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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /drivers/rtc/rtc-armada38x.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'drivers/rtc/rtc-armada38x.c')
-rw-r--r--drivers/rtc/rtc-armada38x.c33
1 files changed, 13 insertions, 20 deletions
diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c
index 2b08cac62..9a3f2a6f5 100644
--- a/drivers/rtc/rtc-armada38x.c
+++ b/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);
@@ -88,23 +81,23 @@ static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct armada38x_rtc *rtc = dev_get_drvdata(dev);
int ret = 0;
- unsigned long time;
+ unsigned long time, flags;
ret = rtc_tm_to_time(tm, &time);
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 = {