rtc: starfive: Improve rtc driver

1. Set initial time if rtc is never set.
2. Add timeout when clearing interrupt flag register.
3. Improve alarm function.

Signed-off-by: Hal Feng <hal.feng@starfivetech.com>

diff --git a/drivers/rtc/rtc-starfive.c b/drivers/rtc/rtc-starfive.c
index 51d6c31..010f31a 100644 (file)
--- a/drivers/rtc/rtc-starfive.c
+++ b/drivers/rtc/rtc-starfive.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
+#include <linux/iopoll.h>
 #include <linux/platform_device.h>
 #include <linux/rtc.h>
 
@@ -80,6 +81,8 @@
 #define DATE_MON_MASK          GENMASK(10, 6)
 #define DATE_YEAR_MASK         GENMASK(18, 11)
 
+#define INT_TIMEOUT_US         180
+
 enum RTC_HOUR_MODE {
        RTC_HOUR_MODE_12H = 0,
        RTC_HOUR_MODE_24H = 1
@@ -275,6 +278,7 @@ static irqreturn_t sft_rtc_irq_handler(int irq, void *data)
        u32 irq_flags = 0;
        u32 irq_mask = 0;
        u32 val;
+       int ret = 0;
 
        val = readl(srtc->regs + SFT_RTC_IRQ_EVEVT);
        if (val & RTC_IRQ_CAL_START)
@@ -297,15 +301,18 @@ static irqreturn_t sft_rtc_irq_handler(int irq, void *data)
        if (val & RTC_IRQ_ALAEM) {
                irq_flags |= RTC_AF;
                irq_mask |= RTC_IRQ_ALAEM;
+               /* Make sure aie_timer will pop out from timerqueue */
+               srtc->rtc_dev->aie_timer.node.expires -= 1 * NSEC_PER_SEC;
+               dev_info(&srtc->rtc_dev->dev, "alarm expires");
        }
 
-       /*
-        * Hardware workaround:
-        * need to keep clearing interrupts until the clearing succeeds
-        */
-       do {
-               writel(irq_mask, srtc->regs + SFT_RTC_IRQ_EVEVT);
-       } while (readl(srtc->regs + SFT_RTC_IRQ_EVEVT) & irq_mask);
+       writel(irq_mask, srtc->regs + SFT_RTC_IRQ_EVEVT);
+
+       /* Wait interrupt flag clear */
+       ret = readl_poll_timeout_atomic(srtc->regs + SFT_RTC_IRQ_EVEVT, val,
+                                       (val & irq_mask) == 0, 0, INT_TIMEOUT_US);
+       if (ret)
+               dev_warn(&srtc->rtc_dev->dev, "fail to clear rtc interrupt flag\n");
 
        if (irq_flags)
                rtc_update_irq(srtc->rtc_dev, 1, irq_flags | RTC_IRQF);
@@ -553,6 +560,7 @@ static int sft_rtc_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct sft_rtc *srtc;
+       struct rtc_time tm;
        int ret;
 
        srtc = devm_kzalloc(dev, sizeof(*srtc), GFP_KERNEL);
@@ -638,6 +646,19 @@ static int sft_rtc_probe(struct platform_device *pdev)
        if (device_property_read_bool(dev, "rtc,hw-adjustment"))
                sft_rtc_hw_adjustment(dev, true);
 
+       /*
+        * If rtc time is out of supported range, reset it to the minimum time.
+        * notice that, actual year = 1900 + tm.tm_year
+        *              actual month = 1 + tm.tm_mon
+        */
+       sft_rtc_read_time(dev, &tm);
+       if (tm.tm_year < 101 || tm.tm_year > 199 || tm.tm_mon < 0 || tm.tm_mon > 11 ||
+           tm.tm_mday < 1 || tm.tm_mday > 31 || tm.tm_hour < 0 || tm.tm_hour > 23 ||
+           tm.tm_min < 0 || tm.tm_min > 59 || tm.tm_sec < 0 || tm.tm_sec > 59) {
+               rtc_time64_to_tm(srtc->rtc_dev->range_min, &tm);
+               sft_rtc_set_time(dev, &tm);
+       }
+
        ret = devm_rtc_register_device(srtc->rtc_dev);
        if (ret)
                goto err_disable_wakeup;