--- /dev/null
+/*
+ * Driver for NEC VR4100 series Real Time Clock unit.
+ *
+ * Copyright (C) 2003-2008 Yoichi Yuasa <yuasa@linux-mips.org>
+ *
+ * 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/err.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/log2.h>
+
+#include <asm/div64.h>
+
+MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
+MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
+MODULE_LICENSE("GPL v2");
+
+/* 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
+
+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 DEFINE_SPINLOCK(rtc_lock);
+static char rtc_name[] = "RTC";
+static unsigned long periodic_count;
+static unsigned int alarm_enabled;
+static int aie_irq;
+static int pie_irq;
+
+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(aie_irq);
+ disable_irq(pie_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);
+ wkalrm->enabled = alarm_enabled;
+
+ 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);
+
+ if (alarm_enabled)
+ disable_irq(aie_irq);
+
+ rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
+ rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
+ rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
+
+ if (wkalrm->enabled)
+ enable_irq(aie_irq);
+
+ alarm_enabled = wkalrm->enabled;
+
+ spin_unlock_irq(&rtc_lock);
+
+ return 0;
+}
+
+static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ 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;
+ epoch = arg;
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+
+static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ spin_lock_irq(&rtc_lock);
+ if (enabled) {
+ if (!alarm_enabled) {
+ enable_irq(aie_irq);
+ alarm_enabled = 1;
+ }
+ } else {
+ if (alarm_enabled) {
+ disable_irq(aie_irq);
+ alarm_enabled = 0;
+ }
+ }
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+}
+
+static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
+{
+ 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, 1, RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
+{
+ 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, 1, RTC_PF);
+
+ return IRQ_HANDLED;
+}
+
+static const 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 rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct rtc_device *rtc;
+ int retval;
+
+ if (pdev->num_resources != 4)
+ return -EBUSY;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -EBUSY;
+
+ rtc1_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (!rtc1_base)
+ return -EBUSY;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!res) {
+ retval = -EBUSY;
+ goto err_rtc1_iounmap;
+ }
+
+ rtc2_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (!rtc2_base) {
+ retval = -EBUSY;
+ goto err_rtc1_iounmap;
+ }
+
+ rtc = devm_rtc_device_register(&pdev->dev, rtc_name, &vr41xx_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ retval = PTR_ERR(rtc);
+ goto err_iounmap_all;
+ }
+
+ rtc->max_user_freq = MAX_PERIODIC_RATE;
+
+ 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);
+
+ aie_irq = platform_get_irq(pdev, 0);
+ if (aie_irq <= 0) {
+ retval = -EBUSY;
+ goto err_iounmap_all;
+ }
+
+ retval = devm_request_irq(&pdev->dev, aie_irq, elapsedtime_interrupt, 0,
+ "elapsed_time", pdev);
+ if (retval < 0)
+ goto err_iounmap_all;
+
+ pie_irq = platform_get_irq(pdev, 1);
+ if (pie_irq <= 0) {
+ retval = -EBUSY;
+ goto err_iounmap_all;
+ }
+
+ retval = devm_request_irq(&pdev->dev, pie_irq, rtclong1_interrupt, 0,
+ "rtclong1", pdev);
+ if (retval < 0)
+ goto err_iounmap_all;
+
+ platform_set_drvdata(pdev, rtc);
+
+ disable_irq(aie_irq);
+ disable_irq(pie_irq);
+
+ dev_info(&pdev->dev, "Real Time Clock of NEC VR4100 series\n");
+
+ return 0;
+
+err_iounmap_all:
+ rtc2_base = NULL;
+
+err_rtc1_iounmap:
+ rtc1_base = NULL;
+
+ return retval;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:RTC");
+
+static struct platform_driver rtc_platform_driver = {
+ .probe = rtc_probe,
+ .driver = {
+ .name = rtc_name,
+ },
+};
+
+module_platform_driver(rtc_platform_driver);
Code Review / kvmfornfv.git / blobdiff