circuitpython/ports/cxd56/common-hal/busio/I2C.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright 2019 Sony Semiconductor Solutions Corporation
 *
 * 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 <arch/chip/pin.h>
#include <nuttx/i2c/i2c_master.h>
#include <cxd56_i2c.h>
#include <cxd56_pinconfig.h>

#include "py/runtime.h"

#include "shared-bindings/busio/I2C.h"

void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *scl,
    const mcu_pin_obj_t *sda, uint32_t frequency, uint32_t timeout) {
    if (frequency != I2C_SPEED_STANDARD && frequency != I2C_SPEED_FAST) {
        mp_raise_ValueError(translate("Unsupported baudrate"));
    }

    if (scl->number != PIN_I2C0_BCK || sda->number != PIN_I2C0_BDT) {
        mp_raise_ValueError(translate("Invalid pins"));
    }

    claim_pin(scl);
    claim_pin(sda);

    self->scl_pin = scl;
    self->sda_pin = sda;
    self->frequency = frequency;
    self->i2c_dev = cxd56_i2cbus_initialize(0);
    CXD56_PIN_CONFIGS(PINCONFS_I2C0);
}

void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
    if (common_hal_busio_i2c_deinited(self)) {
        return;
    }

    cxd56_i2cbus_uninitialize(self->i2c_dev);
    self->i2c_dev = NULL;

    reset_pin_number(self->scl_pin->number);
    reset_pin_number(self->sda_pin->number);
}

bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
    return self->i2c_dev == NULL;
}

bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
    bool grabbed_lock = false;
    if (!self->has_lock) {
        grabbed_lock = true;
        self->has_lock = true;
    }
    return grabbed_lock;
}

bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
    return self->has_lock;
}

void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
    self->has_lock = false;
}

bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
    struct i2c_msg_s msg;

    msg.frequency = self->frequency;
    msg.addr = addr;
    msg.flags = 0;
    msg.buffer = NULL;
    msg.length = 0;
    return I2C_TRANSFER(self->i2c_dev, &msg, 1) < 0 ? false : true;
}

STATIC uint8_t _common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t address, const uint8_t *data, size_t len, bool stop) {
    struct i2c_msg_s msg;

    msg.frequency = self->frequency;
    msg.addr = address;
    msg.flags = (stop ? 0 : I2C_M_NOSTOP);
    msg.buffer = (uint8_t *)data;
    msg.length = len;
    return -I2C_TRANSFER(self->i2c_dev, &msg, 1);
}

uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
    const uint8_t *data, size_t len) {
    return _common_hal_busio_i2c_write(self, addr, data, len, true);
}

uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t address, uint8_t *data, size_t len) {
    struct i2c_msg_s msg;

    msg.frequency = self->frequency;
    msg.addr = address;
    msg.flags = I2C_M_READ;
    msg.buffer = data;
    msg.length = len;
    return -I2C_TRANSFER(self->i2c_dev, &msg, 1);
}

uint8_t common_hal_busio_i2c_write_read(busio_i2c_obj_t *self, uint16_t addr,
    uint8_t *out_data, size_t out_len, uint8_t *in_data, size_t in_len) {
    uint8_t result = _common_hal_busio_i2c_write(self, addr, out_data, out_len, false);
    if (result != 0) {
        return result;
    }

    return common_hal_busio_i2c_read(self, addr, in_data, in_len);
}

void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
    never_reset_pin_number(self->scl_pin->number);
    never_reset_pin_number(self->sda_pin->number);
}