/**
* \brief Configure the interrupt trigger on the given GPIO pins
*
* Sets the Pin direction, analog/digital mode, and pull-up configuration of
* or a set of GPIO pins on a given GPIO port.
*
* @param[in] gpioport GPIO block register address base @ref gpio_reg_base
* @param[in] trigger Trigger configuration (@ref gpio_trigger) \n
* - GPIO_TRIG_LVL_LOW -- Trigger on low level \n
* - GPIO_TRIG_LVL_HIGH -- Trigger on high level \n
* - GPIO_TRIG_EDGE_FALL -- Trigger on falling edges \n
* - GPIO_TRIG_EDGE_RISE -- Trigger on rising edges \n
* - GPIO_TRIG_EDGE_BOTH -- Trigger on all edges
* @param[in] gpios @ref gpio_pin_id. Any combination of pins may be specified
* by OR'ing then together
*/
void gpio_configure_trigger(uint32_t gpioport, enum gpio_trigger trigger,
uint8_t gpios)
{
switch (trigger) {
case GPIO_TRIG_LVL_LOW:
GPIO_IS(gpioport) |= gpios;
GPIO_IEV(gpioport) &= ~gpios;
break;
case GPIO_TRIG_LVL_HIGH:
GPIO_IS(gpioport) |= gpios;
GPIO_IEV(gpioport) |= gpios;
break;
case GPIO_TRIG_EDGE_FALL:
GPIO_IS(gpioport) &= ~gpios;
GPIO_IBE(gpioport) &= ~gpios;
GPIO_IEV(gpioport) &= ~gpios;
break;
case GPIO_TRIG_EDGE_RISE:
GPIO_IS(gpioport) &= ~gpios;
GPIO_IBE(gpioport) &= ~gpios;
GPIO_IEV(gpioport) |= gpios;
break;
case GPIO_TRIG_EDGE_BOTH:
GPIO_IS(gpioport) &= ~gpios;
GPIO_IBE(gpioport) |= gpios;
break;
default:
/* Don't do anything */
break;
}
}
/*
* IRQ setup:
* Trigger an interrupt whenever a button is depressed.
*/
static void irq_setup(void)
{
const u32 btnpins = USR_SW1 | USR_SW2;
/* Configure interrupt as edge-sensitive */
GPIO_IS(GPIOF) &= ~btnpins;
/* Interrupt only respond to rising or falling edge (single-edge) */
GPIO_IBE(GPIOF) &= ~btnpins;
/* Trigger interrupt on rising-edge (when button is depressed) */
GPIO_IEV(GPIOF) |= btnpins;
/* Finally, Enable interrupt */
GPIO_IM(GPIOF) |= btnpins;
/* Enable the interrupt in the NVIC as well */
nvic_enable_irq(NVIC_GPIOF_IRQ);
}
