support keyboard io

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/ps2kbd.c b/drivers/ps2kbd.c
new file mode 100644
index 0000000..5aa9d2a
--- /dev/null
+++ b/drivers/ps2kbd.c
@@ -0,0 +1,104 @@
+/* this is both a PS/2 keyboard driver */
+#include <stdint.h>
+#include <stdio.h>
+#include "io.h"
+#include "isr.h"
+#include "ps2kbd.h"
+#include "ps2_keymaps.h"
+
+static void ps2_wait(void)
+{
+    /* wait for the keyboard */
+    while(1)
+        if ((inb(0x64) & 2) == 0) break;
+}
+
+void ps2kbd_set_leds(uint8_t status)
+{
+    ps2_wait();
+    outb(0x60, 0xED);
+    outb(0x60, status);
+}
+
+#define IDX_UP 0
+#define IDX_LEFT 1
+#define IDX_DOWN 2
+#define IDX_RIGHT 3
+
+static uint8_t ps2_arrowkeys[4];
+
+uint8_t ps2kbd_button_get(void)
+{
+    uint8_t ret = 0;
+    if(ps2_arrowkeys[IDX_UP])
+        ret |= BUTTON_UP;
+    if(ps2_arrowkeys[IDX_LEFT])
+        ret |= BUTTON_LEFT;
+    if(ps2_arrowkeys[IDX_DOWN])
+        ret |= BUTTON_DOWN;
+    if(ps2_arrowkeys[IDX_RIGHT])
+        ret |= BUTTON_RIGHT;
+    return ret;
+}
+
+static void key_handler(struct regs_t *regs)
+{
+    (void) regs;
+    uint8_t scancode = inb(0x60);
+    switch(scancode)
+    {
+        /* ... the only one we care about! */
+    case 0xE0:
+    {
+        uint8_t spec = inb(0x60);
+        switch(spec)
+        {
+        case 0x48:
+            ps2_arrowkeys[IDX_UP] = 1;
+            break;
+        case 0x4B:
+            ps2_arrowkeys[IDX_LEFT] = 1;
+            break;
+        case 0x50:
+            ps2_arrowkeys[IDX_DOWN] = 1;
+            break;
+        case 0x4D:
+            ps2_arrowkeys[IDX_RIGHT] = 1;
+            break;
+        case 0xC8:
+            ps2_arrowkeys[IDX_UP] = 0;
+            break;
+        case 0xCB:
+            ps2_arrowkeys[IDX_LEFT] = 0;
+            break;
+        case 0xD0:
+            ps2_arrowkeys[IDX_DOWN] = 0;
+            break;
+        case 0xCD:
+            ps2_arrowkeys[IDX_RIGHT] = 0;
+            break;
+        }
+        break;
+    }
+    default:
+        break;
+    }
+}
+
+static void ps2_set_scancode_set(uint8_t set)
+{
+    ps2_wait();
+    outb(0x60, 0xF0);
+    outb(0x60, set);
+}
+
+static void keyboard_init(void)
+{
+    set_interrupt_handler(IRQ(1), key_handler);
+    ps2_set_scancode_set(1);
+}
+
+void ps2kbd_init(void)
+{
+    keyboard_init();
+}