Tom Soulanille / RTOS-Serial

An RTOS-friendly Serial interface Its primary benefit is that it never hogs the CPU. An amusing alternative to the traditional ring-bufferd interrupt-serviced systems, it uses short mbed-rtos queues to buffer characters to and from the UART, and a thread to service the transmitter. Short interrupt service routines enqueue received characters and signal the transmit thread when the transmitter is available. WARNING: Do not create RTOS-Serial objects before the RTOS is running! Put them inside your main() block or another function, not in the global initialization.

Dependents:   Test_RDM880_rfid_reader

rtos_serial.h@15:5f38a747ba08, 2013-10-30 (annotated)

Committer:
altasoul
Date:
Wed Oct 30 04:58:10 2013 +0000
Revision:
15:5f38a747ba08
Parent:
14:33d60e4eb215
Child:
16:2d3937773625
First publication

Who changed what in which revision?

UserRevisionLine numberNew contents of line
altasoul 0:0547c8bf304f 1 /*
altasoul 0:0547c8bf304f 2 * Copyright (c) 2013 Tom Soulanille
altasoul 0:0547c8bf304f 3 *
altasoul 0:0547c8bf304f 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
altasoul 0:0547c8bf304f 5 * of this software and associated documentation files (the "Software"), to deal
altasoul 0:0547c8bf304f 6 * in the Software without restriction, including without limitation the rights
altasoul 0:0547c8bf304f 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
altasoul 0:0547c8bf304f 8 * copies of the Software, and to permit persons to whom the Software is
altasoul 0:0547c8bf304f 9 * furnished to do so, subject to the following conditions:
altasoul 0:0547c8bf304f 10 *
altasoul 0:0547c8bf304f 11 * The above copyright notice and this permission notice shall be included in
altasoul 0:0547c8bf304f 12 * all copies or substantial portions of the Software.
altasoul 0:0547c8bf304f 13 *
altasoul 0:0547c8bf304f 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
altasoul 0:0547c8bf304f 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
altasoul 0:0547c8bf304f 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
altasoul 0:0547c8bf304f 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
altasoul 0:0547c8bf304f 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
altasoul 0:0547c8bf304f 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
altasoul 0:0547c8bf304f 20 * SOFTWARE.
altasoul 0:0547c8bf304f 21 */
altasoul 0:0547c8bf304f 22
altasoul 0:0547c8bf304f 23 #ifndef RTOS_SERIAL_H
altasoul 0:0547c8bf304f 24 #define RTOS_SERIAL_H
altasoul 0:0547c8bf304f 25
altasoul 0:0547c8bf304f 26 #include "mbed.h"
altasoul 0:0547c8bf304f 27 #include "rtos.h"
altasoul 0:0547c8bf304f 28
altasoul 0:0547c8bf304f 29 #define MBED_RTOS_SERIAL_VERSION_MAJOR 0
altasoul 8:3644d12758da 30 #define MBED_RTOS_SERIAL_VERSION_MINOR 1
altasoul 11:bc067b42f8e0 31 #define MBED_RTOS_SERIAL_VERSION_EDIT 6
altasoul 0:0547c8bf304f 32
altasoul 9:b664b4f9f93d 33 #define RTOS_SERIAL_TX_THREAD 1
altasoul 12:be7883573c91 34 #define RTOS_SERIAL_TX_THREAD_STACK_SIZE 1024 /* FIXME: figure out good value */
altasoul 0:0547c8bf304f 35
altasoul 0:0547c8bf304f 36 /*
altasoul 0:0547c8bf304f 37 from Serial.h:
altasoul 0:0547c8bf304f 38 class Serial : public Stream {
altasoul 0:0547c8bf304f 39
altasoul 0:0547c8bf304f 40 public:
altasoul 0:0547c8bf304f 41 Serial(PinName tx, PinName rx, const char *name=NULL);
altasoul 0:0547c8bf304f 42 ...
altasoul 0:0547c8bf304f 43 protected:
altasoul 0:0547c8bf304f 44 ...
altasoul 0:0547c8bf304f 45 serial_t _serial;
altasoul 0:0547c8bf304f 46
altasoul 0:0547c8bf304f 47 from serial_api.h:
altasoul 0:0547c8bf304f 48 typedef struct serial_s serial_t;
altasoul 0:0547c8bf304f 49
altasoul 0:0547c8bf304f 50 from objects.h:
altasoul 0:0547c8bf304f 51 struct serial_s {
altasoul 0:0547c8bf304f 52 LPC_UART_TypeDef *uart;
altasoul 0:0547c8bf304f 53 int index;
altasoul 0:0547c8bf304f 54 };
altasoul 0:0547c8bf304f 55
altasoul 0:0547c8bf304f 56 from LPC17xx.h:
altasoul 0:0547c8bf304f 57 typedef struct
altasoul 0:0547c8bf304f 58 {
altasoul 0:0547c8bf304f 59 union {
altasoul 0:0547c8bf304f 60 __I uint8_t RBR;
altasoul 0:0547c8bf304f 61 __O uint8_t THR;
altasoul 0:0547c8bf304f 62 __IO uint8_t DLL;
altasoul 0:0547c8bf304f 63 uint32_t RESERVED0;
altasoul 0:0547c8bf304f 64 };
altasoul 0:0547c8bf304f 65 union {
altasoul 0:0547c8bf304f 66 __IO uint8_t DLM;
altasoul 0:0547c8bf304f 67 __IO uint32_t IER;
altasoul 0:0547c8bf304f 68 };
altasoul 0:0547c8bf304f 69 union {
altasoul 0:0547c8bf304f 70 __I uint32_t IIR;
altasoul 0:0547c8bf304f 71 __O uint8_t FCR;
altasoul 0:0547c8bf304f 72 };
altasoul 0:0547c8bf304f 73 __IO uint8_t LCR;
altasoul 0:0547c8bf304f 74 uint8_t RESERVED1[7];
altasoul 0:0547c8bf304f 75 __I uint8_t LSR;
altasoul 0:0547c8bf304f 76 uint8_t RESERVED2[7];
altasoul 0:0547c8bf304f 77 __IO uint8_t SCR;
altasoul 0:0547c8bf304f 78 uint8_t RESERVED3[3];
altasoul 0:0547c8bf304f 79 __IO uint32_t ACR;
altasoul 0:0547c8bf304f 80 __IO uint8_t ICR;
altasoul 0:0547c8bf304f 81 uint8_t RESERVED4[3];
altasoul 0:0547c8bf304f 82 __IO uint8_t FDR;
altasoul 0:0547c8bf304f 83 uint8_t RESERVED5[7];
altasoul 0:0547c8bf304f 84 __IO uint8_t TER;
altasoul 0:0547c8bf304f 85 uint8_t RESERVED6[39];
altasoul 0:0547c8bf304f 86 __IO uint32_t FIFOLVL;
altasoul 0:0547c8bf304f 87 } LPC_UART_TypeDef;
altasoul 0:0547c8bf304f 88
altasoul 0:0547c8bf304f 89 */
altasoul 0:0547c8bf304f 90
altasoul 15:5f38a747ba08 91 /** An RTOS-friendly serial port
altasoul 15:5f38a747ba08 92 */
altasoul 12:be7883573c91 93 class RTOS_Serial : public RawSerial {
altasoul 0:0547c8bf304f 94 public:
altasoul 0:0547c8bf304f 95
altasoul 15:5f38a747ba08 96 /** Create an RTOS_Serial connected to the specified UART pins
altasoul 15:5f38a747ba08 97 *
altasoul 15:5f38a747ba08 98 * @param tx PinName of the UART output (transmission) pin
altasoul 15:5f38a747ba08 99 * @param rx PinName of the UART input (reception) pin
altasoul 15:5f38a747ba08 100 * @param name (optional) A string to identify the object
altasoul 15:5f38a747ba08 101 */
altasoul 0:0547c8bf304f 102 RTOS_Serial(PinName tx, PinName rx, const char *name=NULL);
altasoul 15:5f38a747ba08 103
altasoul 15:5f38a747ba08 104 /** Send a character
altasoul 15:5f38a747ba08 105 * If the output queue is full it yields until it can enqueue
altasoul 15:5f38a747ba08 106 *
altasoul 15:5f38a747ba08 107 * @param c character to queue for transmission
altasoul 15:5f38a747ba08 108 * @returns c, or EOF on failure (which should never happen)
altasoul 15:5f38a747ba08 109 */
altasoul 15:5f38a747ba08 110 int putc(int c);
altasoul 15:5f38a747ba08 111
altasoul 15:5f38a747ba08 112 /** Get a character
altasoul 15:5f38a747ba08 113 * Yields to other threads until a character is available
altasoul 15:5f38a747ba08 114 *
altasoul 15:5f38a747ba08 115 * @param timeout (optional) milliseconds to wait for a character (default forever)
altasoul 15:5f38a747ba08 116 * @returns the next character, or EOF if none available within timeout
altasoul 15:5f38a747ba08 117 */
altasoul 14:33d60e4eb215 118 int getc(int timeout = osWaitForever);
altasoul 15:5f38a747ba08 119
altasoul 15:5f38a747ba08 120 /** Put a null-terminated string of characters
altasoul 15:5f38a747ba08 121 *
altasoul 15:5f38a747ba08 122 * @param s the string
altasoul 15:5f38a747ba08 123 * @returns the number of characters enqueued for transmission, or EOF on error
altasoul 15:5f38a747ba08 124 */
altasoul 2:891773cc33fd 125 int puts(const char *s);
altasoul 14:33d60e4eb215 126 // int readable();
altasoul 14:33d60e4eb215 127 // int writeable();
altasoul 0:0547c8bf304f 128 int get_index();
altasoul 15:5f38a747ba08 129 /** Obtain the baud rate of the UART
altasoul 15:5f38a747ba08 130 *
altasoul 15:5f38a747ba08 131 * @returns the baud rate of the UART (tx and rx are the same)
altasoul 15:5f38a747ba08 132 */
altasoul 11:bc067b42f8e0 133 int get_baud();
altasoul 15:5f38a747ba08 134
altasoul 2:891773cc33fd 135 Queue<int, 16> rx_q;
altasoul 12:be7883573c91 136 const char *name;
altasoul 12:be7883573c91 137
altasoul 0:0547c8bf304f 138 protected:
altasoul 0:0547c8bf304f 139 DigitalOut *ledp;
altasoul 5:5d388d1d7987 140 int uart_number;
altasoul 0:0547c8bf304f 141 Queue<int, 16> tx_q;
altasoul 0:0547c8bf304f 142 int parent_putc(int);
altasoul 1:5a66fddad7c4 143
altasoul 12:be7883573c91 144 static void threadStarter(void const *p);
altasoul 13:2fb32235253c 145 void tx_emitter();
altasoul 12:be7883573c91 146
altasoul 12:be7883573c91 147 Thread _tx_thread;
altasoul 8:3644d12758da 148 void rx_isr();
altasoul 8:3644d12758da 149 void tx_isr();
altasoul 0:0547c8bf304f 150 };
altasoul 0:0547c8bf304f 151
altasoul 0:0547c8bf304f 152 #endif