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| 1 | +/* |
| 2 | + * Copyright (c) 2006-2018, RT-Thread Development Team |
| 3 | + * |
| 4 | + * SPDX-License-Identifier: Apache-2.0 |
| 5 | + * |
| 6 | + * Change Logs: |
| 7 | + * Date Author Notes |
| 8 | + * 2019-04-16 misonyo first implementation. |
| 9 | + */ |
| 10 | +/* |
| 11 | + * 程序清单：这是一个串口设备 DMA 接收使用例程 |
| 12 | + * 例程导出了 uart_dma_sample 命令到控制终端 |
| 13 | + * 命令调用格式：uart_dma_sample uart3 |
| 14 | + * 命令解释：命令第二个参数是要使用的串口设备名称，为空则使用默认的串口设备 |
| 15 | + * 程序功能：通过串口输出字符串"hello RT-Thread!"，并通过串口输出接收到的数据，然后打印接收到的数据。 |
| 16 | +*/ |
| 17 | + |
| 18 | +#include <rtthread.h> |
| 19 | + |
| 20 | +#define SAMPLE_UART_NAME "uart3" /* 串口设备名称 */ |
| 21 | + |
| 22 | +/* 串口接收消息结构*/ |
| 23 | +struct rx_msg |
| 24 | +{ |
| 25 | + rt_device_t dev; |
| 26 | + rt_size_t size; |
| 27 | +}; |
| 28 | +/* 串口设备句柄 */ |
| 29 | +static rt_device_t serial; |
| 30 | +/* 消息队列控制块 */ |
| 31 | +static struct rt_messagequeue rx_mq; |
| 32 | + |
| 33 | +/* 接收数据回调函数 */ |
| 34 | +static rt_err_t uart_input(rt_device_t dev, rt_size_t size) |
| 35 | +{ |
| 36 | + struct rx_msg msg; |
| 37 | + rt_err_t result; |
| 38 | + msg.dev = dev; |
| 39 | + msg.size = size; |
| 40 | + |
| 41 | + result = rt_mq_send(&rx_mq, &msg, sizeof(msg)); |
| 42 | + if ( result == -RT_EFULL) |
| 43 | + { |
| 44 | + /* 消息队列满 */ |
| 45 | + rt_kprintf("message queue full！\n"); |
| 46 | + } |
| 47 | + return result; |
| 48 | +} |
| 49 | + |
| 50 | +static void serial_thread_entry(void *parameter) |
| 51 | +{ |
| 52 | + struct rx_msg msg; |
| 53 | + rt_err_t result; |
| 54 | + rt_uint32_t rx_length; |
| 55 | + static char rx_buffer[RT_SERIAL_RB_BUFSZ + 1]; |
| 56 | + |
| 57 | + while (1) |
| 58 | + { |
| 59 | + rt_memset(&msg, 0, sizeof(msg)); |
| 60 | + /* 从消息队列中读取消息*/ |
| 61 | + result = rt_mq_recv(&rx_mq, &msg, sizeof(msg), RT_WAITING_FOREVER); |
| 62 | + if (result == RT_EOK) |
| 63 | + { |
| 64 | + /* 从串口读取数据*/ |
| 65 | + rx_length = rt_device_read(msg.dev, 0, rx_buffer, msg.size); |
| 66 | + rx_buffer[rx_length] = '\0'; |
| 67 | + /* 通过串口设备 serial 输出读取到的消息 */ |
| 68 | + rt_device_write(serial, 0, rx_buffer, rx_length); |
| 69 | + /* 打印数据 */ |
| 70 | + rt_kprintf("%s\n",rx_buffer); |
| 71 | + } |
| 72 | + } |
| 73 | +} |
| 74 | + |
| 75 | +static int uart_dma_sample(int argc, char *argv[]) |
| 76 | +{ |
| 77 | + rt_err_t ret = RT_EOK; |
| 78 | + char uart_name[RT_NAME_MAX]; |
| 79 | + static char msg_pool[256]; |
| 80 | + char str[] = "hello RT-Thread!\r\n"; |
| 81 | + |
| 82 | + if (argc == 2) |
| 83 | + { |
| 84 | + rt_strncpy(uart_name, argv[1], RT_NAME_MAX); |
| 85 | + } |
| 86 | + else |
| 87 | + { |
| 88 | + rt_strncpy(uart_name, SAMPLE_UART_NAME, RT_NAME_MAX); |
| 89 | + } |
| 90 | + |
| 91 | + /* 查找串口设备 */ |
| 92 | + serial = rt_device_find(uart_name); |
| 93 | + if (!serial) |
| 94 | + { |
| 95 | + rt_kprintf("find %s failed!\n", uart_name); |
| 96 | + return RT_ERROR; |
| 97 | + } |
| 98 | + |
| 99 | + /* 初始化消息队列 */ |
| 100 | + rt_mq_init(&rx_mq, "rx_mq", |
| 101 | + msg_pool, /* 存放消息的缓冲区 */ |
| 102 | + sizeof(struct rx_msg), /* 一条消息的最大长度 */ |
| 103 | + sizeof(msg_pool), /* 存放消息的缓冲区大小 */ |
| 104 | + RT_IPC_FLAG_FIFO); /* 如果有多个线程等待，按照先来先得到的方法分配消息 */ |
| 105 | + |
| 106 | + /* 以 DMA 接收及轮询发送方式打开串口设备 */ |
| 107 | + rt_device_open(serial, RT_DEVICE_FLAG_DMA_RX); |
| 108 | + /* 设置接收回调函数 */ |
| 109 | + rt_device_set_rx_indicate(serial, uart_input); |
| 110 | + /* 发送字符串 */ |
| 111 | + rt_device_write(serial, 0, str, (sizeof(str) - 1)); |
| 112 | + |
| 113 | + /* 创建 serial 线程 */ |
| 114 | + rt_thread_t thread = rt_thread_create("serial", serial_thread_entry, RT_NULL, 1024, 25, 10); |
| 115 | + /* 创建成功则启动线程 */ |
| 116 | + if (thread != RT_NULL) |
| 117 | + { |
| 118 | + rt_thread_startup(thread); |
| 119 | + } |
| 120 | + else |
| 121 | + { |
| 122 | + ret = RT_ERROR; |
| 123 | + } |
| 124 | + |
| 125 | + return ret; |
| 126 | +} |
| 127 | +/* 导出到 msh 命令列表中 */ |
| 128 | +MSH_CMD_EXPORT(uart_dma_sample, uart device dma sample); |
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