(rtc->rtc_dev->devt));
return 0;
err_cdev_del:
cdev_del(&rtc->char_dev);
return err;
}
static void rtc_dev_remove_device(struct class_device *class_dev,
struct class_interface *class_intf)
{
struct rtc_device *rtc = to_rtc_device(class_dev);
if (rtc->rtc_dev) {
dev_dbg(class_dev->dev, "removing char %d:%d\n",
MAJOR(rtc->rtc_dev->devt),
MINOR(rtc->rtc_dev->devt));
class_device_unregister(rtc->rtc_dev);
cdev_del(&rtc->char_dev);
}
}
/* interface registration */
static struct class_interface rtc_dev_interface = {
.add = &rtc_dev_add_device,
.remove = &rtc_dev_remove_device,
};
static int __init rtc_dev_init(void)
{
int err;
rtc_dev_class = class_create(THIS_MODULE, "rtc-dev");
if (IS_ERR(rtc_dev_class))
return PTR_ERR(rtc_dev_class);
err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
if (err < 0) {
printk(KERN_ERR "%s: failed to allocate char dev region\n",
__FILE__);
goto err_destroy_class;
}
err = rtc_interface_register(&rtc_dev_interface);
if (err < 0) {
printk(KERN_ERR "%s: failed to register the interface\n",
__FILE__);
goto err_unregister_chrdev;
}
return 0;
err_unregister_chrdev:
unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
err_destroy_class:
class_destroy(rtc_dev_class);
return err;
}
static void __exit rtc_dev_exit(void)
{
class_interface_unregister(&rtc_dev_interface);
class_destroy(rtc_dev_class);
unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
}
module_init(rtc_dev_init);
module_exit(rtc_dev_exit);
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("RTC class dev interface");
MODULE_LICENSE("GPL");
