3 files changed, 519 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2ccd351c52e..18c5be168a5 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -509,6 +509,17 @@ config RTC_DRV_M48T59
           This driver can also be built as a module, if so, the module
           will be called "rtc-m48t59".
 
+config RTC_MXC
+        tristate "Freescale MXC Real Time Clock"
+        depends on ARCH_MXC
+        depends on RTC_CLASS
+        help
+           If you say yes here you get support for the Freescale MXC
+           RTC module.
+
+           This driver can also be built as a module, if so, the module
+           will be called "rtc-mxc".
+
 config RTC_DRV_BQ4802
         tristate "TI BQ4802"
         help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 0e9414995ca..5c16333fd91 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_RTC_DRV_M41T94)	+= rtc-m41t94.o
 obj-$(CONFIG_RTC_DRV_M48T35)    += rtc-m48t35.o
 obj-$(CONFIG_RTC_DRV_M48T59)    += rtc-m48t59.o
 obj-$(CONFIG_RTC_DRV_M48T86)    += rtc-m48t86.o
+obj-$(CONFIG_RTC_MXC)           += rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_BQ4802)    += rtc-bq4802.o
 obj-$(CONFIG_RTC_DRV_SUN4V)     += rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_STARFIRE)  += rtc-starfire.o
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
new file mode 100644
index 00000000000..6bd5072d4eb
--- /dev/null
+++ b/drivers/rtc/rtc-mxc.c
@@ -0,0 +1,507 @@
+/*
+ * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/io.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <mach/hardware.h>
+
+#define RTC_INPUT_CLK_32768HZ   (0x00 << 5)
+#define RTC_INPUT_CLK_32000HZ   (0x01 << 5)
+#define RTC_INPUT_CLK_38400HZ   (0x02 << 5)
+
+#define RTC_SW_BIT      (1 << 0)
+#define RTC_ALM_BIT     (1 << 2)
+#define RTC_1HZ_BIT     (1 << 4)
+#define RTC_2HZ_BIT     (1 << 7)
+#define RTC_SAM0_BIT    (1 << 8)
+#define RTC_SAM1_BIT    (1 << 9)
+#define RTC_SAM2_BIT    (1 << 10)
+#define RTC_SAM3_BIT    (1 << 11)
+#define RTC_SAM4_BIT    (1 << 12)
+#define RTC_SAM5_BIT    (1 << 13)
+#define RTC_SAM6_BIT    (1 << 14)
+#define RTC_SAM7_BIT    (1 << 15)
+#define PIT_ALL_ON      (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
+                         RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
+                         RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
+
+#define RTC_ENABLE_BIT  (1 << 7)
+
+#define MAX_PIE_NUM     9
+#define MAX_PIE_FREQ    512
+static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
+        { 2,            RTC_2HZ_BIT },
+        { 4,            RTC_SAM0_BIT },
+        { 8,            RTC_SAM1_BIT },
+        { 16,           RTC_SAM2_BIT },
+        { 32,           RTC_SAM3_BIT },
+        { 64,           RTC_SAM4_BIT },
+        { 128,          RTC_SAM5_BIT },
+        { 256,          RTC_SAM6_BIT },
+        { MAX_PIE_FREQ, RTC_SAM7_BIT },
+};
+
+/* Those are the bits from a classic RTC we want to mimic */
+#define RTC_IRQF        0x80    /* any of the following 3 is active */
+#define RTC_PF          0x40    /* Periodic interrupt */
+#define RTC_AF          0x20    /* Alarm interrupt */
+#define RTC_UF          0x10    /* Update interrupt for 1Hz RTC */
+
+#define MXC_RTC_TIME    0
+#define MXC_RTC_ALARM   1
+
+#define RTC_HOURMIN     0x00    /*  32bit rtc hour/min counter reg */
+#define RTC_SECOND      0x04    /*  32bit rtc seconds counter reg */
+#define RTC_ALRM_HM     0x08    /*  32bit rtc alarm hour/min reg */
+#define RTC_ALRM_SEC    0x0C    /*  32bit rtc alarm seconds reg */
+#define RTC_RTCCTL      0x10    /*  32bit rtc control reg */
+#define RTC_RTCISR      0x14    /*  32bit rtc interrupt status reg */
+#define RTC_RTCIENR     0x18    /*  32bit rtc interrupt enable reg */
+#define RTC_STPWCH      0x1C    /*  32bit rtc stopwatch min reg */
+#define RTC_DAYR        0x20    /*  32bit rtc days counter reg */
+#define RTC_DAYALARM    0x24    /*  32bit rtc day alarm reg */
+#define RTC_TEST1       0x28    /*  32bit rtc test reg 1 */
+#define RTC_TEST2       0x2C    /*  32bit rtc test reg 2 */
+#define RTC_TEST3       0x30    /*  32bit rtc test reg 3 */
+
+struct rtc_plat_data {
+        struct rtc_device *rtc;
+        void __iomem *ioaddr;
+        int irq;
+        struct clk *clk;
+        unsigned int irqen;
+        int alrm_sec;
+        int alrm_min;
+        int alrm_hour;
+        int alrm_mday;
+        struct timespec mxc_rtc_delta;
+        struct rtc_time g_rtc_alarm;
+};
+
+/*
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ */
+static u32 get_alarm_or_time(struct device *dev, int time_alarm)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+        u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
+
+        switch (time_alarm) {
+        case MXC_RTC_TIME:
+                day = readw(ioaddr + RTC_DAYR);
+                hr_min = readw(ioaddr + RTC_HOURMIN);
+                sec = readw(ioaddr + RTC_SECOND);
+                break;
+        case MXC_RTC_ALARM:
+                day = readw(ioaddr + RTC_DAYALARM);
+                hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
+                sec = readw(ioaddr + RTC_ALRM_SEC);
+                break;
+        }
+
+        hr = hr_min >> 8;
+        min = hr_min & 0xff;
+
+        return (((day * 24 + hr) * 60) + min) * 60 + sec;
+}
+
+/*
+ * This function sets the RTC alarm value or the time value.
+ */
+static void set_alarm_or_time(struct device *dev, int time_alarm, u32 time)
+{
+        u32 day, hr, min, sec, temp;
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        day = time / 86400;
+        time -= day * 86400;
+
+        /* time is within a day now */
+        hr = time / 3600;
+        time -= hr * 3600;
+
+        /* time is within an hour now */
+        min = time / 60;
+        sec = time - min * 60;
+
+        temp = (hr << 8) + min;
+
+        switch (time_alarm) {
+        case MXC_RTC_TIME:
+                writew(day, ioaddr + RTC_DAYR);
+                writew(sec, ioaddr + RTC_SECOND);
+                writew(temp, ioaddr + RTC_HOURMIN);
+                break;
+        case MXC_RTC_ALARM:
+                writew(day, ioaddr + RTC_DAYALARM);
+                writew(sec, ioaddr + RTC_ALRM_SEC);
+                writew(temp, ioaddr + RTC_ALRM_HM);
+                break;
+        }
+}
+
+/*
+ * This function updates the RTC alarm registers and then clears all the
+ * interrupt status bits.
+ */
+static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
+{
+        struct rtc_time alarm_tm, now_tm;
+        unsigned long now, time;
+        int ret;
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        now = get_alarm_or_time(dev, MXC_RTC_TIME);
+        rtc_time_to_tm(now, &now_tm);
+        alarm_tm.tm_year = now_tm.tm_year;
+        alarm_tm.tm_mon = now_tm.tm_mon;
+        alarm_tm.tm_mday = now_tm.tm_mday;
+        alarm_tm.tm_hour = alrm->tm_hour;
+        alarm_tm.tm_min = alrm->tm_min;
+        alarm_tm.tm_sec = alrm->tm_sec;
+        rtc_tm_to_time(&now_tm, &now);
+        rtc_tm_to_time(&alarm_tm, &time);
+
+        if (time < now) {
+                time += 60 * 60 * 24;
+                rtc_time_to_tm(time, &alarm_tm);
+        }
+
+        ret = rtc_tm_to_time(&alarm_tm, &time);
+
+        /* clear all the interrupt status bits */
+        writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
+        set_alarm_or_time(dev, MXC_RTC_ALARM, time);
+
+        return ret;
+}
+
+/* This function is the RTC interrupt service routine. */
+static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
+{
+        struct platform_device *pdev = dev_id;
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+        u32 status;
+        u32 events = 0;
+
+        spin_lock_irq(&pdata->rtc->irq_lock);
+        status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
+        /* clear interrupt sources */
+        writew(status, ioaddr + RTC_RTCISR);
+
+        /* clear alarm interrupt if it has occurred */
+        if (status & RTC_ALM_BIT)
+                status &= ~RTC_ALM_BIT;
+
+        /* update irq data & counter */
+        if (status & RTC_ALM_BIT)
+                events |= (RTC_AF | RTC_IRQF);
+
+        if (status & RTC_1HZ_BIT)
+                events |= (RTC_UF | RTC_IRQF);
+
+        if (status & PIT_ALL_ON)
+                events |= (RTC_PF | RTC_IRQF);
+
+        if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm))
+                rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
+
+        rtc_update_irq(pdata->rtc, 1, events);
+        spin_unlock_irq(&pdata->rtc->irq_lock);
+
+        return IRQ_HANDLED;
+}
+
+/*
+ * Clear all interrupts and release the IRQ
+ */
+static void mxc_rtc_release(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        spin_lock_irq(&pdata->rtc->irq_lock);
+
+        /* Disable all rtc interrupts */
+        writew(0, ioaddr + RTC_RTCIENR);
+
+        /* Clear all interrupt status */
+        writew(0xffffffff, ioaddr + RTC_RTCISR);
+
+        spin_unlock_irq(&pdata->rtc->irq_lock);
+}
+
+static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
+                                unsigned int enabled)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+        u32 reg;
+
+        spin_lock_irq(&pdata->rtc->irq_lock);
+        reg = readw(ioaddr + RTC_RTCIENR);
+
+        if (enabled)
+                reg |= bit;
+        else
+                reg &= ~bit;
+
+        writew(reg, ioaddr + RTC_RTCIENR);
+        spin_unlock_irq(&pdata->rtc->irq_lock);
+}
+
+static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+        mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
+        return 0;
+}
+
+static int mxc_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
+{
+        mxc_rtc_irq_enable(dev, RTC_1HZ_BIT, enabled);
+        return 0;
+}
+
+/*
+ * This function reads the current RTC time into tm in Gregorian date.
+ */
+static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        u32 val;
+
+        /* Avoid roll-over from reading the different registers */
+        do {
+                val = get_alarm_or_time(dev, MXC_RTC_TIME);
+        } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+        rtc_time_to_tm(val, tm);
+
+        return 0;
+}
+
+/*
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ */
+static int mxc_rtc_set_mmss(struct device *dev, unsigned long time)
+{
+        /* Avoid roll-over from reading the different registers */
+        do {
+                set_alarm_or_time(dev, MXC_RTC_TIME, time);
+        } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+        return 0;
+}
+
+/*
+ * This function reads the current alarm value into the passed in 'alrm'
+ * argument. It updates the alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ */
+static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        rtc_time_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
+        alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
+
+        return 0;
+}
+
+/*
+ * This function sets the RTC alarm based on passed in alrm.
+ */
+static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        int ret;
+
+        if (rtc_valid_tm(&alrm->time)) {
+                if (alrm->time.tm_sec > 59 ||
+                    alrm->time.tm_hour > 23 ||
+                    alrm->time.tm_min > 59)
+                        return -EINVAL;
+
+                ret = rtc_update_alarm(dev, &alrm->time);
+        } else {
+                ret = rtc_valid_tm(&alrm->time);
+                if (ret)
+                        return ret;
+
+                ret = rtc_update_alarm(dev, &alrm->time);
+        }
+
+        if (ret)
+                return ret;
+
+        memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+        mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
+
+        return 0;
+}
+
+/* RTC layer */
+static struct rtc_class_ops mxc_rtc_ops = {
+        .release                = mxc_rtc_release,
+        .read_time              = mxc_rtc_read_time,
+        .set_mmss               = mxc_rtc_set_mmss,
+        .read_alarm             = mxc_rtc_read_alarm,
+        .set_alarm              = mxc_rtc_set_alarm,
+        .alarm_irq_enable       = mxc_rtc_alarm_irq_enable,
+        .update_irq_enable      = mxc_rtc_update_irq_enable,
+};
+
+static int __init mxc_rtc_probe(struct platform_device *pdev)
+{
+        struct clk *clk;
+        struct resource *res;
+        struct rtc_device *rtc;
+        struct rtc_plat_data *pdata = NULL;
+        u32 reg;
+        int ret, rate;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENODEV;
+
+        pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        pdata->ioaddr = ioremap(res->start, resource_size(res));
+
+        clk = clk_get(&pdev->dev, "ckil");
+        if (IS_ERR(clk))
+                return PTR_ERR(clk);
+
+        rate = clk_get_rate(clk);
+        clk_put(clk);
+
+        if (rate == 32768)
+                reg = RTC_INPUT_CLK_32768HZ;
+        else if (rate == 32000)
+                reg = RTC_INPUT_CLK_32000HZ;
+        else if (rate == 38400)
+                reg = RTC_INPUT_CLK_38400HZ;
+        else {
+                dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n",
+                        clk_get_rate(clk));
+                ret = -EINVAL;
+                goto exit_free_pdata;
+        }
+
+        reg |= RTC_ENABLE_BIT;
+        writew(reg, (pdata->ioaddr + RTC_RTCCTL));
+        if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
+                dev_err(&pdev->dev, "hardware module can't be enabled!\n");
+                ret = -EIO;
+                goto exit_free_pdata;
+        }
+
+        pdata->clk = clk_get(&pdev->dev, "rtc");
+        if (IS_ERR(pdata->clk)) {
+                dev_err(&pdev->dev, "unable to get clock!\n");
+                ret = PTR_ERR(pdata->clk);
+                goto exit_free_pdata;
+        }
+
+        clk_enable(pdata->clk);
+
+        rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
+                                  THIS_MODULE);
+        if (IS_ERR(rtc)) {
+                ret = PTR_ERR(rtc);
+                goto exit_put_clk;
+        }
+
+        pdata->rtc = rtc;
+        platform_set_drvdata(pdev, pdata);
+
+        /* Configure and enable the RTC */
+        pdata->irq = platform_get_irq(pdev, 0);
+
+        if (pdata->irq >= 0 &&
+            request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED,
+                        pdev->name, pdev) < 0) {
+                dev_warn(&pdev->dev, "interrupt not available.\n");
+                pdata->irq = -1;
+        }
+
+        return 0;
+
+exit_put_clk:
+        clk_put(pdata->clk);
+
+exit_free_pdata:
+        kfree(pdata);
+
+        return ret;
+}
+
+static int __exit mxc_rtc_remove(struct platform_device *pdev)
+{
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+        rtc_device_unregister(pdata->rtc);
+
+        if (pdata->irq >= 0)
+                free_irq(pdata->irq, pdev);
+
+        clk_disable(pdata->clk);
+        clk_put(pdata->clk);
+        kfree(pdata);
+        platform_set_drvdata(pdev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver mxc_rtc_driver = {
+        .driver = {
+                   .name        = "mxc_rtc",
+                   .owner       = THIS_MODULE,
+        },
+        .remove         = __exit_p(mxc_rtc_remove),
+};
+
+static int __init mxc_rtc_init(void)
+{
+        return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe);
+}
+
+static void __exit mxc_rtc_exit(void)
+{
+        platform_driver_unregister(&mxc_rtc_driver);
+}
+
+module_init(mxc_rtc_init);
+module_exit(mxc_rtc_exit);
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MXC");
+MODULE_LICENSE("GPL");
+