diff --git a/src/jtag/drivers/ep93xx.c b/src/jtag/drivers/ep93xx.c
index e7c993b3b..5130bd422 100644
--- a/src/jtag/drivers/ep93xx.c
+++ b/src/jtag/drivers/ep93xx.c
@@ -24,7 +24,7 @@
 
 static uint8_t output_value;
 static int dev_mem_fd;
-static void *gpio_controller;
+static uint8_t *gpio_controller;
 static volatile uint8_t *gpio_data_register;
 static volatile uint8_t *gpio_data_direction_register;
 
@@ -110,19 +110,16 @@ static int ep93xx_reset(int trst, int srst)
 
 static int set_gonk_mode(void)
 {
-	void *syscon;
-	uint32_t devicecfg;
-
-	syscon = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
+	void *syscon = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
 			MAP_SHARED, dev_mem_fd, 0x80930000);
 	if (syscon == MAP_FAILED) {
 		LOG_ERROR("mmap: %s", strerror(errno));
 		return ERROR_JTAG_INIT_FAILED;
 	}
 
-	devicecfg = *((volatile int *)(syscon + 0x80));
-	*((volatile int *)(syscon + 0xc0)) = 0xaa;
-	*((volatile int *)(syscon + 0x80)) = devicecfg | 0x08000000;
+	uint32_t devicecfg = *((volatile uint32_t *)((uintptr_t)syscon + 0x80));
+	*((volatile uint32_t *)((uintptr_t)syscon + 0xc0)) = 0xaa;
+	*((volatile uint32_t *)((uintptr_t)syscon + 0x80)) = devicecfg | 0x08000000;
 
 	munmap(syscon, 4096);