2 FreeRTOS V8.1.2 - Copyright (C) 2014 Real Time Engineers Ltd.
\r
5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS provides completely free yet professionally developed, *
\r
10 * robust, strictly quality controlled, supported, and cross *
\r
11 * platform software that has become a de facto standard. *
\r
13 * Help yourself get started quickly and support the FreeRTOS *
\r
14 * project by purchasing a FreeRTOS tutorial book, reference *
\r
15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
19 ***************************************************************************
\r
21 This file is part of the FreeRTOS distribution.
\r
23 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
24 the terms of the GNU General Public License (version 2) as published by the
\r
25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
27 >>! NOTE: The modification to the GPL is included to allow you to !<<
\r
28 >>! distribute a combined work that includes FreeRTOS without being !<<
\r
29 >>! obliged to provide the source code for proprietary components !<<
\r
30 >>! outside of the FreeRTOS kernel. !<<
\r
32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
35 link: http://www.freertos.org/a00114.html
\r
39 ***************************************************************************
\r
41 * Having a problem? Start by reading the FAQ "My application does *
\r
42 * not run, what could be wrong?" *
\r
44 * http://www.FreeRTOS.org/FAQHelp.html *
\r
46 ***************************************************************************
\r
48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
49 license and Real Time Engineers Ltd. contact details.
\r
51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
57 licenses offer ticketed support, indemnification and middleware.
\r
59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
60 engineered and independently SIL3 certified version for use in safety and
\r
61 mission critical applications that require provable dependability.
\r
67 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
70 /* Standard includes. */
\r
73 /* Scheduler includes. */
\r
74 #include "FreeRTOS.h"
\r
77 /* Demo application includes. */
\r
80 /* Library includes. */
\r
81 #include "usart/usart.h"
\r
82 #include "pmc/pmc.h"
\r
83 #include "irq/irq.h"
\r
84 #include "pio/pio.h"
\r
86 /*-----------------------------------------------------------*/
\r
88 /* Interrupt control macros. */
\r
89 #define serINTERRUPT_LEVEL ( 5 )
\r
90 #define vInterruptOn() BOARD_USART_BASE->US_IER = ( AT91C_US_TXRDY | AT91C_US_RXRDY )
\r
91 #define vInterruptOff() BOARD_USART_BASE->US_IDR = AT91C_US_TXRDY
\r
93 /* Misc constants. */
\r
94 #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 )
\r
95 #define serHANDLE ( ( xComPortHandle ) 1 )
\r
96 #define serNO_BLOCK ( ( TickType_t ) 0 )
\r
97 #define serNO_TIMEGUARD ( ( unsigned long ) 0 )
\r
98 #define serNO_PERIPHERAL_B_SETUP ( ( unsigned long ) 0 )
\r
101 /* Queues used to hold received characters, and characters waiting to be
\r
103 static QueueHandle_t xRxedChars;
\r
104 static QueueHandle_t xCharsForTx;
\r
106 /*-----------------------------------------------------------*/
\r
108 /* The interrupt service routine - called from the assembly entry point. */
\r
109 void vSerialISR( void );
\r
111 /*-----------------------------------------------------------*/
\r
114 * See the serial2.h header file.
\r
116 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
118 xComPortHandle xReturn = serHANDLE;
\r
119 extern void ( vUART_ISR )( void );
\r
120 const Pin xUSART_Pins[] = { BOARD_PIN_USART_RXD, BOARD_PIN_USART_TXD };
\r
123 /* Create the queues used to hold Rx and Tx characters. */
\r
124 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
125 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
127 /* If the queues were created correctly then setup the serial port
\r
129 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
131 portENTER_CRITICAL();
\r
133 /* Enable the peripheral clock in the PMC. */
\r
134 PMC_EnablePeripheral( BOARD_ID_USART );
\r
136 /* Configure the USART. */
\r
137 USART_Configure( BOARD_USART_BASE, AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE | AT91C_US_NBSTOP_1_BIT, ulWantedBaud, configCPU_CLOCK_HZ );
\r
139 /* Configure the interrupt. Note the pre-emption priority is set
\r
140 in bits [8:15] of the priority value passed as the parameter. */
\r
141 IRQ_ConfigureIT( BOARD_ID_USART, ( configMAX_SYSCALL_INTERRUPT_PRIORITY << 8 ), vSerialISR );
\r
142 IRQ_EnableIT( BOARD_ID_USART );
\r
144 /* Enable receiver & transmitter. */
\r
145 USART_SetTransmitterEnabled( BOARD_USART_BASE, pdTRUE );
\r
146 USART_SetReceiverEnabled( BOARD_USART_BASE, pdTRUE );
\r
148 /* Configure IO for USART use. */
\r
149 PIO_Configure( xUSART_Pins, PIO_LISTSIZE( xUSART_Pins ) );
\r
151 portEXIT_CRITICAL();
\r
155 xReturn = ( xComPortHandle ) 0;
\r
158 /* This demo file only supports a single port but we have to return
\r
159 something to comply with the standard demo header file. */
\r
162 /*-----------------------------------------------------------*/
\r
164 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
\r
166 /* The port handle is not required as this driver only supports one port. */
\r
169 /* Get the next character from the buffer. Return false if no characters
\r
170 are available, or arrive before xBlockTime expires. */
\r
171 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
180 /*-----------------------------------------------------------*/
\r
182 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
184 signed char *pxNext;
\r
186 /* A couple of parameters that this port does not use. */
\r
187 ( void ) usStringLength;
\r
190 /* NOTE: This implementation does not handle the queue being full as no
\r
191 block time is used! */
\r
193 /* The port handle is not required as this driver only supports UART0. */
\r
196 /* Send each character in the string, one at a time. */
\r
197 pxNext = ( signed char * ) pcString;
\r
200 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
204 /*-----------------------------------------------------------*/
\r
206 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
\r
208 /* Place the character in the queue of characters to be transmitted. */
\r
209 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
214 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
215 queue and send it. This does not need to be in a critical section as
\r
216 if the interrupt has already removed the character the next interrupt
\r
217 will simply turn off the Tx interrupt again. */
\r
222 /*-----------------------------------------------------------*/
\r
224 void vSerialClose( xComPortHandle xPort )
\r
226 /* Not supported as not required by the demo application. */
\r
228 /*-----------------------------------------------------------*/
\r
230 void vSerialISR( void )
\r
232 unsigned long ulStatus;
\r
234 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
236 /* What caused the interrupt? */
\r
237 ulStatus = BOARD_USART_BASE->US_CSR &= BOARD_USART_BASE->US_IMR;
\r
239 if( ulStatus & AT91C_US_TXRDY )
\r
241 /* The interrupt was caused by the THR becoming empty. Are there any
\r
242 more characters to transmit? */
\r
243 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
245 /* A character was retrieved from the queue so can be sent to the
\r
247 BOARD_USART_BASE->US_THR = cChar;
\r
251 /* Queue empty, nothing to send so turn off the Tx interrupt. */
\r
256 if( ulStatus & AT91C_US_RXRDY )
\r
258 /* The interrupt was caused by a character being received. Grab the
\r
259 character from the RHR and place it in the queue or received
\r
261 cChar = BOARD_USART_BASE->US_RHR;
\r
262 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
265 /* If a task was woken by either a character being received or a character
\r
266 being transmitted then we may need to switch to another task. */
\r
267 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r