kaguya
195 lines
8.9 KiB
C
195 lines
8.9 KiB
C
#include "ps2.h"
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#include "drivers/input/input.h"
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#include "arch/x86_64/sys/irq.h"
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#include "arch/x86_64/boot/isr.h"
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#include "arch/x86_64/cpu/io.h"
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#include "arch/x86_64/sys/ioapic.h"
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#include "arch/x86_64/sys/apic.h"
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#include "libk/stdio.h"
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#include "libk/debug.h"
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#include "drivers/video/render.h"
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/* ── PS/2 I/O ports ───────────────────────────────────────────────────────── */
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#define PS2_DATA_PORT 0x60 /* Read: scancode / Write: command data */
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#define PS2_STATUS_PORT 0x64 /* Read: controller status */
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#define PS2_CMD_PORT 0x64 /* Write: controller command */
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/* Status register bits */
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#define PS2_STATUS_OBF (1 << 0) /* Output buffer full (data ready to read) */
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#define PS2_STATUS_IBF (1 << 1) /* Input buffer full (don't write yet) */
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/* ── IRQ number for the keyboard ─────────────────────────────────────────── */
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#define KBD_IRQ 1
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#define KBD_IDT_VECTOR (0x20 + KBD_IRQ) /* 0x21 with PIC_REMAP_OFFSET=0x20 */
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/* ── Modifier state ───────────────────────────────────────────────────────── */
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static bool s_shift = false;
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static bool s_ctrl = false;
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static bool s_alt = false;
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static bool s_caps_lock = false;
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static bool s_extended = false; /* true after receiving 0xE0 prefix */
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/* ══════════════════════════════════════════════════════════════════════════
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* Set-1 keycode → ASCII translation tables
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*
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* Index = Set-1 make code (0x00–0x58 covers the full AT-101 layout).
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* 0x00 = unmapped / non-printable.
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* ══════════════════════════════════════════════════════════════════════════ */
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static const char s_normal[128] = {
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/*00*/ 0, 0, '1', '2', '3', '4', '5', '6',
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/*08*/ '7', '8', '9', '0', '-', '=', '\b', '\t',
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/*10*/ 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i',
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/*18*/ 'o', 'p', '[', ']', '\n', 0, 'a', 's',
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/*20*/ 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',
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/*28*/ '\'','`', 0, '\\','z', 'x', 'c', 'v',
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/*30*/ 'b', 'n', 'm', ',', '.', '/', 0, '*',
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/*38*/ 0, ' ', 0, 0, 0, 0, 0, 0,
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/*40*/ 0, 0, 0, 0, 0, 0, 0, '7',
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/*48*/ '8', '9', '-', '4', '5', '6', '+', '1',
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/*50*/ '2', '3', '0', '.', 0, 0, 0, 0,
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/*58*/ 0
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};
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static const char s_shifted[128] = {
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/*00*/ 0, 0, '!', '@', '#', '$', '%', '^',
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/*08*/ '&', '*', '(', ')', '_', '+', '\b', '\t',
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/*10*/ 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I',
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/*18*/ 'O', 'P', '{', '}', '\n', 0, 'A', 'S',
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/*20*/ 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':',
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/*28*/ '"', '~', 0, '|', 'Z', 'X', 'C', 'V',
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/*30*/ 'B', 'N', 'M', '<', '>', '?', 0, '*',
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/*38*/ 0, ' ', 0, 0, 0, 0, 0, 0,
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/*40*/ 0, 0, 0, 0, 0, 0, 0, '7',
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/*48*/ '8', '9', '-', '4', '5', '6', '+', '1',
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/*50*/ '2', '3', '0', '.', 0, 0, 0, 0,
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/*58*/ 0
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};
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/* ══════════════════════════════════════════════════════════════════════════
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* Extended (0xE0-prefixed) make codes we care about
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* ══════════════════════════════════════════════════════════════════════════ */
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typedef enum {
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/* Regular Set-1 make codes (non-extended) */
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SC_LSHIFT = 0x2A,
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SC_RSHIFT = 0x36,
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SC_LCTRL = 0x1D,
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SC_LALT = 0x38,
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SC_CAPSLOCK = 0x3A,
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SC_BACKSPACE= 0x0E,
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SC_ENTER = 0x1C,
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SC_TAB = 0x0F,
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SC_ESC = 0x01,
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/* Function keys */
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SC_F1 = 0x3B, SC_F2 = 0x3C, SC_F3 = 0x3D, SC_F4 = 0x3E,
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SC_F5 = 0x3F, SC_F6 = 0x40, SC_F7 = 0x41, SC_F8 = 0x42,
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SC_F9 = 0x43, SC_F10 = 0x44, SC_F11 = 0x57, SC_F12 = 0x58,
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} scancode_t;
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/* ══════════════════════════════════════════════════════════════════════════
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* IRQ1 handler
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* ══════════════════════════════════════════════════════════════════════════ */
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void ps2_kbd_handler(Registers *regs)
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{
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(void)regs;
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/*
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* Always drain the output buffer even if we don't handle the byte,
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* otherwise the PS/2 controller stalls and stops sending interrupts.
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*/
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uint8_t status = x86_64_inb(PS2_STATUS_PORT);
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if (!(status & PS2_STATUS_OBF)) {
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/* Spurious interrupt with no data — just return */
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return;
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}
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uint8_t byte = x86_64_inb(PS2_DATA_PORT);
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/* ── Handle 0xE0 extended-key prefix ─────────────────────────────── */
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if (byte == 0xE0) {
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s_extended = true;
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return;
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}
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/* ── Decode make / break ─────────────────────────────────────────── */
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bool pressed = !(byte & 0x80); /* bit 7 = 0 → make, 1 → break */
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uint8_t scancode = byte & 0x7F; /* strip the break bit */
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bool extended = s_extended;
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s_extended = false;
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/* ── Update modifier keys ────────────────────────────────────────── */
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if (!extended) {
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switch (scancode) {
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case SC_LSHIFT: case SC_RSHIFT:
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s_shift = pressed;
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return; /* don't push a key event for bare modifiers */
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case SC_LCTRL:
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s_ctrl = pressed;
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return;
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case SC_LALT:
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s_alt = pressed;
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return;
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case SC_CAPSLOCK:
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if (pressed) s_caps_lock = !s_caps_lock;
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return;
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}
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}
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/* ── Translate to ASCII ──────────────────────────────────────────── */
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char ascii = 0;
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if (!extended && scancode < 128) {
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bool use_upper = s_shift ^ s_caps_lock; /* XOR: caps inverts shift */
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ascii = use_upper ? s_shifted[scancode] : s_normal[scancode];
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}
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/* Extended keys (arrows, home, end, etc.) leave ascii=0 */
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/* ── Push event ──────────────────────────────────────────────────── */
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input_push_key(scancode, ascii, pressed);
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if (pressed && ascii) {
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input_push_char(ascii);
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}
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}
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/* ══════════════════════════════════════════════════════════════════════════
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* Public helpers
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* ══════════════════════════════════════════════════════════════════════════ */
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uint8_t ps2_kbd_read_scancode(void)
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{
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/* Spin until data is available (for early/polled use only) */
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while (!(x86_64_inb(PS2_STATUS_PORT) & PS2_STATUS_OBF))
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asm volatile("pause");
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return x86_64_inb(PS2_DATA_PORT);
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}
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/* ══════════════════════════════════════════════════════════════════════════
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* Initialisation
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* ══════════════════════════════════════════════════════════════════════════ */
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void ps2_kbd_init(void)
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{
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/*
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* ── Step 1: Flush the PS/2 output buffer ─────────────────────────
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*
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* Any leftover bytes from before boot will cause the controller to
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* withhold interrupts. Drain them now.
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*/
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int attempts = 16;
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while (attempts-- && (x86_64_inb(PS2_STATUS_PORT) & PS2_STATUS_OBF))
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(void)x86_64_inb(PS2_DATA_PORT);
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x86_64_APIC_IRQ_RedirectAndRegister(1, 0x21, ps2_kbd_handler);
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kprintf("[PS2] Keyboard driver initialised (IRQ%d vector 0x%02x)\n",
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KBD_IRQ, KBD_IDT_VECTOR);
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} |