i2cdev.c

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Ruslan V. Uss <unclerus@gmail.com>
 *
 * 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.
 */

/**
 * @file i2cdev.c
 *
 * ESP-IDF I2C master thread-safe functions for communication with I2C slave
 *
 * Copyright (c) 2018 Ruslan V. Uss <unclerus@gmail.com>
 *
 * MIT Licensed as described in the file LICENSE
 */
#include <string.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <esp_log.h>
#include "i2cdev.h"

static const char *TAG = "i2cdev";

typedef struct {
    SemaphoreHandle_t lock;
    i2c_config_t config;
    bool installed;
} i2c_port_state_t;

static i2c_port_state_t states[I2C_NUM_MAX];

#if CONFIG_I2CDEV_NOLOCK
#define SEMAPHORE_TAKE(port)
#else
#define SEMAPHORE_TAKE(port) do { \
        if (!xSemaphoreTake(states[port].lock, pdMS_TO_TICKS(CONFIG_I2CDEV_TIMEOUT))) \
        { \
            ESP_LOGE(TAG, "Could not take port mutex %d", port); \
            return ESP_ERR_TIMEOUT; \
        } \
        } while (0)
#endif

#if CONFIG_I2CDEV_NOLOCK
#define SEMAPHORE_GIVE(port)
#else
#define SEMAPHORE_GIVE(port) do { \
        if (!xSemaphoreGive(states[port].lock)) \
        { \
            ESP_LOGE(TAG, "Could not give port mutex %d", port); \
            return ESP_FAIL; \
        } \
        } while (0)
#endif

esp_err_t i2cdev_init()
{
    memset(states, 0, sizeof(states));

#if !CONFIG_I2CDEV_NOLOCK
    for (int i = 0; i < I2C_NUM_MAX; i++)
    {
        states[i].lock = xSemaphoreCreateMutex();
        if (!states[i].lock)
        {
            ESP_LOGE(TAG, "Could not create port mutex %d", i);
            return ESP_FAIL;
        }
    }
#endif

    return ESP_OK;
}

esp_err_t i2cdev_done()
{
    for (int i = 0; i < I2C_NUM_MAX; i++)
    {
        if (!states[i].lock) continue;

        if (states[i].installed)
        {
            SEMAPHORE_TAKE(i);
            i2c_driver_delete(i);
            states[i].installed = false;
            SEMAPHORE_GIVE(i);
        }
#if !CONFIG_I2CDEV_NOLOCK
        vSemaphoreDelete(states[i].lock);
#endif
        states[i].lock = NULL;
    }
    return ESP_OK;
}

esp_err_t i2c_dev_create_mutex(i2c_dev_t *dev)
{
#if !CONFIG_I2CDEV_NOLOCK
    if (!dev) return ESP_ERR_INVALID_ARG;

    ESP_LOGV(TAG, "[0x%02x at %d] creating mutex", dev->addr, dev->port);

    dev->mutex = xSemaphoreCreateMutex();
    if (!dev->mutex)
    {
        ESP_LOGE(TAG, "[0x%02x at %d] Could not create device mutex", dev->addr, dev->port);
        return ESP_FAIL;
    }
#endif

    return ESP_OK;
}

esp_err_t i2c_dev_delete_mutex(i2c_dev_t *dev)
{
#if !CONFIG_I2CDEV_NOLOCK
    if (!dev) return ESP_ERR_INVALID_ARG;

    ESP_LOGV(TAG, "[0x%02x at %d] deleting mutex", dev->addr, dev->port);

    vSemaphoreDelete(dev->mutex);
#endif
    return ESP_OK;
}

esp_err_t i2c_dev_take_mutex(i2c_dev_t *dev)
{
#if !CONFIG_I2CDEV_NOLOCK
    if (!dev) return ESP_ERR_INVALID_ARG;

    ESP_LOGV(TAG, "[0x%02x at %d] taking mutex", dev->addr, dev->port);

    if (!xSemaphoreTake(dev->mutex, pdMS_TO_TICKS(CONFIG_I2CDEV_TIMEOUT)))
    {
        ESP_LOGE(TAG, "[0x%02x at %d] Could not take device mutex", dev->addr, dev->port);
        return ESP_ERR_TIMEOUT;
    }
#endif
    return ESP_OK;
}

esp_err_t i2c_dev_give_mutex(i2c_dev_t *dev)
{
#if !CONFIG_I2CDEV_NOLOCK
    if (!dev) return ESP_ERR_INVALID_ARG;

    ESP_LOGV(TAG, "[0x%02x at %d] giving mutex", dev->addr, dev->port);

    if (!xSemaphoreGive(dev->mutex))
    {
        ESP_LOGE(TAG, "[0x%02x at %d] Could not give device mutex", dev->addr, dev->port);
        return ESP_FAIL;
    }
#endif
    return ESP_OK;
}

inline static bool cfg_equal(const i2c_config_t *a, const i2c_config_t *b)
{
    return a->scl_io_num == b->scl_io_num
        && a->sda_io_num == b->sda_io_num
#if HELPER_TARGET_IS_ESP32
        && a->master.clk_speed == b->master.clk_speed
#elif HELPER_TARGET_IS_ESP8266
        && a->clk_stretch_tick == b->clk_stretch_tick
#endif
        && a->scl_pullup_en == b->scl_pullup_en
        && a->sda_pullup_en == b->sda_pullup_en;
}

static esp_err_t i2c_setup_port(const i2c_dev_t *dev)
{
    if (dev->port >= I2C_NUM_MAX) return ESP_ERR_INVALID_ARG;

    esp_err_t res;
    if (!cfg_equal(&dev->cfg, &states[dev->port].config))
    {
        ESP_LOGD(TAG, "Reconfiguring I2C driver on port %d", dev->port);
        i2c_config_t temp;
        memcpy(&temp, &dev->cfg, sizeof(i2c_config_t));
        temp.mode = I2C_MODE_MASTER;

        // Driver reinstallation
        if (states[dev->port].installed)
            i2c_driver_delete(dev->port);
#if HELPER_TARGET_IS_ESP32
        if ((res = i2c_param_config(dev->port, &temp)) != ESP_OK)
            return res;
        if ((res = i2c_driver_install(dev->port, temp.mode, 0, 0, 0)) != ESP_OK)
            return res;
#endif
#if HELPER_TARGET_IS_ESP8266
        // Clock Stretch time, depending on CPU frequency
        temp.clk_stretch_tick = dev->timeout_ticks ? dev->timeout_ticks : I2CDEV_MAX_STRETCH_TIME;
        if ((res = i2c_driver_install(dev->port, temp.mode)) != ESP_OK)
            return res;
        if ((res = i2c_param_config(dev->port, &temp)) != ESP_OK)
            return res;
#endif
        states[dev->port].installed = true;

        memcpy(&states[dev->port].config, &temp, sizeof(i2c_config_t));
        ESP_LOGD(TAG, "I2C driver successfully reconfigured on port %d", dev->port);
    }
#if HELPER_TARGET_IS_ESP32
    int t;
    if ((res = i2c_get_timeout(dev->port, &t)) != ESP_OK)
        return res;
    // Timeout cannot be 0
    uint32_t ticks = dev->timeout_ticks ? dev->timeout_ticks : I2CDEV_MAX_STRETCH_TIME;
    if ((ticks != t) && (res = i2c_set_timeout(dev->port, ticks)) != ESP_OK)
        return res;
    ESP_LOGD(TAG, "Timeout: ticks = %d (%d usec) on port %d", dev->timeout_ticks, dev->timeout_ticks / 80, dev->port);
#endif

    return ESP_OK;
}

esp_err_t i2c_dev_read(const i2c_dev_t *dev, const void *out_data, size_t out_size, void *in_data, size_t in_size)
{
    if (!dev || !in_data || !in_size) return ESP_ERR_INVALID_ARG;

    SEMAPHORE_TAKE(dev->port);

    esp_err_t res = i2c_setup_port(dev);
    if (res == ESP_OK)
    {
        i2c_cmd_handle_t cmd = i2c_cmd_link_create();
        if (out_data && out_size)
        {
            i2c_master_start(cmd);
            i2c_master_write_byte(cmd, dev->addr << 1, true);
            i2c_master_write(cmd, (void *)out_data, out_size, true);
        }
        i2c_master_start(cmd);
        i2c_master_write_byte(cmd, (dev->addr << 1) | 1, true);
        i2c_master_read(cmd, in_data, in_size, I2C_MASTER_LAST_NACK);
        i2c_master_stop(cmd);

        res = i2c_master_cmd_begin(dev->port, cmd, pdMS_TO_TICKS(CONFIG_I2CDEV_TIMEOUT));
        if (res != ESP_OK)
            ESP_LOGE(TAG, "Could not read from device [0x%02x at %d]: %d (%s)", dev->addr, dev->port, res, esp_err_to_name(res));

        i2c_cmd_link_delete(cmd);
    }

    SEMAPHORE_GIVE(dev->port);
    return res;
}

esp_err_t i2c_dev_write(const i2c_dev_t *dev, const void *out_reg, size_t out_reg_size, const void *out_data, size_t out_size)
{
    if (!dev || !out_data || !out_size) return ESP_ERR_INVALID_ARG;

    SEMAPHORE_TAKE(dev->port);

    esp_err_t res = i2c_setup_port(dev);
    if (res == ESP_OK)
    {
        i2c_cmd_handle_t cmd = i2c_cmd_link_create();
        i2c_master_start(cmd);
        i2c_master_write_byte(cmd, dev->addr << 1, true);
        if (out_reg && out_reg_size)
            i2c_master_write(cmd, (void *)out_reg, out_reg_size, true);
        i2c_master_write(cmd, (void *)out_data, out_size, true);
        i2c_master_stop(cmd);
        res = i2c_master_cmd_begin(dev->port, cmd, pdMS_TO_TICKS(CONFIG_I2CDEV_TIMEOUT));
        if (res != ESP_OK)
            ESP_LOGE(TAG, "Could not write to device [0x%02x at %d]: %d (%s)", dev->addr, dev->port, res, esp_err_to_name(res));
        i2c_cmd_link_delete(cmd);
    }

    SEMAPHORE_GIVE(dev->port);
    return res;
}

esp_err_t i2c_dev_read_reg(const i2c_dev_t *dev, uint8_t reg,
        void *in_data, size_t in_size)
{
    return i2c_dev_read(dev, &reg, 1, in_data, in_size);
}

esp_err_t i2c_dev_write_reg(const i2c_dev_t *dev, uint8_t reg,
        const void *out_data, size_t out_size)
{
    return i2c_dev_write(dev, &reg, 1, out_data, out_size);
}