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cpu/sam0_common: RTC: only write TAMPCTRL when tamper is enabled

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If we configure TAMPCTRL early, GPIO events will set bits in the
TAMPCTRL register.
That means that after a wake-up, we can't tell if the bit was set
because it was the wake-up source or if it was already set by a
run-time GPIO event.
This commit is contained in:
Benjamin Valentin 2021-03-14 19:31:39 +01:00 committed by Benjamin Valentin
parent 55c95cd8fd
commit 9d482c4448
1 changed files with 30 additions and 20 deletions
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50
cpu/sam0_common/periph/rtc_rtt.c
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@ -281,6 +281,7 @@ void rtt_init(void)
#if RTC_NUM_OF_TAMPERS
static rtc_state_t tamper_cb;
static uint32_t tampctr;
/* check if pin is a RTC tamper pin */
static int _rtc_pin(gpio_t pin)
@ -294,20 +295,32 @@ static int _rtc_pin(gpio_t pin)
return -1;
}
static void _set_tampctrl(uint32_t reg)
{
_rtc_set_enabled(0);
RTC->MODE0.TAMPCTRL.reg = reg;
_rtc_set_enabled(1);
}
void rtc_tamper_init(void)
{
if (IS_ACTIVE(MODULE_PERIPH_RTC) ||
IS_ACTIVE(MODULE_PERIPH_RTT) ||
_power_is_on()) {
return;
DEBUG("tamper init\n");
/* configure RTC clock only if it is not already configured */
if (!IS_ACTIVE(MODULE_PERIPH_RTC) &&
!IS_ACTIVE(MODULE_PERIPH_RTT)) {
if (!_power_is_on()) {
_rtt_clock_setup();
_poweron();
}
/* disable all interrupt sources */
RTC->MODE0.INTENCLR.reg = RTC_MODE0_INTENCLR_MASK;
}
_rtt_clock_setup();
_poweron();
/* disable all interrupt sources */
RTC->MODE0.INTENCLR.reg = RTC_MODE0_INTENCLR_MASK;
/* disable old tamper events */
_set_tampctrl(0);
NVIC_EnableIRQ(RTC_IRQn);
}
@ -319,20 +332,14 @@ int rtc_tamper_register(gpio_t pin, gpio_flank_t flank)
return -1;
}
/* TAMPCTRL is enable-protected */
_rtc_set_enabled(0);
RTC->MODE0.TAMPCTRL.reg |= RTC_TAMPCTRL_IN0ACT_WAKE << (2 * in);
tampctr |= RTC_TAMPCTRL_IN0ACT_WAKE << (2 * in);
if (flank == GPIO_RISING) {
RTC->MODE0.TAMPCTRL.reg |= RTC_TAMPCTRL_TAMLVL0 << in;
tampctr |= RTC_TAMPCTRL_TAMLVL0 << in;
} else if (flank == GPIO_FALLING) {
RTC->MODE0.TAMPCTRL.reg &= ~(RTC_TAMPCTRL_TAMLVL0 << in);
tampctr &= ~(RTC_TAMPCTRL_TAMLVL0 << in);
}
/* enable the RTC again */
_rtc_set_enabled(1);
return 0;
}
@ -341,7 +348,10 @@ void rtc_tamper_enable(void)
DEBUG("enable tamper\n");
/* clear tamper id */
RTC->MODE0.TAMPID.reg = 0xF;
RTC->MODE0.TAMPID.reg = 0x1F;
/* write TAMPCTRL register */
_set_tampctrl(tampctr);
/* work around errata 2.17.4:
* ignore the first tamper event on the rising edge */