kext: add PS/2 keyboard/mouse driver

kexts/ps2kbd/extension.yaml

@@ -0,0 +1,8 @@
+name: ps2kbd
+description: |
+  PS2 Keyboard and Mouse Driver
+id: net.doorstuck.socks.ps2kbd
+license: BSD-3-Clause
+copyright: Copyright © Max Wash 2023
+sources:
+  - main.c

kexts/ps2kbd/main.c

@@ -0,0 +1,228 @@
+#include <socks/printk.h>
+#include <socks/device.h>
+#include <socks/kext.h>
+#include <socks/libc/stdio.h>
+#include <arch/ports.h>
+#include <arch/irq.h>
+
+#define PS2_CMD_P1ON 0xae
+#define PS2_CMD_P1OFF 0xad
+#define PS2_CMD_P2ON 0xa8
+#define PS2_CMD_P2OFF 0xa7
+
+#define PS2_CFG_P1_IRQ (1 << 0)
+#define PS2_CFG_P2_IRQ (1 << 1)
+#define PS2_CFG_SYSFLAG (1 << 2)
+#define PS2_CFG_ZERO1 (1 << 3)
+#define PS2_CFG_P1_CLOCK (1 << 4)
+#define PS2_CFG_P2_CLOCK (1 << 5)
+#define PS2_CFG_P1_TRL (1 << 6)
+#define PS2_CFG_ZERO2 (1 << 7)
+
+#define PS2_SC2_PSBRK 0xe1
+#define PS2_SC2_RELEASED 0xf0
+
+#define NEXT_MAP 0xffffffff
+
+#define PS2_ACK 0xfa
+#define PS2_RESEND 0xfe
+
+#define PS2_IO_DATA 0x60
+#define PS2_IO_STATUS 0x64
+#define PS2_IO_CMD 0x64
+
+static struct input_device *keyboard = NULL, *mouse = NULL;
+
+static void send_cmd(uint8_t cmd)
+{
+	/* prevent the compiler from optimising this away */
+	volatile int _i = 0;
+	while (inportb(PS2_IO_STATUS) & 0x2) {
+		_i++;
+	}
+
+	outportb(PS2_IO_CMD, cmd);
+}
+
+static void send_data(uint8_t data)
+{
+	/* prevent the compiler from optimising this away */
+	volatile int _i = 0;
+	while (inportb(PS2_IO_STATUS) & 0x2) {
+		_i++;
+	}
+
+	outportb(PS2_IO_DATA, data);
+}
+
+static uint8_t recv_data()
+{
+	/* prevent the compiler from optimising this away */
+	volatile int _i = 0;
+	while (!(inportb(PS2_IO_STATUS) & 0x1)) {
+		_i++;
+	}
+
+	return inportb(PS2_IO_DATA);
+}
+
+static int data_avail()
+{
+	return inportb(PS2_IO_STATUS) & 0x1;
+}
+
+static void flush_buffer()
+{
+	while (data_avail()) {
+		recv_data();
+	}
+}
+
+static uint8_t read_config()
+{
+	send_cmd(0x20);
+	return recv_data();
+}
+
+static void set_config(uint8_t cfg)
+{
+	send_cmd(0x60);
+	send_data(cfg);
+}
+
+static int int_handler(void)
+{
+	static int scancode_level = 0;
+	static bool released = false;
+
+	if (scancode_level == PS2_SC2_PSBRK) {
+		/* TODO pause break keycode */
+		scancode_level = 0;
+		return 0;
+	}
+
+	while (data_avail()) {
+		unsigned char scancode = recv_data();
+
+		/* the only scancode set that begins with 0xe1 is the Pause key.
+		 * Rather than try and interpret a sequence of 8 codes, we just
+		 * assume the pause key was pressed */
+		if (scancode == PS2_SC2_PSBRK) {
+			flush_buffer();
+			/* TODO pause break keycode */
+			//mdk_input_event ev = { .type = MDK_INPUT_DEVICE_KEYBOARD };
+			scancode_level = PS2_SC2_PSBRK;
+			break;
+		}
+
+		if (scancode == PS2_SC2_RELEASED) {
+			released = true;
+			continue;
+		}
+
+		printk("ps2: got scancode 0x%02x (%s)", scancode, released ? "up" : "down");
+		scancode_level = 0;
+	}
+
+	return 0;
+}
+
+static int init_controller(void)
+{
+	/* disable ps2 devices */
+	send_cmd(PS2_CMD_P1OFF);
+	send_cmd(PS2_CMD_P2OFF);
+
+	flush_buffer();
+
+	/* configure the controller */
+	uint8_t config = read_config();
+	config &= ~(PS2_CFG_P1_IRQ | PS2_CFG_P2_IRQ | PS2_CFG_P1_TRL);
+	set_config(config);
+
+	send_cmd(0xaa);
+	uint8_t response = recv_data();
+	if (response != 0x55) {
+		return -1;
+	}
+
+	set_config(config);
+
+	/* Switch to scancode set 2 */
+	send_data(0xf0);
+	send_data(0x02);
+	if (recv_data() != PS2_ACK) {
+		return -1;
+	}
+
+	/* enable 1st port */
+	send_cmd(PS2_CMD_P1ON);
+
+	/* enable interrupts */
+	config = read_config();
+	config |= PS2_CFG_P1_IRQ;
+	set_config(config);
+
+	/* perform keyboard test */
+	send_data(0xff);
+	uint8_t response1 = recv_data();
+	uint8_t response2 = recv_data();
+	if ((response1 != 0xaa && response2 != 0xfa) &&
+            (response1 != 0xfa && response2 != 0xaa)) {
+		return -1;
+	}
+
+	return 0;
+}
+
+static kern_status_t create_devices(void)
+{
+	struct input_device *kbd = input_device_create();
+	struct device *kbd_base = input_device_base(kbd);
+	snprintf(kbd_base->dev_name, sizeof kbd_base->dev_name, "ps2kbd");
+
+	struct input_device *ms = input_device_create();
+	struct device *ms_base = input_device_base(ms);
+	snprintf(ms_base->dev_name, sizeof ms_base->dev_name, "ps2ms");
+
+	kern_status_t status = device_register(kbd_base, misc_device());
+	if (status != KERN_OK) {
+		/* TODO destroy devices */
+		return status;
+	}
+
+	status = device_register(ms_base, misc_device());
+	if (status != KERN_OK) {
+		return status;
+	}
+
+	keyboard = kbd;
+	mouse = ms;
+
+	return KERN_OK;
+}
+
+static struct irq_hook ps2_hook = {
+	.irq_callback = int_handler,
+};
+
+static kern_status_t online(struct kext *self)
+{
+	int result = init_controller();
+	if (result != 0) {
+		return KERN_UNSUPPORTED;
+	}
+
+	kern_status_t status = create_devices();
+	if (status != KERN_OK) {
+		return status;
+	}
+
+	hook_irq(IRQ1, &ps2_hook);
+	printk("ps2: controller initialised");
+	return KERN_OK;
+}
+
+DEFINE_KEXT("net.doorstuck.socks.ps2kbd",
+	    online, NULL,
+	    KEXT_NO_DEPENDENCIES);