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static int i2c_slave_read(i2c_port_t i2c_num, uint8_t* data, size_t max_size, TickType_t ticks_to_wait)
{
    i2c_obj_t* p_i2c = p_i2c_obj[i2c_num];
    size_t size = 0;
    uint8_t* pdata = (uint8_t*) xRingbufferReceiveUpTo(p_i2c->rx_ring_buf, &size, ticks_to_wait, max_size);
    if (pdata && size > 0) {
        memcpy(data, pdata, size);
        vRingbufferReturnItem(p_i2c->rx_ring_buf, pdata);
    }
    return size;
}

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/**
 * @brief I2C slave read data from internal buffer. When I2C slave receive data, isr will copy received data
 *        from hardware rx fifo to internal ringbuffer. Then users can read from internal ringbuffer.
 *        @note
 *        Only call this function in I2C slave mode
 *
 * @param i2c_num I2C port number
 * @param data data pointer to write into internal buffer
 * @param max_size Maximum data size to read
 * @param ticks_to_wait Maximum waiting ticks
 *
 * @return
 *     - ESP_FAIL(-1) Parameter error
 *     - Others(>=0) The number of data bytes that read from I2C slave buffer.
 */
 int i2c_slave_read_buffer(i2c_port_t i2c_num, uint8_t* data, size_t max_size, TickType_t ticks_to_wait);

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int i2c_slave_read_buffer(i2c_port_t i2c_num, uint8_t *data, size_t max_size, portBASE_TYPE ticks_to_wait)