rtc-mv: add support for Alarm

This patch adds the Alarm support, this mode enabled when adding
IORESOURCE_IRQ to the platform device resources.

The patch also enables the wakeup mode, so the wakealarm sysfs file (under
/sys/class/rtc/rtcX/) can be used to configure the alarm clock.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 154 insertions, 3 deletions

diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c
index e0263d2005ee..dc052ce6e63a 100644
--- a/drivers/rtc/rtc-mv.c
+++ b/drivers/rtc/rtc-mv.c
@@ -27,10 +27,17 @@
 #define RTC_MONTH_OFFS          8
 #define RTC_YEAR_OFFS           16
 
+#define RTC_ALARM_TIME_REG_OFFS 8
+#define RTC_ALARM_DATE_REG_OFFS 0xc
+#define RTC_ALARM_VALID         (1 << 7)
+
+#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS       0x10
+#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS      0x14
 
 struct rtc_plat_data {
         struct rtc_device *rtc;
         void __iomem *ioaddr;
+        int             irq;
 };
 
 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
@@ -84,12 +91,134 @@ static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
         return rtc_valid_tm(tm);
 }
 
+static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+        void __iomem *ioaddr = pdata->ioaddr;
+        u32     rtc_time, rtc_date;
+        unsigned int year, month, day, hour, minute, second, wday;
+
+        rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
+        rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
+
+        second = rtc_time & 0x7f;
+        minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
+        hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
+        wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
+
+        day = rtc_date & 0x3f;
+        month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
+        year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
+
+        alm->time.tm_sec = bcd2bin(second);
+        alm->time.tm_min = bcd2bin(minute);
+        alm->time.tm_hour = bcd2bin(hour);
+        alm->time.tm_mday = bcd2bin(day);
+        alm->time.tm_wday = bcd2bin(wday);
+        alm->time.tm_mon = bcd2bin(month) - 1;
+        /* hw counts from year 2000, but tm_year is relative to 1900 */
+        alm->time.tm_year = bcd2bin(year) + 100;
+
+        if (rtc_valid_tm(&alm->time) < 0) {
+                dev_err(dev, "retrieved alarm date/time is not valid.\n");
+                rtc_time_to_tm(0, &alm->time);
+        }
+
+        alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
+        return 0;
+}
+
+static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+        struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+        void __iomem *ioaddr = pdata->ioaddr;
+        u32 rtc_reg = 0;
+
+        if (alm->time.tm_sec >= 0)
+                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
+                        << RTC_SECONDS_OFFS;
+        if (alm->time.tm_min >= 0)
+                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
+                        << RTC_MINUTES_OFFS;
+        if (alm->time.tm_hour >= 0)
+                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
+                        << RTC_HOURS_OFFS;
+
+        writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
+
+        if (alm->time.tm_mday >= 0)
+                rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
+                        << RTC_MDAY_OFFS;
+        else
+                rtc_reg = 0;
+
+        if (alm->time.tm_mon >= 0)
+                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
+                        << RTC_MONTH_OFFS;
+
+        if (alm->time.tm_year >= 0)
+                rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100))
+                        << RTC_YEAR_OFFS;
+
+        writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
+        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
+        writel(alm->enabled ? 1 : 0,
+               ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
+
+        return 0;
+}
+
+static int mv_rtc_ioctl(struct device *dev, unsigned int cmd,
+                        unsigned long arg)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        if (pdata->irq < 0)
+                return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
+        switch (cmd) {
+        case RTC_AIE_OFF:
+                writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
+                break;
+        case RTC_AIE_ON:
+                writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
+                break;
+        default:
+                return -ENOIOCTLCMD;
+        }
+        return 0;
+}
+
+static irqreturn_t mv_rtc_interrupt(int irq, void *data)
+{
+        struct rtc_plat_data *pdata = data;
+        void __iomem *ioaddr = pdata->ioaddr;
+
+        /* alarm irq? */
+        if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
+                return IRQ_NONE;
+
+        /* clear interrupt */
+        writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
+        rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
+        return IRQ_HANDLED;
+}
+
 static const struct rtc_class_ops mv_rtc_ops = {
         .read_time      = mv_rtc_read_time,
         .set_time       = mv_rtc_set_time,
 };
 
-static int __init mv_rtc_probe(struct platform_device *pdev)
+static const struct rtc_class_ops mv_rtc_alarm_ops = {
+        .read_time      = mv_rtc_read_time,
+        .set_time       = mv_rtc_set_time,
+        .read_alarm     = mv_rtc_read_alarm,
+        .set_alarm      = mv_rtc_set_alarm,
+        .ioctl          = mv_rtc_ioctl,
+};
+
+static int __devinit mv_rtc_probe(struct platform_device *pdev)
 {
         struct resource *res;
         struct rtc_plat_data *pdata;
@@ -130,12 +259,31 @@ static int __init mv_rtc_probe(struct platform_device *pdev)
                 }
         }
 
+        pdata->irq = platform_get_irq(pdev, 0);
+
         platform_set_drvdata(pdev, pdata);
-        pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
-                                         &mv_rtc_ops, THIS_MODULE);
+
+        if (pdata->irq >= 0) {
+                device_init_wakeup(&pdev->dev, 1);
+                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
+                                                 &mv_rtc_alarm_ops,
+                                                 THIS_MODULE);
+        } else
+                pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
+                                                 &mv_rtc_ops, THIS_MODULE);
         if (IS_ERR(pdata->rtc))
                 return PTR_ERR(pdata->rtc);
 
+        if (pdata->irq >= 0) {
+                writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
+                if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
+                                     IRQF_DISABLED | IRQF_SHARED,
+                                     pdev->name, pdata) < 0) {
+                        dev_warn(&pdev->dev, "interrupt not available.\n");
+                        pdata->irq = -1;
+                }
+        }
+
         return 0;
 }
 
@@ -143,6 +291,9 @@ static int __exit mv_rtc_remove(struct platform_device *pdev)
 {
         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
+        if (pdata->irq >= 0)
+                device_init_wakeup(&pdev->dev, 0);
+
         rtc_device_unregister(pdata->rtc);
         return 0;
 }