altos: Fix broken EXTI edge mode selections. Clear pending exti on enable

Make sure the edge mode registers are set according to the requested
mode.

Clear any pending interrupt when enabling to avoid spurious isr call

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/stm/ao_exti_stm.c b/src/stm/ao_exti_stm.c
index 2108e8b5d4181fcaefe79169e0fa2a01e8646f35..0fa241889279b58049c22b49700709fb4b054df7 100644 (file)
--- a/src/stm/ao_exti_stm.c
+++ b/src/stm/ao_exti_stm.c
@@ -75,11 +75,14 @@ ao_exti_setup (struct stm_gpio *gpio, uint8_t pin, uint8_t mode, void (*callback
 
        /* Set interrupt mask and rising/falling mode */
        stm_exti.imr &= ~mask;
-       stm_exti.rtsr |= mask;
        if (mode & AO_EXTI_MODE_RISING)
                stm_exti.rtsr |= mask;
+       else
+               stm_exti.rtsr &= ~mask;
        if (mode & AO_EXTI_MODE_FALLING)
                stm_exti.ftsr |= mask;
+       else
+               stm_exti.ftsr &= ~mask;
 
        if (pin <= 4)
                irq = STM_ISR_EXTI0_POS + pin;
@@ -93,12 +96,16 @@ ao_exti_setup (struct stm_gpio *gpio, uint8_t pin, uint8_t mode, void (*callback
 
 void
 ao_exti_enable(struct stm_gpio *gpio, uint8_t pin) {
+       uint32_t        mask = (1 << pin);
+       stm_exti.pr = mask;
        stm_exti.imr |= (1 << pin);
 }
 
 void
 ao_exti_disable(struct stm_gpio *gpio, uint8_t pin) {
-       stm_exti.imr &= ~(1 << pin);
+       uint32_t        mask = (1 << pin);
+       stm_exti.imr &= ~mask;
+       stm_exti.pr = mask;
 }
 
 void