Updated ps2 mouse documentation in readme

readme.md

@@ -1191,7 +1191,7 @@ Please note the USB port can only supply a limited amount of power to the keyboa
 
 Its possible to hook up a PS/2 mouse (for example touchpads or trackpoints) to your keyboard as a composite device.
 
-Then, decide whether to use USART (best), interrupts (better) or busywait (not recommended), and enable the relevant option.
+There are three available modes for hooking up PS/2 devices: USART (best), interrupts (better) or busywait (not recommended).
 
 ### Busywait version
 
@@ -1316,6 +1316,116 @@ In your keyboard config.h:
 #endif
 ```
 
+### Additional Settings
+
+#### PS/2 mouse features
+
+These enable settings supported by the PS/2 mouse protocol: http://www.computer-engineering.org/ps2mouse/
+
+```
+/* Use remote mode instead of the default stream mode (see link) */
+#define PS2_MOUSE_USE_REMOTE_MODE  
+
+/* Enable the scrollwheel or scroll gesture on your mouse or touchpad */
+#define PS2_MOUSE_ENABLE_SCROLLING
+
+/* Some mice will need a scroll mask to be configured. The default is 0xFF. */
+#define PS2_MOUSE_SCROLL_MASK 0x0F
+
+/* Applies a transformation to the movement before sending to the host (see link) */
+#define PS2_MOUSE_USE_2_1_SCALING
+
+/* The time to wait after initializing the ps2 host */
+#define PS2_MOUSE_INIT_DELAY 1000 /* Default */
+```
+
+You can also call the following functions from ps2_mouse.h
+
+```
+void ps2_mouse_disable_data_reporting(void);
+
+void ps2_mouse_enable_data_reporting(void);
+
+void ps2_mouse_set_remote_mode(void);
+
+void ps2_mouse_set_stream_mode(void);
+
+void ps2_mouse_set_scaling_2_1(void);
+
+void ps2_mouse_set_scaling_1_1(void);
+
+void ps2_mouse_set_resolution(ps2_mouse_resolution_t resolution);
+
+void ps2_mouse_set_sample_rate(ps2_mouse_sample_rate_t sample_rate);
+```
+
+#### Fine control
+
+Use the following defines to change the sensitivity and speed of the mouse.
+Note: you can also use `ps2_mouse_set_resolution` for the same effect (not supported on most touchpads).
+
+```
+#define PS2_MOUSE_X_MULTIPLIER 3
+#define PS2_MOUSE_Y_MULTIPLIER 3
+#define PS2_MOUSE_V_MULTIPLIER 1
+```
+
+#### Scroll button
+
+If you're using a trackpoint, you will likely want to be able to use it for scrolling.
+Its possible to enable a "scroll button/s" that when pressed will cause the mouse to scroll instead of moving.
+To enable the feature, you must set a scroll button mask as follows:
+
+```
+#define PS2_MOUSE_SCROLL_BTN_MASK (1<<PS2_MOUSE_BUTTON_MIDDLE) /* Default */
+```
+
+To disable the scroll button feature:
+
+```
+#define PS2_MOUSE_SCROLL_BTN_MASK 0
+```
+
+The available buttons are:
+
+```
+#define PS2_MOUSE_BTN_LEFT      0
+#define PS2_MOUSE_BTN_RIGHT     1
+#define PS2_MOUSE_BTN_MIDDLE    2
+```
+
+You can also combine buttons in the mask by `|`ing them together.
+
+Once you've configured your scroll button mask, you must configure the scroll button send interval.
+This is the interval before which if the scroll buttons were released they would be sent to the host.
+After this interval, they will cause the mouse to scroll and will not be sent.
+
+```
+#define PS2_MOUSE_SCROLL_BTN_SEND 300 /* Default */
+```
+
+To disable sending the scroll buttons:
+```
+#define PS2_MOUSE_SCROLL_BTN_SEND 0
+```
+
+Fine control over the scrolling is supported with the following defines:
+
+```
+#define PS2_MOUSE_SCROLL_DIVISOR_H 2
+#define PS2_MOUSE_SCROLL_DIVISOR_V 2
+```
+
+#### Debug settings
+
+To debug the mouse, add `debug_mouse = true` or enable via bootmagic.
+
+```
+/* To debug the mouse reports */
+#define PS2_MOUSE_DEBUG_HID
+#define PS2_MOUSE_DEBUG_RAW
+```
+
 ## Safety Considerations
 
 You probably don't want to "brick" your keyboard, making it impossible