[PATCH v1 07/16] rtc: mediatek: replace a poll with regmap_read_poll_timeout

[sean.wang]

From: Sean Wang <sean.w...@mediatek.com>

Reuse the helper regmap_read_poll_timeout instead to simpify the logic.

Furthermore, the time for a wait in each iteration changed from cpu_relax
to 20us is for matching the usage of the helper, but it wouldn't acctually
break any the existent functionality according to a good test on MT6323
PMIC.

Signed-off-by: Sean Wang <sean.w...@mediatek.com>
---
 drivers/rtc/rtc-mt6397.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index 4411c08..b62eaa8 100644
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -18,6 +18,7 @@
 #include <linux/regmap.h>
 #include <linux/rtc.h>
 #include <linux/irqdomain.h>
+#include <linux/jiffies.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
@@ -63,6 +64,9 @@
 #define RTC_NUM_YEARS          128
 #define RTC_MIN_YEAR_OFFSET    (RTC_MIN_YEAR - RTC_BASE_YEAR)
 
+#define MTK_RTC_POLL_DELAY_US  10
+#define MTK_RTC_POLL_TIMEOUT   (jiffies_to_usecs(HZ))
+
 struct mt6397_rtc {
        struct device           *dev;
        struct rtc_device       *rtc_dev;
@@ -74,7 +78,6 @@ struct mt6397_rtc {
 
 static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
 {
-       unsigned long timeout = jiffies + HZ;
        int ret;
        u32 data;
 
@@ -82,19 +85,13 @@ static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
        if (ret < 0)
                return ret;
 
-       while (1) {
-               ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_BBPU,
-                                 &data);
-               if (ret < 0)
-                       break;
-               if (!(data & RTC_BBPU_CBUSY))
-                       break;
-               if (time_after(jiffies, timeout)) {
-                       ret = -ETIMEDOUT;
-                       break;
-               }
-               cpu_relax();
-       }
+       ret = regmap_read_poll_timeout(rtc->regmap,
+                                      rtc->addr_base + RTC_BBPU, data,
+                                      !(data & RTC_BBPU_CBUSY),
+                                      MTK_RTC_POLL_DELAY_US,
+                                      MTK_RTC_POLL_TIMEOUT);
+       if (ret)
+               dev_err(rtc->dev, "failed to write WRTGE: %d\n", ret);
 
        return ret;
 }
-- 
2.7.4