diff --git a/drivers/ps2/ps2_mouse.c b/drivers/ps2/ps2_mouse.c
index 19a84e41c2d1..04acf7804621 100644
--- a/drivers/ps2/ps2_mouse.c
+++ b/drivers/ps2/ps2_mouse.c
@@ -27,7 +27,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "pointing_device.h"
 #include "pointing_device_internal.h"
 
-/* ============================= MACROS ============================ */
+/* ============================= HELPERS ============================ */
 
 static inline void ps2_mouse_convert_report_to_hid(ps2_mouse_report_t *ps2_report, report_mouse_t *mouse_report);
 static inline void ps2_mouse_enable_scrolling(void);
@@ -149,6 +149,42 @@ void ps2_mouse_set_sample_rate(ps2_mouse_sample_rate_t sample_rate) {
     PS2_MOUSE_SET_SAFE(PS2_MOUSE_SET_SAMPLE_RATE, sample_rate, "ps2 mouse set sample rate");
 }
 
+/* Note: PS/2 mouse uses counts/mm */
+uint16_t ps2_mouse_get_cpi(void) {
+    uint8_t rcv, cpm;
+    rcv = ps2_host_send(PS2_MOUSE_STATUS_REQUEST);
+    if (rcv == PS2_ACK) {
+        rcv = ps2_host_recv_response();
+        cpm = ps2_host_recv_response();
+        rcv = ps2_host_recv_response();
+
+        return (1 << cpm);
+    }
+
+    return 0;
+}
+
+/* Note: PS/2 mouse uses counts/mm */
+void ps2_mouse_set_cpi(uint16_t cpi) {
+    switch (cpi) {
+        case 1:
+            ps2_mouse_set_resolution(PS2_MOUSE_1_COUNT_MM);
+            break;
+        case 2:
+            ps2_mouse_set_resolution(PS2_MOUSE_2_COUNT_MM);
+            break;
+        case 4:
+            ps2_mouse_set_resolution(PS2_MOUSE_4_COUNT_MM);
+            break;
+        case 8:
+            ps2_mouse_set_resolution(PS2_MOUSE_8_COUNT_MM);
+            break;
+        default:
+            pd_dprintf("ps2_mouse: invalid cpi: %u\n", cpi);
+            break;
+    }
+}
+
 /* ============================= HELPERS ============================ */
 
 #define min(a,b) ((a)<(b)?(a):(b))
@@ -178,6 +214,7 @@ static inline void ps2_mouse_convert_report_to_hid(ps2_mouse_report_t *ps2_repor
     mouse_report->y = -mouse_report->y;
 
 #ifdef PS2_MOUSE_ENABLE_SCROLLING
+    // Valid z values are in the range -8 to +7
     mouse_report->v = -(ps2_report->z & PS2_MOUSE_SCROLL_MASK);
     mouse_report->v *= PS2_MOUSE_V_MULTIPLIER;
 #endif
@@ -210,38 +247,3 @@ static inline void ps2_mouse_enable_scrolling(void) {
     wait_ms(20);
 }
 
-/* Note: PS/2 mouse uses counts/mm */
-uint16_t ps2_mouse_get_cpi(void) {
-    uint8_t rcv, cpm;
-    rcv = ps2_host_send(PS2_MOUSE_STATUS_REQUEST);
-    if (rcv == PS2_ACK) {
-        rcv = ps2_host_recv_response();
-        cpm = ps2_host_recv_response();
-        rcv = ps2_host_recv_response();
-
-        return (1 << cpm);
-    }
-
-    return 0;
-}
-
-/* Note: PS/2 mouse uses counts/mm */
-void ps2_mouse_set_cpi(uint16_t cpi) {
-    switch (cpi) {
-        case 1:
-            ps2_mouse_set_resolution(PS2_MOUSE_1_COUNT_MM);
-            break;
-        case 2:
-            ps2_mouse_set_resolution(PS2_MOUSE_2_COUNT_MM);
-            break;
-        case 4:
-            ps2_mouse_set_resolution(PS2_MOUSE_4_COUNT_MM);
-            break;
-        case 8:
-            ps2_mouse_set_resolution(PS2_MOUSE_8_COUNT_MM);
-            break;
-        default:
-            pd_dprintf("ps2_mouse: invalid cpi: %u\n", cpi);
-            break;
-    }
-}