///////////////////////////////////////////////////////////////////////////////
//
//  Roman Piksaykin [piksaykin@gmail.com], R2BDY
//  https://www.qrz.com/db/r2bdy
//
///////////////////////////////////////////////////////////////////////////////
//
//
//  dco.pio Digital controlled radio freq oscillator based on PIO.
// 
//
//  DESCRIPTION
//  -
//
//  PLATFORM
//      Raspberry Pi pico.
//
//  REVISION HISTORY
// 
//      Rev 0.1   05 Nov 2023
//  Initial release.
//
//  LICENCE
//      MIT License (http://www.opensource.org/licenses/mit-license.php)
//
//  Copyright (c) 2023 by Roman Piksaykin
//  
//  Permission is hereby granted, free of charge,to any person obtaining a copy
//  of this software and associated documentation files (the Software), to deal
//  in the Software without restriction,including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY,WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
///////////////////////////////////////////////////////////////////////////////
.program dco
    set x, 0
    set y, 0

.wrap_target        //                                              CYCLES
    pull            // load full 32-bit register.                   1c
    out y, 8        // load 8-bit delay value.                      2c
    mov x, y        // copy value in order to do next PI cycle.     3c
LOOP0:
    jmp x-- LOOP0   // do exactly X*CPU CLK delay.                  4c+x
    set pins, 1 [3] // set output high.                             5c+x
    
LOOP1:
    jmp y-- LOOP1   // do exactly X*CPU CLK delay.                  8c+x
    set pins, 0     // set output high.                             9c+x

    // RPix: The next sections repeat aforementioned algo 3 times.
    out y, 8
    mov x, y [1]
LOOP2:
    jmp x-- LOOP2
    set pins, 1 [3]
LOOP3:
    jmp y-- LOOP3
    set pins, 0


    out y, 8
    mov x, y [1]
LOOP4:
    jmp x-- LOOP4
    set pins, 1 [3]
LOOP5:
    jmp y-- LOOP5
    set pins, 0


    out y, 8
    mov x, y [1]
LOOP6:
    jmp x-- LOOP6
    set pins, 1 [3]
LOOP7:
    jmp y-- LOOP7
    set pins, 0

.wrap

% c-sdk {

#define PIOASM_DELAY_CYCLES 5

static inline void dco_program_init(PIO pio, uint sm, uint offset, uint pin)
{
    pio_sm_config c = dco_program_get_default_config(offset);
    sm_config_set_out_pins(&c, pin, 1);
    pio_gpio_init(pio, pin);

    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
    //sm_config_set_out_shift(&c, true, true, 32);           // Autopull.

    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
    
    sm_config_set_clkdiv_int_frac(&c, 1u, 0u);

    pio_sm_init(pio, sm, offset, &c);
    pio_sm_set_enabled(pio, sm, true);
}
//
static inline void dco_program_puts(PIO pio, uint sm, const uint32_t *s)
{
    pio_sm_put_blocking(pio, sm, s[0]);
    pio_sm_put_blocking(pio, sm, s[1]);
    pio_sm_put_blocking(pio, sm, s[2]);
    pio_sm_put_blocking(pio, sm, s[3]);
    pio_sm_put_blocking(pio, sm, s[4]);
    pio_sm_put_blocking(pio, sm, s[5]);
    pio_sm_put_blocking(pio, sm, s[6]);
    pio_sm_put_blocking(pio, sm, s[7]);
}

static inline void dco_program_puts1w(PIO pio, uint sm, const uint32_t val)
{
    pio_sm_put_blocking(pio, sm, val);
}
%}