xref: /FreeRTOS-Plus-TCP-v3.1.0/source/portable/NetworkInterface/LPC17xx/NetworkInterface.c (revision 37bdfe577f3b728058de714e2e747d3c78803f26)
1 /*
2  * FreeRTOS+TCP V3.1.0
3  * Copyright (C) 2022 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
4  *
5  * SPDX-License-Identifier: MIT
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy of
8  * this software and associated documentation files (the "Software"), to deal in
9  * the Software without restriction, including without limitation the rights to
10  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11  * the Software, and to permit persons to whom the Software is furnished to do so,
12  * subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in all
15  * copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
20  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
21  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * http://aws.amazon.com/freertos
25  * http://www.FreeRTOS.org
26  */
27 
28 /* Standard includes. */
29 #include <stdint.h>
30 
31 /* FreeRTOS includes. */
32 #include "FreeRTOS.h"
33 #include "task.h"
34 #include "queue.h"
35 #include "semphr.h"
36 
37 /* Hardware abstraction. */
38 #include "FreeRTOS_IO.h"
39 
40 /* FreeRTOS+TCP includes. */
41 #include "FreeRTOS_UDP_IP.h"
42 #include "FreeRTOS_Sockets.h"
43 #include "NetworkBufferManagement.h"
44 
45 /* Driver includes. */
46 #include "lpc17xx_emac.h"
47 #include "lpc17xx_pinsel.h"
48 
49 /* Demo includes. */
50 #include "NetworkInterface.h"
51 
52 #if ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES != 1
53     #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer )    eProcessBuffer
54 #else
55     #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer )    eConsiderFrameForProcessing( ( pucEthernetBuffer ) )
56 #endif
57 
58 /* When a packet is ready to be sent, if it cannot be sent immediately then the
59  * task performing the transmit will block for niTX_BUFFER_FREE_WAIT
60  * milliseconds.  It will do this a maximum of niMAX_TX_ATTEMPTS before giving
61  * up. */
62 #define niTX_BUFFER_FREE_WAIT       ( pdMS_TO_TICKS( 2UL ) )
63 #define niMAX_TX_ATTEMPTS           ( 5 )
64 
65 /* The length of the queue used to send interrupt status words from the
66  * interrupt handler to the deferred handler task. */
67 #define niINTERRUPT_QUEUE_LENGTH    ( 10 )
68 
69 /*-----------------------------------------------------------*/
70 
71 /*
72  * A deferred interrupt handler task that processes
73  */
74 static void prvEMACHandlerTask( void * pvParameters );
75 
76 /*-----------------------------------------------------------*/
77 
78 /* The queue used to communicate Ethernet events with the IP task. */
79 extern QueueHandle_t xNetworkEventQueue;
80 
81 /* The semaphore used to wake the deferred interrupt handler task when an Rx
82  * interrupt is received. */
83 static SemaphoreHandle_t xEMACRxEventSemaphore = NULL;
84 /*-----------------------------------------------------------*/
85 
xNetworkInterfaceInitialise(void)86 BaseType_t xNetworkInterfaceInitialise( void )
87 {
88     EMAC_CFG_Type Emac_Config;
89     PINSEL_CFG_Type xPinConfig;
90     BaseType_t xStatus, xReturn;
91 
92     /* Enable Ethernet Pins */
93     boardCONFIGURE_ENET_PINS( xPinConfig );
94 
95     Emac_Config.Mode = EMAC_MODE_AUTO;
96     Emac_Config.pbEMAC_Addr = ipLOCAL_MAC_ADDRESS;
97     xStatus = EMAC_Init( &Emac_Config );
98 
99     LPC_EMAC->IntEnable &= ~( EMAC_INT_TX_DONE );
100 
101     if( xStatus != ERROR )
102     {
103         vSemaphoreCreateBinary( xEMACRxEventSemaphore );
104         configASSERT( xEMACRxEventSemaphore != NULL );
105 
106         /* The handler task is created at the highest possible priority to
107          * ensure the interrupt handler can return directly to it. */
108         xTaskCreate( prvEMACHandlerTask, "EMAC", configMINIMAL_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL );
109 
110         /* Enable the interrupt and set its priority to the minimum
111          * interrupt priority.  */
112         NVIC_SetPriority( ENET_IRQn, configMAC_INTERRUPT_PRIORITY );
113         NVIC_EnableIRQ( ENET_IRQn );
114 
115         xReturn = pdPASS;
116     }
117     else
118     {
119         xReturn = pdFAIL;
120     }
121 
122     configASSERT( xStatus != ERROR );
123 
124     return xReturn;
125 }
126 /*-----------------------------------------------------------*/
127 
xNetworkInterfaceOutput(NetworkBufferDescriptor_t * const pxNetworkBuffer)128 BaseType_t xNetworkInterfaceOutput( NetworkBufferDescriptor_t * const pxNetworkBuffer )
129 {
130     BaseType_t xReturn = pdFAIL;
131     int32_t x;
132     extern void EMAC_StartTransmitNextBuffer( uint32_t ulLength );
133     extern void EMAC_SetNextPacketToSend( uint8_t * pucBuffer );
134 
135 
136     /* Attempt to obtain access to a Tx buffer. */
137     for( x = 0; x < niMAX_TX_ATTEMPTS; x++ )
138     {
139         if( EMAC_CheckTransmitIndex() == TRUE )
140         {
141             /* Will the data fit in the Tx buffer? */
142             if( pxNetworkBuffer->xDataLength < EMAC_ETH_MAX_FLEN ) /*_RB_ The size needs to come from FreeRTOSIPConfig.h. */
143             {
144                 /* Assign the buffer to the Tx descriptor that is now known to
145                  * be free. */
146                 EMAC_SetNextPacketToSend( pxNetworkBuffer->pucBuffer );
147 
148                 /* The EMAC now owns the buffer. */
149                 pxNetworkBuffer->pucBuffer = NULL;
150 
151                 /* Initiate the Tx. */
152                 EMAC_StartTransmitNextBuffer( pxNetworkBuffer->xDataLength );
153                 iptraceNETWORK_INTERFACE_TRANSMIT();
154 
155                 /* The Tx has been initiated. */
156                 xReturn = pdPASS;
157             }
158 
159             break;
160         }
161         else
162         {
163             vTaskDelay( niTX_BUFFER_FREE_WAIT );
164         }
165     }
166 
167     /* Finished with the network buffer. */
168     vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
169 
170     return xReturn;
171 }
172 /*-----------------------------------------------------------*/
173 
ENET_IRQHandler(void)174 void ENET_IRQHandler( void )
175 {
176     uint32_t ulInterruptCause;
177 
178     while( ( ulInterruptCause = LPC_EMAC->IntStatus ) != 0 )
179     {
180         /* Clear the interrupt. */
181         LPC_EMAC->IntClear = ulInterruptCause;
182 
183         /* Clear fatal error conditions.  NOTE:  The driver does not clear all
184          * errors, only those actually experienced.  For future reference, range
185          * errors are not actually errors so can be ignored. */
186         if( ( ulInterruptCause & EMAC_INT_TX_UNDERRUN ) != 0U )
187         {
188             LPC_EMAC->Command |= EMAC_CR_TX_RES;
189         }
190 
191         /* Unblock the deferred interrupt handler task if the event was an
192          * Rx. */
193         if( ( ulInterruptCause & EMAC_INT_RX_DONE ) != 0UL )
194         {
195             xSemaphoreGiveFromISR( xEMACRxEventSemaphore, NULL );
196         }
197     }
198 
199     /* ulInterruptCause is used for convenience here.  A context switch is
200      * wanted, but coding portEND_SWITCHING_ISR( 1 ) would likely result in a
201      * compiler warning. */
202     portEND_SWITCHING_ISR( ulInterruptCause );
203 }
204 /*-----------------------------------------------------------*/
205 
prvEMACHandlerTask(void * pvParameters)206 static void prvEMACHandlerTask( void * pvParameters )
207 {
208     size_t xDataLength;
209     const uint16_t usCRCLength = 4;
210     NetworkBufferDescriptor_t * pxNetworkBuffer;
211     IPStackEvent_t xRxEvent = { eNetworkRxEvent, NULL };
212 
213 /* This is not included in the header file for some reason. */
214     extern uint8_t * EMAC_NextPacketToRead( void );
215 
216     ( void ) pvParameters;
217     configASSERT( xEMACRxEventSemaphore != NULL );
218 
219     for( ; ; )
220     {
221         /* Wait for the EMAC interrupt to indicate that another packet has been
222          * received.  The while() loop is only needed if INCLUDE_vTaskSuspend is
223          * set to 0 in FreeRTOSConfig.h. */
224         while( xSemaphoreTake( xEMACRxEventSemaphore, portMAX_DELAY ) == pdFALSE )
225         {
226         }
227 
228         /* At least one packet has been received. */
229         while( EMAC_CheckReceiveIndex() != FALSE )
230         {
231             /* Obtain the length, minus the CRC.  The CRC is four bytes
232              * but the length is already minus 1. */
233             xDataLength = ( size_t ) EMAC_GetReceiveDataSize() - ( usCRCLength - 1U );
234 
235             if( xDataLength > 0U )
236             {
237                 /* Obtain a network buffer to pass this data into the
238                  * stack.  No storage is required as the network buffer
239                  * will point directly to the buffer that already holds
240                  * the	received data. */
241                 pxNetworkBuffer = pxGetNetworkBufferWithDescriptor( 0, ( TickType_t ) 0 );
242 
243                 if( pxNetworkBuffer != NULL )
244                 {
245                     pxNetworkBuffer->pucBuffer = EMAC_NextPacketToRead();
246                     pxNetworkBuffer->xDataLength = xDataLength;
247                     xRxEvent.pvData = ( void * ) pxNetworkBuffer;
248 
249                     /* Data was received and stored.  Send a message to the IP
250                      * task to let it know. */
251                     if( xSendEventStructToIPTask( &xRxEvent, ( TickType_t ) 0 ) == pdFAIL )
252                     {
253                         vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
254                         iptraceETHERNET_RX_EVENT_LOST();
255                     }
256                 }
257                 else
258                 {
259                     iptraceETHERNET_RX_EVENT_LOST();
260                 }
261 
262                 iptraceNETWORK_INTERFACE_RECEIVE();
263             }
264 
265             /* Release the frame. */
266             EMAC_UpdateRxConsumeIndex();
267         }
268     }
269 }
270 /*-----------------------------------------------------------*/
271