diff --git a/plat/arm/common/arm_nor_psci_mem_protect.c b/plat/arm/common/arm_nor_psci_mem_protect.c
index c01e4ed..1b0b1da 100644
--- a/plat/arm/common/arm_nor_psci_mem_protect.c
+++ b/plat/arm/common/arm_nor_psci_mem_protect.c
@@ -51,14 +51,14 @@
  ******************************************************************************/
 int arm_nor_psci_write_mem_protect(int val)
 {
-	int enable = (val != 0);
+	int enable = (val != 0) ? 1 : 0;
 
 	if (nor_unlock(PLAT_ARM_MEM_PROT_ADDR) != 0) {
 		ERROR("unlocking memory protect variable\n");
 		return -1;
 	}
 
-	if (enable != 0) {
+	if (enable == 1) {
 		/*
 		 * If we want to write a value different than 0
 		 * then we have to erase the full block because
@@ -117,14 +117,14 @@
 {
 	int enable;
 
-	arm_psci_read_mem_protect(&enable);
+	(void) arm_psci_read_mem_protect(&enable);
 	if (enable == 0)
 		return;
 
 	INFO("PSCI: Overwriting non secure memory\n");
 	clear_mem_regions(arm_ram_ranges,
 			  ARRAY_SIZE(arm_ram_ranges));
-	arm_nor_psci_write_mem_protect(0);
+	(void) arm_nor_psci_write_mem_protect(0);
 }
 
 /*******************************************************************************
diff --git a/plat/arm/common/arm_pm.c b/plat/arm/common/arm_pm.c
index d0350d6..a8289ff 100644
--- a/plat/arm/common/arm_pm.c
+++ b/plat/arm/common/arm_pm.c
@@ -30,11 +30,11 @@
 int arm_validate_power_state(unsigned int power_state,
 			    psci_power_state_t *req_state)
 {
-	int pstate = psci_get_pstate_type(power_state);
-	int pwr_lvl = psci_get_pstate_pwrlvl(power_state);
-	int i;
+	unsigned int pstate = psci_get_pstate_type(power_state);
+	unsigned int pwr_lvl = psci_get_pstate_pwrlvl(power_state);
+	unsigned int i;
 
-	assert(req_state);
+	assert(req_state > 0U);
 
 	if (pwr_lvl > PLAT_MAX_PWR_LVL)
 		return PSCI_E_INVALID_PARAMS;
@@ -59,7 +59,7 @@
 	/*
 	 * We expect the 'state id' to be zero.
 	 */
-	if (psci_get_pstate_id(power_state))
+	if (psci_get_pstate_id(power_state) != 0U)
 		return PSCI_E_INVALID_PARAMS;
 
 	return PSCI_E_SUCCESS;