Re: Small patch for asynMask bitmask values

[Angus Gratton <angus.gratton@anu.edu.au>]

On Fri, 2010-08-20 at 11:31 +1000, Angus Gratton wrote:
> Hi everyone,
> 
> I have a trivial patch for asyn 4-13-1, I thought I'd send it to the
> list for comment as well as to Mark directly.

Blech, sorry. Updated version of the patch, removed some unnecessary bad
errno fiddling.

- Angus

Index: documentation/asynDriver.html
===================================================================
--- documentation/asynDriver.html	(revision 16)
+++ documentation/asynDriver.html	(working copy)
@@ -3933,7 +3933,9 @@
     interface asynUInt32Digital. The INP or OUT field must define asynMask. The mask
     specified in the argument to asynMask is used in the calls to asynUInt32Digital
     methods. In addition it is used to set the mask fields in bi and bo records and
-    the mask and shft fields in mbbi, mbbo, mbbiDirect, and mbboDirect records.</p>
+    the mask and shft fields in mbbi, mbbo, mbbiDirect, and mbboDirect records. Mask
+    values can be specified as decimal or hexadecimal integers, or a single bit can be
+    identified using the notation 'bitX' (equivalent to the C expression 1<<X.)</p>
   <ul>
     <li>biRecord
       <p>
@@ -3992,7 +3994,7 @@
     Binary Output Example Record</p>
   <pre>record(bo,"boUInt32Bit2") {
     field(DTYP,"asynUInt32Digital")
-    field(OUT,"@asynMask( $(port) , 0, 0x4 , 1.0) ")
+    field(OUT,"@asynMask( $(port) , 0, bit2 , 1.0) ")
     field(ZNAM,"zero")
     field(ONAM,"one")
 }</pre>
Index: asyn/devEpics/asynEpicsUtils.c
===================================================================
--- asyn/devEpics/asynEpicsUtils.c	(revision 16)
+++ asyn/devEpics/asynEpicsUtils.c	(working copy)
@@ -155,7 +155,17 @@
     }
     return(asynSuccess);
 }
-
+
+// Scan a value for a bitmask, which can be either a number suitable for
+// strtoul or a value 'bitX' for X in the range 0-31
+epicsUInt32 scanMaskValue(const char *start, char **end)
+{
+    if(strncmp(start, "bit", 3) == 0) {
+	     return strtoul(start+3,end,0);
+    }
+    return strtoul(start,end,0);
+}
+
 static asynStatus parseLinkMask(asynUser *pasynUser, DBLINK *plink, 
                    char **port, int *addr, epicsUInt32 *mask,char **userParam)
 {
@@ -196,7 +206,7 @@
     pnext = skipWhite(pnext,1);
     if(*pnext==0 || *pnext==')') goto error;
     errno = 0;
-    *mask = strtoul(pnext,&endp,0);
+    *mask = scanMaskValue(pnext, &endp);
     if(errno) goto error;
     /*next is timeout*/
     pnext = endp;