These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / rtc / rtc-armada38x.c

diff --git a/kernel/drivers/rtc/rtc-armada38x.c b/kernel/drivers/rtc/rtc-armada38x.c
index 4b62d1a..9a3f2a6 100644 (file)
--- a/kernel/drivers/rtc/rtc-armada38x.c
+++ b/kernel/drivers/rtc/rtc-armada38x.c
@@ -40,13 +40,6 @@ struct armada38x_rtc {
        void __iomem        *regs;
        void __iomem        *regs_soc;
        spinlock_t          lock;
-       /*
-        * While setting the time, the RTC TIME register should not be
-        * accessed. Setting the RTC time involves sleeping during
-        * 100ms, so a mutex instead of a spinlock is used to protect
-        * it
-        */
-       struct mutex        mutex_time;
        int                 irq;
 };
 
@@ -64,9 +57,9 @@ static void rtc_delayed_write(u32 val, struct armada38x_rtc *rtc, int offset)
 static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
        struct armada38x_rtc *rtc = dev_get_drvdata(dev);
-       unsigned long time, time_check;
+       unsigned long time, time_check, flags;
 
-       mutex_lock(&rtc->mutex_time);
+       spin_lock_irqsave(&rtc->lock, flags);
        time = readl(rtc->regs + RTC_TIME);
        /*
         * WA for failing time set attempts. As stated in HW ERRATA if
@@ -77,7 +70,7 @@ static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm)
        if ((time_check - time) > 1)
                time_check = readl(rtc->regs + RTC_TIME);
 
-       mutex_unlock(&rtc->mutex_time);
+       spin_unlock_irqrestore(&rtc->lock, flags);
 
        rtc_time_to_tm(time_check, tm);
 
@@ -95,16 +88,16 @@ static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
        if (ret)
                goto out;
        /*
-        * Setting the RTC time not always succeeds. According to the
-        * errata we need to first write on the status register and
-        * then wait for 100ms before writing to the time register to be
-        * sure that the data will be taken into account.
+        * According to errata FE-3124064, Write to RTC TIME register
+        * may fail. As a workaround, after writing to RTC TIME
+        * register, issue a dummy write of 0x0 twice to RTC Status
+        * register.
         */
-       mutex_lock(&rtc->mutex_time);
-       rtc_delayed_write(0, rtc, RTC_STATUS);
-       msleep(100);
+       spin_lock_irqsave(&rtc->lock, flags);
        rtc_delayed_write(time, rtc, RTC_TIME);
-       mutex_unlock(&rtc->mutex_time);
+       rtc_delayed_write(0, rtc, RTC_STATUS);
+       rtc_delayed_write(0, rtc, RTC_STATUS);
+       spin_unlock_irqrestore(&rtc->lock, flags);
 
 out:
        return ret;
@@ -229,7 +222,6 @@ static __init int armada38x_rtc_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        spin_lock_init(&rtc->lock);
-       mutex_init(&rtc->mutex_time);
 
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc");
        rtc->regs = devm_ioremap_resource(&pdev->dev, res);
@@ -303,6 +295,7 @@ static const struct of_device_id armada38x_rtc_of_match_table[] = {
        { .compatible = "marvell,armada-380-rtc", },
        {}
 };
+MODULE_DEVICE_TABLE(of, armada38x_rtc_of_match_table);
 #endif
 
 static struct platform_driver armada38x_rtc_driver = {