[PATCH v2 12/20] rtc: omap: silence bogus power-up reset message at probe

Johan Hovold
2014-10-21T17:37:58Z

Some legacy RTC IP revisions has a power-up reset flag in the status
register that later revisions lack.

As this flag is always read back as set on later revisions (or is
overloaded with a different flag), make sure to only clear the flag and
print the info message on legacy platforms.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/rtc/rtc-omap.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 1abd88e24c22..ee20f2d36065 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -106,6 +106,7 @@ struct omap_rtc_device_type {
bool has_32kclk_en;
bool has_kicker;
bool has_irqwakeen;
+ bool has_power_up_reset;
};

struct omap_rtc {
@@ -346,6 +347,7 @@ static struct rtc_class_ops omap_rtc_ops = {
};

static const struct omap_rtc_device_type omap_rtc_default_type = {
+ .has_power_up_reset = true,
};

static const struct omap_rtc_device_type omap_rtc_am3352_type = {
@@ -391,7 +393,7 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
{
struct omap_rtc *rtc;
struct resource *res;
- u8 reg, new_ctrl;
+ u8 reg, mask, new_ctrl;
const struct platform_device_id *id_entry;
const struct of_device_id *of_id;
int ret;
@@ -448,12 +450,17 @@ static int __init omap_rtc_probe(struct platform_device *pdev)

/* clear old status */
reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
- if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
- dev_info(&pdev->dev, "RTC power up reset detected\n");
- rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_POWER_UP);
+
+ mask = OMAP_RTC_STATUS_ALARM;
+
+ if (rtc->type->has_power_up_reset) {
+ mask |= OMAP_RTC_STATUS_POWER_UP;
+ if (reg & OMAP_RTC_STATUS_POWER_UP)
+ dev_info(&pdev->dev, "RTC power up reset detected\n");
}
- if (reg & (u8) OMAP_RTC_STATUS_ALARM)
- rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM);
+
+ if (reg & mask)
+ rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);

/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
--
2.0.4