circuitpython/ports/atmel-samd/common-hal/displayio/ParallelBus.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Scott Shawcroft 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 "shared-bindings/displayio/ParallelBus.h"

#include <stdint.h>

#include "common-hal/microcontroller/Pin.h"
#include "py/runtime.h"
#include "shared-bindings/digitalio/DigitalInOut.h"
#include "shared-bindings/microcontroller/__init__.h"

void common_hal_displayio_parallelbus_construct(displayio_parallelbus_obj_t* self,
    const mcu_pin_obj_t* data0, const mcu_pin_obj_t* command, const mcu_pin_obj_t* chip_select,
    const mcu_pin_obj_t* write, const mcu_pin_obj_t* read, const mcu_pin_obj_t* reset) {

    uint8_t data_pin = data0->number;
    if (data_pin % 8 != 0) {
        mp_raise_ValueError(translate("Data 0 pin must be byte aligned"));
    }
    for (uint8_t i = 0; i < 8; i++) {
        if (!pin_number_is_free(data_pin + i)) {
            mp_raise_ValueError_varg(translate("Bus pin %d is already in use"), i);
        }
    }
    PortGroup *const g = &PORT->Group[data0->number / 32];
    g->DIRSET.reg = 0xff << (data_pin % 32);
    uint32_t wrconfig = PORT_WRCONFIG_WRPINCFG | PORT_WRCONFIG_DRVSTR;
    if (data_pin % 32 > 15) {
        wrconfig |= PORT_WRCONFIG_HWSEL | (0xff << ((data_pin % 32) - 16));
    } else {
        wrconfig |= 0xff << (data_pin % 32);
    }
    g->WRCONFIG.reg = wrconfig;
    self->bus = ((uint8_t*) &g->OUT.reg) + (data0->number % 32 / 8);

    self->command.base.type = &digitalio_digitalinout_type;
    common_hal_digitalio_digitalinout_construct(&self->command, command);
    common_hal_digitalio_digitalinout_switch_to_output(&self->command, true, DRIVE_MODE_PUSH_PULL);

    self->chip_select.base.type = &digitalio_digitalinout_type;
    common_hal_digitalio_digitalinout_construct(&self->chip_select, chip_select);
    common_hal_digitalio_digitalinout_switch_to_output(&self->chip_select, true, DRIVE_MODE_PUSH_PULL);

    self->write.base.type = &digitalio_digitalinout_type;
    common_hal_digitalio_digitalinout_construct(&self->write, write);
    common_hal_digitalio_digitalinout_switch_to_output(&self->write, true, DRIVE_MODE_PUSH_PULL);

    self->read.base.type = &digitalio_digitalinout_type;
    common_hal_digitalio_digitalinout_construct(&self->read, read);
    common_hal_digitalio_digitalinout_switch_to_output(&self->read, true, DRIVE_MODE_PUSH_PULL);

    self->data0_pin = data_pin;
    self->write_group = &PORT->Group[write->number / 32];
    self->write_mask = 1 << (write->number % 32);

    self->reset.base.type = &mp_type_NoneType;
    if (reset != NULL) {
        self->reset.base.type = &digitalio_digitalinout_type;
        common_hal_digitalio_digitalinout_construct(&self->reset, reset);
        common_hal_digitalio_digitalinout_switch_to_output(&self->reset, true, DRIVE_MODE_PUSH_PULL);
        never_reset_pin_number(reset->number);
        common_hal_displayio_parallelbus_reset(self);
    }

    never_reset_pin_number(command->number);
    never_reset_pin_number(chip_select->number);
    never_reset_pin_number(write->number);
    never_reset_pin_number(read->number);
    for (uint8_t i = 0; i < 8; i++) {
        never_reset_pin_number(data_pin + i);
    }
}

void common_hal_displayio_parallelbus_deinit(displayio_parallelbus_obj_t* self) {
    for (uint8_t i = 0; i < 8; i++) {
        reset_pin_number(self->data0_pin + i);
    }

    reset_pin_number(self->command.pin->number);
    reset_pin_number(self->chip_select.pin->number);
    reset_pin_number(self->write.pin->number);
    reset_pin_number(self->read.pin->number);
    reset_pin_number(self->reset.pin->number);
}

bool common_hal_displayio_parallelbus_reset(mp_obj_t obj) {
    displayio_parallelbus_obj_t* self = MP_OBJ_TO_PTR(obj);
    if (self->reset.base.type == &mp_type_NoneType) {
        return false;
    }

    common_hal_digitalio_digitalinout_set_value(&self->reset, false);
    common_hal_mcu_delay_us(4);
    common_hal_digitalio_digitalinout_set_value(&self->reset, true);
    return true;
}

bool common_hal_displayio_parallelbus_bus_free(mp_obj_t obj) {
    return true;
}

bool common_hal_displayio_parallelbus_begin_transaction(mp_obj_t obj) {
    displayio_parallelbus_obj_t* self = MP_OBJ_TO_PTR(obj);
    common_hal_digitalio_digitalinout_set_value(&self->chip_select, false);
    return true;
}

void common_hal_displayio_parallelbus_send(mp_obj_t obj, display_byte_type_t byte_type,
    display_chip_select_behavior_t chip_select, const uint8_t *data, uint32_t data_length) {
    displayio_parallelbus_obj_t* self = MP_OBJ_TO_PTR(obj);
    common_hal_digitalio_digitalinout_set_value(&self->command, byte_type == DISPLAY_DATA);
    uint32_t* clear_write = (uint32_t*) &self->write_group->OUTCLR.reg;
    uint32_t* set_write = (uint32_t*) &self->write_group->OUTSET.reg;
    uint32_t mask = self->write_mask;
    for (uint32_t i = 0; i < data_length; i++) {
        *clear_write = mask;
        *self->bus = data[i];
        *set_write = mask;
    }
}

void common_hal_displayio_parallelbus_end_transaction(mp_obj_t obj) {
    displayio_parallelbus_obj_t* self = MP_OBJ_TO_PTR(obj);
    common_hal_digitalio_digitalinout_set_value(&self->chip_select, true);
}