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
  28 //#define LOGF_ENABLE
  29 #include "logf.h"
  30
  31 #ifdef USB_SERIAL
  32
  33 /* serial interface */
  34 static struct usb_interface_descriptor __attribute__((aligned(2)))
  35                                 interface_descriptor =
  36 {
  37     .bLength            = sizeof(struct usb_interface_descriptor),
  38     .bDescriptorType    = USB_DT_INTERFACE,
  39     .bInterfaceNumber   = 0,
  40     .bAlternateSetting  = 0,
  41     .bNumEndpoints      = 2,
  42     .bInterfaceClass    = USB_CLASS_CDC_DATA,
  43     .bInterfaceSubClass = 0,
  44     .bInterfaceProtocol = 0,
  45     .iInterface         = 0
  46 };
  47
  48
  49 static struct usb_endpoint_descriptor __attribute__((aligned(2))) endpoint_descriptor =
  50 {
  51     .bLength          = sizeof(struct usb_endpoint_descriptor),
  52     .bDescriptorType  = USB_DT_ENDPOINT,
  53     .bEndpointAddress = 0,
  54     .bmAttributes     = USB_ENDPOINT_XFER_BULK,
  55     .wMaxPacketSize   = 0,
  56     .bInterval        = 0
  57 };
  58
  59 #define BUFFER_SIZE 512
  60 static unsigned char send_buffer[BUFFER_SIZE]
  61     USB_DEVBSS_ATTR __attribute__((aligned(32)));
  62 static unsigned char receive_buffer[32]
  63     USB_DEVBSS_ATTR __attribute__((aligned(32)));
  64
  65 static void sendout(void);
  66
  67 static int buffer_start;
  68 /* The number of bytes to transfer that haven't been given to the USB stack yet */
  69 static int buffer_length;
  70 /* The number of bytes to transfer that have been given to the USB stack */
  71 static int buffer_transitlength;
  72 static bool active = false;
  73
  74 static int ep_in, ep_out;
  75 static int usb_interface;
  76
  77 int usb_serial_request_endpoints(struct usb_class_driver *drv)
  78 {
  79     ep_in = usb_core_request_endpoint(USB_DIR_IN, drv);
  80
  81     if (ep_in < 0)
  82         return -1;
  83
  84     ep_out = usb_core_request_endpoint(USB_DIR_OUT, drv);
  85
  86     if (ep_out < 0) {
  87         usb_core_release_endpoint(ep_in);
  88         return -1;
  89     }
  90
  91     return 0;
  92 }
  93
  94 int usb_serial_set_first_interface(int interface)
  95 {
  96     usb_interface = interface;
  97     return interface + 1;
  98 }
  99
 100
 101 int usb_serial_get_config_descriptor(unsigned char *dest,int max_packet_size)
 102 {
 103     unsigned char *orig_dest = dest;
 104
 105     endpoint_descriptor.wMaxPacketSize=max_packet_size;
 106     interface_descriptor.bInterfaceNumber=usb_interface;
 107
 108     memcpy(dest,&interface_descriptor,sizeof(struct usb_interface_descriptor));
 109     dest+=sizeof(struct usb_interface_descriptor);
 110
 111     endpoint_descriptor.bEndpointAddress = ep_in;
 112     memcpy(dest,&endpoint_descriptor,sizeof(struct usb_endpoint_descriptor));
 113     dest+=sizeof(struct usb_endpoint_descriptor);
 114
 115     endpoint_descriptor.bEndpointAddress = ep_out;
 116     memcpy(dest,&endpoint_descriptor,sizeof(struct usb_endpoint_descriptor));
 117     dest+=sizeof(struct usb_endpoint_descriptor);
 118
 119     return (dest - orig_dest);
 120 }
 121
 122 /* called by usb_core_control_request() */
 123 bool usb_serial_control_request(struct usb_ctrlrequest* req)
 124 {
 125     bool handled = false;
 126     switch (req->bRequest) {
 127         default:
 128             logf("serial: unhandeld req %d", req->bRequest);
 129     }
 130     return handled;
 131 }
 132
 133 void usb_serial_init_connection(void)
 134 {
 135     /* prime rx endpoint */
 136     usb_drv_recv(ep_out, receive_buffer, sizeof receive_buffer);
 137
 138     /* we come here too after a bus reset, so reset some data */
 139     buffer_transitlength = 0;
 140     if(buffer_length>0)
 141     {
 142         sendout();
 143     }
 144     active=true;
 145 }
 146
 147 /* called by usb_code_init() */
 148 void usb_serial_init(void)
 149 {
 150     logf("serial: init");
 151     buffer_start = 0;
 152     buffer_length = 0;
 153     buffer_transitlength = 0;
 154     active = true;
 155 }
 156
 157 void usb_serial_disconnect(void)
 158 {
 159     active = false;
 160 }
 161
 162 static void sendout(void)
 163 {
 164     if(buffer_start+buffer_length >= BUFFER_SIZE)
 165     {
 166         /* Buffer wraps. Only send the first part */
 167         buffer_transitlength=BUFFER_SIZE - buffer_start;
 168     }
 169     else
 170     {
 171         /* Send everything */
 172         buffer_transitlength=buffer_length;
 173     }
 174     if(buffer_transitlength>0)
 175     {
 176         buffer_length-=buffer_transitlength;
 177         usb_drv_send_nonblocking(ep_in, &send_buffer[buffer_start],
 178                                  buffer_transitlength);
 179     }
 180 }
 181
 182 void usb_serial_send(unsigned char *data,int length)
 183 {
 184     if(!active)
 185         return;
 186     if(length<=0)
 187         return;
 188     int freestart=(buffer_start+buffer_length+buffer_transitlength)%BUFFER_SIZE;
 189     if(buffer_start+buffer_transitlength+buffer_length >= BUFFER_SIZE)
 190     {
 191         /* current buffer wraps, so new data can't */
 192         int available_space = BUFFER_SIZE - buffer_length - buffer_transitlength;
 193         length=MIN(length,available_space);
 194         memcpy(&send_buffer[freestart],
 195                data,length);
 196         buffer_length+=length;
 197     }
 198     else
 199     {
 200         /* current buffer doesn't wrap, so new data might */
 201         int available_end_space = (BUFFER_SIZE - (buffer_start+buffer_length+buffer_transitlength));
 202         int first_chunk = MIN(length,available_end_space);
 203         memcpy(&send_buffer[freestart],data,first_chunk);
 204         length-=first_chunk;
 205         buffer_length+=first_chunk;
 206         if(length>0)
 207         {
 208             /* wrap */
 209             memcpy(&send_buffer[0],&data[first_chunk],MIN(length,buffer_start));
 210             buffer_length+=MIN(length,buffer_start);
 211         }
 212     }
 213     if(buffer_transitlength>0)
 214     {
 215         /* Do nothing. The transfer completion handler will pick it up */
 216     }
 217     else
 218     {
 219         sendout();
 220     }
 221 }
 222
 223 /* called by usb_core_transfer_complete() */
 224 void usb_serial_transfer_complete(int ep,int dir, int status, int length)
 225 {
 226     (void)ep;
 227     switch (dir) {
 228         case USB_DIR_OUT:
 229             logf("serial: %s", receive_buffer);
 230             /* Data received. TODO : Do something with it ? */
 231
 232             /* Get the next bit */
 233             usb_drv_recv(ep_out, receive_buffer, sizeof receive_buffer);
 234             break;
 235
 236         case USB_DIR_IN:
 237             /* Data sent out. Update circular buffer */
 238             if(status == 0)
 239             {
 240                 if(length!=buffer_transitlength)
 241                 {
 242                     /* do something? */
 243                 }
 244                 buffer_start = (buffer_start + buffer_transitlength)%BUFFER_SIZE;
 245                 buffer_transitlength = 0;
 246             }
 247
 248             if(buffer_length>0)
 249             {
 250                 sendout();
 251             }
 252             break;
 253     }
 254 }
 255
 256
 257 #endif /*USB_SERIAL*/