/*
* Driver for NEC VR4100 series Real Time Clock unit.
*
* Copyright (C) 2003-2005 Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/mc146818rtc.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <asm/div64.h>
#include <asm/io.h>
#include <asm/time.h>
#include <asm/uaccess.h>
#include <asm/vr41xx/vr41xx.h>
MODULE_AUTHOR("Yoichi Yuasa <yuasa@hh.iij4u.or.jp>");
MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
MODULE_LICENSE("GPL");
#define RTC1_TYPE1_START 0x0b0000c0UL
#define RTC1_TYPE1_END 0x0b0000dfUL
#define RTC2_TYPE1_START 0x0b0001c0UL
#define RTC2_TYPE1_END 0x0b0001dfUL
#define RTC1_TYPE2_START 0x0f000100UL
#define RTC1_TYPE2_END 0x0f00011fUL
#define RTC2_TYPE2_START 0x0f000120UL
#define RTC2_TYPE2_END 0x0f00013fUL
#define RTC1_SIZE 0x20
#define RTC2_SIZE 0x20
/* RTC 1 registers */
#define ETIMELREG 0x00
#define ETIMEMREG 0x02
#define ETIMEHREG 0x04
/* RFU */
#define ECMPLREG 0x08
#define ECMPMREG 0x0a
#define ECMPHREG 0x0c
/* RFU */
#define RTCL1LREG 0x10
#define RTCL1HREG 0x12
#define RTCL1CNTLREG 0x14
#define RTCL1CNTHREG 0x16
#define RTCL2LREG 0x18
#define RTCL2HREG 0x1a
#define RTCL2CNTLREG 0x1c
#define RTCL2CNTHREG 0x1e
/* RTC 2 registers */
#define TCLKLREG 0x00
#define TCLKHREG 0x02
#define TCLKCNTLREG 0x04
#define TCLKCNTHREG 0x06
/* RFU */
#define RTCINTREG 0x1e
#define TCLOCK_INT 0x08
#define RTCLONG2_INT 0x04
#define RTCLONG1_INT 0x02
#define ELAPSEDTIME_INT 0x01
#define RTC_FREQUENCY 32768
#define MAX_PERIODIC_RATE 6553
#define MAX_USER_PERIODIC_RATE 64
static void __iomem *rtc1_base;
static void __iomem *rtc2_base;
#define rtc1_read(offset) readw(rtc1_base + (offset))
#define rtc1_write(offset, value) writew((value), rtc1_base + (offset))
#define rtc2_read(offset) readw(rtc2_base + (offset))
#define rtc2_write(offset, value) writew((value), rtc2_base + (offset))
static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */
static spinlock_t rtc_task_lock;
static wait_queue_head_t rtc_wait;
static unsigned long rtc_irq_data;
static struct fasync_struct *rtc_async_queue;
static rtc_task_t *rtc_callback;
static char rtc_name[] = "RTC";
static unsigned long periodic_frequency;
static unsigned long periodic_count;
typedef enum {
RTC_RELEASE,
RTC_OPEN,
} rtc_status_t;
static rtc_status_t rtc_status;
typedef enum {
FUNCTION_RTC_IOCTL,
FUNCTION_RTC_CONTROL,
} rtc_callfrom_t;
struct resource rtc_resource[2] = {
{ .name = rtc_name,
.flags = IORESOURCE_MEM, },
{ .name = rtc_name,
.flags = IORESOURCE_MEM, },
};
#define RTC_NUM_RESOURCES sizeof(rtc_resource) / sizeof(struct resource)
static inline unsigned long read_elapsed_second(void)
{
unsigned long first_low, first_mid, first_high;
unsigned long second_low, second_mid, second_high;
do {
first_low = rtc1_read(ETIMELREG);
first_mid = rtc1_read(ETIMEMREG);
first_high = rtc1_read(ETIMEHREG);
second_low = rtc1_read(ETIMELREG);
second_mid = rtc1_read(ETIMEMREG);
second_high = rtc1_read(ETIMEHREG);
} while (first_low != second_low || first_mid != second_mid ||
first_high != second_high);
return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
}
static inline void write_elapsed_second(unsigned long sec)
{
spin_lock_irq(&rtc_lock);
rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
spin_unlock_irq(&rtc_lock);
}
static void set_alarm(struct rtc_time *time)
{
unsigned long alarm_sec;
alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
time->tm_hour, time->tm_min, time->tm_sec);
spin_lock_irq(&rtc_lock);
rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
spin_unlock_irq(&rtc_lock);
}
static void read_alarm(struct rtc_time *time)
{
unsigned long low, mid, high;
spin_lock_irq(&rtc_lock);
low = rtc1_read(ECMPLREG);
mid = rtc1_read(ECMPMREG);
high = rtc1_read(ECMPHREG);
spin_unlock_irq(&rtc_lock);
to_tm((high << 17) | (mid << 1) | (low >> 15), time);
time->tm_year -= 1900;
}
static void read_time(struct rtc_time *time)
{
unsigned long epoch_sec, elapsed_sec;
epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
elapsed_sec = read_elapsed_second();
to_tm(epoch_sec + elapsed_sec, time);
time->tm_year -= 1900;
}
static void set_time(struct rtc_time *time)
{
unsigned long epoch_sec, current_sec;
epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
time->tm_hour, time->tm_min, time->tm_sec);
write_elapsed_second(current_sec - epoch_sec);
}
static ssize_t rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
DECLARE_WAITQUEUE(wait, current);
unsigned long irq_data;
int retval = 0;
if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
return -EINVAL;
add_wait_queue(&rtc_wait, &wait);
do {
__set_current_state(TASK_INTERRUPTIBLE);
spin_lock_irq(&rtc_lock);
irq_data = rtc_irq_data;
rtc_irq_data = 0;
spin_unlock_irq(&rtc_lock);
if (irq_data != 0)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
} while (1);
if (retval == 0) {
if (count == sizeof(unsigned int)) {
retval = put_user(irq_data, (unsigned int __user *)buf);
if (retval == 0)
retval = sizeof(unsigned int);
} else {
retval = put_user(irq_data, (unsigned long __user *)buf);
if (retval == 0)
retval = sizeof(unsigned long);
}
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(&rtc_wait, &wait);
return retval;
}
static unsigned int rtc_poll(struct file *file, struct poll_table_struct *table)
{
poll_wait(file, &rtc_wait, table);
if (rtc_irq_data != 0)
return POLLIN | POLLRDNORM;
return 0;
}
static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, rtc_callfrom_t from)
{
struct rtc_time time;
unsigned long count;
switch (cmd) {
case RTC_AIE_ON:
enable_irq(ELAPSEDTIME_IRQ);
break;
case RTC_AIE_OFF:
disable_irq(ELAPSEDTIME_IRQ);
break;
case RTC_PIE_ON:
enable_irq(RTCLONG1_IRQ);
break;
case RTC_PIE_OFF:
disable_irq(RTCLONG1_IRQ);
break;
case RTC_ALM_SET:
if (copy_from_user(&time, (struct rtc_time __user *)arg,
sizeof(struct rtc_time)))
return -EFAULT;
set_alarm(&time);
break;
case RTC_ALM_READ:
memset(&time, 0, sizeof(struct rtc_time));
read_alarm(&time);
break;
case RTC_RD_TIME:
memset(&time, 0, sizeof(struct rtc_time));
read_time(&time);
if (copy_to_user((void __user *)arg, &time, sizeof(struct rtc_time)))
return -EFAULT;
break;
case RTC_SET_TIME:
if (capable(CAP_SYS_TIME) == 0)
return -EACCES;
if (copy_from_user(&time, (struct rtc_time __user *)arg,
sizeof(struct rtc_time)))
return -EFAULT;
set_time(&time);
break;
case RTC_IRQP_READ:
return put_user(periodic_frequency, (unsigned long __user *)arg);
break;
case RTC_IRQP_SET:
if (arg > MAX_PERIODIC_RATE)
return -EINVAL;
if (from == FUNCTION_RTC_IOCTL && arg > MAX_USER_PERIODIC_RATE &&
capable(CAP_SYS_RESOURCE) == 0)
return -EACCES;
periodic_frequency = arg;
count = RTC_FREQUENCY;
do_div(count, arg);
periodic_count = count;
spin_lock_irq(&rtc_lock);
rtc1_write(RTCL1LREG, count);
rtc1_write(RTCL1HREG, count >> 16);
spin_unlock_irq(&rtc_lock);
break;
case RTC_EPOCH_READ:
return put_user(epoch, (unsigned long __user *)arg);
case RTC_EPOCH_SET:
/* Doesn't support before 1900 */
if (arg < 1900)
return -EINVAL;
if (capable(CAP_SYS_TIME) == 0)
return -EACCES;
epoch = arg;
break;
default:
return -EINVAL;
}
return 0;
}
static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
return rtc_do_ioctl(cmd, arg, FUNCTION_RTC_IOCTL);
}
static int rtc_open(struct inode *inode, struct file *file)
{
spin_lock_irq(&rtc_lock);
if (rtc_status == RTC_OPEN) {
spin_unlock_irq(&rtc_lock);
return -EBUSY;
}
rtc_status = RTC_OPEN;
rtc_irq_data = 0;
spin_unlock_irq(&rtc_lock);
return 0;
}
static int rtc_release(struct inode *inode, struct file *file)
{
if (file->f_flags & FASYNC)
(void)fasync_helper(-1, file, 0, &rtc_async_queue);
spin_lock_irq(&rtc_lock);
rtc1_write(ECMPLREG, 0);
rtc1_write(ECMPMREG, 0);
rtc1_write(ECMPHREG, 0);
rtc1_write(RTCL1LREG, 0);
rtc1_write(RTCL1HREG, 0);
rtc_status = RTC_RELEASE;
spin_unlock_irq(&rtc_lock);
disable_irq(ELAPSEDTIME_IRQ);
disable_irq(RTCLONG1_IRQ);
return 0;
}
static int rtc_fasync(int fd, struct file *file, int on)
{
return fasync_helper(fd, file, on, &rtc_async_queue);
}
static struct file_operations rtc_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = rtc_read,
.poll = rtc_poll,
.ioctl = rtc_ioctl,
.open = rtc_open,
.release = rtc_release,
.fasync = rtc_fasync,
};
static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
spin_lock(&rtc_lock);
rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
rtc_irq_data += 0x100;
rtc_irq_data &= ~0xff;
rtc_irq_data |= RTC_AF;
spin_unlock(&rtc_lock);
spin_lock(&rtc_lock);
if (rtc_callback)
rtc_callback->func(rtc_callback->private_data);
spin_unlock(&rtc_lock);
wake_up_interruptible(&rtc_wait);
kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
return IRQ_HANDLED;
}
static irqreturn_t rtclong1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long count = periodic_count;
spin_lock(&rtc_lock);
rtc2_write(RTCINTREG, RTCLONG1_INT);
rtc1_write(RTCL1LREG, count);
rtc1_write(RTCL1HREG, count >> 16);
rtc_irq_data += 0x100;
rtc_irq_data &= ~0xff;
rtc_irq_data |= RTC_PF;
spin_unlock(&rtc_lock);
spin_lock(&rtc_task_lock);
if (rtc_callback)
rtc_callback->func(rtc_callback->private_data);
spin_unlock(&rtc_task_lock);
wake_up_interruptible(&rtc_wait);
kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
return IRQ_HANDLED;
}
int rtc_register(rtc_task_t *task)
{
if (task == NULL || task->func == NULL)
return -EINVAL;
spin_lock_irq(&rtc_lock);
if (rtc_status == RTC_OPEN) {
spin_unlock_irq(&rtc_lock);
return -EBUSY;
}
spin_lock(&rtc_task_lock);
if (rtc_callback != NULL) {
spin_unlock(&rtc_task_lock);
spin_unlock_irq(&rtc_task_lock);
return -EBUSY;
}
rtc_callback = task;
spin_unlock(&rtc_task_lock);
rtc_status = RTC_OPEN;
spin_unlock_irq(&rtc_lock);
return 0;
}
EXPORT_SYMBOL_GPL(rtc_register);
int rtc_unregister(rtc_task_t *task)
{
spin_lock_irq(&rtc_task_lock);
if (task == NULL || rtc_callback != task) {
spin_unlock_irq(&rtc_task_lock);
return -ENXIO;
}
spin_lock(&rtc_lock);
rtc1_write(ECMPLREG, 0);
rtc1_write(ECMPMREG, 0);
rtc1_write(ECMPHREG, 0);
rtc1_write(RTCL1LREG, 0);
rtc1_write(RTCL1HREG, 0);
rtc_status = RTC_RELEASE;
spin_unlock(&rtc_lock);
rtc_callback = NULL;
spin_unlock_irq(&rtc_task_lock);
disable_irq(ELAPSEDTIME_IRQ);
disable_irq(RTCLONG1_IRQ);
return 0;
}
EXPORT_SYMBOL_GPL(rtc_unregister);
int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
{
int retval = 0;
spin_lock_irq(&rtc_task_lock);
if (rtc_callback != task)
retval = -ENXIO;
else
rtc_do_ioctl(cmd, arg, FUNCTION_RTC_CONTROL);
spin_unlock_irq(&rtc_task_lock);
return retval;
}
EXPORT_SYMBOL_GPL(rtc_control);
static struct miscdevice rtc_miscdevice = {
.minor = RTC_MINOR,
.name = rtc_name,
.fops = &rtc_fops,
};
static int rtc_probe(struct device *dev)
{
struct platform_device *pdev;
unsigned int irq;
int retval;
pdev = to_platform_device(dev);
if (pdev->num_resources != 2)
return -EBUSY;
rtc1_base = ioremap(pdev->resource[0].start, RTC1_SIZE);
if (rtc1_base == NULL)
return -EBUSY;
rtc2_base = ioremap(pdev->resource[1].start, RTC2_SIZE);
if (rtc2_base == NULL) {
iounmap(rtc1_base);
rtc1_base = NULL;
return -EBUSY;
}
retval = misc_register(&rtc_miscdevice);
if (retval < 0) {
iounmap(rtc1_base);
iounmap(rtc2_base);
rtc1_base = NULL;
rtc2_base = NULL;
return retval;
}
spin_lock_irq(&rtc_lock);
rtc1_write(ECMPLREG, 0);
rtc1_write(ECMPMREG, 0);
rtc1_write(ECMPHREG, 0);
rtc1_write(RTCL1LREG, 0);
rtc1_write(RTCL1HREG, 0);
rtc_status = RTC_RELEASE;
rtc_irq_data = 0;
spin_unlock_irq(&rtc_lock);
init_waitqueue_head(&rtc_wait);
irq = ELAPSEDTIME_IRQ;
retval = request_irq(irq, elapsedtime_interrupt, SA_INTERRUPT,
"elapsed_time", NULL);
if (retval == 0) {
irq = RTCLONG1_IRQ;
retval = request_irq(irq, rtclong1_interrupt, SA_INTERRUPT,
"rtclong1", NULL);
}
if (retval < 0) {
printk(KERN_ERR "rtc: IRQ%d is busy\n", irq);
if (irq == RTCLONG1_IRQ)
free_irq(ELAPSEDTIME_IRQ, NULL);
iounmap(rtc1_base);
iounmap(rtc2_base);
rtc1_base = NULL;
rtc2_base = NULL;
return retval;
}
disable_irq(ELAPSEDTIME_IRQ);
disable_irq(RTCLONG1_IRQ);
spin_lock_init(&rtc_task_lock);
printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
return 0;
}
static int rtc_remove(struct device *dev)
{
int retval;
retval = misc_deregister(&rtc_miscdevice);
if (retval < 0)
return retval;
free_irq(ELAPSEDTIME_IRQ, NULL);
free_irq(RTCLONG1_IRQ, NULL);
if (rtc1_base != NULL)
iounmap(rtc1_base);
if (rtc2_base != NULL)
iounmap(rtc2_base);
return 0;
}
static struct platform_device *rtc_platform_device;
static struct device_driver rtc_device_driver = {
.name = rtc_name,
.bus = &platform_bus_type,
.probe = rtc_probe,
.remove = rtc_remove,
};
static int __devinit vr41xx_rtc_init(void)
{
int retval;
switch (current_cpu_data.cputype) {
case CPU_VR4111:
case CPU_VR4121:
rtc_resource[0].start = RTC1_TYPE1_START;
rtc_resource[0].end = RTC1_TYPE1_END;
rtc_resource[1].start = RTC2_TYPE1_START;
rtc_resource[1].end = RTC2_TYPE1_END;
break;
case CPU_VR4122:
case CPU_VR4131:
case CPU_VR4133:
rtc_resource[0].start = RTC1_TYPE2_START;
rtc_resource[0].end = RTC1_TYPE2_END;
rtc_resource[1].start = RTC2_TYPE2_START;
rtc_resource[1].end = RTC2_TYPE2_END;
break;
default:
return -ENODEV;
break;
}
rtc_platform_device = platform_device_register_simple("RTC", -1, rtc_resource, RTC_NUM_RESOURCES);
if (IS_ERR(rtc_platform_device))
return PTR_ERR(rtc_platform_device);
retval = driver_register(&rtc_device_driver);
if (retval < 0)
platform_device_unregister(rtc_platform_device);
return retval;
}
static void __devexit vr41xx_rtc_exit(void)
{
driver_unregister(&rtc_device_driver);
platform_device_unregister(rtc_platform_device);
}
module_init(vr41xx_rtc_init);
module_exit(vr41xx_rtc_exit);
