owner-nrf52sdk/nRF5_SDK_17.0.2/components/libraries/uart/app_uart.c

/**
 * Copyright (c) 2015 - 2020, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * 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, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, 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 Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
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 */
#include "sdk_common.h"
#if NRF_MODULE_ENABLED(APP_UART)
#include "app_uart.h"
#include "nrf_drv_uart.h"
#include "nrf_assert.h"

static uint8_t tx_buffer[1];
static uint8_t rx_buffer[1];
static volatile bool rx_done;
static app_uart_event_handler_t   m_event_handler;            /**< Event handler function. */
static nrf_drv_uart_t app_uart_inst = NRF_DRV_UART_INSTANCE(APP_UART_DRIVER_INSTANCE);

static void uart_event_handler(nrf_drv_uart_event_t * p_event, void* p_context)
{
    if (p_event->type == NRF_DRV_UART_EVT_RX_DONE)
    {
        // Received bytes counter has to be checked, because there could be event from RXTO interrupt
        if (p_event->data.rxtx.bytes)
        {
            app_uart_evt_t app_uart_event;
            app_uart_event.evt_type   = APP_UART_DATA;
            app_uart_event.data.value = p_event->data.rxtx.p_data[0];
            rx_done = true;
            m_event_handler(&app_uart_event);
        }
        (void)nrf_drv_uart_rx(&app_uart_inst, rx_buffer, 1);
    }
    else if (p_event->type == NRF_DRV_UART_EVT_ERROR)
    {
        app_uart_evt_t app_uart_event;
        app_uart_event.evt_type                 = APP_UART_COMMUNICATION_ERROR;
        app_uart_event.data.error_communication = p_event->data.error.error_mask;
        (void)nrf_drv_uart_rx(&app_uart_inst, rx_buffer, 1);
        m_event_handler(&app_uart_event);
    }
    else if (p_event->type == NRF_DRV_UART_EVT_TX_DONE)
    {
       // Last byte from FIFO transmitted, notify the application.
       // Notify that new data is available if this was first byte put in the buffer.
       app_uart_evt_t app_uart_event;
       app_uart_event.evt_type = APP_UART_TX_EMPTY;
       m_event_handler(&app_uart_event);
    }
}

uint32_t app_uart_init(const app_uart_comm_params_t * p_comm_params,
                       app_uart_buffers_t           * p_buffers,
                       app_uart_event_handler_t       event_handler,
                       app_irq_priority_t             irq_priority)
{
    nrf_drv_uart_config_t config = NRF_DRV_UART_DEFAULT_CONFIG;
    config.baudrate = (nrf_uart_baudrate_t)p_comm_params->baud_rate;
    config.hwfc = (p_comm_params->flow_control == APP_UART_FLOW_CONTROL_DISABLED) ?
            NRF_UART_HWFC_DISABLED : NRF_UART_HWFC_ENABLED;
    config.interrupt_priority = irq_priority;
    config.parity = p_comm_params->use_parity ? NRF_UART_PARITY_INCLUDED : NRF_UART_PARITY_EXCLUDED;
    config.pselcts = p_comm_params->cts_pin_no;
    config.pselrts = p_comm_params->rts_pin_no;
    config.pselrxd = p_comm_params->rx_pin_no;
    config.pseltxd = p_comm_params->tx_pin_no;

    m_event_handler = event_handler;

    rx_done = false;

    uint32_t err_code = nrf_drv_uart_init(&app_uart_inst, &config, uart_event_handler);
    VERIFY_SUCCESS(err_code);

    // Turn on receiver if RX pin is connected
    if (p_comm_params->rx_pin_no != UART_PIN_DISCONNECTED)
    {
        return nrf_drv_uart_rx(&app_uart_inst, rx_buffer,1);
    }
    else
    {
        return NRF_SUCCESS;
    }
}


uint32_t app_uart_get(uint8_t * p_byte)
{
    ASSERT(p_byte);
    uint32_t err_code = NRF_SUCCESS;
    if (rx_done)
    {
        *p_byte = rx_buffer[0];
        rx_done = false;
    }
    else
    {
        err_code = NRF_ERROR_NOT_FOUND;
    }
    return err_code;
}

uint32_t app_uart_put(uint8_t byte)
{
    tx_buffer[0] = byte;
    ret_code_t ret =  nrf_drv_uart_tx(&app_uart_inst, tx_buffer, 1);
    if (NRF_ERROR_BUSY == ret)
    {
        return NRF_ERROR_NO_MEM;
    }
    else if (ret != NRF_SUCCESS)
    {
        return NRF_ERROR_INTERNAL;
    }
    else
    {
        return NRF_SUCCESS;
    }
}

uint32_t app_uart_flush(void)
{
    return NRF_SUCCESS;
}

uint32_t app_uart_close(void)
{
    nrf_drv_uart_uninit(&app_uart_inst);
    return NRF_SUCCESS;
}
#endif //NRF_MODULE_ENABLED(APP_UART)