usb-serial.c

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/*
 * Copyright (c) 2012, Philippe Retornaz
 * Copyright (c) 2012, EPFL STI IMT LSRO1 -- Mobots group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * \addtogroup cc2538-usb
 * @{
 *
 * \file
 * Platform process which implements a UART-like functionality over the
 * cc2538's USB hardware.
 *
 * This has been ported over from platform/cc2530dk
 *
 * \author
 *  - Philippe Retornaz (EPFL) - Original code
 *  - George Oikonomou - <oikonomou@users.sourceforge.net>
 *    Turned this to a 'serial over USB' platform process, ported for cc2538
 */
#include "contiki.h"
#include "sys/process.h"
#include "net/linkaddr.h"
#include "usb-api.h"
#include "usb.h"
#include "usb-arch.h"
#include "cdc-acm/cdc-acm.h"
#include "ieee-addr.h"

#include <stdint.h>
/*---------------------------------------------------------------------------*/
#define DEBUG 0

#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
struct lang_id {
  uint8_t size;
  uint8_t type;
  uint16_t langid;
};
static const struct lang_id lang_id = { sizeof(lang_id), 3, 0x0409 };
/*---------------------------------------------------------------------------*/
struct serial_nr {
  uint8_t size;
  uint8_t type;
  uint16_t string[16];
};
static struct serial_nr serial_nr = {
  sizeof(serial_nr),
  3, {
    'A', 'A', 'A', 'A', 'A', 'A', 'A', 'A',
    'A', 'A', 'A', 'A', 'A', 'A', 'A', 'A'
  }
};
/*---------------------------------------------------------------------------*/
struct manufacturer {
  uint8_t size;
  uint8_t type;
  uint16_t string[17];
};
static const struct manufacturer manufacturer = {
  sizeof(manufacturer),
  3,
  {
    'T', 'e', 'x', 'a', 's', ' ',
    'I', 'n', 's', 't', 'r', 'u', 'm', 'e', 'n', 't', 's'
  }
};
/*---------------------------------------------------------------------------*/
struct product {
  uint8_t size;
  uint8_t type;
  uint16_t string[21];
};
static const struct product product = {
  sizeof(product),
  3,
  {
    'c', 'c', '2', '5', '3', '8', ' ',
    'S', 'y', 's', 't', 'e', 'm', '-', 'o', 'n', '-', 'C', 'h', 'i', 'p'
  }
};
/*---------------------------------------------------------------------------*/
#define EPIN  0x82
#define EPOUT 0x03

#define RX_BUFFER_SIZE USB_EP3_SIZE
#define TX_BUFFER_SIZE (USB_EP2_SIZE - 1)

typedef struct _USBBuffer usb_buffer;

static usb_buffer data_rx_urb;
static usb_buffer data_tx_urb;
static uint8_t usb_rx_data[RX_BUFFER_SIZE];
static uint8_t enabled = 0;

#define SLIP_END 0300
static uint8_t usb_tx_data[TX_BUFFER_SIZE];
static uint8_t buffered_data = 0;

/* Callback to the input handler */
static int (* input_handler)(unsigned char c);
/*---------------------------------------------------------------------------*/
uint8_t *
usb_class_get_string_descriptor(uint16_t lang, uint8_t string)
{
  switch (string) {
  case 0:
    return (uint8_t *)&lang_id;
  case 1:
    return (uint8_t *)&manufacturer;
  case 2:
    return (uint8_t *)&product;
  case 3:
    return (uint8_t *)&serial_nr;
  default:
    return NULL;
  }
}
/*---------------------------------------------------------------------------*/
static void
set_serial_number(void)
{
  uint8_t i;
  uint8_t ieee[8];
  uint8_t lown, highn;
  uint8_t c;

  ieee_addr_cpy_to(ieee, 8);

  for(i = 0; i < 8; i++) {
    lown = ieee[i] & 0x0F;
    highn = ieee[i] >> 4;
    c = lown > 9 ? 'A' + lown - 0xA : lown + '0';
    serial_nr.string[i * 2 + 1] = c;
    c = highn > 9 ? 'A' + highn - 0xA : highn + '0';
    serial_nr.string[i * 2] = c;
  }
}
/*---------------------------------------------------------------------------*/
static void
queue_rx_urb(void)
{
  data_rx_urb.flags = USB_BUFFER_PACKET_END;
  data_rx_urb.flags |= USB_BUFFER_NOTIFY;
  data_rx_urb.data = usb_rx_data;
  data_rx_urb.left = RX_BUFFER_SIZE;
  data_rx_urb.next = NULL;
  usb_submit_recv_buffer(EPOUT, &data_rx_urb);
}
/*---------------------------------------------------------------------------*/
static void
do_work(void)
{
  unsigned int events;

  events = usb_get_global_events();
  if(events & USB_EVENT_CONFIG) {
    /* Configure EPs. Don't enable them yet, until the CDC line is up */
    usb_setup_bulk_endpoint(EPIN);
    usb_setup_bulk_endpoint(EPOUT);

    queue_rx_urb();
  }
  if(events & USB_EVENT_RESET) {
    enabled = 0;
  }

  events = usb_cdc_acm_get_events();
  if(events & USB_CDC_ACM_LINE_STATE) {
    uint8_t line_state = usb_cdc_acm_get_line_state();
    PRINTF("CDC-ACM event 0x%04x, Line State = %u\n", events, line_state);
    if(line_state & USB_CDC_ACM_DTE) {
      enabled = 1;
    } else {
      enabled = 0;
    }
  }

  if(!enabled) {
    return;
  }

  events = usb_get_ep_events(EPOUT);
  if((events & USB_EP_EVENT_NOTIFICATION)
     && !(data_rx_urb.flags & USB_BUFFER_SUBMITTED)) {
    if(!(data_rx_urb.flags & USB_BUFFER_FAILED)) {
      if(input_handler) {
        uint8_t len;
        uint8_t i;

        len = RX_BUFFER_SIZE - data_rx_urb.left;
        for(i = 0; i < len; i++) {
          input_handler(usb_rx_data[i]);
        }
      }
    }
    queue_rx_urb();
  }
}
/*---------------------------------------------------------------------------*/
void
usb_serial_flush()
{
  if(buffered_data == 0) {
    return;
  }

  data_tx_urb.flags = USB_BUFFER_SHORT_END;
  data_tx_urb.flags |= USB_BUFFER_NOTIFY;
  data_tx_urb.next = NULL;
  data_tx_urb.data = usb_tx_data;
  data_tx_urb.left = buffered_data;
  buffered_data = 0;
  usb_submit_xmit_buffer(EPIN, &data_tx_urb);
}
/*---------------------------------------------------------------------------*/
void
usb_serial_writeb(uint8_t b)
{
  if(!enabled) {
    buffered_data = 0;
    return;
  }

  usb_tx_data[buffered_data] = b;
  buffered_data++;

  if(buffered_data == TX_BUFFER_SIZE) {
    usb_serial_flush();
  }
}
/*---------------------------------------------------------------------------*/
PROCESS(usb_serial_process, "USB-Serial process");
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(usb_serial_process, ev, data)
{

  PROCESS_BEGIN();

  set_serial_number();

  usb_setup();
  usb_cdc_acm_setup();
  usb_set_global_event_process(&usb_serial_process);
  usb_cdc_acm_set_event_process(&usb_serial_process);
  usb_set_ep_event_process(EPIN, &usb_serial_process);
  usb_set_ep_event_process(EPOUT, &usb_serial_process);

  while(1) {
    PROCESS_WAIT_EVENT();
    if(ev == PROCESS_EVENT_EXIT) {
      break;
    }
    if(ev == PROCESS_EVENT_POLL) {
      do_work();
    }
  }

  PROCESS_END();
}
/*---------------------------------------------------------------------------*/
void
usb_serial_set_input(int (* input)(unsigned char c))
{
  input_handler = input;
}
/*---------------------------------------------------------------------------*/
void
usb_serial_init()
{
  process_start(&usb_serial_process, NULL);
}
/*---------------------------------------------------------------------------*/

/** @} */