ps2 driver

1 files changed, 183 insertions, 0 deletions

diff --git a/kc/core/i8042.c b/kc/core/i8042.c
new file mode 100644
index 0000000..0ba12dc
--- /dev/null
+++ b/kc/core/i8042.c
@@ -0,0 +1,183 @@
+#include "input.h"
+#include "port.h"
+#include "i8042.h"
+#include "pic8259.h"
+#include <lib/kstdio.h>
+
+static void i8042_init(void);
+static void i8042_enable(void) {}
+static void i8042_disable(void) {}
+
+static int i8042_append_callback(input_callback func) {(void)func; return 0;}
+static void i8042_delete_callback(input_callback func) {(void)func;}
+
+const struct input_source i8042_input_source =
+{
+    "i8042",
+    i8042_init,
+    i8042_enable,
+    i8042_disable,
+
+    i8042_append_callback,
+    i8042_delete_callback,
+};
+
+#define PS2_STATUS 0x64
+#define PS2_COMMAND 0x64
+#define PS2_DATA 0x60
+#define PS2_IRQ 1
+
+static void i8042_disable_ports()
+{
+    outb(PS2_COMMAND, 0xad);
+    outb(PS2_COMMAND, 0xa7);
+}
+
+static uint8_t i8042_command(int c)
+{
+    outb(PS2_COMMAND, c);
+    return (uint8_t)c;
+}
+
+static uint8_t i8042_status()
+{
+    return inb(PS2_STATUS);
+}
+
+static bool i8042_read(uint8_t *b)
+{
+    if (i8042_status() & 1)
+    {
+        (b != NULL) ? *b = inb(PS2_DATA) : inb(PS2_DATA);
+        return true;
+    }
+
+    return false;
+}
+
+static void i8042_flush()
+{
+    while(i8042_status() & 1)
+    {
+        i8042_read(NULL);
+    }
+}
+
+static int i8042_callback(uint8_t irq)
+{
+    (void)irq;
+    i8042_flush();
+    return 0;
+}
+
+
+#define I8042_MAX_TRIES 4096
+
+static bool i8042_write(uint8_t b)
+{
+    for (int i = 0; i < I8042_MAX_TRIES; i++)
+    {
+        if (i8042_status() & 2)
+        {
+            continue;
+        }
+
+        outb(PS2_DATA, b);
+        return true;
+    }
+
+    return false;
+}
+
+static void i8042_set_config(void)
+{
+    bool channel_a_enable = false;
+    bool channel_b_enable = false;
+
+    bool maybe_dual_channel = false;
+    bool is_dual_channel = false;
+    i8042_command(0x20);
+    uint8_t config_byte;
+    i8042_read(&config_byte);
+    kprintf("i8042: current config: %#0.2x\n", config_byte);
+    config_byte &= 0xfc;
+    if (config_byte & (0x1 << 5))
+    {
+        maybe_dual_channel = true;
+    }
+    config_byte |= 0x01;
+    kprintf("i8042: new config: %#0.2x\n", config_byte);
+    i8042_command(0x60);
+    i8042_write(config_byte);
+    i8042_command(0xaa);
+    uint8_t bist_result;
+    if (i8042_read(&bist_result) && bist_result != 0x55)
+    {
+        kprintf("i8042: warning: error self-testing device. aborting.\n");
+        return;
+    }
+    
+    if (maybe_dual_channel)
+    {
+        i8042_command(0xa8);
+        i8042_command(0x20);
+        uint8_t config_byte;
+        if (i8042_read(&config_byte) && config_byte & (0x1 << 5))
+        {
+            kprintf("i8042: single-channel controller detected\n");
+        }
+        else
+        {
+            kprintf("i8042: dual-channel controller detected\n");
+            is_dual_channel = true;
+        }
+    }
+    
+    outb(PS2_COMMAND, 0xab);
+    if (inb(PS2_DATA) != 0x00)
+    {
+        kprintf("i8042: failed testing port a\n");
+    }
+    else
+    {
+        channel_a_enable = true;
+    }
+    if (is_dual_channel)
+    {
+        outb(PS2_COMMAND, 0xa9);
+        if (inb(PS2_DATA) != 0x00)
+        {
+            kprintf("i8042: failed testing port b\n");
+        }
+        else
+        {
+            channel_b_enable = true;
+        }
+        i8042_disable_ports();
+    }
+
+    if (channel_a_enable)
+    {
+        outb(PS2_COMMAND, 0xae);
+        i8042_write(0xff);
+        if(inb(PS2_DATA) == 0xfa && inb(PS2_DATA) == 0xaa)
+        {
+            kprintf("i8042: detected device on channel, type %#0.2x\n", inb(PS2_DATA));
+        }
+    }
+
+    i8042_flush();
+    (void)channel_b_enable;
+}
+
+static void i8042_init(void)
+{
+    i8042_disable_ports();
+    i8042_flush();
+    i8042_set_config();
+
+    pic8259_irq_install(PS2_IRQ, i8042_callback);
+    pic8259_irq_unmask(PS2_IRQ);
+}
+
+