TCL scripts: collect duplicated procedures

TCL procedures mrw and mmw, originally in DaVinci target code,
are duplicated in other TCL scripts.
Moved in a common helper file, and added help/usage description.

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>

tcl/mem_helper.tcl

@@ -0,0 +1,22 @@
+# Helper for common memory read/modify/write procedures
+
+# mrw: "memory read word", returns value of $reg
+proc mrw {reg} {
+	set value ""
+	ocd_mem2array value 32 $reg 1
+	return $value(0)
+}
+
+add_usage_text mrw "address"
+add_help_text mrw "Returns value of word in memory."
+
+# mmw: "memory modify word", updates value of $reg
+#       $reg <== ((value & ~$clearbits) | $setbits)
+proc mmw {reg setbits clearbits} {
+	set old [mrw $reg]
+	set new [expr ($old & ~$clearbits) | $setbits]
+	mww $reg $new
+}
+
+add_usage_text mmw "address setbits clearbits"
+add_help_text mmw "Modify word in memory. new_val = (old_val & ~clearbits) | setbits;"

tcl/target/c100helper.tcl

@@ -25,13 +25,7 @@ proc helpC100 {} {
     puts "22) flashUBOOT:        will prgram NOR sectors 0-3 with u-boot.bin"
 }
 
-# mrw,mmw from davinci.cfg
-# mrw: "memory read word", returns value of $reg
-proc mrw {reg} {
-    set value ""
-    mem2array value 32 $reg 1
-    return $value(0)
-}
+source [find mem_helper.tcl]
 
 # read a 64-bit register (memory mapped)
 proc mr64bit {reg} {
@@ -50,14 +44,6 @@ proc mw64bit {reg value} {
     mww [expr $reg+4] $high
 }
 
-# mmw: "memory modify word", updates value of $reg
-#	$reg <== ((value & ~$clearbits) | $setbits)
-proc mmw {reg setbits clearbits} {
-    set old [mrw $reg]
-    set new [expr ($old & ~$clearbits) | $setbits]
-    mww $reg $new
-}
-
 
 proc showNOR {} {
     puts "This is the current NOR setup"

tcl/target/davinci.cfg

@@ -7,20 +7,7 @@ proc davinci_pinmux {soc reg value} {
 	mww [expr [dict get $soc sysbase] + 4 * $reg] $value
 }
 
-# mrw: "memory read word", returns value of $reg
-proc mrw {reg} {
-	set value ""
-	mem2array value 32 $reg 1
-	return $value(0)
-}
-
-# mmw: "memory modify word", updates value of $reg
-#	$reg <== ((value & ~$clearbits) | $setbits)
-proc mmw {reg setbits clearbits} {
-	set old [mrw $reg]
-	set new [expr ($old & ~$clearbits) | $setbits]
-	mww $reg $new
-}
+source [find mem_helper.tcl]
 
 #
 # pll_setup: initialize PLL

tcl/target/stellaris.cfg

@@ -46,12 +46,7 @@ $_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE
 # this, if you're using a slower clock.
 adapter_khz 500
 
-# mrw: "memory read word", returns value of $reg
-proc mrw {reg} {
-	set value ""
-	mem2array value 32 $reg 1
-	return $value(0)
-}
+source [find mem_helper.tcl]
 
 $_TARGETNAME configure -event reset-start {
 	adapter_khz 500