esp-idf-lib/components/pcf8591/pcf8591.c

/*
 * Copyright (c) 2017 Pham Ngoc Thanh <pnt239@gmail.com>
 * Copyright (c) 2017 Ruslan V. Uss <unclerus@gmail.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of itscontributors
 *    may be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file pcf8591.c
 *
 * ESP-IDF driver for 8-bit analog-to-digital conversion and
 * an 8-bit digital-to-analog conversion PCF8591
 *
 * Ported from esp-open-rtos
 *
 * Copyright (c) 2017 Pham Ngoc Thanh <pnt239@gmail.com>\n
 * Copyright (c) 2017, 2018 Ruslan V. Uss <unclerus@gmail.com>
 *
 * BSD Licensed as described in the file LICENSE
 */
#include <stddef.h>
#include <esp_log.h>
#include <esp_idf_lib_helpers.h>
#include "pcf8591.h"

static const char *TAG = "pcf8591";

#define I2C_FREQ_HZ 100000

#define BV(x) (1 << (x))

#define CTRL_AD_CH_MASK 0x03

#define CTRL_AD_IN_PRG 4
#define CTRL_AD_IN_PRG_MASK (0x03 << CTRL_AD_IN_PRG)

#define CTRL_DA_OUT_EN 6

#define CHECK_ARG(VAL) do { if (!(VAL)) return ESP_ERR_INVALID_ARG; } while (0)

esp_err_t pcf8591_init_desc(i2c_dev_t *dev, uint8_t addr, i2c_port_t port, gpio_num_t sda_gpio, gpio_num_t scl_gpio)
{
    CHECK_ARG(dev);
    if ((addr & PCF8591_DEFAULT_ADDRESS) != PCF8591_DEFAULT_ADDRESS)
    {
        ESP_LOGE(TAG, "Invalid I2C address 0x%02x", addr);
        return ESP_ERR_INVALID_ARG;
    }

    dev->port = port;
    dev->addr = addr;
    dev->cfg.sda_io_num = sda_gpio;
    dev->cfg.scl_io_num = scl_gpio;
#if HELPER_TARGET_IS_ESP32
    dev->cfg.master.clk_speed = I2C_FREQ_HZ;
#endif
    i2c_dev_create_mutex(dev);

    return ESP_OK;
}

esp_err_t pcf8591_free_desc(i2c_dev_t *dev)
{
    CHECK_ARG(dev);

    return i2c_dev_delete_mutex(dev);
}

esp_err_t pcf8591_read(i2c_dev_t *dev, pcf8591_input_conf_t conf, uint8_t channel, uint8_t *value)
{
    CHECK_ARG(dev && value);
    if (channel >= 4)
    {
        ESP_LOGE(TAG, "Invalid channel number %d", channel);
        return ESP_ERR_INVALID_ARG;
    }

    uint8_t control_reg =
            ((conf << CTRL_AD_IN_PRG) & CTRL_AD_IN_PRG_MASK) |
            (channel & CTRL_AD_CH_MASK) |
            BV(CTRL_DA_OUT_EN);

    I2C_DEV_TAKE_MUTEX(dev);
    I2C_DEV_CHECK(dev, i2c_dev_read_reg(dev, control_reg, value, 1));
    I2C_DEV_GIVE_MUTEX(dev);

    return ESP_OK;
}

esp_err_t pcf8591_write(i2c_dev_t *dev, uint8_t value)
{
    CHECK_ARG(dev);

    uint8_t buf[2] = { BV(CTRL_DA_OUT_EN), value };

    I2C_DEV_TAKE_MUTEX(dev);
    I2C_DEV_CHECK(dev, i2c_dev_write(dev, NULL, 0, buf, sizeof(buf)));
    I2C_DEV_GIVE_MUTEX(dev);

    return ESP_OK;
}