firmware/usbstack/usb_serial.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2007 by Christian Gmeiner
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "string.h"
  22 #include "system.h"
  23 #include "usb_core.h"
  24 #include "usb_drv.h"
  25 #include "kernel.h"
  26 #include "usb_serial.h"
  27 #include "usb_class_driver.h"
  28 /*#define LOGF_ENABLE*/
  29 #include "logf.h"
  30
  31 /* serial interface */
  32 static struct usb_interface_descriptor __attribute__((aligned(2)))
  33     interface_descriptor =
  34 {
  35     .bLength            = sizeof(struct usb_interface_descriptor),
  36     .bDescriptorType    = USB_DT_INTERFACE,
  37     .bInterfaceNumber   = 0,
  38     .bAlternateSetting  = 0,
  39     .bNumEndpoints      = 2,
  40     .bInterfaceClass    = USB_CLASS_CDC_DATA,
  41     .bInterfaceSubClass = 0,
  42     .bInterfaceProtocol = 0,
  43     .iInterface         = 0
  44 };
  45
  46
  47 static struct usb_endpoint_descriptor __attribute__((aligned(2)))
  48     endpoint_descriptor =
  49 {
  50     .bLength          = sizeof(struct usb_endpoint_descriptor),
  51     .bDescriptorType  = USB_DT_ENDPOINT,
  52     .bEndpointAddress = 0,
  53     .bmAttributes     = USB_ENDPOINT_XFER_BULK,
  54     .wMaxPacketSize   = 0,
  55     .bInterval        = 0
  56 };
  57
  58 #define BUFFER_SIZE 512
  59 static unsigned char send_buffer[BUFFER_SIZE]
  60     USB_DEVBSS_ATTR __attribute__((aligned(32)));
  61 static unsigned char receive_buffer[32]
  62     USB_DEVBSS_ATTR __attribute__((aligned(32)));
  63
  64 static void sendout(void);
  65
  66 static int buffer_start;
  67 /* The number of bytes to transfer that haven't been given to the USB stack yet */
  68 static int buffer_length;
  69 /* The number of bytes to transfer that have been given to the USB stack */
  70 static int buffer_transitlength;
  71 static bool active = false;
  72
  73 static int ep_in, ep_out;
  74 static int usb_interface;
  75
  76 int usb_serial_request_endpoints(struct usb_class_driver *drv)
  77 {
  78     ep_in = usb_core_request_endpoint(USB_ENDPOINT_XFER_BULK, USB_DIR_IN, drv);
  79     if (ep_in < 0)
  80         return -1;
  81
  82     ep_out = usb_core_request_endpoint(USB_ENDPOINT_XFER_BULK, USB_DIR_OUT,
  83             drv);
  84     if (ep_out < 0) {
  85         usb_core_release_endpoint(ep_in);
  86         return -1;
  87     }
  88
  89     return 0;
  90 }
  91
  92 int usb_serial_set_first_interface(int interface)
  93 {
  94     usb_interface = interface;
  95     return interface + 1;
  96 }
  97
  98 int usb_serial_get_config_descriptor(unsigned char *dest, int max_packet_size)
  99 {
 100     unsigned char *orig_dest = dest;
 101
 102     interface_descriptor.bInterfaceNumber = usb_interface;
 103     PACK_DATA(dest, interface_descriptor);
 104
 105     endpoint_descriptor.wMaxPacketSize = max_packet_size;
 106
 107     endpoint_descriptor.bEndpointAddress = ep_in;
 108     PACK_DATA(dest, endpoint_descriptor);
 109
 110     endpoint_descriptor.bEndpointAddress = ep_out;
 111     PACK_DATA(dest, endpoint_descriptor);
 112
 113     return (dest - orig_dest);
 114 }
 115
 116 /* called by usb_core_control_request() */
 117 bool usb_serial_control_request(struct usb_ctrlrequest* req, unsigned char* dest)
 118 {
 119     bool handled = false;
 120
 121     (void)dest;
 122     switch (req->bRequest) {
 123         default:
 124             logf("serial: unhandeld req %d", req->bRequest);
 125     }
 126     return handled;
 127 }
 128
 129 void usb_serial_init_connection(void)
 130 {
 131     /* prime rx endpoint */
 132     usb_drv_recv(ep_out, receive_buffer, sizeof receive_buffer);
 133
 134     /* we come here too after a bus reset, so reset some data */
 135     buffer_transitlength = 0;
 136     if(buffer_length>0)
 137     {
 138         sendout();
 139     }
 140     active=true;
 141 }
 142
 143 /* called by usb_code_init() */
 144 void usb_serial_init(void)
 145 {
 146     logf("serial: init");
 147     buffer_start = 0;
 148     buffer_length = 0;
 149     buffer_transitlength = 0;
 150     active = true;
 151 }
 152
 153 void usb_serial_disconnect(void)
 154 {
 155     active = false;
 156 }
 157
 158 static void sendout(void)
 159 {
 160     buffer_transitlength = MIN(buffer_length,BUFFER_SIZE-buffer_start);
 161     /* For unknown reasons packets larger than 96 bytes are not sent. We play
 162      * safe and limit to 32. TODO: find the real bug */
 163     buffer_transitlength = MIN(buffer_transitlength,32);
 164     if(buffer_transitlength > 0)
 165     {
 166         buffer_length -= buffer_transitlength;
 167         usb_drv_send_nonblocking(ep_in, &send_buffer[buffer_start],
 168                 buffer_transitlength);
 169     }
 170 }
 171
 172 void usb_serial_send(const unsigned char *data,int length)
 173 {
 174     int freestart, available_end_space, i;
 175
 176     if (!active||length<=0)
 177         return;
 178
 179     i=buffer_start+buffer_length+buffer_transitlength;
 180     freestart=i%BUFFER_SIZE;
 181     available_end_space=BUFFER_SIZE-i;
 182
 183     if (0>=available_end_space)
 184     {
 185         /* current buffer wraps, so new data can't wrap */
 186         int available_space = BUFFER_SIZE -
 187             (buffer_length + buffer_transitlength);
 188
 189         length = MIN(length,available_space);
 190         memcpy(&send_buffer[freestart],data,length);
 191         buffer_length+=length;
 192     }
 193     else
 194     {
 195         /* current buffer doesn't wrap, so new data might */
 196         int first_chunk = MIN(length,available_end_space);
 197
 198         memcpy(&send_buffer[freestart],data,first_chunk);
 199         length-=first_chunk;
 200         buffer_length+=first_chunk;
 201         if(length>0)
 202         {
 203             /* wrap */
 204             memcpy(&send_buffer[0],&data[first_chunk],MIN(length,buffer_start));
 205             buffer_length+=MIN(length,buffer_start);
 206         }
 207     }
 208
 209     if (buffer_transitlength==0)
 210         sendout();
 211     /* else do nothing. The transfer completion handler will pick it up */
 212 }
 213
 214 /* called by usb_core_transfer_complete() */
 215 void usb_serial_transfer_complete(int ep,int dir, int status, int length)
 216 {
 217     (void)ep;
 218     (void)length;
 219
 220     switch (dir) {
 221         case USB_DIR_OUT:
 222             logf("serial: %s", receive_buffer);
 223             /* Data received. TODO : Do something with it ? */
 224
 225             /* Get the next bit */
 226             usb_drv_recv(ep_out, receive_buffer, sizeof receive_buffer);
 227             break;
 228
 229         case USB_DIR_IN:
 230             /* Data sent out. Update circular buffer */
 231             if(status == 0)
 232             {
 233                 /* TODO: Handle (length != buffer_transitlength) */
 234
 235                 buffer_start=(buffer_start+buffer_transitlength)%BUFFER_SIZE;
 236                 buffer_transitlength = 0;
 237             }
 238
 239             if(buffer_length>0)
 240                 sendout();
 241             break;
 242     }
 243 }