On Wed, Jul 25, 2018 at 11:21:22AM +0530, Keerthy wrote:
> Cut down the shutdown time from 2 seconds to 1 sec. In case of roll
> over try again.
>
> Signed-off-by: Keerthy <j-keer...@ti.com>
> ---
>
> Changes in v5:
>
> * Added an additional check to see if ALARM2 status is not set
> before retrying.
> * Cleaned up comments
> * Also reduced mdelay to 1S lesser as per this commit
>
> drivers/rtc/rtc-omap.c | 28 ++++++++++++++++++----------
> 1 file changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index 44ff4cc..caa6da6 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -421,12 +421,6 @@ static int omap_rtc_set_alarm(struct device *dev, struct
> rtc_wkalrm *alm)
> * The RTC can be used to control an external PMIC via the pmic_power_en pin,
> * which can be configured to transition to OFF on ALARM2 events.
> *
> - * Notes:
> - * The two-second alarm offset is the shortest offset possible as the alarm
> - * registers must be set before the next timer update and the offset
> - * calculation is too heavy for everything to be done within a single access
> - * period (~15 us).
> - *
> * Called with local interrupts disabled.
> */
> static void omap_rtc_power_off(void)
> @@ -435,17 +429,20 @@ static void omap_rtc_power_off(void)
> struct rtc_time tm;
> unsigned long now;
> u32 val;
> + int seconds;
Nit: I'd place this above val to maintain the reverse xmas-tree style.
>
> rtc->type->unlock(rtc);
> /* enable pmic_power_en control */
> val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
> rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
>
> - /* set alarm two seconds from now */
> +again:
> + /* set alarm one second from now */
> omap_rtc_read_time_raw(rtc, &tm);
> + seconds = tm.tm_sec;
> bcd2tm(&tm);
> rtc_tm_to_time(&tm, &now);
> - rtc_time_to_tm(now + 2, &tm);
> + rtc_time_to_tm(now + 1, &tm);
>
> if (tm2bcd(&tm) < 0) {
> dev_err(&rtc->rtc->dev, "power off failed\n");
> @@ -470,14 +467,25 @@ static void omap_rtc_power_off(void)
> val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
> rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
> val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
> +
> + /*
> + * first check if ALARM2 has fired, if not then check if
> + * our calculations started right before the rollover, try again
> + * in case of rollover
> + */
This is unnecessarily verbose; I'd rephrase it as something like:
/* Retry in case roll over happened before alarm was armed. */
> + if (!(OMAP_RTC_STATUS_ALARM2 && rtc_read(omap_rtc_power_off_rtc,
> + OMAP_RTC_STATUS_REG)) &&
> + seconds != rtc_read(omap_rtc_power_off_rtc, OMAP_RTC_SECONDS_REG))
> + goto again;
And this is clearly broken. First, you use boolean && instead of the &
bit operation.
Second, you need to check the status register *after* checking for
roll-over, as I already mentioned.
Also, use the rtc pointer rather than omap_rtc_power_off_rtc, which will
allow for more readable code.
I also strongly suggest you split the conditional, and use val to store
the status register value, that is:
if (rtc_read(rtc, OMAP_RTC_SECONDS_REG) != seconds) {
val = rtc_read(rtc, OMAP_RTC_STATUS_REG);
if (!(val & OMAP_RTC_STATUS_ALARM2))
goto again;
}
> +
> rtc->type->lock(rtc);
>
> /*
> - * Wait for alarm to trigger (within two seconds) and external PMIC to
> + * Wait for alarm to trigger (within one second) and external PMIC to
> * power off the system. Add a 500 ms margin for external latencies
> * (e.g. debounce circuits).
> */
> - mdelay(2500);
> + mdelay(1500);
> }
>
> static const struct rtc_class_ops omap_rtc_ops = {
Johan
