usbd_cdc_interface.c 16.4 KB
Newer Older
1
2
3
4
5
6
7
/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * Taken from ST Cube library and heavily modified.  See below for original
 * copyright header.
 */

8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
/**
  ******************************************************************************
  * @file    USB_Device/CDC_Standalone/Src/usbd_cdc_interface.c
  * @author  MCD Application Team
  * @version V1.0.1
  * @date    26-February-2014
  * @brief   Source file for USBD CDC interface
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include <stdbool.h>
#include "stm32f4xx_hal.h"
38
#include "usbd_cdc_msc_hid.h"
39
40
41
42
#include "usbd_cdc_interface.h"
#include "pendsv.h"
#include "usb.h"

43
44
45
46
47
48
49
50
51
52
53
// CDC control commands
#define CDC_SEND_ENCAPSULATED_COMMAND               0x00
#define CDC_GET_ENCAPSULATED_RESPONSE               0x01
#define CDC_SET_COMM_FEATURE                        0x02
#define CDC_GET_COMM_FEATURE                        0x03
#define CDC_CLEAR_COMM_FEATURE                      0x04
#define CDC_SET_LINE_CODING                         0x20
#define CDC_GET_LINE_CODING                         0x21
#define CDC_SET_CONTROL_LINE_STATE                  0x22
#define CDC_SEND_BREAK                              0x23

54
55
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
56
#define APP_RX_DATA_SIZE  1024 // I think this must be at least CDC_DATA_FS_OUT_PACKET_SIZE=64 (APP_RX_DATA_SIZE was 2048)
57
58
59
60
61
#define APP_TX_DATA_SIZE  1024 // I think this can be any value (was 2048)

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

62
63
static uint8_t dev_is_connected = 0; // indicates if we are connected

64
65
66
67
68
69
static uint8_t UserRxBuffer[APP_RX_DATA_SIZE]; // received data from USB OUT endpoint is stored in this buffer
static uint16_t UserRxBufCur = 0; // points to next available character in UserRxBuffer
static uint16_t UserRxBufLen = 0; // counts number of valid characters in UserRxBuffer

static uint8_t UserTxBuffer[APP_TX_DATA_SIZE]; // data for USB IN endpoind is stored in this buffer
static uint16_t UserTxBufPtrIn = 0; // increment this pointer modulo APP_TX_DATA_SIZE when new data is available
70
static __IO uint16_t UserTxBufPtrOut = 0; // increment this pointer modulo APP_TX_DATA_SIZE when data is drained
71
72
static uint16_t UserTxBufPtrOutShadow = 0; // shadow of above
static uint8_t UserTxBufPtrWaitCount = 0; // used to implement a timeout waiting for low-level USB driver
73
static uint8_t UserTxNeedEmptyPacket = 0; // used to flush the USB IN endpoint if the last packet was exactly the endpoint packet size
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

static int user_interrupt_char = VCP_CHAR_NONE;
static void *user_interrupt_data = NULL;

/* USB handler declaration */
extern USBD_HandleTypeDef hUSBDDevice;

/* Private function prototypes -----------------------------------------------*/
static int8_t CDC_Itf_Init     (void);
static int8_t CDC_Itf_DeInit   (void);
static int8_t CDC_Itf_Control  (uint8_t cmd, uint8_t* pbuf, uint16_t length);
static int8_t CDC_Itf_Receive  (uint8_t* pbuf, uint32_t *Len);

const USBD_CDC_ItfTypeDef USBD_CDC_fops = {
    CDC_Itf_Init,
    CDC_Itf_DeInit,
    CDC_Itf_Control,
    CDC_Itf_Receive
};

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  CDC_Itf_Init
  *         Initializes the CDC media low layer
  * @param  None
  * @retval Result of the opeartion: USBD_OK if all operations are OK else USBD_FAIL
  */
static int8_t CDC_Itf_Init(void)
{
#if 0
  /*##-1- Configure the UART peripheral ######################################*/
  /* Put the USART peripheral in the Asynchronous mode (UART Mode) */
  /* USART configured as follow:
      - Word Length = 8 Bits
      - Stop Bit    = One Stop bit
      - Parity      = No parity
      - BaudRate    = 115200 baud
      - Hardware flow control disabled (RTS and CTS signals) */
  UartHandle.Instance        = USARTx;
  UartHandle.Init.BaudRate   = 115200;
  UartHandle.Init.WordLength = UART_WORDLENGTH_8B;
  UartHandle.Init.StopBits   = UART_STOPBITS_1;
  UartHandle.Init.Parity     = UART_PARITY_NONE;
  UartHandle.Init.HwFlowCtl  = UART_HWCONTROL_NONE;
  UartHandle.Init.Mode       = UART_MODE_TX_RX;
  
  if(HAL_UART_Init(&UartHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
  
  /*##-2- Put UART peripheral in IT reception process ########################*/
  /* Any data received will be stored in "UserTxBuffer" buffer  */
  if(HAL_UART_Receive_IT(&UartHandle, (uint8_t *)UserTxBuffer, 1) != HAL_OK)
  {
    /* Transfer error in reception process */
    Error_Handler();
  }
  
  /*##-3- Configure the TIM Base generation  #################################*/
136
  now done in HAL_MspInit
137
  TIM_Config();
138
#endif
139
  
140
141
142
    /*##-4- Start the TIM Base generation in interrupt mode ####################*/
    /* Start Channel1 */
    __HAL_TIM_ENABLE_IT(&TIM3_Handle, TIM_IT_UPDATE);
143
  
144
145
146
    /*##-5- Set Application Buffers ############################################*/
    USBD_CDC_SetTxBuffer(&hUSBDDevice, UserTxBuffer, 0);
    USBD_CDC_SetRxBuffer(&hUSBDDevice, UserRxBuffer);
147
148
149
150

    UserRxBufCur = 0;
    UserRxBufLen = 0;
  
151
152
153
154
    /* NOTE: we cannot reset these here, because USBD_CDC_SetInterrupt
     * may be called before this init function to set these values.
     * This can happen if the USB enumeration occurs after the call to
     * USBD_CDC_SetInterrupt.
155
156
    user_interrupt_char = VCP_CHAR_NONE;
    user_interrupt_data = NULL;
157
    */
158

159
    return (USBD_OK);
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
}

/**
  * @brief  CDC_Itf_DeInit
  *         DeInitializes the CDC media low layer
  * @param  None
  * @retval Result of the opeartion: USBD_OK if all operations are OK else USBD_FAIL
  */
static int8_t CDC_Itf_DeInit(void)
{
#if 0
  /* DeInitialize the UART peripheral */
  if(HAL_UART_DeInit(&UartHandle) != HAL_OK)
  {
    /* Initialization Error */
  }
#endif
  return (USBD_OK);
}

/**
  * @brief  CDC_Itf_Control
  *         Manage the CDC class requests
  * @param  Cmd: Command code            
  * @param  Buf: Buffer containing command data (request parameters)
  * @param  Len: Number of data to be sent (in bytes)
  * @retval Result of the opeartion: USBD_OK if all operations are OK else USBD_FAIL
  */
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
static int8_t CDC_Itf_Control(uint8_t cmd, uint8_t* pbuf, uint16_t length) {
    switch (cmd) {
        case CDC_SEND_ENCAPSULATED_COMMAND:
            /* Add your code here */
            break;

        case CDC_GET_ENCAPSULATED_RESPONSE:
            /* Add your code here */
            break;

        case CDC_SET_COMM_FEATURE:
            /* Add your code here */
            break;

        case CDC_GET_COMM_FEATURE:
            /* Add your code here */
            break;

        case CDC_CLEAR_COMM_FEATURE:
            /* Add your code here */
            break;

        case CDC_SET_LINE_CODING:
            #if 0
            LineCoding.bitrate    = (uint32_t)(pbuf[0] | (pbuf[1] << 8) |\
                                    (pbuf[2] << 16) | (pbuf[3] << 24));
            LineCoding.format     = pbuf[4];
            LineCoding.paritytype = pbuf[5];
            LineCoding.datatype   = pbuf[6];
            /* Set the new configuration */
            #endif
            break;

        case CDC_GET_LINE_CODING:
            #if 0
            pbuf[0] = (uint8_t)(LineCoding.bitrate);
            pbuf[1] = (uint8_t)(LineCoding.bitrate >> 8);
            pbuf[2] = (uint8_t)(LineCoding.bitrate >> 16);
            pbuf[3] = (uint8_t)(LineCoding.bitrate >> 24);
            pbuf[4] = LineCoding.format;
            pbuf[5] = LineCoding.paritytype;
            pbuf[6] = LineCoding.datatype;
            #endif

            /* Add your code here */
            pbuf[0] = (uint8_t)(115200);
            pbuf[1] = (uint8_t)(115200 >> 8);
            pbuf[2] = (uint8_t)(115200 >> 16);
            pbuf[3] = (uint8_t)(115200 >> 24);
            pbuf[4] = 0; // stop bits (1)
            pbuf[5] = 0; // parity (none)
            pbuf[6] = 8; // number of bits (8)
            break;

        case CDC_SET_CONTROL_LINE_STATE:
            dev_is_connected = length & 1; // wValue is passed in Len (bit of a hack)
            break;

        case CDC_SEND_BREAK:
            /* Add your code here */
            break;

        default:
            break;
    }

    return USBD_OK;
255
256
257
258
259
260
261
}

/**
  * @brief  TIM period elapsed callback
  * @param  htim: TIM handle
  * @retval None
  */
262
void USBD_CDC_HAL_TIM_PeriodElapsedCallback(void) {
263
264
265
    if (!dev_is_connected) {
        // CDC device is not connected to a host, so we are unable to send any data
        return;
266
    }
267

268
    if (UserTxBufPtrOut == UserTxBufPtrIn && !UserTxNeedEmptyPacket) {
269
270
        // No outstanding data to send
        return;
271
    }
272
273
274
275

    if (UserTxBufPtrOut != UserTxBufPtrOutShadow) {
        // We have sent data and are waiting for the low-level USB driver to
        // finish sending it over the USB in-endpoint.
276
277
        // We have a 15 * 10ms = 150ms timeout
        if (UserTxBufPtrWaitCount < 15) {
278
279
            PCD_HandleTypeDef *hpcd = hUSBDDevice.pData;
            USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;
280
            if (USBx_INEP(CDC_IN_EP & 0x7f)->DIEPTSIZ & USB_OTG_DIEPTSIZ_XFRSIZ) {
281
282
283
284
285
286
                // USB in-endpoint is still reading the data
                UserTxBufPtrWaitCount++;
                return;
            }
        }
        UserTxBufPtrOut = UserTxBufPtrOutShadow;
287
    }
288

289
    if (UserTxBufPtrOutShadow != UserTxBufPtrIn || UserTxNeedEmptyPacket) {
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
        uint32_t buffptr;
        uint32_t buffsize;

        if (UserTxBufPtrOutShadow > UserTxBufPtrIn) { // rollback
            buffsize = APP_TX_DATA_SIZE - UserTxBufPtrOutShadow;
        } else {
            buffsize = UserTxBufPtrIn - UserTxBufPtrOutShadow;
        }

        buffptr = UserTxBufPtrOutShadow;

        USBD_CDC_SetTxBuffer(&hUSBDDevice, (uint8_t*)&UserTxBuffer[buffptr], buffsize);

        if (USBD_CDC_TransmitPacket(&hUSBDDevice) == USBD_OK) {
            UserTxBufPtrOutShadow += buffsize;
            if (UserTxBufPtrOutShadow == APP_TX_DATA_SIZE) {
                UserTxBufPtrOutShadow = 0;
            }
            UserTxBufPtrWaitCount = 0;
309
310
311
312
313
314
315
316

            // According to the USB specification, a packet size of 64 bytes (CDC_DATA_FS_MAX_PACKET_SIZE)
            // gets held at the USB host until the next packet is sent.  This is because a
            // packet of maximum size is considered to be part of a longer chunk of data, and
            // the host waits for all data to arrive (ie, waits for a packet < max packet size).
            // To flush a packet of exactly max packet size, we need to send a zero-size packet.
            // See eg http://www.cypress.com/?id=4&rID=92719
            UserTxNeedEmptyPacket = (buffsize == CDC_DATA_FS_MAX_PACKET_SIZE && UserTxBufPtrOutShadow == UserTxBufPtrIn);
317
        }
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
    }
}

/**
  * @brief  CDC_Itf_DataRx
  *         Data received over USB OUT endpoint is processed here.
  * @param  Buf: Buffer of data received
  * @param  Len: Number of data received (in bytes)
  * @retval Result of the opeartion: USBD_OK if all operations are OK else USBD_FAIL
  * @note   The buffer we are passed here is just UserRxBuffer, so we are
  *         free to modify it.
  */
static int8_t CDC_Itf_Receive(uint8_t* Buf, uint32_t *Len) {
#if 0
    // this sends the data over the UART using DMA
    HAL_UART_Transmit_DMA(&UartHandle, Buf, *Len);
#endif

336
337
338
339
340
341
342
343
344
345
346
    // TODO improve this function to implement a circular buffer

    // if we have processed all the characters, reset the buffer counters
    if (UserRxBufCur > 0 && UserRxBufCur >= UserRxBufLen) {
        memmove(UserRxBuffer, UserRxBuffer + UserRxBufLen, *Len);
        UserRxBufCur = 0;
        UserRxBufLen = 0;
    }

    uint32_t delta_len;

347
348
    if (user_interrupt_char == VCP_CHAR_NONE) {
        // no special interrupt character
349
        delta_len = *Len;
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373

    } else {
        // filter out sepcial interrupt character from the buffer
        bool char_found = false;
        uint8_t *dest = Buf;
        uint8_t *src = Buf;
        uint8_t *buf_top = Buf + *Len;
        for (; src < buf_top; src++) {
            if (*src == user_interrupt_char) {
                char_found = true;
            } else {
                if (char_found) {
                    *dest = *src;
                }
                dest++;
            }
        }

        if (char_found) {
            // raise exception when interrupts are finished
            user_interrupt_char = VCP_CHAR_NONE;
            pendsv_nlr_jump(user_interrupt_data);
        }

374
375
376
        // length of remaining characters
        delta_len = dest - Buf;
    }
377

378
379
380
381
382
383
    if (UserRxBufLen + delta_len + CDC_DATA_FS_MAX_PACKET_SIZE > APP_RX_DATA_SIZE) {
        // if we keep this data then the buffer can overflow on the next USB rx
        // so we don't increment the length, and throw this data away
    } else {
        // data fits, leaving room for another CDC_DATA_FS_OUT_PACKET_SIZE
        UserRxBufLen += delta_len;
384
385
    }

386
387
388
389
390
    // initiate next USB packet transfer, to append to existing data in buffer
    USBD_CDC_SetRxBuffer(&hUSBDDevice, UserRxBuffer + UserRxBufLen);
    USBD_CDC_ReceivePacket(&hUSBDDevice);

    return USBD_OK;
391
392
}

393
394
395
396
int USBD_CDC_IsConnected(void) {
    return dev_is_connected;
}

397
398
399
400
401
402
403
void USBD_CDC_SetInterrupt(int chr, void *data) {
    user_interrupt_char = chr;
    user_interrupt_data = data;
}

void USBD_CDC_Tx(const char *str, uint32_t len) {
    for (int i = 0; i < len; i++) {
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
        // If the CDC device is not connected to the host then we don't have anyone to receive our data.
        // The device may become connected in the future, so we should at least try to fill the buffer
        // and hope that it doesn't overflow by the time the device connects.
        // If the device is not connected then we should go ahead and fill the buffer straight away,
        // ignoring overflow.  Otherwise, we should make sure that we have enough room in the buffer.
        if (dev_is_connected) {
            // If the buffer is full, wait until it gets drained, with a timeout of 500ms
            // (wraparound of tick is taken care of by 2's complement arithmetic).
            uint32_t start = HAL_GetTick();
            while (((UserTxBufPtrIn + 1) & (APP_TX_DATA_SIZE - 1)) == UserTxBufPtrOut && HAL_GetTick() - start <= 500) {
                __WFI(); // enter sleep mode, waiting for interrupt
            }

            // Some unused code that makes sure the low-level USB buffer is drained.
            // Waiting for low-level is handled in USBD_CDC_HAL_TIM_PeriodElapsedCallback.
            /*
            start = HAL_GetTick();
            PCD_HandleTypeDef *hpcd = hUSBDDevice.pData;
            if (hpcd->IN_ep[0x83 & 0x7f].is_in) {
                //volatile uint32_t *xfer_count = &hpcd->IN_ep[0x83 & 0x7f].xfer_count;
                //volatile uint32_t *xfer_len = &hpcd->IN_ep[0x83 & 0x7f].xfer_len;
                USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;
                while (
                    // *xfer_count < *xfer_len // using this works
                    // (USBx_INEP(3)->DIEPTSIZ & USB_OTG_DIEPTSIZ_XFRSIZ) // using this works
                    && HAL_GetTick() - start <= 2000) {
                    __WFI(); // enter sleep mode, waiting for interrupt
                }
            }
            */
434
        }
435

436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
        UserTxBuffer[UserTxBufPtrIn] = str[i];
        UserTxBufPtrIn = (UserTxBufPtrIn + 1) & (APP_TX_DATA_SIZE - 1);
    }
}

int USBD_CDC_RxNum(void) {
    return UserRxBufLen - UserRxBufCur;
}

int USBD_CDC_RxGet(void) {
    // wait for buffer to have at least 1 character in it
    while (USBD_CDC_RxNum() == 0) {
        __WFI();
    }

    // get next character
    int c = UserRxBuffer[UserRxBufCur++];
453

454
455
    return c;
}