driverPIO.pio

; RP2040 PIO driver specific program

; stepper_timer program generate an interrupt at a settable period interval 
.program stepper_timer

    pull noblock    ; Pull timer period from the TX FIFO, loads X into OSR if empty
    mov x osr       ; Reload X from OSR
    mov y x
count:
    jmp y-- count
    irq 0         
   
% c-sdk {
static inline void stepper_timer_program_init(PIO pio, uint sm, uint offset, float div ) {
    pio_sm_config c = stepper_timer_program_get_default_config(offset);

    // Load our configuration, and jump to the start of the program
    pio_sm_init(pio, sm, offset, &c);
    // Set the clock divider
    pio_sm_set_clkdiv(pio, sm, div);
}

static inline void stepper_timer_set_period(PIO pio, uint sm, uint offset, uint32_t period) {

    static uint32_t period_prev = 0;

    if(period_prev != period) {
        period_prev = period;
        pio_sm_put(pio, sm, period);
        pio_sm_exec(pio, sm, pio_encode_jmp(offset));
    }

    if(!(pio->ctrl & (1 << sm))) {
        pio_sm_set_enabled(pio, sm, true);
        pio->inte0 |= PIO_INTR_SM0_BITS;
    }
 }

static inline void stepper_timer_stop(PIO pio, uint sm) {
    pio_sm_set_enabled(pio, sm, false);
    pio->inte0 &= ~PIO_INTR_SM0_BITS;
}

static inline void stepper_timer_irq_clear(PIO pio) {
    pio->irq = 1;
}
%}

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; step pulse program generate a step pulse with a settable delay before the step is generated and a settable pulse length
.program step_pulse

    pull block
    out x, 8
delay:
    jmp x-- delay
    out x, 8
    out pins, 6
 pulse:
    jmp x-- pulse
    out pins, 6

% c-sdk {
static inline void step_pulse_program_init(PIO pio, uint sm, uint offset, uint32_t startPin, uint pinCount) {
    pio_sm_config c = step_pulse_program_get_default_config(offset); 

    // Map the state machine's OUT pin group to the provided pin in pin count in parameters
    sm_config_set_out_pins(&c, startPin, pinCount);
    // Set these pins GPIO function (connect PIO to the pad)
    for(uint i=0;i<pinCount;i++)
        pio_gpio_init(pio, startPin+i);
    // Set the pin direction to output at the PIO
    pio_sm_set_consecutive_pindirs(pio, sm, startPin, pinCount, true);
    // Set the set pins group to the same pins as the out pins group to reset the pins when the steps are finished
    sm_config_set_set_pins(&c, startPin, pinCount);
    // Load our configuration, and jump to the start of the program
    pio_sm_init(pio, sm, offset, &c);
    pio_sm_set_clkdiv(pio, sm, 12.5f);
    // Set the state machine running
    pio_sm_set_enabled(pio, sm, true);
}

static inline void step_pulse_generate(PIO pio, uint sm, uint32_t stepPulse) {
    pio_sm_put(pio, sm, stepPulse);
}
%}