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

sean.wang
2018-03-23T09:18:46Z

From: Sean Wang <sean.wang@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.wang@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