This patch adds the dev interface to the RTC
subsystem.
The first RTC driver that registers with the class
will be available under /dev/rtc .
Signed-off-by: Alessandro Zummo <[email protected]>
--
drivers/rtc/Kconfig | 11 +
drivers/rtc/Makefile | 1
drivers/rtc/rtc-dev.c | 336 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 348 insertions(+)
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-nslu2/drivers/rtc/rtc-dev.c 2005-12-20 20:43:58.000000000 +0100
@@ -0,0 +1,336 @@
+/*
+ * rtc-dev.c - rtc subsystem, dev interface
+ *
+ * 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/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kdev_t.h>
+#include <linux/gfp.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/poll.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+
+#include <asm/rtc.h>
+#include <asm/semaphore.h>
+
+static struct class_device *rtc_dev = NULL;
+
+static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
+static struct fasync_struct *rtc_async_queue;
+
+/*
+ * rtc_lock protects rtc_irq_data
+ */
+static DEFINE_SPINLOCK(rtc_lock);
+static unsigned long rtc_irq_data;
+
+/*
+ * rtc_sem protects rtc_inuse and rtc_dev
+ */
+static DECLARE_MUTEX(rtc_sem);
+static unsigned long rtc_inuse;
+
+
+static int rtc_dev_open(struct inode *inode, struct file *file)
+{
+ int err;
+
+ struct rtc_class_ops *ops = class_get_devdata(rtc_dev);
+
+ down(&rtc_sem);
+
+ if (rtc_inuse) {
+ err = -EBUSY;
+ } else if (!try_module_get(ops->owner)) {
+ err = -ENODEV;
+ } else {
+ file->private_data = rtc_dev;
+
+ err = ops->open ? ops->open(rtc_dev->dev) : 0;
+ if (err == 0) {
+ spin_lock_irq(&rtc_lock);
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_lock);
+
+ rtc_inuse = 1;
+ }
+ }
+ up(&rtc_sem);
+
+ return err;
+}
+
+
+static ssize_t
+rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ unsigned long data;
+ ssize_t ret;
+
+ if (count < sizeof(unsigned long))
+ return -EINVAL;
+
+ add_wait_queue(&rtc_wait, &wait);
+ do {
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_lock_irq(&rtc_lock);
+ data = rtc_irq_data;
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_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_wait, &wait);
+
+ if (ret == 0) {
+ ret = put_user(data, (unsigned long __user *)buf);
+ if (ret == 0)
+ ret = sizeof(unsigned long);
+ }
+ return ret;
+}
+
+static unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
+{
+ unsigned long data;
+
+ poll_wait(file, &rtc_wait, wait);
+
+ spin_lock_irq(&rtc_lock);
+ data = rtc_irq_data;
+ spin_unlock_irq(&rtc_lock);
+
+ 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 = -EINVAL;
+ struct class_device *class_dev = file->private_data;
+ struct rtc_class_ops *ops = class_get_devdata(class_dev);
+ struct rtc_time tm;
+ struct rtc_wkalrm alrm;
+ void __user *uarg = (void __user *)arg;
+
+ /* try the driver's ioctl interface */
+ if (ops->ioctl) {
+ err = ops->ioctl(class_dev->dev, cmd, arg);
+ if (err < 0 && 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:
+ if ((err = rtc_read_alarm(class_dev, &alrm)) < 0)
+ return err;
+
+ if ((err = copy_to_user(uarg, &alrm.time, sizeof(tm))))
+ return -EFAULT;
+ break;
+
+ case RTC_ALM_SET:
+ if ((err = copy_from_user(&alrm.time, uarg, sizeof(tm))))
+ return -EFAULT;
+
+ alrm.enabled = 0;
+ alrm.pending = 0;
+ alrm.time.tm_mday = -1;
+ alrm.time.tm_mon = -1;
+ alrm.time.tm_year = -1;
+ alrm.time.tm_wday = -1;
+ alrm.time.tm_yday = -1;
+ alrm.time.tm_isdst = -1;
+ err = rtc_set_alarm(class_dev, &alrm);
+ break;
+
+ case RTC_RD_TIME:
+ if ((err = rtc_read_time(class_dev, &tm)) < 0)
+ return err;
+
+ if ((err = copy_to_user(uarg, &tm, sizeof(tm))))
+ return -EFAULT;
+ break;
+
+ case RTC_SET_TIME:
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+
+ if ((err = 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 ((err = copy_from_user(&alrm, uarg, sizeof(alrm))))
+ return -EFAULT;
+
+ err = rtc_set_alarm(class_dev, &alrm);
+ break;
+
+ case RTC_WKALM_RD:
+ if ((err = rtc_read_alarm(class_dev, &alrm)) < 0)
+ return err;
+
+ if ((err = copy_to_user(uarg, &alrm, sizeof(alrm))))
+ return -EFAULT;
+ break;
+
+ default:
+ if (ops->ioctl)
+ err = ops->ioctl(class_dev->dev, cmd, arg);
+ break;
+ }
+
+ return err;
+}
+
+static int rtc_dev_release(struct inode *inode, struct file *file)
+{
+ struct class_device *class_dev = file->private_data;
+ struct rtc_class_ops *ops = class_get_devdata(class_dev);
+
+ if (ops->release)
+ ops->release(class_dev->dev);
+
+ spin_lock_irq(&rtc_lock);
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_lock);
+
+ module_put(ops->owner);
+ rtc_inuse = 0;
+
+ return 0;
+}
+
+static int rtc_dev_fasync(int fd, struct file *file, int on)
+{
+ 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,
+};
+
+static struct miscdevice rtc_misc_dev = {
+ .minor = RTC_MINOR,
+ .name = "rtc",
+ .fops = &rtc_dev_fops,
+};
+
+/* insertion/removal hooks */
+
+static int rtc_dev_add_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ down(&rtc_sem);
+ if (rtc_dev == NULL) {
+ rtc_dev = class_dev;
+ misc_register(&rtc_misc_dev);
+ dev_info(class_dev->dev, "rtc intf: dev\n");
+ }
+ up(&rtc_sem);
+
+ return 0;
+}
+
+static void rtc_dev_remove_device(struct class_device *class_dev,
+ struct class_interface *class_intf)
+{
+ down(&rtc_sem);
+ if (class_dev == rtc_dev) {
+ misc_deregister(&rtc_misc_dev);
+ rtc_dev = NULL;
+ }
+ up(&rtc_sem);
+}
+
+/* interface registration */
+
+struct class_interface rtc_dev_interface = {
+ .add = &rtc_dev_add_device,
+ .remove = &rtc_dev_remove_device,
+};
+
+static int __init rtc_dev_init(void)
+{
+ return rtc_interface_register(&rtc_dev_interface);
+}
+
+static void __exit rtc_dev_exit(void)
+{
+ class_interface_unregister(&rtc_dev_interface);
+}
+
+module_init(rtc_dev_init);
+module_exit(rtc_dev_exit);
+
+MODULE_AUTHOR("Alessandro Zummo <[email protected]>");
+MODULE_DESCRIPTION("RTC class dev interface");
+MODULE_LICENSE("GPL");
--- linux-nslu2.orig/drivers/rtc/Kconfig 2005-12-20 20:43:57.000000000 +0100
+++ linux-nslu2/drivers/rtc/Kconfig 2005-12-20 20:44:01.000000000 +0100
@@ -41,6 +41,17 @@ config RTC_INTF_PROC
This driver can also be built as a module. If so, the module
will be called rtc-proc.
+config RTC_INTF_DEV
+ tristate "dev"
+ depends on RTC_CLASS
+ default RTC_CLASS
+ help
+ Say yes here if you want to use your RTC using the dev
+ interface, /dev/rtc .
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-dev.
+
comment "RTC drivers"
depends on RTC_CLASS
--- linux-nslu2.orig/drivers/rtc/Makefile 2005-12-20 20:43:57.000000000 +0100
+++ linux-nslu2/drivers/rtc/Makefile 2005-12-20 20:44:01.000000000 +0100
@@ -8,3 +8,4 @@ rtc-core-y := class.o intf.o
rtc-core-objs := $(rtc-core-y)
obj-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
obj-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o
+obj-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o