diff --git a/tcl/chip/atmel/at91/sam9_smc.cfg b/tcl/chip/atmel/at91/sam9_smc.cfg
index db943cb24..0628d4d18 100644
--- a/tcl/chip/atmel/at91/sam9_smc.cfg
+++ b/tcl/chip/atmel/at91/sam9_smc.cfg
@@ -26,30 +26,30 @@
 # tdf_cycles
 proc sam9_smc_config { cs smc_config } {
 	;# Setup Register for CS n
-	set AT91_SMC_SETUP [expr ($::AT91_SMC + 0x00 + ((cs)*0x10))]
-	set val [expr ($smc_config(nwe_setup) << 0)]
-	set val [expr ($val | $smc_config(ncs_write_setup) << 8]
-	set val [expr ($val | $smc_config(nrd_setup)) << 16]
-	set val [expr ($val | $smc_config(ncs_read_setup) << 24]
+	set AT91_SMC_SETUP [expr {$::AT91_SMC + 0x00 + $cs * 0x10}]
+	set val [expr {$smc_config(nwe_setup) << 0}]
+	set val [expr {$val | $smc_config(ncs_write_setup) << 8}]
+	set val [expr {$val | $smc_config(nrd_setup)) << 16}]
+	set val [expr {$val | $smc_config(ncs_read_setup) << 24}]
 	mww $AT91_SMC_SETUP $val
 
 	;# Pulse Register for CS n
-	set AT91_SMC_PULSE [expr ($::AT91_SMC + 0x04 + ((cs)*0x10))]
-	set val [expr ($smc_config(nwe_pulse) << 0)]
-	set val [expr ($val | $smc_config(ncs_write_pulse) << 8]
-	set val [expr ($val | $smc_config(nrd_pulse) << 16]
-	set val [expr ($val | $smc_config(ncs_read_pulse) << 24]
+	set AT91_SMC_PULSE [expr {$::AT91_SMC + 0x04 + $cs * 0x10}]
+	set val [expr {$smc_config(nwe_pulse) << 0}]
+	set val [expr {$val | $smc_config(ncs_write_pulse) << 8}]
+	set val [expr {$val | $smc_config(nrd_pulse) << 16}]
+	set val [expr {$val | $smc_config(ncs_read_pulse) << 24}]
 	mww $AT91_SMC_PULSE $val
 
 	;# Cycle Register for CS n
-	set AT91_SMC_CYCLE [expr ($::AT91_SMC + 0x08 + ((cs)*0x10))]
-	set val [expr ($smc_config(write_cycle) << 0)]
-	set val [expr ($val | $smc_config(read_cycle) << 16]
+	set AT91_SMC_CYCLE [expr {$::AT91_SMC + 0x08 + $cs * 0x10}]
+	set val [expr {$smc_config(write_cycle) << 0}]
+	set val [expr {$val | $smc_config(read_cycle) << 16}]
 	mww $AT91_SMC_CYCLE $val
 
 	;# Mode Register for CS n
-	set AT91_SMC_MODE [expr ($::AT91_SMC + 0x0c + ((cs)*0x10))]
-	set val [expr ($smc_config(mode) << 0)]
-	set val [expr ($val | $smc_config(tdf_cycles) << 16]
+	set AT91_SMC_MODE [expr {$::AT91_SMC + 0x0c + $cs * 0x10}]
+	set val [expr {$smc_config(mode) << 0}]
+	set val [expr {$val | $smc_config(tdf_cycles) << 16}]
 	mww $AT91_SMC_MODE $val
 }