From 858e4a2a614946f1900f5a80c5c4af6b530bac57 Mon Sep 17 00:00:00 2001
From: Eugene Lozovoy <uzix.ls@gmail.com>
Date: Tue, 24 Sep 2024 23:45:27 +0300
Subject: [PATCH] mouse: add scroll support

---
 TSConf.sv                   |  8 +++++---
 rtl/periph/kempston_mouse.v | 11 +++++++----
 rtl/tsconf.v                |  2 +-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/TSConf.sv b/TSConf.sv
index e68db5b..20617a7 100644
--- a/TSConf.sv
+++ b/TSConf.sv
@@ -166,12 +166,13 @@ wire  [7:0] key_code;
 
 wire  [8:0] mouse_x;
 wire  [8:0] mouse_y;
+wire  [3:0] mouse_z;
 wire  [7:0] mouse_flags;
 wire        mouse_strobe;
 
-wire        mouse_b0 = st_mouseswap? mouse_flags[0] : mouse_flags[1];
-wire        mouse_b1 = st_mouseswap? mouse_flags[1] : mouse_flags[0];
-wire [24:0] ps2_mouse = { mouse_strobe_level, mouse_y[7:0], mouse_x[7:0], mouse_flags[7:2], mouse_b1, mouse_b0 };
+wire        mouse_b0 = st_mouseswap? mouse_flags[1] : mouse_flags[0];
+wire        mouse_b1 = st_mouseswap? mouse_flags[0] : mouse_flags[1];
+wire [28:0] ps2_mouse = { mouse_strobe_level, mouse_z, mouse_y[7:0], mouse_x[7:0], mouse_flags[7:2], mouse_b1, mouse_b0 };
 reg         mouse_strobe_level;
 always @(posedge clk_sys) if (mouse_strobe) mouse_strobe_level <= ~mouse_strobe_level;
 
@@ -207,6 +208,7 @@ user_io #(.STRLEN($size(CONF_STR)>>3), .SD_IMAGES(2), .FEATURES(32'h0 | (BIG_OSD
 
 	.mouse_x(mouse_x),
 	.mouse_y(mouse_y),
+	.mouse_z(mouse_z),
 	.mouse_flags(mouse_flags),
 	.mouse_strobe(mouse_strobe),
 
diff --git a/rtl/periph/kempston_mouse.v b/rtl/periph/kempston_mouse.v
index 32292c6..7cb2876 100644
--- a/rtl/periph/kempston_mouse.v
+++ b/rtl/periph/kempston_mouse.v
@@ -24,7 +24,7 @@ module kempston_mouse
 	input        clk_sys,
 	input        reset,
 
-	input [24:0] ps2_mouse,
+	input [28:0] ps2_mouse,
 	
 	input  [2:0] addr,
 	output       sel,
@@ -36,6 +36,7 @@ assign sel  = port_sel;
 
 reg [11:0] dx;
 reg [11:0] dy;
+reg  [3:0] dz;
 
 reg  [7:0] data;
 reg        port_sel;
@@ -44,22 +45,24 @@ always @* begin
 	casex(addr)
 		 3'b011: data = dx[7:0];
 		 3'b111: data = dy[7:0];
-		 3'bX10: data = ~{5'b00000,ps2_mouse[2], ps2_mouse[0], ps2_mouse[1]} ;
+		 3'bX10: data = {dz, 1'b1, ~ps2_mouse[2:0]};
 		default: {port_sel,data} = 8'hFF;
 	endcase
 end
 
 always @(posedge clk_sys) begin
 	reg old_status;
-	old_status <= ps2_mouse[24];
+	old_status <= ps2_mouse[28];
 
 	if(reset) begin
 		dx <= 128; // dx != dy for better mouse detection
 		dy <= 0;
+		dz <= 4'b1111;
 	end
-	else if(old_status != ps2_mouse[24]) begin
+	else if(old_status != ps2_mouse[28]) begin
 		dx <= dx + {{4{ps2_mouse[4]}},ps2_mouse[15:8]};
 		dy <= dy + {{4{ps2_mouse[5]}},ps2_mouse[23:16]};
+		dz <= dz - ps2_mouse[27:24];
 	end
 end
 
diff --git a/rtl/tsconf.v b/rtl/tsconf.v
index ae455e1..cfaba4c 100644
--- a/rtl/tsconf.v
+++ b/rtl/tsconf.v
@@ -60,7 +60,7 @@ module tsconf
 
   // User input
   input  [10:0] PS2_KEY,
-  input  [24:0] PS2_MOUSE,
+  input  [28:0] PS2_MOUSE,
   input   [7:0] JOYSTICK1,
   input   [7:0] JOYSTICK2,