4 files changed, 725 insertions, 38 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 8167e9e6827a..2bb8a8b7ffaf 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -868,4 +868,14 @@ config RTC_DRV_MC13783
         help
           This enables support for the Freescale MC13783 PMIC RTC
 
+config RTC_DRV_MPC5121
+        tristate "Freescale MPC5121 built-in RTC"
+        depends on PPC_MPC512x && RTC_CLASS
+        help
+          If you say yes here you will get support for the
+          built-in RTC MPC5121.
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-mpc5121.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index e5160fddc446..b7148afb8f55 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)   += rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_MC13783)   += rtc-mc13783.o
 obj-$(CONFIG_RTC_DRV_MSM6242)   += rtc-msm6242.o
+obj-$(CONFIG_RTC_DRV_MPC5121)   += rtc-mpc5121.o
 obj-$(CONFIG_RTC_DRV_MV)        += rtc-mv.o
 obj-$(CONFIG_RTC_DRV_NUC900)    += rtc-nuc900.o
 obj-$(CONFIG_RTC_DRV_OMAP)      += rtc-omap.o
diff --git a/drivers/rtc/rtc-mpc5121.c b/drivers/rtc/rtc-mpc5121.c
new file mode 100644
index 000000000000..4313ca03a96d
--- /dev/null
+++ b/drivers/rtc/rtc-mpc5121.c
@@ -0,0 +1,387 @@
+/*
+ * Real-time clock driver for MPC5121
+ *
+ * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
+ * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+
+struct mpc5121_rtc_regs {
+        u8 set_time;            /* RTC + 0x00 */
+        u8 hour_set;            /* RTC + 0x01 */
+        u8 minute_set;          /* RTC + 0x02 */
+        u8 second_set;          /* RTC + 0x03 */
+
+        u8 set_date;            /* RTC + 0x04 */
+        u8 month_set;           /* RTC + 0x05 */
+        u8 weekday_set;         /* RTC + 0x06 */
+        u8 date_set;            /* RTC + 0x07 */
+
+        u8 write_sw;            /* RTC + 0x08 */
+        u8 sw_set;              /* RTC + 0x09 */
+        u16 year_set;           /* RTC + 0x0a */
+
+        u8 alm_enable;          /* RTC + 0x0c */
+        u8 alm_hour_set;        /* RTC + 0x0d */
+        u8 alm_min_set;         /* RTC + 0x0e */
+        u8 int_enable;          /* RTC + 0x0f */
+
+        u8 reserved1;
+        u8 hour;                /* RTC + 0x11 */
+        u8 minute;              /* RTC + 0x12 */
+        u8 second;              /* RTC + 0x13 */
+
+        u8 month;               /* RTC + 0x14 */
+        u8 wday_mday;           /* RTC + 0x15 */
+        u16 year;               /* RTC + 0x16 */
+
+        u8 int_alm;             /* RTC + 0x18 */
+        u8 int_sw;              /* RTC + 0x19 */
+        u8 alm_status;          /* RTC + 0x1a */
+        u8 sw_minute;           /* RTC + 0x1b */
+
+        u8 bus_error_1;         /* RTC + 0x1c */
+        u8 int_day;             /* RTC + 0x1d */
+        u8 int_min;             /* RTC + 0x1e */
+        u8 int_sec;             /* RTC + 0x1f */
+
+        /*
+         * target_time:
+         *      intended to be used for hibernation but hibernation
+         *      does not work on silicon rev 1.5 so use it for non-volatile
+         *      storage of offset between the actual_time register and linux
+         *      time
+         */
+        u32 target_time;        /* RTC + 0x20 */
+        /*
+         * actual_time:
+         *      readonly time since VBAT_RTC was last connected
+         */
+        u32 actual_time;        /* RTC + 0x24 */
+        u32 keep_alive;         /* RTC + 0x28 */
+};
+
+struct mpc5121_rtc_data {
+        unsigned irq;
+        unsigned irq_periodic;
+        struct mpc5121_rtc_regs __iomem *regs;
+        struct rtc_device *rtc;
+        struct rtc_wkalrm wkalarm;
+};
+
+/*
+ * Update second/minute/hour registers.
+ *
+ * This is just so alarm will work.
+ */
+static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
+                                   struct rtc_time *tm)
+{
+        out_8(&regs->second_set, tm->tm_sec);
+        out_8(&regs->minute_set, tm->tm_min);
+        out_8(&regs->hour_set, tm->tm_hour);
+
+        /* set time sequence */
+        out_8(&regs->set_time, 0x1);
+        out_8(&regs->set_time, 0x3);
+        out_8(&regs->set_time, 0x1);
+        out_8(&regs->set_time, 0x0);
+}
+
+static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+        unsigned long now;
+
+        /*
+         * linux time is actual_time plus the offset saved in target_time
+         */
+        now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
+
+        rtc_time_to_tm(now, tm);
+
+        /*
+         * update second minute hour registers
+         * so alarms will work
+         */
+        mpc5121_rtc_update_smh(regs, tm);
+
+        return rtc_valid_tm(tm);
+}
+
+static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+        int ret;
+        unsigned long now;
+
+        /*
+         * The actual_time register is read only so we write the offset
+         * between it and linux time to the target_time register.
+         */
+        ret = rtc_tm_to_time(tm, &now);
+        if (ret == 0)
+                out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
+
+        /*
+         * update second minute hour registers
+         * so alarms will work
+         */
+        mpc5121_rtc_update_smh(regs, tm);
+
+        return 0;
+}
+
+static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+
+        *alarm = rtc->wkalarm;
+
+        alarm->pending = in_8(&regs->alm_status);
+
+        return 0;
+}
+
+static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+
+        /*
+         * the alarm has no seconds so deal with it
+         */
+        if (alarm->time.tm_sec) {
+                alarm->time.tm_sec = 0;
+                alarm->time.tm_min++;
+                if (alarm->time.tm_min >= 60) {
+                        alarm->time.tm_min = 0;
+                        alarm->time.tm_hour++;
+                        if (alarm->time.tm_hour >= 24)
+                                alarm->time.tm_hour = 0;
+                }
+        }
+
+        alarm->time.tm_mday = -1;
+        alarm->time.tm_mon = -1;
+        alarm->time.tm_year = -1;
+
+        out_8(&regs->alm_min_set, alarm->time.tm_min);
+        out_8(&regs->alm_hour_set, alarm->time.tm_hour);
+
+        out_8(&regs->alm_enable, alarm->enabled);
+
+        rtc->wkalarm = *alarm;
+        return 0;
+}
+
+static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+
+        if (in_8(&regs->int_alm)) {
+                /* acknowledge and clear status */
+                out_8(&regs->int_alm, 1);
+                out_8(&regs->alm_status, 1);
+
+                rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+                return IRQ_HANDLED;
+        }
+
+        return IRQ_NONE;
+}
+
+static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+
+        if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
+                /* acknowledge */
+                out_8(&regs->int_sec, 1);
+
+                rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
+                return IRQ_HANDLED;
+        }
+
+        return IRQ_NONE;
+}
+
+static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
+                                        unsigned int enabled)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+        int val;
+
+        if (enabled)
+                val = 1;
+        else
+                val = 0;
+
+        out_8(&regs->alm_enable, val);
+        rtc->wkalarm.enabled = val;
+
+        return 0;
+}
+
+static int mpc5121_rtc_update_irq_enable(struct device *dev,
+                                         unsigned int enabled)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+        int val;
+
+        val = in_8(&regs->int_enable);
+
+        if (enabled)
+                val = (val & ~0x8) | 0x1;
+        else
+                val &= ~0x1;
+
+        out_8(&regs->int_enable, val);
+
+        return 0;
+}
+
+static const struct rtc_class_ops mpc5121_rtc_ops = {
+        .read_time = mpc5121_rtc_read_time,
+        .set_time = mpc5121_rtc_set_time,
+        .read_alarm = mpc5121_rtc_read_alarm,
+        .set_alarm = mpc5121_rtc_set_alarm,
+        .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
+        .update_irq_enable = mpc5121_rtc_update_irq_enable,
+};
+
+static int __devinit mpc5121_rtc_probe(struct of_device *op,
+                                        const struct of_device_id *match)
+{
+        struct mpc5121_rtc_data *rtc;
+        int err = 0;
+        u32 ka;
+
+        rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
+        if (!rtc)
+                return -ENOMEM;
+
+        rtc->regs = of_iomap(op->node, 0);
+        if (!rtc->regs) {
+                dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
+                err = -ENOSYS;
+                goto out_free;
+        }
+
+        device_init_wakeup(&op->dev, 1);
+
+        dev_set_drvdata(&op->dev, rtc);
+
+        rtc->irq = irq_of_parse_and_map(op->node, 1);
+        err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED,
+                                                "mpc5121-rtc", &op->dev);
+        if (err) {
+                dev_err(&op->dev, "%s: could not request irq: %i\n",
+                                                        __func__, rtc->irq);
+                goto out_dispose;
+        }
+
+        rtc->irq_periodic = irq_of_parse_and_map(op->node, 0);
+        err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
+                                IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev);
+        if (err) {
+                dev_err(&op->dev, "%s: could not request irq: %i\n",
+                                                __func__, rtc->irq_periodic);
+                goto out_dispose2;
+        }
+
+        ka = in_be32(&rtc->regs->keep_alive);
+        if (ka & 0x02) {
+                dev_warn(&op->dev,
+                        "mpc5121-rtc: Battery or oscillator failure!\n");
+                out_be32(&rtc->regs->keep_alive, ka);
+        }
+
+        rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev,
+                                        &mpc5121_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc->rtc)) {
+                err = PTR_ERR(rtc->rtc);
+                goto out_free_irq;
+        }
+
+        return 0;
+
+out_free_irq:
+        free_irq(rtc->irq_periodic, &op->dev);
+out_dispose2:
+        irq_dispose_mapping(rtc->irq_periodic);
+        free_irq(rtc->irq, &op->dev);
+out_dispose:
+        irq_dispose_mapping(rtc->irq);
+        iounmap(rtc->regs);
+out_free:
+        kfree(rtc);
+
+        return err;
+}
+
+static int __devexit mpc5121_rtc_remove(struct of_device *op)
+{
+        struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev);
+        struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
+
+        /* disable interrupt, so there are no nasty surprises */
+        out_8(&regs->alm_enable, 0);
+        out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
+
+        rtc_device_unregister(rtc->rtc);
+        iounmap(rtc->regs);
+        free_irq(rtc->irq, &op->dev);
+        free_irq(rtc->irq_periodic, &op->dev);
+        irq_dispose_mapping(rtc->irq);
+        irq_dispose_mapping(rtc->irq_periodic);
+        dev_set_drvdata(&op->dev, NULL);
+        kfree(rtc);
+
+        return 0;
+}
+
+static struct of_device_id mpc5121_rtc_match[] __devinitdata = {
+        { .compatible = "fsl,mpc5121-rtc", },
+        {},
+};
+
+static struct of_platform_driver mpc5121_rtc_driver = {
+        .owner = THIS_MODULE,
+        .name = "mpc5121-rtc",
+        .match_table = mpc5121_rtc_match,
+        .probe = mpc5121_rtc_probe,
+        .remove = __devexit_p(mpc5121_rtc_remove),
+};
+
+static int __init mpc5121_rtc_init(void)
+{
+        return of_register_platform_driver(&mpc5121_rtc_driver);
+}
+module_init(mpc5121_rtc_init);
+
+static void __exit mpc5121_rtc_exit(void)
+{
+        of_unregister_platform_driver(&mpc5121_rtc_driver);
+}
+module_exit(mpc5121_rtc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 0264b117893b..c256aacfa954 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -7,6 +7,9 @@
  *
  * Copyright 2006 (c) MontaVista Software, Inc.
  *
+ * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
+ * Copyright 2010 (c) ST-Ericsson AB
+ *
  * 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
@@ -18,6 +21,9 @@
 #include <linux/interrupt.h>
 #include <linux/amba/bus.h>
 #include <linux/io.h>
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/version.h>
 
 /*
  * Register definitions
@@ -30,35 +36,207 @@
 #define RTC_RIS         0x14    /* Raw interrupt status register */
 #define RTC_MIS         0x18    /* Masked interrupt status register */
 #define RTC_ICR         0x1c    /* Interrupt clear register */
+/* ST variants have additional timer functionality */
+#define RTC_TDR         0x20    /* Timer data read register */
+#define RTC_TLR         0x24    /* Timer data load register */
+#define RTC_TCR         0x28    /* Timer control register */
+#define RTC_YDR         0x30    /* Year data read register */
+#define RTC_YMR         0x34    /* Year match register */
+#define RTC_YLR         0x38    /* Year data load register */
+
+#define RTC_CR_CWEN     (1 << 26)       /* Clockwatch enable bit */
+
+#define RTC_TCR_EN      (1 << 1) /* Periodic timer enable bit */
+
+/* Common bit definitions for Interrupt status and control registers */
+#define RTC_BIT_AI      (1 << 0) /* Alarm interrupt bit */
+#define RTC_BIT_PI      (1 << 1) /* Periodic interrupt bit. ST variants only. */
+
+/* Common bit definations for ST v2 for reading/writing time */
+#define RTC_SEC_SHIFT 0
+#define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
+#define RTC_MIN_SHIFT 6
+#define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
+#define RTC_HOUR_SHIFT 12
+#define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
+#define RTC_WDAY_SHIFT 17
+#define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
+#define RTC_MDAY_SHIFT 20
+#define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
+#define RTC_MON_SHIFT 25
+#define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
+
+#define RTC_TIMER_FREQ 32768
 
 struct pl031_local {
         struct rtc_device *rtc;
         void __iomem *base;
+        u8 hw_designer;
+        u8 hw_revision:4;
 };
 
-static irqreturn_t pl031_interrupt(int irq, void *dev_id)
+static int pl031_alarm_irq_enable(struct device *dev,
+        unsigned int enabled)
+{
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+        unsigned long imsc;
+
+        /* Clear any pending alarm interrupts. */
+        writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+
+        imsc = readl(ldata->base + RTC_IMSC);
+
+        if (enabled == 1)
+                writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
+        else
+                writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
+
+        return 0;
+}
+
+/*
+ * Convert Gregorian date to ST v2 RTC format.
+ */
+static int pl031_stv2_tm_to_time(struct device *dev,
+                                 struct rtc_time *tm, unsigned long *st_time,
+        unsigned long *bcd_year)
+{
+        int year = tm->tm_year + 1900;
+        int wday = tm->tm_wday;
+
+        /* wday masking is not working in hardware so wday must be valid */
+        if (wday < -1 || wday > 6) {
+                dev_err(dev, "invalid wday value %d\n", tm->tm_wday);
+                return -EINVAL;
+        } else if (wday == -1) {
+                /* wday is not provided, calculate it here */
+                unsigned long time;
+                struct rtc_time calc_tm;
+
+                rtc_tm_to_time(tm, &time);
+                rtc_time_to_tm(time, &calc_tm);
+                wday = calc_tm.tm_wday;
+        }
+
+        *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8);
+
+        *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)
+                        |       (tm->tm_mday << RTC_MDAY_SHIFT)
+                        |       ((wday + 1) << RTC_WDAY_SHIFT)
+                        |       (tm->tm_hour << RTC_HOUR_SHIFT)
+                        |       (tm->tm_min << RTC_MIN_SHIFT)
+                        |       (tm->tm_sec << RTC_SEC_SHIFT);
+
+        return 0;
+}
+
+/*
+ * Convert ST v2 RTC format to Gregorian date.
+ */
+static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,
+        struct rtc_time *tm)
+{
+        tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);
+        tm->tm_mon  = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;
+        tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);
+        tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
+        tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);
+        tm->tm_min  = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);
+        tm->tm_sec  = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT);
+
+        tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+        tm->tm_year -= 1900;
+
+        return 0;
+}
+
+static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+
+        pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),
+                        readl(ldata->base + RTC_YDR), tm);
+
+        return 0;
+}
+
+static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm)
+{
+        unsigned long time;
+        unsigned long bcd_year;
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+        int ret;
+
+        ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);
+        if (ret == 0) {
+                writel(bcd_year, ldata->base + RTC_YLR);
+                writel(time, ldata->base + RTC_LR);
+        }
+
+        return ret;
+}
+
+static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
-        struct rtc_device *rtc = dev_id;
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+        int ret;
 
-        rtc_update_irq(rtc, 1, RTC_AF);
+        ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),
+                        readl(ldata->base + RTC_YMR), &alarm->time);
 
-        return IRQ_HANDLED;
+        alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+        alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
+
+        return ret;
 }
 
-static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
         struct pl031_local *ldata = dev_get_drvdata(dev);
+        unsigned long time;
+        unsigned long bcd_year;
+        int ret;
+
+        /* At the moment, we can only deal with non-wildcarded alarm times. */
+        ret = rtc_valid_tm(&alarm->time);
+        if (ret == 0) {
+                ret = pl031_stv2_tm_to_time(dev, &alarm->time,
+                                            &time, &bcd_year);
+                if (ret == 0) {
+                        writel(bcd_year, ldata->base + RTC_YMR);
+                        writel(time, ldata->base + RTC_MR);
+
+                        pl031_alarm_irq_enable(dev, alarm->enabled);
+                }
+        }
+
+        return ret;
+}
+
+static irqreturn_t pl031_interrupt(int irq, void *dev_id)
+{
+        struct pl031_local *ldata = dev_id;
+        unsigned long rtcmis;
+        unsigned long events = 0;
+
+        rtcmis = readl(ldata->base + RTC_MIS);
+        if (rtcmis) {
+                writel(rtcmis, ldata->base + RTC_ICR);
+
+                if (rtcmis & RTC_BIT_AI)
+                        events |= (RTC_AF | RTC_IRQF);
+
+                /* Timer interrupt is only available in ST variants */
+                if ((rtcmis & RTC_BIT_PI) &&
+                        (ldata->hw_designer == AMBA_VENDOR_ST))
+                        events |= (RTC_PF | RTC_IRQF);
+
+                rtc_update_irq(ldata->rtc, 1, events);
 
-        switch (cmd) {
-        case RTC_AIE_OFF:
-                writel(1, ldata->base + RTC_MIS);
-                return 0;
-        case RTC_AIE_ON:
-                writel(0, ldata->base + RTC_MIS);
-                return 0;
+                return IRQ_HANDLED;
         }
 
-        return -ENOIOCTLCMD;
+        return IRQ_NONE;
 }
 
 static int pl031_read_time(struct device *dev, struct rtc_time *tm)
@@ -74,11 +252,14 @@ static int pl031_set_time(struct device *dev, struct rtc_time *tm)
 {
         unsigned long time;
         struct pl031_local *ldata = dev_get_drvdata(dev);
+        int ret;
 
-        rtc_tm_to_time(tm, &time);
-        writel(time, ldata->base + RTC_LR);
+        ret = rtc_tm_to_time(tm, &time);
 
-        return 0;
+        if (ret == 0)
+                writel(time, ldata->base + RTC_LR);
+
+        return ret;
 }
 
 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
@@ -86,8 +267,9 @@ static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
         struct pl031_local *ldata = dev_get_drvdata(dev);
 
         rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
-        alarm->pending = readl(ldata->base + RTC_RIS);
-        alarm->enabled = readl(ldata->base + RTC_IMSC);
+
+        alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+        alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
 
         return 0;
 }
@@ -96,22 +278,71 @@ static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
         struct pl031_local *ldata = dev_get_drvdata(dev);
         unsigned long time;
+        int ret;
+
+        /* At the moment, we can only deal with non-wildcarded alarm times. */
+        ret = rtc_valid_tm(&alarm->time);
+        if (ret == 0) {
+                ret = rtc_tm_to_time(&alarm->time, &time);
+                if (ret == 0) {
+                        writel(time, ldata->base + RTC_MR);
+                        pl031_alarm_irq_enable(dev, alarm->enabled);
+                }
+        }
+
+        return ret;
+}
+
+/* Periodic interrupt is only available in ST variants. */
+static int pl031_irq_set_state(struct device *dev, int enabled)
+{
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+
+        if (enabled == 1) {
+                /* Clear any pending timer interrupt. */
+                writel(RTC_BIT_PI, ldata->base + RTC_ICR);
+
+                writel(readl(ldata->base + RTC_IMSC) | RTC_BIT_PI,
+                        ldata->base + RTC_IMSC);
 
-        rtc_tm_to_time(&alarm->time, &time);
+                /* Now start the timer */
+                writel(readl(ldata->base + RTC_TCR) | RTC_TCR_EN,
+                        ldata->base + RTC_TCR);
 
-        writel(time, ldata->base + RTC_MR);
-        writel(!alarm->enabled, ldata->base + RTC_MIS);
+        } else {
+                writel(readl(ldata->base + RTC_IMSC) & (~RTC_BIT_PI),
+                        ldata->base + RTC_IMSC);
+
+                /* Also stop the timer */
+                writel(readl(ldata->base + RTC_TCR) & (~RTC_TCR_EN),
+                        ldata->base + RTC_TCR);
+        }
+        /* Wait at least 1 RTC32 clock cycle to ensure next access
+         * to RTC_TCR will succeed.
+         */
+        udelay(40);
 
         return 0;
 }
 
-static const struct rtc_class_ops pl031_ops = {
-        .ioctl = pl031_ioctl,
-        .read_time = pl031_read_time,
-        .set_time = pl031_set_time,
-        .read_alarm = pl031_read_alarm,
-        .set_alarm = pl031_set_alarm,
-};
+static int pl031_irq_set_freq(struct device *dev, int freq)
+{
+        struct pl031_local *ldata = dev_get_drvdata(dev);
+
+        /* Cant set timer if it is already enabled */
+        if (readl(ldata->base + RTC_TCR) & RTC_TCR_EN) {
+                dev_err(dev, "can't change frequency while timer enabled\n");
+                return -EINVAL;
+        }
+
+        /* If self start bit in RTC_TCR is set timer will start here,
+         * but we never set that bit. Instead we start the timer when
+         * set_state is called with enabled == 1.
+         */
+        writel(RTC_TIMER_FREQ / freq, ldata->base + RTC_TLR);
+
+        return 0;
+}
 
 static int pl031_remove(struct amba_device *adev)
 {
@@ -131,18 +362,20 @@ static int pl031_probe(struct amba_device *adev, struct amba_id *id)
 {
         int ret;
         struct pl031_local *ldata;
+        struct rtc_class_ops *ops = id->data;
 
         ret = amba_request_regions(adev, NULL);
         if (ret)
                 goto err_req;
 
-        ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL);
+        ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);
         if (!ldata) {
                 ret = -ENOMEM;
                 goto out;
         }
 
         ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
+
         if (!ldata->base) {
                 ret = -ENOMEM;
                 goto out_no_remap;
@@ -150,24 +383,36 @@ static int pl031_probe(struct amba_device *adev, struct amba_id *id)
 
         amba_set_drvdata(adev, ldata);
 
-        if (request_irq(adev->irq[0], pl031_interrupt, IRQF_DISABLED,
-                        "rtc-pl031", ldata->rtc)) {
-                ret = -EIO;
-                goto out_no_irq;
-        }
+        ldata->hw_designer = amba_manf(adev);
+        ldata->hw_revision = amba_rev(adev);
+
+        dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer);
+        dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
 
-        ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops,
-                                         THIS_MODULE);
+        /* Enable the clockwatch on ST Variants */
+        if ((ldata->hw_designer == AMBA_VENDOR_ST) &&
+            (ldata->hw_revision > 1))
+                writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
+                       ldata->base + RTC_CR);
+
+        ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
+                                        THIS_MODULE);
         if (IS_ERR(ldata->rtc)) {
                 ret = PTR_ERR(ldata->rtc);
                 goto out_no_rtc;
         }
 
+        if (request_irq(adev->irq[0], pl031_interrupt,
+                        IRQF_DISABLED | IRQF_SHARED, "rtc-pl031", ldata)) {
+                ret = -EIO;
+                goto out_no_irq;
+        }
+
         return 0;
 
-out_no_rtc:
-        free_irq(adev->irq[0], ldata->rtc);
 out_no_irq:
+        rtc_device_unregister(ldata->rtc);
+out_no_rtc:
         iounmap(ldata->base);
         amba_set_drvdata(adev, NULL);
 out_no_remap:
@@ -175,13 +420,57 @@ out_no_remap:
 out:
         amba_release_regions(adev);
 err_req:
+
         return ret;
 }
 
+/* Operations for the original ARM version */
+static struct rtc_class_ops arm_pl031_ops = {
+        .read_time = pl031_read_time,
+        .set_time = pl031_set_time,
+        .read_alarm = pl031_read_alarm,
+        .set_alarm = pl031_set_alarm,
+        .alarm_irq_enable = pl031_alarm_irq_enable,
+};
+
+/* The First ST derivative */
+static struct rtc_class_ops stv1_pl031_ops = {
+        .read_time = pl031_read_time,
+        .set_time = pl031_set_time,
+        .read_alarm = pl031_read_alarm,
+        .set_alarm = pl031_set_alarm,
+        .alarm_irq_enable = pl031_alarm_irq_enable,
+        .irq_set_state = pl031_irq_set_state,
+        .irq_set_freq = pl031_irq_set_freq,
+};
+
+/* And the second ST derivative */
+static struct rtc_class_ops stv2_pl031_ops = {
+        .read_time = pl031_stv2_read_time,
+        .set_time = pl031_stv2_set_time,
+        .read_alarm = pl031_stv2_read_alarm,
+        .set_alarm = pl031_stv2_set_alarm,
+        .alarm_irq_enable = pl031_alarm_irq_enable,
+        .irq_set_state = pl031_irq_set_state,
+        .irq_set_freq = pl031_irq_set_freq,
+};
+
 static struct amba_id pl031_ids[] __initdata = {
         {
                 .id = 0x00041031,
                 .mask = 0x000fffff,
+                .data = &arm_pl031_ops,
+        },
+        /* ST Micro variants */
+        {
+                .id = 0x00180031,
+                .mask = 0x00ffffff,
+                .data = &stv1_pl031_ops,
+        },
+        {
+                .id = 0x00280031,
+                .mask = 0x00ffffff,
+                .data = &stv2_pl031_ops,
         },
         {0, 0},
 };