flight/pios/stm32f4xx/pios_usb_cdc.c

   1 /**
   2  ******************************************************************************
   3  * @addtogroup PIOS PIOS Core hardware abstraction layer
   4  * @{
   5  * @addtogroup   PIOS_USB_COM USB COM Functions
   6  * @brief PIOS USB COM implementation for CDC interfaces
   7  * @notes      This implements a CDC Serial Port
   8  * @{
   9  *
  10  * @file       pios_usb_com_cdc.c
  11  * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
  12  * @brief      USB COM functions (STM32 dependent code)
  13  * @see        The GNU Public License (GPL) Version 3
  14  *
  15  *****************************************************************************/
  16 /*
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 3 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful, but
  23  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  24  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  25  * for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License along
  28  * with this program; if not, write to the Free Software Foundation, Inc.,
  29  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  30  */
  31
  32 #include "pios.h"
  33
  34 #ifdef PIOS_INCLUDE_USB_CDC
  35
  36 #include "pios_usb_cdc_priv.h"
  37 #include "pios_usb_board_data.h" /* PIOS_BOARD_*_DATA_LENGTH */
  38 #include "pios_usbhook.h" /* PIOS_USBHOOK_* */
  39 #include "usb_core.h" /* USB_OTG_EP_RX_VALID */
  40
  41 /* Implement COM layer driver API */
  42 static void PIOS_USB_CDC_RegisterTxCallback(uint32_t usbcdc_id, pios_com_callback tx_out_cb, uint32_t context);
  43 static void PIOS_USB_CDC_RegisterRxCallback(uint32_t usbcdc_id, pios_com_callback rx_in_cb, uint32_t context);
  44 static void PIOS_USB_CDC_RegisterCtrlLineCallback(uint32_t usbcdc_id, pios_com_callback_ctrl_line ctrl_line_cb, uint32_t context);
  45 static void PIOS_USB_CDC_RegisterBaudRateCallback(uint32_t usbcdc_id, pios_com_callback_baud_rate baud_rate_cb, uint32_t context);
  46 static void PIOS_USB_CDC_RegisterAvailableCallback(uint32_t usbcdc_id, pios_com_callback_available baud_rate_cb, uint32_t context);
  47 static void PIOS_USB_CDC_ChangeConnectionState(bool connected, uint32_t usbcdc_id);
  48 static void PIOS_USB_CDC_TxStart(uint32_t usbcdc_id, uint16_t tx_bytes_avail);
  49 static void PIOS_USB_CDC_RxStart(uint32_t usbcdc_id, uint16_t rx_bytes_avail);
  50 static uint32_t PIOS_USB_CDC_Available(uint32_t usbcdc_id);
  51
  52 const struct pios_com_driver pios_usb_cdc_com_driver = {
  53     .tx_start   = PIOS_USB_CDC_TxStart,
  54     .rx_start   = PIOS_USB_CDC_RxStart,
  55     .bind_tx_cb = PIOS_USB_CDC_RegisterTxCallback,
  56     .bind_rx_cb = PIOS_USB_CDC_RegisterRxCallback,
  57     .bind_ctrl_line_cb = PIOS_USB_CDC_RegisterCtrlLineCallback,
  58     .bind_baud_rate_cb = PIOS_USB_CDC_RegisterBaudRateCallback,
  59     .available  = PIOS_USB_CDC_Available,
  60     .bind_available_cb = PIOS_USB_CDC_RegisterAvailableCallback,
  61 };
  62
  63 enum pios_usb_cdc_dev_magic {
  64     PIOS_USB_CDC_DEV_MAGIC = 0xAABBCCDD,
  65 };
  66
  67 struct pios_usb_cdc_dev {
  68     enum pios_usb_cdc_dev_magic   magic;
  69     const struct pios_usb_cdc_cfg *cfg;
  70
  71     uint32_t lower_id;
  72
  73     pios_com_callback rx_in_cb;
  74     uint32_t rx_in_context;
  75     pios_com_callback tx_out_cb;
  76     uint32_t tx_out_context;
  77     pios_com_callback_ctrl_line ctrl_line_cb;
  78     uint32_t ctrl_line_context;
  79     pios_com_callback_baud_rate baud_rate_cb;
  80     uint32_t baud_rate_context;
  81     pios_com_callback_available available_cb;
  82     uint32_t available_context;
  83
  84     bool     usb_ctrl_if_enabled;
  85     bool     usb_data_if_enabled;
  86
  87     uint8_t  rx_packet_buffer[PIOS_USB_BOARD_CDC_DATA_LENGTH] __attribute__((aligned(4)));
  88
  89     /*
  90      * NOTE: This is -1 as somewhat of a hack.  It ensures that we always send packets
  91      * that are strictly < maxPacketSize for this interface which means we never have
  92      * to bother with zero length packets (ZLP).
  93      */
  94     uint8_t  tx_packet_buffer[PIOS_USB_BOARD_CDC_DATA_LENGTH - 1] __attribute__((aligned(4)));
  95     volatile bool tx_active;
  96
  97     uint8_t  ctrl_tx_packet_buffer[PIOS_USB_BOARD_CDC_MGMT_LENGTH] __attribute__((aligned(4)));
  98
  99     uint32_t rx_dropped;
 100     uint32_t rx_oversize;
 101
 102     /*
 103      * Used to hold the current state of the simulated UART.  Changes to this
 104      * variable may trigger new USB CDC Notification packets to be sent to the host.
 105      */
 106     volatile uint16_t prev_uart_state;
 107 };
 108
 109 static bool PIOS_USB_CDC_validate(struct pios_usb_cdc_dev *usb_cdc_dev)
 110 {
 111     return usb_cdc_dev && (usb_cdc_dev->magic == PIOS_USB_CDC_DEV_MAGIC);
 112 }
 113
 114 #if defined(PIOS_INCLUDE_FREERTOS)
 115 static struct pios_usb_cdc_dev *PIOS_USB_CDC_alloc(void)
 116 {
 117     struct pios_usb_cdc_dev *usb_cdc_dev;
 118
 119     usb_cdc_dev = (struct pios_usb_cdc_dev *)pios_malloc(sizeof(struct pios_usb_cdc_dev));
 120     if (!usb_cdc_dev) {
 121         return NULL;
 122     }
 123
 124     memset(usb_cdc_dev, 0, sizeof(struct pios_usb_cdc_dev));
 125     usb_cdc_dev->magic = PIOS_USB_CDC_DEV_MAGIC;
 126     return usb_cdc_dev;
 127 }
 128 #else
 129 static struct pios_usb_cdc_dev pios_usb_cdc_devs[PIOS_USB_CDC_MAX_DEVS];
 130 static uint8_t pios_usb_cdc_num_devs;
 131 static struct pios_usb_cdc_dev *PIOS_USB_CDC_alloc(void)
 132 {
 133     struct pios_usb_cdc_dev *usb_cdc_dev;
 134
 135     if (pios_usb_cdc_num_devs >= PIOS_USB_CDC_MAX_DEVS) {
 136         return NULL;
 137     }
 138
 139     usb_cdc_dev = &pios_usb_cdc_devs[pios_usb_cdc_num_devs++];
 140
 141     memset(usb_cdc_dev, 0, sizeof(struct pios_usb_cdc_dev));
 142     usb_cdc_dev->magic = PIOS_USB_CDC_DEV_MAGIC;
 143
 144     return usb_cdc_dev;
 145 }
 146 #endif /* if defined(PIOS_INCLUDE_FREERTOS) */
 147
 148 /* Implement USB_IFOPS for CDC Control Interface */
 149 static void PIOS_USB_CDC_CTRL_IF_Init(uint32_t usb_cdc_id);
 150 static void PIOS_USB_CDC_CTRL_IF_DeInit(uint32_t usb_cdc_id);
 151 static bool PIOS_USB_CDC_CTRL_IF_Setup(uint32_t usb_cdc_id, struct usb_setup_request *req);
 152 static void PIOS_USB_CDC_CTRL_IF_CtrlDataOut(uint32_t usb_cdc_id, const struct usb_setup_request *req);
 153
 154 static struct pios_usb_ifops usb_cdc_ctrl_ifops = {
 155     .init   = PIOS_USB_CDC_CTRL_IF_Init,
 156     .deinit = PIOS_USB_CDC_CTRL_IF_DeInit,
 157     .setup  = PIOS_USB_CDC_CTRL_IF_Setup,
 158     .ctrl_data_out = PIOS_USB_CDC_CTRL_IF_CtrlDataOut,
 159 };
 160
 161 /* Implement USB_IFOPS for CDC Data Interface */
 162 static void PIOS_USB_CDC_DATA_IF_Init(uint32_t usb_cdc_id);
 163 static void PIOS_USB_CDC_DATA_IF_DeInit(uint32_t usb_cdc_id);
 164 static bool PIOS_USB_CDC_DATA_IF_Setup(uint32_t usb_cdc_id, struct usb_setup_request *req);
 165 static void PIOS_USB_CDC_DATA_IF_CtrlDataOut(uint32_t usb_cdc_id, const struct usb_setup_request *req);
 166
 167 static struct pios_usb_ifops usb_cdc_data_ifops = {
 168     .init   = PIOS_USB_CDC_DATA_IF_Init,
 169     .deinit = PIOS_USB_CDC_DATA_IF_DeInit,
 170     .setup  = PIOS_USB_CDC_DATA_IF_Setup,
 171     .ctrl_data_out = PIOS_USB_CDC_DATA_IF_CtrlDataOut,
 172 };
 173
 174 static uint32_t pios_usb_cdc_id;
 175
 176 int32_t PIOS_USB_CDC_Init(uint32_t *usbcdc_id, const struct pios_usb_cdc_cfg *cfg, uint32_t lower_id)
 177 {
 178     PIOS_Assert(usbcdc_id);
 179     PIOS_Assert(cfg);
 180
 181     struct pios_usb_cdc_dev *usb_cdc_dev;
 182
 183     usb_cdc_dev = (struct pios_usb_cdc_dev *)PIOS_USB_CDC_alloc();
 184     if (!usb_cdc_dev) {
 185         goto out_fail;
 186     }
 187
 188     /* Bind the configuration to the device instance */
 189     usb_cdc_dev->cfg = cfg;
 190     usb_cdc_dev->lower_id = lower_id;
 191
 192     pios_usb_cdc_id  = (uint32_t)usb_cdc_dev;
 193
 194     /* Tx is not active yet */
 195     usb_cdc_dev->tx_active           = false;
 196
 197     /* Clear stats */
 198     usb_cdc_dev->rx_dropped          = 0;
 199     usb_cdc_dev->rx_oversize         = 0;
 200
 201     /* Initialize the uart state */
 202     usb_cdc_dev->prev_uart_state     = 0;
 203
 204     /* Register class specific interface callbacks with the USBHOOK layer */
 205     usb_cdc_dev->usb_ctrl_if_enabled = false;
 206     PIOS_USBHOOK_RegisterIfOps(cfg->ctrl_if, &usb_cdc_ctrl_ifops, (uint32_t)usb_cdc_dev);
 207
 208     /* Register class specific interface callbacks with the USBHOOK layer */
 209     usb_cdc_dev->usb_data_if_enabled = false;
 210     PIOS_USBHOOK_RegisterIfOps(cfg->data_if, &usb_cdc_data_ifops, (uint32_t)usb_cdc_dev);
 211
 212     PIOS_USB_RegisterConnectionStateCallback(PIOS_USB_CDC_ChangeConnectionState, (uint32_t)usb_cdc_dev);
 213
 214     *usbcdc_id = (uint32_t)usb_cdc_dev;
 215
 216     return 0;
 217
 218 out_fail:
 219     return -1;
 220 }
 221
 222 static bool PIOS_USB_CDC_SendData(struct pios_usb_cdc_dev *usb_cdc_dev)
 223 {
 224     uint16_t bytes_to_tx;
 225
 226     if (!usb_cdc_dev->tx_out_cb) {
 227         return false;
 228     }
 229
 230     bool need_yield = false;
 231     bytes_to_tx = (usb_cdc_dev->tx_out_cb)(usb_cdc_dev->tx_out_context,
 232                                            usb_cdc_dev->tx_packet_buffer,
 233                                            sizeof(usb_cdc_dev->tx_packet_buffer),
 234                                            NULL,
 235                                            &need_yield);
 236     if (bytes_to_tx == 0) {
 237         return false;
 238     }
 239
 240     /*
 241      * Mark this endpoint as being tx active _before_ actually transmitting
 242      * to make sure we don't race with the Tx completion interrupt
 243      */
 244     usb_cdc_dev->tx_active = true;
 245
 246     PIOS_USBHOOK_EndpointTx(usb_cdc_dev->cfg->data_tx_ep,
 247                             usb_cdc_dev->tx_packet_buffer,
 248                             bytes_to_tx);
 249
 250 #if defined(PIOS_INCLUDE_FREERTOS)
 251     if (need_yield) {
 252         vPortYield();
 253     }
 254 #endif /* PIOS_INCLUDE_FREERTOS */
 255
 256     return true;
 257 }
 258
 259 static void PIOS_USB_CDC_RxStart(uint32_t usbcdc_id, uint16_t rx_bytes_avail)
 260 {
 261     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 262
 263     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 264
 265     PIOS_Assert(valid);
 266
 267     /* Make sure this USB interface has been initialized */
 268     if (!usb_cdc_dev->usb_data_if_enabled) {
 269         return;
 270     }
 271
 272     if (!PIOS_USB_CheckAvailable(usb_cdc_dev->lower_id)) {
 273         return;
 274     }
 275
 276     // If endpoint was stalled and there is now space make it valid
 277     if ((PIOS_USBHOOK_EndpointGetStatus(usb_cdc_dev->cfg->data_rx_ep) != USB_OTG_EP_RX_VALID)
 278         && (rx_bytes_avail >= PIOS_USB_BOARD_CDC_DATA_LENGTH)) {
 279         PIOS_USBHOOK_EndpointRx(usb_cdc_dev->cfg->data_rx_ep,
 280                                 usb_cdc_dev->rx_packet_buffer,
 281                                 sizeof(usb_cdc_dev->rx_packet_buffer));
 282     }
 283 }
 284
 285 static void PIOS_USB_CDC_TxStart(uint32_t usbcdc_id, __attribute__((unused)) uint16_t tx_bytes_avail)
 286 {
 287     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 288
 289     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 290
 291     PIOS_Assert(valid);
 292
 293     /* Make sure this USB interface has been initialized */
 294     if (!usb_cdc_dev->usb_data_if_enabled) {
 295         return;
 296     }
 297
 298     if (!PIOS_USB_CheckAvailable(usb_cdc_dev->lower_id)) {
 299         return;
 300     }
 301
 302     if (!usb_cdc_dev->tx_active) {
 303         /* Transmitter is not currently active, send a report */
 304         PIOS_USB_CDC_SendData(usb_cdc_dev);
 305     }
 306 }
 307
 308 static void PIOS_USB_CDC_RegisterRxCallback(uint32_t usbcdc_id, pios_com_callback rx_in_cb, uint32_t context)
 309 {
 310     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 311
 312     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 313
 314     PIOS_Assert(valid);
 315
 316     /*
 317      * Order is important in these assignments since ISR uses _cb
 318      * field to determine if it's ok to dereference _cb and _context
 319      */
 320     usb_cdc_dev->rx_in_context = context;
 321     usb_cdc_dev->rx_in_cb = rx_in_cb;
 322 }
 323
 324 static void PIOS_USB_CDC_RegisterTxCallback(uint32_t usbcdc_id, pios_com_callback tx_out_cb, uint32_t context)
 325 {
 326     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 327
 328     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 329
 330     PIOS_Assert(valid);
 331
 332     /*
 333      * Order is important in these assignments since ISR uses _cb
 334      * field to determine if it's ok to dereference _cb and _context
 335      */
 336     usb_cdc_dev->tx_out_context = context;
 337     usb_cdc_dev->tx_out_cb = tx_out_cb;
 338 }
 339
 340 static void PIOS_USB_CDC_RegisterCtrlLineCallback(uint32_t usbcdc_id, pios_com_callback_ctrl_line ctrl_line_cb, uint32_t context)
 341 {
 342     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 343
 344     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 345
 346     PIOS_Assert(valid);
 347
 348     /*
 349      * Order is important in these assignments since ISR uses _cb
 350      * field to determine if it's ok to dereference _cb and _context
 351      */
 352     usb_cdc_dev->ctrl_line_context = context;
 353     usb_cdc_dev->ctrl_line_cb = ctrl_line_cb;
 354 }
 355
 356 static void PIOS_USB_CDC_RegisterBaudRateCallback(uint32_t usbcdc_id, pios_com_callback_baud_rate baud_rate_cb, uint32_t context)
 357 {
 358     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 359
 360     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 361
 362     PIOS_Assert(valid);
 363
 364     /*
 365      * Order is important in these assignments since ISR uses _cb
 366      * field to determine if it's ok to dereference _cb and _context
 367      */
 368     usb_cdc_dev->baud_rate_context = context;
 369     usb_cdc_dev->baud_rate_cb = baud_rate_cb;
 370 }
 371
 372 static bool PIOS_USB_CDC_CTRL_EP_IN_Callback(uint32_t usb_cdc_id, uint8_t epnum, uint16_t len);
 373
 374 static void PIOS_USB_CDC_CTRL_IF_Init(uint32_t usb_cdc_id)
 375 {
 376     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 377
 378     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 379         return;
 380     }
 381
 382     /* Register endpoint specific callbacks with the USBHOOK layer */
 383     PIOS_USBHOOK_RegisterEpInCallback(usb_cdc_dev->cfg->ctrl_tx_ep,
 384                                       sizeof(usb_cdc_dev->ctrl_tx_packet_buffer),
 385                                       PIOS_USB_CDC_CTRL_EP_IN_Callback,
 386                                       (uint32_t)usb_cdc_dev);
 387     usb_cdc_dev->usb_ctrl_if_enabled = true;
 388 }
 389
 390 static void PIOS_USB_CDC_CTRL_IF_DeInit(uint32_t usb_cdc_id)
 391 {
 392     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 393
 394     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 395         return;
 396     }
 397
 398     /* DeRegister endpoint specific callbacks with the USBHOOK layer */
 399     usb_cdc_dev->usb_ctrl_if_enabled = false;
 400 }
 401
 402 static uint8_t cdc_altset;
 403 static struct usb_cdc_line_coding line_coding = {
 404     .dwDTERate   = htousbl(57600),
 405     .bCharFormat = USB_CDC_LINE_CODING_STOP_1,
 406     .bParityType = USB_CDC_LINE_CODING_PARITY_NONE,
 407     .bDataBits   = 8,
 408 };
 409
 410 static uint16_t control_line_state;
 411
 412 static bool PIOS_USB_CDC_CTRL_IF_Setup(uint32_t usb_cdc_id, struct usb_setup_request *req)
 413 {
 414     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 415
 416     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 417         return false;
 418     }
 419
 420     /* Make sure this is a request for an interface we know about */
 421     uint8_t ifnum = req->wIndex & 0xFF;
 422     if (ifnum != usb_cdc_dev->cfg->ctrl_if) {
 423         return false;
 424     }
 425
 426     switch (req->bmRequestType & (USB_REQ_TYPE_MASK | USB_REQ_RECIPIENT_MASK)) {
 427     case (USB_REQ_TYPE_STANDARD | USB_REQ_RECIPIENT_INTERFACE):
 428         switch (req->bRequest) {
 429         case USB_REQ_GET_INTERFACE:
 430             PIOS_USBHOOK_CtrlTx(&cdc_altset, 1);
 431             break;
 432         case USB_REQ_SET_INTERFACE:
 433             cdc_altset = (uint8_t)(req->wValue);
 434             break;
 435         default:
 436             /* Unhandled standard request */
 437             return false;
 438
 439             break;
 440         }
 441         break;
 442     case (USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE):
 443         switch (req->bRequest) {
 444         case USB_CDC_REQ_SET_LINE_CODING:
 445             PIOS_USBHOOK_CtrlRx((uint8_t *)&line_coding, sizeof(line_coding));
 446             break;
 447         case USB_CDC_REQ_GET_LINE_CODING:
 448             PIOS_USBHOOK_CtrlTx((uint8_t *)&line_coding, sizeof(line_coding));
 449             break;
 450         case USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 451             control_line_state = req->wValue;
 452             if (usb_cdc_dev->ctrl_line_cb) {
 453                 (usb_cdc_dev->ctrl_line_cb)(usb_cdc_dev->ctrl_line_context,
 454                                             0xff,
 455                                             control_line_state);
 456             }
 457             break;
 458         default:
 459             /* Unhandled class request */
 460             return false;
 461
 462             break;
 463         }
 464         break;
 465     default:
 466         /* Unhandled request */
 467         return false;
 468     }
 469
 470     return true;
 471 }
 472
 473 static uint32_t PIOS_USB_CDC_Available(uint32_t usbcdc_id)
 474 {
 475     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 476
 477     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 478
 479     PIOS_Assert(valid);
 480
 481     return PIOS_USB_CheckAvailable(usb_cdc_dev->lower_id) ? COM_AVAILABLE_RXTX : COM_AVAILABLE_NONE;
 482 }
 483
 484 /**
 485  * Called *after* the data has been written to the buffer provided in the setup stage.  The
 486  * setup request is passed in here again so we know *which* EP0 data out has just completed.
 487  */
 488 static void PIOS_USB_CDC_CTRL_IF_CtrlDataOut(uint32_t usb_cdc_id, const struct usb_setup_request *req)
 489 {
 490     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 491
 492     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 493         return;
 494     }
 495
 496     /* Make sure this is a request for an interface we know about */
 497     uint8_t ifnum = req->wIndex & 0xFF;
 498     if (ifnum != usb_cdc_dev->cfg->ctrl_if) {
 499         return;
 500     }
 501
 502     switch (req->bmRequestType & (USB_REQ_TYPE_MASK | USB_REQ_RECIPIENT_MASK)) {
 503     case (USB_REQ_TYPE_STANDARD | USB_REQ_RECIPIENT_INTERFACE):
 504         switch (req->bRequest) {
 505         default:
 506             /* Unhandled standard request */
 507             return;
 508
 509             break;
 510         }
 511         break;
 512     case (USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE):
 513         switch (req->bRequest) {
 514         case USB_CDC_REQ_SET_LINE_CODING:
 515             if (usb_cdc_dev->baud_rate_cb) {
 516                 usb_cdc_dev->baud_rate_cb(usb_cdc_dev->baud_rate_context, usbltoh(line_coding.dwDTERate));
 517             }
 518             break;
 519         default:
 520             /* Unhandled class request */
 521             return;
 522
 523             break;
 524         }
 525         break;
 526     default:
 527         /* Unhandled request */
 528         return;
 529     }
 530 }
 531
 532 static struct usb_cdc_serial_state_report uart_state = {
 533     .bmRequestType = 0xA1,
 534     .bNotification = USB_CDC_NOTIFICATION_SERIAL_STATE,
 535     .wValue      = 0,
 536     .wIndex      = htousbs(1),
 537     .wLength     = htousbs(2),
 538     .bmUartState = htousbs(0),
 539 };
 540
 541 static bool PIOS_USB_CDC_CTRL_EP_IN_Callback(
 542     __attribute__((unused)) uint32_t usb_cdc_id,
 543     __attribute__((unused)) uint8_t epnum,
 544     __attribute__((unused)) uint16_t len)
 545 {
 546     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)pios_usb_cdc_id;
 547
 548     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 549
 550     PIOS_Assert(valid);
 551
 552     /* Give back UART State Bitmap */
 553     /* UART State Bitmap
 554      *   15-7: reserved
 555      *      6:  bOverRun    overrun error
 556      *      5:  bParity     parity error
 557      *      4:  bFraming    framing error
 558      *      3:  bRingSignal RI
 559      *      2:  bBreak      break reception
 560      *      1:  bTxCarrier  DSR
 561      *      0:  bRxCarrier  DCD
 562      */
 563
 564     /* Currently, we only handle TxCarrier and RxCarrier reporting */
 565     uint16_t new_uart_state = 0;
 566     if (usb_cdc_dev->tx_out_cb) {
 567         /* Someone is going to providing FC->PC data, advertise an RxCarrier to the host */
 568         new_uart_state |= 0x1;
 569     }
 570     if (usb_cdc_dev->rx_in_cb) {
 571         /* Someone is consuming PC->FC data, advertise a TxCarrier to the host */
 572         new_uart_state |= 0x2;
 573     }
 574
 575     /* Has anything changed since we last sent a notification? */
 576     if ((new_uart_state ^ usb_cdc_dev->prev_uart_state) & 0x3) {
 577         usb_cdc_dev->prev_uart_state = new_uart_state;
 578
 579         uart_state.bmUartState = htousbs(new_uart_state);
 580
 581         PIOS_USBHOOK_EndpointTx(usb_cdc_dev->cfg->ctrl_tx_ep,
 582                                 (uint8_t *)&uart_state,
 583                                 sizeof(uart_state));
 584     }
 585
 586     return true;
 587 }
 588
 589 static bool PIOS_USB_CDC_DATA_EP_IN_Callback(uint32_t usb_cdc_id, uint8_t epnum, uint16_t len);
 590 static bool PIOS_USB_CDC_DATA_EP_OUT_Callback(uint32_t usb_cdc_id, uint8_t epnum, uint16_t len);
 591
 592 static void PIOS_USB_CDC_DATA_IF_Init(uint32_t usb_cdc_id)
 593 {
 594     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 595
 596     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 597         return;
 598     }
 599
 600     /* Register endpoint specific callbacks with the USBHOOK layer */
 601     PIOS_USBHOOK_RegisterEpInCallback(usb_cdc_dev->cfg->data_tx_ep,
 602                                       sizeof(usb_cdc_dev->tx_packet_buffer),
 603                                       PIOS_USB_CDC_DATA_EP_IN_Callback,
 604                                       (uint32_t)usb_cdc_dev);
 605     PIOS_USBHOOK_RegisterEpOutCallback(usb_cdc_dev->cfg->data_rx_ep,
 606                                        sizeof(usb_cdc_dev->rx_packet_buffer),
 607                                        PIOS_USB_CDC_DATA_EP_OUT_Callback,
 608                                        (uint32_t)usb_cdc_dev);
 609     usb_cdc_dev->usb_data_if_enabled = true;
 610     usb_cdc_dev->tx_active = false;
 611 }
 612
 613 static void PIOS_USB_CDC_DATA_IF_DeInit(uint32_t usb_cdc_id)
 614 {
 615     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usb_cdc_id;
 616
 617     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 618         return;
 619     }
 620
 621     /* DeRegister endpoint specific callbacks with the USBHOOK layer */
 622     usb_cdc_dev->usb_data_if_enabled = false;
 623     PIOS_USBHOOK_DeRegisterEpInCallback(usb_cdc_dev->cfg->data_tx_ep);
 624     PIOS_USBHOOK_DeRegisterEpOutCallback(usb_cdc_dev->cfg->data_rx_ep);
 625 }
 626
 627 static bool PIOS_USB_CDC_DATA_IF_Setup(
 628     __attribute__((unused)) uint32_t usb_cdc_id,
 629     __attribute__((unused)) struct usb_setup_request *req)
 630 {
 631     /* There are no valid EP0 transactions for CDC DATA interfaces */
 632     PIOS_Assert(0);
 633
 634     return false;
 635 }
 636
 637 /**
 638  * Called *after* the data has been written to the buffer provided in the setup stage.  The
 639  * setup request is passed in here again so we know *which* EP0 data out has just completed.
 640  */
 641 static void PIOS_USB_CDC_DATA_IF_CtrlDataOut(
 642     __attribute__((unused)) uint32_t usb_cdc_id,
 643     __attribute__((unused)) const struct usb_setup_request *req)
 644 {
 645     /* CDC DATA interfaces don't have any OUT data stages on the control endpoint */
 646     PIOS_Assert(0);
 647 }
 648
 649 /**
 650  * @brief Callback used to indicate a transmission from device INto host completed
 651  * Checks if any data remains, pads it into HID packet and sends.
 652  */
 653 static bool PIOS_USB_CDC_DATA_EP_IN_Callback(
 654     __attribute__((unused)) uint32_t usb_cdc_id,
 655     __attribute__((unused)) uint8_t epnum,
 656     __attribute__((unused)) uint16_t len)
 657 {
 658     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)pios_usb_cdc_id;
 659
 660     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 661
 662     PIOS_Assert(valid);
 663
 664     bool rc = PIOS_USB_CDC_SendData(usb_cdc_dev);
 665     if (!rc) {
 666         /* No additional data was transmitted, note that tx is no longer active */
 667         usb_cdc_dev->tx_active = false;
 668     }
 669
 670     return rc;
 671 }
 672
 673 static bool PIOS_USB_CDC_DATA_EP_OUT_Callback(
 674     __attribute__((unused)) uint32_t usb_cdc_id,
 675     __attribute__((unused)) uint8_t epnum,
 676     uint16_t len)
 677 {
 678     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)pios_usb_cdc_id;
 679
 680     if (!PIOS_USB_CDC_validate(usb_cdc_dev)) {
 681         return false;
 682     }
 683
 684     if (len > sizeof(usb_cdc_dev->rx_packet_buffer)) {
 685         len = sizeof(usb_cdc_dev->rx_packet_buffer);
 686     }
 687
 688     if (!usb_cdc_dev->rx_in_cb) {
 689         /* No Rx call back registered, disable the receiver */
 690         return false;
 691     }
 692
 693     uint16_t headroom;
 694     bool need_yield = false;
 695     uint16_t bytes_rxed;
 696     bytes_rxed = (usb_cdc_dev->rx_in_cb)(usb_cdc_dev->rx_in_context,
 697                                          usb_cdc_dev->rx_packet_buffer,
 698                                          len,
 699                                          &headroom,
 700                                          &need_yield);
 701
 702     if (bytes_rxed < len) {
 703         /* Lost bytes on rx */
 704         usb_cdc_dev->rx_dropped += (len - bytes_rxed);
 705     }
 706
 707     bool rc;
 708     if (headroom >= sizeof(usb_cdc_dev->rx_packet_buffer)) {
 709         /* We have room for a maximum length message */
 710         PIOS_USBHOOK_EndpointRx(usb_cdc_dev->cfg->data_rx_ep,
 711                                 usb_cdc_dev->rx_packet_buffer,
 712                                 sizeof(usb_cdc_dev->rx_packet_buffer));
 713         rc = true;
 714     } else {
 715         /* Not enough room left for a message, apply backpressure */
 716         rc = false;
 717     }
 718
 719 #if defined(PIOS_INCLUDE_FREERTOS)
 720     if (need_yield) {
 721         vPortYield();
 722     }
 723 #endif /* PIOS_INCLUDE_FREERTOS */
 724
 725     return rc;
 726 }
 727
 728 static void PIOS_USB_CDC_ChangeConnectionState(__attribute__((unused)) bool connected, uint32_t usbcdc_id)
 729 {
 730     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 731
 732     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 733
 734     PIOS_Assert(valid);
 735
 736     if (usb_cdc_dev->available_cb) {
 737         (usb_cdc_dev->available_cb)(usb_cdc_dev->available_context, PIOS_USB_CDC_Available(usbcdc_id));
 738     }
 739 }
 740
 741
 742 static void PIOS_USB_CDC_RegisterAvailableCallback(uint32_t usbcdc_id, pios_com_callback_available available_cb, uint32_t context)
 743 {
 744     struct pios_usb_cdc_dev *usb_cdc_dev = (struct pios_usb_cdc_dev *)usbcdc_id;
 745
 746     bool valid = PIOS_USB_CDC_validate(usb_cdc_dev);
 747
 748     PIOS_Assert(valid);
 749
 750     /*
 751      * Order is important in these assignments since ISR uses _cb
 752      * field to determine if it's ok to dereference _cb and _context
 753      */
 754     usb_cdc_dev->available_context = context;
 755     usb_cdc_dev->available_cb = available_cb;
 756 }
 757
 758 #endif /* PIOS_INCLUDE_USB_CDC */