kernel/amd64: isa: Add i8042 driver

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 272 insertions, 0 deletions

diff --git a/sys/arch/amd64/isa/i8042.c b/sys/arch/amd64/isa/i8042.c
new file mode 100644
index 0000000..9b9e254
--- /dev/null
+++ b/sys/arch/amd64/isa/i8042.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <sys/driver.h>
+#include <sys/errno.h>
+#include <sys/spinlock.h>
+#include <sys/tty.h>
+#include <machine/ioapic.h>
+#include <machine/idt.h>
+#include <machine/io.h>
+#include <machine/lapic.h>
+#include <machine/hpet.h>
+#include <machine/sysvec.h>
+#include <machine/isa/i8042regs.h>
+
+__MODULE_NAME("i8042");
+__KERNEL_META("$Hyra$: i8042.c, Ian Marco Moffett, "
+              "i8042 PS/2 driver");
+
+static struct spinlock data_lock;
+static bool shift_key = false;
+static bool capslock = false;
+
+static int dev_send(bool aux, uint8_t data);
+
+static char keytab[] = {
+    '\0', '\0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
+    '-', '=', '\b', '\t', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i',
+    'o', 'p', '[', ']', '\n', '\0', 'a', 's', 'd', 'f', 'g', 'h',
+    'j', 'k', 'l', ';', '\'', '`', '\0', '\\', 'z', 'x', 'c', 'v',
+    'b', 'n', 'm', ',', '.',  '/', '\0', '\0', '\0', ' '
+};
+
+static char keytab_shift[] = {
+    '\0', '\0', '!', '@', '#',  '$', '%', '^',  '&', '*', '(', ')',
+    '_', '+', '\b', '\t', 'Q',  'W', 'E', 'R',  'T', 'Y', 'U', 'I',
+    'O', 'P', '{', '}', '\n',  '\0', 'A', 'S',  'D', 'F', 'G', 'H',
+    'J', 'K', 'L', ':', '\"', '~', '\0', '|', 'Z', 'X', 'C', 'V',
+    'B', 'N', 'M', '<', '>',  '?', '\0', '\0', '\0', ' '
+};
+
+static char keytab_caps[] = {
+    '\0', '\0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
+    '-','=', '\b', '\t', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I',
+    'O', 'P', '[', ']', '\n', '\0', 'A', 'S', 'D', 'F', 'G', 'H',
+    'J', 'K', 'L', ';', '\'', '`', '\0', '\\', 'Z', 'X', 'C', 'V',
+    'B', 'N', 'M', ',', '.', '/', '\0', '\0', '\0', ' '
+};
+
+static void
+kbd_set_leds(uint8_t mask)
+{
+    dev_send(false, 0xED);
+    dev_send(false, mask);
+}
+
+/*
+ * Convert scancode to character
+ *
+ * @sc: Scancode
+ * @chr: Character output
+ *
+ * Returns 0 when a char is given back.
+ */
+static int
+scancode_to_chr(uint8_t sc, char *chr)
+{
+    bool release = __TEST(sc, __BIT(7));
+
+    switch (sc) {
+    /* Capslock */
+    case 0x3A:
+        capslock = !capslock;
+
+        if (!capslock) {
+            kbd_set_leds(0);
+        } else {
+            kbd_set_leds(I8042_LED_CAPS);
+        }
+        return -EAGAIN;
+    /* Shift */
+    case 0x36:
+    case 0xAA:
+    case 0x2A:
+    case 0xB6:
+        if (!release) {
+            shift_key = true;
+        } else {
+            shift_key = false;
+        }
+        return -EAGAIN;
+    }
+
+    if (release) {
+        return -EAGAIN;
+    }
+
+    if (capslock) {
+        *chr = keytab_caps[sc];
+        return 0;
+    }
+
+    if (shift_key) {
+        *chr = keytab_shift[sc];
+        return 0;
+    }
+
+    *chr = keytab[sc];
+    return 0;
+}
+
+/*
+ * Write to an i8042 register.
+ *
+ * @port: I/O port
+ * @val: Value to write
+ */
+static void
+i8042_write(uint16_t port, uint8_t val)
+{
+    while (__TEST(I8042_STATUS, I8042_IBUF_FULL));
+    outb(port, val);
+}
+
+/*
+ * Read the i8042 config register
+ */
+static uint8_t
+i8042_read_conf(void)
+{
+    i8042_write(I8042_COMMAND, I8042_GET_CONFB);
+    return inb(I8042_DATA);
+}
+
+/*
+ * Write the i8042 config register
+ */
+static void
+i8042_write_conf(uint8_t value)
+{
+    i8042_write(I8042_COMMAND, I8042_SET_CONFB);
+    i8042_write(I8042_DATA, value);
+}
+
+/*
+ * Flush the data register until it is empty.
+ */
+static void
+i8042_drain(void)
+{
+    spinlock_acquire(&data_lock);
+    while (__TEST(inb(I8042_STATUS), I8042_OBUF_FULL)) {
+        inb(I8042_DATA);
+    }
+
+    spinlock_release(&data_lock);
+}
+
+/*
+ * Send a data to a device
+ *
+ * @aux: If true, send to aux device (mouse)
+ * @data: Data to send.
+ */
+static int
+dev_send(bool aux, uint8_t data)
+{
+    if (aux) {
+        i8042_write(I8042_COMMAND, I8042_PORT1_SEND);
+    }
+
+    for (;;) {
+        if (!__TEST(inb(I8042_STATUS), I8042_IBUF_FULL)) {
+            break;
+        }
+    }
+
+    i8042_write(I8042_DATA, data);
+    inb(0x80);      /* Waste a cycle */
+    return inb(I8042_DATA);
+}
+
+__attr(interrupt)
+static void
+kb_isr(void *sf)
+{
+    uint8_t data;
+    char c;
+
+    spinlock_acquire(&data_lock);
+    while (__TEST(inb(I8042_STATUS), I8042_OBUF_FULL)) {
+        data = inb(I8042_DATA);
+        if (scancode_to_chr(data, &c) == 0) {
+            tty_putc(&g_root_tty, c);
+        }
+    }
+    tty_flush(&g_root_tty);
+    spinlock_release(&data_lock);
+    lapic_send_eoi();
+}
+
+static int
+i8042_init(void)
+{
+    uint8_t conf;
+
+    /*
+     * Disable the ports and drain the output buffer
+     * to avoid interferance with the initialization
+     * process.
+     */
+    i8042_write(I8042_COMMAND, I8042_DISABLE_PORT0);
+    i8042_write(I8042_COMMAND, I8042_DISABLE_PORT1);
+    i8042_drain();
+
+    /* Disable aux data streaming */
+    dev_send(true, I8042_AUX_DISABLE);
+    i8042_drain();
+
+    /* Setup kbd interrupts */
+    idt_set_desc(SYSVEC_PCKBD, IDT_INT_GATE_FLAGS, (uintptr_t)kb_isr, 0);
+    ioapic_set_vec(1, SYSVEC_PCKBD);
+    ioapic_irq_unmask(1);
+
+    /* Setup config bits */
+    conf = i8042_read_conf();
+    conf |= I8042_PORT0_INTR;
+    conf &= ~I8042_PORT1_INTR;
+    i8042_write_conf(conf);
+
+    /* Enable the keyboard */
+    i8042_write(I8042_COMMAND, I8042_ENABLE_PORT0);
+
+    /*
+     * It seems one I/O bus cycle isn't enough to wait for data
+     * to accumulate on some machines... Give it around 50ms then
+     * drain the output buffer.
+     */
+    hpet_msleep(50);
+    i8042_drain();
+    return 0;
+}
+
+DRIVER_EXPORT(i8042_init);