From a78033acc941fc4bcf6188f1d48fd8e012673fff Mon Sep 17 00:00:00 2001
From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com>
Date: Thu, 15 Jun 2023 22:36:39 -0400
Subject: initial commit

---
 kernel/arch/i386/ps2_controller.cpp | 191 ++++++++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)
 create mode 100644 kernel/arch/i386/ps2_controller.cpp

(limited to 'kernel/arch/i386/ps2_controller.cpp')

diff --git a/kernel/arch/i386/ps2_controller.cpp b/kernel/arch/i386/ps2_controller.cpp
new file mode 100644
index 0000000..9424233
--- /dev/null
+++ b/kernel/arch/i386/ps2_controller.cpp
@@ -0,0 +1,191 @@
+#include <io.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <arch/i386/ps2_controller.h>
+
+#define PS2_DATA 0x60 // data port
+#define PS2_STATUS 0x64 // status register
+#define PS2_COMMAND 0x64 // command register
+
+// set to true if 2nd ps2 port is available
+bool ps2SecondaryEnabled = false;
+
+void initialize_ps2_controller() {
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xAD); // disable devices
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xA7);
+    
+    outputbuffer_wait();
+    inb(PS2_DATA); // flush output buffer
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+    inb(PS2_DATA);
+
+    
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0x20); // set controller configuration byte
+    outputbuffer_wait();
+    uint8_t conconfig = inb(PS2_DATA);
+    conconfig &= 0b00110100;
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0x60);
+    inputbuffer_wait();
+    outb(PS2_DATA, conconfig);
+
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xAA); // performs controller self test
+    outputbuffer_wait();
+    if (inb(PS2_DATA) == 0xFC) {
+        printf("PS/2 controller failed self test\n");
+    }
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0x60); // in case the controller resets from the test
+    inputbuffer_wait();
+    outb(PS2_DATA, conconfig);
+
+    int portcount = 1;
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xA8); // check if ps2 controller is dual channel
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0x20);
+    outputbuffer_wait();
+    conconfig = inb(PS2_DATA);
+    if ((conconfig & 0b00100000) == 0b00000000) { // checks if bit 5 is cleared
+        ps2SecondaryEnabled = true;
+        //printf("Dual channel PS/2\n");
+        portcount = 2;
+    } else {
+        //printf("Single channel PS/2\n");
+    }
+    
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xAB); // tests ps2 ports
+    outputbuffer_wait();
+    if (inb(PS2_DATA) != 0x00) {
+        printf("PS/2 port 1 failed self test\n");
+        --portcount;
+    }
+    if (ps2SecondaryEnabled) {
+        inputbuffer_wait();
+        outb(PS2_COMMAND, 0xA9);
+        outputbuffer_wait();
+        if (inb(PS2_DATA) != 0x00) {
+            printf("PS/2 port 2 failed self test\n");
+            --portcount;
+        }
+    }
+    if (!portcount) {
+        printf("PS/2 initialization failed\n");
+        return;
+    }
+
+    conconfig |= 0b00000011;
+    inputbuffer_wait();
+    outb(PS2_COMMAND, 0xAE); // enable ps2 ports
+    conconfig |= 0b00000001;
+    if (ps2SecondaryEnabled) {
+        inputbuffer_wait();
+        outb(PS2_COMMAND, 0xA8);
+        outb(PS2_COMMAND, 0x60);
+        conconfig |= 0b00000011;
+        outb(PS2_DATA, conconfig);
+    } else {
+        inputbuffer_wait();
+        outb(PS2_COMMAND, 0x60);
+        conconfig |= 0b00000001;
+        outb(PS2_DATA, conconfig);
+    }
+
+    //ps2_dev_send_command(0, 0xFF); // reset devices
+    //inb(PS2_DATA);
+    //io_wait();
+    if (ps2SecondaryEnabled) {
+        //ps2_dev_send_command(1, 0xFF);
+        //inb(PS2_DATA);
+        //io_wait();
+    }
+
+    //printf("PS/2 controller initialized\n");
+}
+
+// waits for input buffer (write) to be filled
+void inputbuffer_wait() {
+    for (int i = 0; i < 15; i++) {
+        uint8_t status_reg = inb(PS2_STATUS);
+        if ((status_reg & 0b00000010)) {
+            return;
+        }
+        io_wait();
+    }
+}
+
+// waits for outbut buffer (read) to be filled
+void outputbuffer_wait() {
+    for (int i = 0; i < 15; i++) {
+        uint8_t status_reg = inb(PS2_STATUS);
+        if ((status_reg & 0b00000001)) {
+            return;
+        }
+        io_wait();
+    }
+}
+
+// checks if inpbut buffer is set
+bool inputbuffer_check() {
+    uint8_t status_reg = inb(PS2_STATUS);
+    if ((status_reg & 0b00000010)) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+bool outputbuffer_check() {
+    uint8_t status_reg = inb(PS2_STATUS);
+    if ((status_reg & 0b00000001)) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+/* Sends a command byte to a ps2 device 
+Port numbers start from 0 */
+int ps2_dev_send_command(int port, unsigned char command) {
+    //bool commandRecieved = false;
+    switch (port)
+        {
+        case 0:
+            for (int i = 0; i < 5; i++) {
+                uint8_t status_reg = inb(PS2_STATUS);
+                if ((status_reg & 0b00000010) == 0b00000000) {
+                    outb(PS2_DATA, command);
+                    return 0;
+                }
+                inb(PS2_DATA);
+                io_wait();
+            }
+            return 1; // error returned if timeout expires
+        case 1:
+            outb(PS2_COMMAND, 0xD4);
+            for (int i = 0; i < 5; i++) {
+                uint8_t status_reg = inb(PS2_STATUS);
+                if ((status_reg & 0b00000010) == 0b00000000) {
+                    outb(PS2_DATA, command);
+                    return 0;
+                }
+                inb(PS2_DATA);
+                io_wait();
+            }
+            return 1;
+        default:
+            return 2; // out of port range
+        }
+}
\ No newline at end of file
-- 
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