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/*! rief Setup the function select for a GPIO to use output from the given PIO instance
 * ...
 * Note that this is not necessary for a state machine to be able to read the *input* value from a GPIO, but only for it to set the output value or output enable.
 */

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gpio_set_function(pin, GPIO_FUNC_SIO);

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pio_gpio_init(pio, pin);

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.program in_out
.side_set 1
 wait 1 pin 0 side 0 ; Wait for rising edge
 wait 0 pin 0 side 1 ; Wait for falling edge, set side=1 during transition

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% c-sdk{
 static inline void in_out_program_init(PIO pio, uint sm, uint offset, uint pin, uint sideset_pin)
 {
 pio_sm_config c = in_out_program_get_default_config(offset);
 sm_config_set_in_pins(&c, pin); // For wait and in instructions
 sm_config_set_jmp_pin(&c, pin); // For jmp instructions
 pio_gpio_init(pio, pin);
 pio_gpio_init(pio, sideset_pin);
 pio_sm_set_consecutive_pindirs(pio, sm, sideset_pin, 1, true);
 sm_config_set_sideset_pins(&c, sideset_pin);
 pio_sm_init(pio, sm, offset, &c); // Load configuration
 pio_sm_set_enabled(pio, sm, true); // Start the state machine
 }
%}

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/*! \brief Setup the function select for a GPIO to use output from the given PIO instance
 * \ingroup hardware_pio
 *
 * PIO appears as an alternate function in the GPIO muxing, just like an SPI
 * or UART. This function configures that multiplexing to connect a given PIO
 * instance to a GPIO. Note that this is not necessary for a state machine to
 * be able to read the *input* value from a GPIO, but only for it to set the
 * output value or output enable.
 *
 * \param pio The PIO instance; e.g. \ref pio0 or \ref pio1
 * \param pin the GPIO pin whose function select to set
 */
static inline void pio_gpio_init(PIO pio, uint pin) {
 check_pio_param(pio);
 valid_params_if(HARDWARE_PIO, pin < NUM_BANK0_GPIOS);
 gpio_set_function(pin, PIO_FUNCSEL_NUM(pio, pin));
}