[PATCH] RTC subsystem: VR41XX driver

This patch updates VR4100 series RTC driver.

* This driver supports new RTC subsystem.
* Simple set time/read time test worked fine.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 471 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c
new file mode 100644
index 0000000..4d49fd5
--- /dev/null
+++ b/drivers/rtc/rtc-vr41xx.c
@@ -0,0 +1,471 @@
+/*
+ *  Driver for NEC VR4100 series Real Time Clock unit.
+ *
+ *  Copyright (C) 2003-2006  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.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/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/div64.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/vr41xx/vr41xx.h>
+
+MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.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_lock = SPIN_LOCK_UNLOCKED;
+static char rtc_name[] = "RTC";
+static unsigned long periodic_frequency;
+static unsigned long periodic_count;
+
+struct resource rtc_resource[2] = {
+	{	.name	= rtc_name,
+		.flags	= IORESOURCE_MEM,	},
+	{	.name	= rtc_name,
+		.flags	= IORESOURCE_MEM,	},
+};
+
+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 vr41xx_rtc_release(struct device *dev)
+{
+
+	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);
+
+	spin_unlock_irq(&rtc_lock);
+
+	disable_irq(ELAPSEDTIME_IRQ);
+	disable_irq(RTCLONG1_IRQ);
+}
+
+static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
+{
+	unsigned long epoch_sec, elapsed_sec;
+
+	epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
+	elapsed_sec = read_elapsed_second();
+
+	rtc_time_to_tm(epoch_sec + elapsed_sec, time);
+
+	return 0;
+}
+
+static int vr41xx_rtc_set_time(struct device *dev, 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);
+
+	return 0;
+}
+
+static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
+{
+	unsigned long low, mid, high;
+	struct rtc_time *time = &wkalrm->time;
+
+	spin_lock_irq(&rtc_lock);
+
+	low = rtc1_read(ECMPLREG);
+	mid = rtc1_read(ECMPMREG);
+	high = rtc1_read(ECMPHREG);
+
+	spin_unlock_irq(&rtc_lock);
+
+	rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
+
+	return 0;
+}
+
+static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
+{
+	unsigned long alarm_sec;
+	struct rtc_time *time = &wkalrm->time;
+
+	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);
+
+	return 0;
+}
+
+static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	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_IRQP_READ:
+		return put_user(periodic_frequency, (unsigned long __user *)arg);
+		break;
+	case RTC_IRQP_SET:
+		if (arg > MAX_PERIODIC_RATE)
+			return -EINVAL;
+
+		if (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 irqreturn_t elapsedtime_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct platform_device *pdev = (struct platform_device *)dev_id;
+	struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+	rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
+
+	rtc_update_irq(&rtc->class_dev, 1, RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t rtclong1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct platform_device *pdev = (struct platform_device *)dev_id;
+	struct rtc_device *rtc = platform_get_drvdata(pdev);
+	unsigned long count = periodic_count;
+
+	rtc2_write(RTCINTREG, RTCLONG1_INT);
+
+	rtc1_write(RTCL1LREG, count);
+	rtc1_write(RTCL1HREG, count >> 16);
+
+	rtc_update_irq(&rtc->class_dev, 1, RTC_PF);
+
+	return IRQ_HANDLED;
+}
+
+static struct rtc_class_ops vr41xx_rtc_ops = {
+	.release	= vr41xx_rtc_release,
+	.ioctl		= vr41xx_rtc_ioctl,
+	.read_time	= vr41xx_rtc_read_time,
+	.set_time	= vr41xx_rtc_set_time,
+	.read_alarm	= vr41xx_rtc_read_alarm,
+	.set_alarm	= vr41xx_rtc_set_alarm,
+};
+
+static int __devinit rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	unsigned int irq;
+	int retval;
+
+	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;
+	}
+
+	rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		iounmap(rtc1_base);
+		iounmap(rtc2_base);
+		rtc1_base = NULL;
+		rtc2_base = NULL;
+		return PTR_ERR(rtc);
+	}
+
+	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);
+
+	spin_unlock_irq(&rtc_lock);
+
+	irq = ELAPSEDTIME_IRQ;
+	retval = request_irq(irq, elapsedtime_interrupt, SA_INTERRUPT,
+	                     "elapsed_time", pdev);
+	if (retval == 0) {
+		irq = RTCLONG1_IRQ;
+		retval = request_irq(irq, rtclong1_interrupt, SA_INTERRUPT,
+		                     "rtclong1", pdev);
+	}
+
+	if (retval < 0) {
+		printk(KERN_ERR "rtc: IRQ%d is busy\n", irq);
+		rtc_device_unregister(rtc);
+		if (irq == RTCLONG1_IRQ)
+			free_irq(ELAPSEDTIME_IRQ, NULL);
+		iounmap(rtc1_base);
+		iounmap(rtc2_base);
+		rtc1_base = NULL;
+		rtc2_base = NULL;
+		return retval;
+	}
+
+	platform_set_drvdata(pdev, rtc);
+
+	disable_irq(ELAPSEDTIME_IRQ);
+	disable_irq(RTCLONG1_IRQ);
+
+	printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
+
+	return 0;
+}
+
+static int __devexit rtc_remove(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+
+	rtc = platform_get_drvdata(pdev);
+	if (rtc != NULL)
+		rtc_device_unregister(rtc);
+
+	platform_set_drvdata(pdev, NULL);
+
+	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 platform_driver rtc_platform_driver = {
+	.probe		= rtc_probe,
+	.remove		= __devexit_p(rtc_remove),
+	.driver		= {
+		.name	= rtc_name,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init 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_alloc("RTC", -1);
+	if (rtc_platform_device == NULL)
+		return -ENOMEM;
+
+	retval = platform_device_add_resources(rtc_platform_device,
+				rtc_resource, ARRAY_SIZE(rtc_resource));
+
+	if (retval == 0)
+		retval = platform_device_add(rtc_platform_device);
+
+	if (retval < 0) {
+		platform_device_put(rtc_platform_device);
+		return retval;
+	}
+
+	retval = platform_driver_register(&rtc_platform_driver);
+	if (retval < 0)
+		platform_device_unregister(rtc_platform_device);
+
+	return retval;
+}
+
+static void __exit vr41xx_rtc_exit(void)
+{
+	platform_driver_unregister(&rtc_platform_driver);
+	platform_device_unregister(rtc_platform_device);
+}
+
+module_init(vr41xx_rtc_init);
+module_exit(vr41xx_rtc_exit);