6 files changed, 684 insertions, 12 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 4941cade319f..e1878877399c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -985,4 +985,14 @@ config RTC_DRV_LPC32XX
           This driver can also be buillt as a module. If so, the module
           will be called rtc-lpc32xx.
 
+config RTC_DRV_TEGRA
+        tristate "NVIDIA Tegra Internal RTC driver"
+        depends on RTC_CLASS && ARCH_TEGRA
+        help
+          If you say yes here you get support for the
+          Tegra 200 series internal RTC module.
+
+          This drive can also be built as a module. If so, the module
+          will be called rtc-tegra.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 5f6c3838dcf6..ca91c3c42e98 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_RTC_DRV_STARFIRE)	+= rtc-starfire.o
 obj-$(CONFIG_RTC_DRV_STK17TA8)  += rtc-stk17ta8.o
 obj-$(CONFIG_RTC_DRV_STMP)      += rtc-stmp3xxx.o
 obj-$(CONFIG_RTC_DRV_SUN4V)     += rtc-sun4v.o
+obj-$(CONFIG_RTC_DRV_TEGRA)     += rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)      += rtc-test.o
 obj-$(CONFIG_RTC_DRV_TWL4030)   += rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TX4939)    += rtc-tx4939.o
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index d834a63ec4b0..e6e71deb188f 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -25,6 +25,7 @@
 #include <linux/bcd.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
+#include <linux/pm.h>
 
 #define DS1374_REG_TOD0         0x00 /* Time of Day */
 #define DS1374_REG_TOD1         0x01
@@ -409,32 +410,38 @@ static int __devexit ds1374_remove(struct i2c_client *client)
 }
 
 #ifdef CONFIG_PM
-static int ds1374_suspend(struct i2c_client *client, pm_message_t state)
+static int ds1374_suspend(struct device *dev)
 {
+        struct i2c_client *client = to_i2c_client(dev);
+
         if (client->irq >= 0 && device_may_wakeup(&client->dev))
                 enable_irq_wake(client->irq);
         return 0;
 }
 
-static int ds1374_resume(struct i2c_client *client)
+static int ds1374_resume(struct device *dev)
 {
+        struct i2c_client *client = to_i2c_client(dev);
+
         if (client->irq >= 0 && device_may_wakeup(&client->dev))
                 disable_irq_wake(client->irq);
         return 0;
 }
+
+static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
+
+#define DS1374_PM (&ds1374_pm)
 #else
-#define ds1374_suspend  NULL
-#define ds1374_resume   NULL
+#define DS1374_PM NULL
 #endif
 
 static struct i2c_driver ds1374_driver = {
         .driver = {
                 .name = "rtc-ds1374",
                 .owner = THIS_MODULE,
+                .pm = DS1374_PM,
         },
         .probe = ds1374_probe,
-        .suspend = ds1374_suspend,
-        .resume = ds1374_resume,
         .remove = __devexit_p(ds1374_remove),
         .id_table = ds1374_id,
 };
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
index 3fffd708711f..fbabc773dded 100644
--- a/drivers/rtc/rtc-ds1511.c
+++ b/drivers/rtc/rtc-ds1511.c
@@ -468,7 +468,7 @@ ds1511_nvram_write(struct file *filp, struct kobject *kobj,
 static struct bin_attribute ds1511_nvram_attr = {
         .attr = {
                 .name = "nvram",
-                .mode = S_IRUGO | S_IWUGO,
+                .mode = S_IRUGO | S_IWUSR,
         },
         .size = DS1511_RAM_MAX,
         .read = ds1511_nvram_read,
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
index 468200c38ecb..da8beb8cae51 100644
--- a/drivers/rtc/rtc-isl1208.c
+++ b/drivers/rtc/rtc-isl1208.c
@@ -39,6 +39,8 @@
 #define ISL1208_REG_SR_BAT     (1<<1)   /* battery */
 #define ISL1208_REG_SR_RTCF    (1<<0)   /* rtc fail */
 #define ISL1208_REG_INT 0x08
+#define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
+#define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
 #define ISL1208_REG_09  0x09    /* reserved */
 #define ISL1208_REG_ATR 0x0a
 #define ISL1208_REG_DTR 0x0b
@@ -202,6 +204,30 @@ isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
 }
 
 static int
+isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
+{
+        int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
+
+        if (icr < 0) {
+                dev_err(&client->dev, "%s: reading INT failed\n", __func__);
+                return icr;
+        }
+
+        if (enable)
+                icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
+        else
+                icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
+
+        icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
+        if (icr < 0) {
+                dev_err(&client->dev, "%s: writing INT failed\n", __func__);
+                return icr;
+        }
+
+        return 0;
+}
+
+static int
 isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
 {
         struct i2c_client *const client = to_i2c_client(dev);
@@ -288,9 +314,8 @@ isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 {
         struct rtc_time *const tm = &alarm->time;
         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
-        int sr;
+        int icr, yr, sr = isl1208_i2c_get_sr(client);
 
-        sr = isl1208_i2c_get_sr(client);
         if (sr < 0) {
                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
                 return sr;
@@ -313,6 +338,73 @@ isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
                 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
         tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
 
+        /* The alarm doesn't store the year so get it from the rtc section */
+        yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
+        if (yr < 0) {
+                dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
+                return yr;
+        }
+        tm->tm_year = bcd2bin(yr) + 100;
+
+        icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
+        if (icr < 0) {
+                dev_err(&client->dev, "%s: reading INT failed\n", __func__);
+                return icr;
+        }
+        alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
+
+        return 0;
+}
+
+static int
+isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
+{
+        struct rtc_time *alarm_tm = &alarm->time;
+        u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
+        const int offs = ISL1208_REG_SCA;
+        unsigned long rtc_secs, alarm_secs;
+        struct rtc_time rtc_tm;
+        int err, enable;
+
+        err = isl1208_i2c_read_time(client, &rtc_tm);
+        if (err)
+                return err;
+        err = rtc_tm_to_time(&rtc_tm, &rtc_secs);
+        if (err)
+                return err;
+        err = rtc_tm_to_time(alarm_tm, &alarm_secs);
+        if (err)
+                return err;
+
+        /* If the alarm time is before the current time disable the alarm */
+        if (!alarm->enabled || alarm_secs <= rtc_secs)
+                enable = 0x00;
+        else
+                enable = 0x80;
+
+        /* Program the alarm and enable it for each setting */
+        regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
+        regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
+        regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
+                ISL1208_REG_HR_MIL | enable;
+
+        regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
+        regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
+        regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
+
+        /* write ALARM registers */
+        err = isl1208_i2c_set_regs(client, offs, regs,
+                                  ISL1208_ALARM_SECTION_LEN);
+        if (err < 0) {
+                dev_err(&client->dev, "%s: writing ALARM section failed\n",
+                        __func__);
+                return err;
+        }
+
+        err = isl1208_rtc_toggle_alarm(client, enable);
+        if (err)
+                return err;
+
         return 0;
 }
 
@@ -391,12 +483,63 @@ isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
         return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
 }
 
+static int
+isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
+}
+
+static irqreturn_t
+isl1208_rtc_interrupt(int irq, void *data)
+{
+        unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+        struct i2c_client *client = data;
+        int handled = 0, sr, err;
+
+        /*
+         * I2C reads get NAK'ed if we read straight away after an interrupt?
+         * Using a mdelay/msleep didn't seem to help either, so we work around
+         * this by continually trying to read the register for a short time.
+         */
+        while (1) {
+                sr = isl1208_i2c_get_sr(client);
+                if (sr >= 0)
+                        break;
+
+                if (time_after(jiffies, timeout)) {
+                        dev_err(&client->dev, "%s: reading SR failed\n",
+                                __func__);
+                        return sr;
+                }
+        }
+
+        if (sr & ISL1208_REG_SR_ALM) {
+                dev_dbg(&client->dev, "alarm!\n");
+
+                /* Clear the alarm */
+                sr &= ~ISL1208_REG_SR_ALM;
+                sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
+                if (sr < 0)
+                        dev_err(&client->dev, "%s: writing SR failed\n",
+                                __func__);
+                else
+                        handled = 1;
+
+                /* Disable the alarm */
+                err = isl1208_rtc_toggle_alarm(client, 0);
+                if (err)
+                        return err;
+        }
+
+        return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
 static const struct rtc_class_ops isl1208_rtc_ops = {
         .proc = isl1208_rtc_proc,
         .read_time = isl1208_rtc_read_time,
         .set_time = isl1208_rtc_set_time,
         .read_alarm = isl1208_rtc_read_alarm,
-        /*.set_alarm    = isl1208_rtc_set_alarm, */
+        .set_alarm = isl1208_rtc_set_alarm,
 };
 
 /* sysfs interface */
@@ -488,11 +631,29 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
         dev_info(&client->dev,
                  "chip found, driver version " DRV_VERSION "\n");
 
+        if (client->irq > 0) {
+                rc = request_threaded_irq(client->irq, NULL,
+                                          isl1208_rtc_interrupt,
+                                          IRQF_SHARED,
+                                          isl1208_driver.driver.name, client);
+                if (!rc) {
+                        device_init_wakeup(&client->dev, 1);
+                        enable_irq_wake(client->irq);
+                } else {
+                        dev_err(&client->dev,
+                                "Unable to request irq %d, no alarm support\n",
+                                client->irq);
+                        client->irq = 0;
+                }
+        }
+
         rtc = rtc_device_register(isl1208_driver.driver.name,
                                   &client->dev, &isl1208_rtc_ops,
                                   THIS_MODULE);
-        if (IS_ERR(rtc))
-                return PTR_ERR(rtc);
+        if (IS_ERR(rtc)) {
+                rc = PTR_ERR(rtc);
+                goto exit_free_irq;
+        }
 
         i2c_set_clientdata(client, rtc);
 
@@ -514,6 +675,9 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 exit_unregister:
         rtc_device_unregister(rtc);
+exit_free_irq:
+        if (client->irq)
+                free_irq(client->irq, client);
 
         return rc;
 }
@@ -525,6 +689,8 @@ isl1208_remove(struct i2c_client *client)
 
         sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
         rtc_device_unregister(rtc);
+        if (client->irq)
+                free_irq(client->irq, client);
 
         return 0;
 }
diff --git a/drivers/rtc/rtc-tegra.c b/drivers/rtc/rtc-tegra.c
new file mode 100644
index 000000000000..2fc31aac3f4e
--- /dev/null
+++ b/drivers/rtc/rtc-tegra.c
@@ -0,0 +1,488 @@
+/*
+ * An RTC driver for the NVIDIA Tegra 200 series internal RTC.
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+
+/* set to 1 = busy every eight 32kHz clocks during copy of sec+msec to AHB */
+#define TEGRA_RTC_REG_BUSY                      0x004
+#define TEGRA_RTC_REG_SECONDS                   0x008
+/* when msec is read, the seconds are buffered into shadow seconds. */
+#define TEGRA_RTC_REG_SHADOW_SECONDS            0x00c
+#define TEGRA_RTC_REG_MILLI_SECONDS             0x010
+#define TEGRA_RTC_REG_SECONDS_ALARM0            0x014
+#define TEGRA_RTC_REG_SECONDS_ALARM1            0x018
+#define TEGRA_RTC_REG_MILLI_SECONDS_ALARM0      0x01c
+#define TEGRA_RTC_REG_INTR_MASK                 0x028
+/* write 1 bits to clear status bits */
+#define TEGRA_RTC_REG_INTR_STATUS               0x02c
+
+/* bits in INTR_MASK */
+#define TEGRA_RTC_INTR_MASK_MSEC_CDN_ALARM      (1<<4)
+#define TEGRA_RTC_INTR_MASK_SEC_CDN_ALARM       (1<<3)
+#define TEGRA_RTC_INTR_MASK_MSEC_ALARM          (1<<2)
+#define TEGRA_RTC_INTR_MASK_SEC_ALARM1          (1<<1)
+#define TEGRA_RTC_INTR_MASK_SEC_ALARM0          (1<<0)
+
+/* bits in INTR_STATUS */
+#define TEGRA_RTC_INTR_STATUS_MSEC_CDN_ALARM    (1<<4)
+#define TEGRA_RTC_INTR_STATUS_SEC_CDN_ALARM     (1<<3)
+#define TEGRA_RTC_INTR_STATUS_MSEC_ALARM        (1<<2)
+#define TEGRA_RTC_INTR_STATUS_SEC_ALARM1        (1<<1)
+#define TEGRA_RTC_INTR_STATUS_SEC_ALARM0        (1<<0)
+
+struct tegra_rtc_info {
+        struct platform_device  *pdev;
+        struct rtc_device       *rtc_dev;
+        void __iomem            *rtc_base; /* NULL if not initialized. */
+        int                     tegra_rtc_irq; /* alarm and periodic irq */
+        spinlock_t              tegra_rtc_lock;
+};
+
+/* RTC hardware is busy when it is updating its values over AHB once
+ * every eight 32kHz clocks (~250uS).
+ * outside of these updates the CPU is free to write.
+ * CPU is always free to read.
+ */
+static inline u32 tegra_rtc_check_busy(struct tegra_rtc_info *info)
+{
+        return readl(info->rtc_base + TEGRA_RTC_REG_BUSY) & 1;
+}
+
+/* Wait for hardware to be ready for writing.
+ * This function tries to maximize the amount of time before the next update.
+ * It does this by waiting for the RTC to become busy with its periodic update,
+ * then returning once the RTC first becomes not busy.
+ * This periodic update (where the seconds and milliseconds are copied to the
+ * AHB side) occurs every eight 32kHz clocks (~250uS).
+ * The behavior of this function allows us to make some assumptions without
+ * introducing a race, because 250uS is plenty of time to read/write a value.
+ */
+static int tegra_rtc_wait_while_busy(struct device *dev)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+
+        int retries = 500; /* ~490 us is the worst case, ~250 us is best. */
+
+        /* first wait for the RTC to become busy. this is when it
+         * posts its updated seconds+msec registers to AHB side. */
+        while (tegra_rtc_check_busy(info)) {
+                if (!retries--)
+                        goto retry_failed;
+                udelay(1);
+        }
+
+        /* now we have about 250 us to manipulate registers */
+        return 0;
+
+retry_failed:
+        dev_err(dev, "write failed:retry count exceeded.\n");
+        return -ETIMEDOUT;
+}
+
+static int tegra_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned long sec, msec;
+        unsigned long sl_irq_flags;
+
+        /* RTC hardware copies seconds to shadow seconds when a read
+         * of milliseconds occurs. use a lock to keep other threads out. */
+        spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
+
+        msec = readl(info->rtc_base + TEGRA_RTC_REG_MILLI_SECONDS);
+        sec = readl(info->rtc_base + TEGRA_RTC_REG_SHADOW_SECONDS);
+
+        spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags);
+
+        rtc_time_to_tm(sec, tm);
+
+        dev_vdbg(dev, "time read as %lu. %d/%d/%d %d:%02u:%02u\n",
+                sec,
+                tm->tm_mon + 1,
+                tm->tm_mday,
+                tm->tm_year + 1900,
+                tm->tm_hour,
+                tm->tm_min,
+                tm->tm_sec
+        );
+
+        return 0;
+}
+
+static int tegra_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned long sec;
+        int ret;
+
+        /* convert tm to seconds. */
+        ret = rtc_valid_tm(tm);
+        if (ret)
+                return ret;
+
+        rtc_tm_to_time(tm, &sec);
+
+        dev_vdbg(dev, "time set to %lu. %d/%d/%d %d:%02u:%02u\n",
+                sec,
+                tm->tm_mon+1,
+                tm->tm_mday,
+                tm->tm_year+1900,
+                tm->tm_hour,
+                tm->tm_min,
+                tm->tm_sec
+        );
+
+        /* seconds only written if wait succeeded. */
+        ret = tegra_rtc_wait_while_busy(dev);
+        if (!ret)
+                writel(sec, info->rtc_base + TEGRA_RTC_REG_SECONDS);
+
+        dev_vdbg(dev, "time read back as %d\n",
+                readl(info->rtc_base + TEGRA_RTC_REG_SECONDS));
+
+        return ret;
+}
+
+static int tegra_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned long sec;
+        unsigned tmp;
+
+        sec = readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
+
+        if (sec == 0) {
+                /* alarm is disabled. */
+                alarm->enabled = 0;
+                alarm->time.tm_mon = -1;
+                alarm->time.tm_mday = -1;
+                alarm->time.tm_year = -1;
+                alarm->time.tm_hour = -1;
+                alarm->time.tm_min = -1;
+                alarm->time.tm_sec = -1;
+        } else {
+                /* alarm is enabled. */
+                alarm->enabled = 1;
+                rtc_time_to_tm(sec, &alarm->time);
+        }
+
+        tmp = readl(info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
+        alarm->pending = (tmp & TEGRA_RTC_INTR_STATUS_SEC_ALARM0) != 0;
+
+        return 0;
+}
+
+static int tegra_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned status;
+        unsigned long sl_irq_flags;
+
+        tegra_rtc_wait_while_busy(dev);
+        spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
+
+        /* read the original value, and OR in the flag. */
+        status = readl(info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
+        if (enabled)
+                status |= TEGRA_RTC_INTR_MASK_SEC_ALARM0; /* set it */
+        else
+                status &= ~TEGRA_RTC_INTR_MASK_SEC_ALARM0; /* clear it */
+
+        writel(status, info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
+
+        spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags);
+
+        return 0;
+}
+
+static int tegra_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned long sec;
+
+        if (alarm->enabled)
+                rtc_tm_to_time(&alarm->time, &sec);
+        else
+                sec = 0;
+
+        tegra_rtc_wait_while_busy(dev);
+        writel(sec, info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
+        dev_vdbg(dev, "alarm read back as %d\n",
+                readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
+
+        /* if successfully written and alarm is enabled ... */
+        if (sec) {
+                tegra_rtc_alarm_irq_enable(dev, 1);
+
+                dev_vdbg(dev, "alarm set as %lu. %d/%d/%d %d:%02u:%02u\n",
+                        sec,
+                        alarm->time.tm_mon+1,
+                        alarm->time.tm_mday,
+                        alarm->time.tm_year+1900,
+                        alarm->time.tm_hour,
+                        alarm->time.tm_min,
+                        alarm->time.tm_sec);
+        } else {
+                /* disable alarm if 0 or write error. */
+                dev_vdbg(dev, "alarm disabled\n");
+                tegra_rtc_alarm_irq_enable(dev, 0);
+        }
+
+        return 0;
+}
+
+static int tegra_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+        if (!dev || !dev->driver)
+                return 0;
+
+        return seq_printf(seq, "name\t\t: %s\n", dev_name(dev));
+}
+
+static irqreturn_t tegra_rtc_irq_handler(int irq, void *data)
+{
+        struct device *dev = data;
+        struct tegra_rtc_info *info = dev_get_drvdata(dev);
+        unsigned long events = 0;
+        unsigned status;
+        unsigned long sl_irq_flags;
+
+        status = readl(info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
+        if (status) {
+                /* clear the interrupt masks and status on any irq. */
+                tegra_rtc_wait_while_busy(dev);
+                spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
+                writel(0, info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
+                writel(status, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
+                spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags);
+        }
+
+        /* check if Alarm */
+        if ((status & TEGRA_RTC_INTR_STATUS_SEC_ALARM0))
+                events |= RTC_IRQF | RTC_AF;
+
+        /* check if Periodic */
+        if ((status & TEGRA_RTC_INTR_STATUS_SEC_CDN_ALARM))
+                events |= RTC_IRQF | RTC_PF;
+
+        rtc_update_irq(info->rtc_dev, 1, events);
+
+        return IRQ_HANDLED;
+}
+
+static struct rtc_class_ops tegra_rtc_ops = {
+        .read_time      = tegra_rtc_read_time,
+        .set_time       = tegra_rtc_set_time,
+        .read_alarm     = tegra_rtc_read_alarm,
+        .set_alarm      = tegra_rtc_set_alarm,
+        .proc           = tegra_rtc_proc,
+        .alarm_irq_enable = tegra_rtc_alarm_irq_enable,
+};
+
+static int __devinit tegra_rtc_probe(struct platform_device *pdev)
+{
+        struct tegra_rtc_info *info;
+        struct resource *res;
+        int ret;
+
+        info = kzalloc(sizeof(struct tegra_rtc_info), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(&pdev->dev,
+                        "Unable to allocate resources for device.\n");
+                ret = -EBUSY;
+                goto err_free_info;
+        }
+
+        if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+                dev_err(&pdev->dev,
+                        "Unable to request mem region for device.\n");
+                ret = -EBUSY;
+                goto err_free_info;
+        }
+
+        info->tegra_rtc_irq = platform_get_irq(pdev, 0);
+        if (info->tegra_rtc_irq <= 0) {
+                ret = -EBUSY;
+                goto err_release_mem_region;
+        }
+
+        info->rtc_base = ioremap_nocache(res->start, resource_size(res));
+        if (!info->rtc_base) {
+                dev_err(&pdev->dev, "Unable to grab IOs for device.\n");
+                ret = -EBUSY;
+                goto err_release_mem_region;
+        }
+
+        /* set context info. */
+        info->pdev = pdev;
+        info->tegra_rtc_lock = __SPIN_LOCK_UNLOCKED(info->tegra_rtc_lock);
+
+        platform_set_drvdata(pdev, info);
+
+        /* clear out the hardware. */
+        writel(0, info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
+        writel(0xffffffff, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
+        writel(0, info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
+
+        device_init_wakeup(&pdev->dev, 1);
+
+        info->rtc_dev = rtc_device_register(
+                pdev->name, &pdev->dev, &tegra_rtc_ops, THIS_MODULE);
+        if (IS_ERR(info->rtc_dev)) {
+                ret = PTR_ERR(info->rtc_dev);
+                info->rtc_dev = NULL;
+                dev_err(&pdev->dev,
+                        "Unable to register device (err=%d).\n",
+                        ret);
+                goto err_iounmap;
+        }
+
+        ret = request_irq(info->tegra_rtc_irq, tegra_rtc_irq_handler,
+                IRQF_TRIGGER_HIGH, "rtc alarm", &pdev->dev);
+        if (ret) {
+                dev_err(&pdev->dev,
+                        "Unable to request interrupt for device (err=%d).\n",
+                        ret);
+                goto err_dev_unreg;
+        }
+
+        dev_notice(&pdev->dev, "Tegra internal Real Time Clock\n");
+
+        return 0;
+
+err_dev_unreg:
+        rtc_device_unregister(info->rtc_dev);
+err_iounmap:
+        iounmap(info->rtc_base);
+err_release_mem_region:
+        release_mem_region(res->start, resource_size(res));
+err_free_info:
+        kfree(info);
+
+        return ret;
+}
+
+static int __devexit tegra_rtc_remove(struct platform_device *pdev)
+{
+        struct tegra_rtc_info *info = platform_get_drvdata(pdev);
+        struct resource *res;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -EBUSY;
+
+        free_irq(info->tegra_rtc_irq, &pdev->dev);
+        rtc_device_unregister(info->rtc_dev);
+        iounmap(info->rtc_base);
+        release_mem_region(res->start, resource_size(res));
+        kfree(info);
+
+        platform_set_drvdata(pdev, NULL);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int tegra_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct device *dev = &pdev->dev;
+        struct tegra_rtc_info *info = platform_get_drvdata(pdev);
+
+        tegra_rtc_wait_while_busy(dev);
+
+        /* only use ALARM0 as a wake source. */
+        writel(0xffffffff, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
+        writel(TEGRA_RTC_INTR_STATUS_SEC_ALARM0,
+                info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
+
+        dev_vdbg(dev, "alarm sec = %d\n",
+                readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
+
+        dev_vdbg(dev, "Suspend (device_may_wakeup=%d) irq:%d\n",
+                device_may_wakeup(dev), info->tegra_rtc_irq);
+
+        /* leave the alarms on as a wake source. */
+        if (device_may_wakeup(dev))
+                enable_irq_wake(info->tegra_rtc_irq);
+
+        return 0;
+}
+
+static int tegra_rtc_resume(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct tegra_rtc_info *info = platform_get_drvdata(pdev);
+
+        dev_vdbg(dev, "Resume (device_may_wakeup=%d)\n",
+                device_may_wakeup(dev));
+        /* alarms were left on as a wake source, turn them off. */
+        if (device_may_wakeup(dev))
+                disable_irq_wake(info->tegra_rtc_irq);
+
+        return 0;
+}
+#endif
+
+static void tegra_rtc_shutdown(struct platform_device *pdev)
+{
+        dev_vdbg(&pdev->dev, "disabling interrupts.\n");
+        tegra_rtc_alarm_irq_enable(&pdev->dev, 0);
+}
+
+MODULE_ALIAS("platform:tegra_rtc");
+static struct platform_driver tegra_rtc_driver = {
+        .remove         = __devexit_p(tegra_rtc_remove),
+        .shutdown       = tegra_rtc_shutdown,
+        .driver         = {
+                .name   = "tegra_rtc",
+                .owner  = THIS_MODULE,
+        },
+#ifdef CONFIG_PM
+        .suspend        = tegra_rtc_suspend,
+        .resume         = tegra_rtc_resume,
+#endif
+};
+
+static int __init tegra_rtc_init(void)
+{
+        return platform_driver_probe(&tegra_rtc_driver, tegra_rtc_probe);
+}
+module_init(tegra_rtc_init);
+
+static void __exit tegra_rtc_exit(void)
+{
+        platform_driver_unregister(&tegra_rtc_driver);
+}
+module_exit(tegra_rtc_exit);
+
+MODULE_AUTHOR("Jon Mayo <jmayo@nvidia.com>");
+MODULE_DESCRIPTION("driver for Tegra internal RTC");
+MODULE_LICENSE("GPL");