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path: root/drivers/char/vr41xx_rtc.c
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-rw-r--r--drivers/char/vr41xx_rtc.c709
1 files changed, 709 insertions, 0 deletions
diff --git a/drivers/char/vr41xx_rtc.c b/drivers/char/vr41xx_rtc.c
new file mode 100644
index 0000000..a6dbe4d
--- /dev/null
+++ b/drivers/char/vr41xx_rtc.c
@@ -0,0 +1,709 @@
+/*
+ * 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);
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