USB docs change

To avoid confusion can the usb docs be changed.

Lines 155 to 166 should be removed because R6-R8 are not used by DeviceFS_CallDevice in DeviceFS or when the action code (r0) is USB Control Request.

The docs defines USB Control Request as follows:

  145: USB Control Request                                                           Yes      Yes        
  146: R0        1<<31 + 0   Send request to a device's default control pipe and                         
  147:                       return the reply.                                                           
  148: R1                    Device name eg "usbd"                                                       
  149: R3        Byte 0      BmRequestType                                                               
  150:           Byte 1      BRequest                                                                    
  151:           Bytes 2,3   WValue                                                                      
  152: R4        Bytes 0,1   WIndex                                                                      
  153:           Bytes 2,3   WLength                                                                     
  154: R5                    Pointer to data buffer.                                                     
  155: R6        0           Return on command completion, command failure,                              
  156:                       or command timeout.                                                         
  157:           Bit 0 = 1   Return after commencing the command with R7 containing                      
  158:                       the address of a pollable status byte. See                                  
  159:                       below for details of return values                                          
  160:           Bit 1 = 1   On entry, R7 contains the address of a routine to be                        
  161:                       called on command completion. R8 will contain the                           
  162:                       value to be used for the R12 value when this is                             
  163:                       called. See below for details of this call.                                 
  164: R7                    Callback address if R6 bit 1 set.                                           
  165: R8                    Private word for Callback address in R7 if                                  
  166:                       R6 bit 1 set.                                                               

DeviceFS_CallDevice in devicefs is defined like this:

 1411: ; DeviceFS_CallDevice
 1412: ;
 1413: ; in:   r0  = reason code
 1414: ;       r1 -> parent record (device handle)
 1415: ;          -> path (can include "$.")
 1416: ;           = 0 broadcast to all devices
 1417: ;
 1418: ;   r2..r7  = parameters passed to device
 1419: ;       wp -> workspace
 1420: ;
 1421: ; out:  V clear, registers setup as defined by call
 1422: ;       V set, r0 -> error block.

So r6,r7,r8 isn’t being passed to DeviceFS_CallDevice for use by DeviceFS_CallDevice itself.

And in usbmodule the control request action code does this:

3092:     case DeviceFSCallDevice_USBRequest:
3093:         {
3094:             struct req { int a, b; } rq = (struct req) { r→r3, r→r4 };
3095:             int err = usbd_do_request (udev→sc_udev, (void*) &rq, (char*)r→r5);
3096: #if 1
3097:             if (err != 0) return uerror (E_BadRequest);
3098: #else
3099:             if (err != 0)
3100:             {
3101:                 static _kernel_oserror e;
3102:                 char cc5, *cp;
3103:                 sprintf (cc, “CC%02d”, err);
3104:                 swix (MessageTransLookup, INR|OUT,
3105:                     &mod_messages, cc, 0, &cp);
3106:                 return swix (MessageTransErrorLookup, _INR(0,4),
3107:                     E_BadRequest, &mod_messages, &e, sizeof e, cp);
3108:             }
3109: #endif
3110:
3111:             break;
3112:         }

So USB control request doesn’t use r6,r7,r8

I note when changing the docs you just marked r6-r8 as ‘not on iyonix’ but still possible for the podule . If it is possible to use these registers for a podule then it may be a good idea to require require r6 to be 0 on the iyonix so that code is compatible with both systems.

On another subject can I make a plea that comments in files and when committing changes are hard line wrapped. When reading the CVS logs and ‘markup’ files online, comments can go on for a number of horizontal screenfuls as they appear as a single line.

it may be a good idea to require require r6 to be 0

If you note my notes in the notes I noted this as a note already.