[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 000000000000..4d49fd501198
--- /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);