ENGR00171064 [MX6]Complete SNVS RTC feature

Add ioctl support to complete RTC feature.

Signed-off-by: Anson Huang <b20788@freescale.com>

diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index 0fd8b23a5d1a29e0e1938edb4c0af41d47eb3ead..aa3dedb6b10fec8cd93c20e7a999a59bf210ef86 100644 (file)
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -78,6 +78,10 @@
 #define        SSM_ST_NON_SECURE       0xB
 #define        CNTR_TO_SECS_SH 15      /* Converts 47-bit counter to 32-bit seconds */
 
+#define RTC_READ_TIME_47BIT    _IOR('p', 0x20, unsigned long long)
+/* blocks until LPSCMR is set, returns difference */
+#define RTC_WAIT_TIME_SET      _IOR('p', 0x21, int64_t)
+
 struct rtc_drv_data {
        struct rtc_device *rtc;
        void __iomem *ioaddr;
@@ -89,6 +93,8 @@ struct rtc_drv_data {
 static unsigned long rtc_status;
 
 static DEFINE_SPINLOCK(rtc_lock);
+DECLARE_COMPLETION(snvs_completion);
+static int64_t time_diff;
 
 /*!
  * LP counter register reads should always use this function.
@@ -294,11 +300,16 @@ static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
        unsigned long time;
        int ret;
        u32 lp_cr;
+       u64 old_time_47bit, new_time_47bit;
 
        ret = rtc_tm_to_time(tm, &time);
        if (ret != 0)
                return ret;
 
+       old_time_47bit = (((u64) (__raw_readl(ioaddr + SNVS_LPSRTCMR) &
+               ((0x1 << CNTR_TO_SECS_SH) - 1)) << 32) |
+               ((u64) __raw_readl(ioaddr + SNVS_LPSRTCLR)));
+
        /* Disable RTC first */
        lp_cr = __raw_readl(ioaddr + SNVS_LPCR) & ~SNVS_LPCR_SRTC_ENV;
        __raw_writel(lp_cr, ioaddr + SNVS_LPCR);
@@ -314,6 +325,22 @@ static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
        while (!(__raw_readl(ioaddr + SNVS_LPCR) & SNVS_LPCR_SRTC_ENV))
                ;
 
+       rtc_write_sync_lp(ioaddr);
+
+       new_time_47bit = (((u64) (__raw_readl(ioaddr + SNVS_LPSRTCMR) &
+               ((0x1 << CNTR_TO_SECS_SH) - 1)) << 32) |
+               ((u64) __raw_readl(ioaddr + SNVS_LPSRTCLR)));
+
+       time_diff = new_time_47bit - old_time_47bit;
+
+       /* signal all waiting threads that time changed */
+       complete_all(&snvs_completion);
+
+       /* allow signalled threads to handle the time change notification */
+       schedule();
+
+       /* reinitialize completion variable */
+       INIT_COMPLETION(snvs_completion);
        return 0;
 }
 
@@ -446,6 +473,58 @@ static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
        return 0;
 }
 
+/*!
+ * This function is used to support some ioctl calls directly.
+ * Other ioctl calls are supported indirectly through the
+ * arm/common/rtctime.c file.
+ *
+ * @param  cmd          ioctl command as defined in include/linux/rtc.h
+ * @param  arg          value for the ioctl command
+ *
+ * @return  0 if successful or negative value otherwise.
+ */
+static int snvs_rtc_ioctl(struct device *dev, unsigned int cmd,
+                        unsigned long arg)
+{
+       struct rtc_drv_data *pdata = dev_get_drvdata(dev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       u64 time_47bit;
+       int retVal;
+
+       switch (cmd) {
+       case RTC_READ_TIME_47BIT:
+               time_47bit = (((u64) (__raw_readl(ioaddr + SNVS_LPSRTCMR) &
+                       ((0x1 << CNTR_TO_SECS_SH) - 1)) << 32) |
+                       ((u64) __raw_readl(ioaddr + SNVS_LPSRTCLR)));
+
+               if (arg && copy_to_user((u64 *) arg, &time_47bit, sizeof(u64)))
+                       return -EFAULT;
+
+               return 0;
+
+       /* This IOCTL to be used by processes to be notified of time changes */
+       case RTC_WAIT_TIME_SET:
+               /* don't block without releasing mutex first */
+               mutex_unlock(&pdata->rtc->ops_lock);
+
+               /* sleep until awakened by SRTC driver when LPSCMR is changed */
+               wait_for_completion(&snvs_completion);
+
+               /* relock mutex because rtc_dev_ioctl will unlock again */
+               retVal = mutex_lock_interruptible(&pdata->rtc->ops_lock);
+
+               /* copy the new time difference = new time - previous time
+                 * to the user param. The difference is a signed value */
+               if (arg && copy_to_user((int64_t *) arg, &time_diff,
+                       sizeof(int64_t)))
+                       return -EFAULT;
+
+               return retVal;
+
+       }
+
+       return -ENOIOCTLCMD;
+}
 /*!
  * The RTC driver structure
  */
@@ -457,6 +536,7 @@ static struct rtc_class_ops snvs_rtc_ops = {
        .read_alarm = snvs_rtc_read_alarm,
        .set_alarm = snvs_rtc_set_alarm,
        .proc = snvs_rtc_proc,
+       .ioctl = snvs_rtc_ioctl,
        .alarm_irq_enable = snvs_rtc_alarm_irq_enable,
 };