circuitpython/ports/raspberrypi/common-hal/imagecapture/ParallelImageCapture.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2021 Jeff Epler for Adafruit Industries
 *
 * 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.
 */

#include "py/obj.h"
#include "py/runtime.h"

#include "lib/utils/context_manager_helpers.h"
#include "lib/utils/interrupt_char.h"

#include "bindings/rp2pio/StateMachine.h"
#include "bindings/rp2pio/__init__.h"
#include "common-hal/imagecapture/ParallelImageCapture.h"
#include "shared-bindings/imagecapture/ParallelImageCapture.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/microcontroller/Processor.h"
#include "shared-bindings/microcontroller/__init__.h"

#include "src/rp2_common/hardware_pio/include/hardware/pio.h"
#include "src/rp2_common/hardware_pio/include/hardware/pio_instructions.h"

// Define this to (1), and you can scope the instruction-pointer of the state machine on D26..28 (note the weird encoding though!)
#define DEBUG_STATE_MACHINE (0)
#if DEBUG_STATE_MACHINE
#define SIDE(x) ((x) << 8)
#else
#define SIDE(x) (0)
#endif

#define _0 SIDE(0b11100)
#define _1 SIDE(0b00000)
#define _2 SIDE(0b10000)
#define _3 SIDE(0b10100)
#define _4 SIDE(0b11000)
#define _5 SIDE(0b10100)

#define IMAGECAPTURE_CODE(width, pclk, vsync, href) \
    { \
/* 0 */ pio_encode_wait_gpio(0, vsync) | _0, \
/* 1 */ pio_encode_wait_gpio(1, vsync) | _1, \
        /* .wrap_target */  \
/* 2 */ pio_encode_wait_gpio(1, href) | _2, \
/* 3 */ pio_encode_wait_gpio(1, pclk) | _3, \
/* 4 */ pio_encode_in(pio_pins, width) | _4, \
/* 5 */ pio_encode_wait_gpio(0, pclk) | _5, \
        /* .wrap */ \
    }

mcu_pin_obj_t *pin_from_number(uint8_t number) {
    const mp_map_t *mcu_map = &mcu_pin_globals.map;
    for (uint8_t i = 0; i < mcu_map->alloc; i++) {
        mp_obj_t val = mcu_map->table[i].value;
        if (!mp_obj_is_type(val, &mcu_pin_type)) {
            continue;
        }
        mcu_pin_obj_t *pin = MP_OBJ_TO_PTR(val);
        if (pin->number == number) {
            return pin;
        }
    }
    return NULL;
}

void common_hal_imagecapture_parallelimagecapture_construct(imagecapture_parallelimagecapture_obj_t *self,
    const uint8_t data_pins[],
    uint8_t data_count,
    const mcu_pin_obj_t *data_clock,
    const mcu_pin_obj_t *vertical_sync,
    const mcu_pin_obj_t *horizontal_reference) {

    for (int i = 1; i < data_count; i++) {
        if (data_pins[i] - data_pins[0] != i) {
            mp_raise_RuntimeError(translate("Pins must be sequential"));
        }
    }

    uint16_t imagecapture_code[] = IMAGECAPTURE_CODE(data_count, data_clock->number, vertical_sync->number, horizontal_reference->number);

    common_hal_rp2pio_statemachine_construct(&self->state_machine,
        imagecapture_code, MP_ARRAY_SIZE(imagecapture_code),
        common_hal_mcu_processor_get_frequency(), // full speed (4 instructions per loop -> max pclk 30MHz @ 120MHz)
        0, 0, // init
        NULL, 0, 0, 0, // out pins
        pin_from_number(data_pins[0]), data_count, // in pins
        0, 0, // in pulls
        NULL, 0, 0, 0, // set pins
        #if DEBUG_STATE_MACHINE
        &pin_GPIO26, 3, 7, 7, // sideset pins
        #else
        NULL, 0, 0, 0, // sideset pins
        #endif
        (1 << vertical_sync->number) | (1 << horizontal_reference->number) | (1 << data_clock->number), // wait gpio pins
        true, // exclusive pin use
        false, 32, false, // out settings
        false, // wait for txstall
        true, 32, true); // in settings

    PIO pio = self->state_machine.pio;
    uint8_t pio_index = pio_get_index(pio);
    uint sm = self->state_machine.state_machine;
    rp2pio_statemachine_set_wrap(&self->state_machine, 2, 5);
}

void common_hal_imagecapture_parallelimagecapture_deinit(imagecapture_parallelimagecapture_obj_t *self) {
    if (common_hal_imagecapture_parallelimagecapture_deinited(self)) {
        return;
    }
    return common_hal_rp2pio_statemachine_deinit(&self->state_machine);
}

bool common_hal_imagecapture_parallelimagecapture_deinited(imagecapture_parallelimagecapture_obj_t *self) {
    return common_hal_rp2pio_statemachine_deinited(&self->state_machine);
}

void common_hal_imagecapture_parallelimagecapture_capture(imagecapture_parallelimagecapture_obj_t *self, void *buffer, size_t bufsize) {
    PIO pio = self->state_machine.pio;
    uint sm = self->state_machine.state_machine;
    uint8_t offset = rp2pio_statemachine_program_offset(&self->state_machine);

    pio_sm_set_enabled(pio, sm, false);
    pio_sm_clear_fifos(pio, sm);

    pio_sm_restart(pio, sm);
    pio_sm_exec(pio, sm, pio_encode_jmp(offset));
    pio_sm_set_enabled(pio, sm, true);

    common_hal_rp2pio_statemachine_readinto(&self->state_machine, buffer, bufsize, 4);

    pio_sm_set_enabled(pio, sm, false);
}