kernel: implement tty driver system

kernel/tty/driver.c

@@ -0,0 +1,71 @@
+#include <socks/tty.h>
+
+static struct vm_cache tty_driver_cache = {
+	.c_name = "tty_driver",
+	.c_obj_size = sizeof(struct tty_driver),
+};
+
+static struct queue tty_drivers;
+static spin_lock_t tty_drivers_lock;
+
+kern_status_t tty_init(void)
+{
+	vm_cache_init(&tty_driver_cache);
+	tty_drivers = QUEUE_INIT;
+	tty_drivers_lock = SPIN_LOCK_INIT;
+
+	return KERN_OK;
+}
+
+struct tty_driver *tty_driver_create(struct kext *self, const char *name)
+{
+	struct tty_driver *driver = vm_cache_alloc(&tty_driver_cache, VM_NORMAL);
+	if (!driver) {
+		return NULL;
+	}
+
+	kern_status_t status = driver_init(&driver->tty_base, self, name);
+	if (status != KERN_OK) {
+		vm_cache_free(&tty_driver_cache, driver);
+		return NULL;
+	}
+
+	strncpy(driver->tty_name, name, sizeof driver->tty_name - 1);
+
+	return driver;
+}
+
+kern_status_t tty_driver_destroy(struct tty_driver *driver)
+{
+	/* TODO */
+	return KERN_UNIMPLEMENTED;
+}
+
+kern_status_t tty_driver_register(struct tty_driver *driver)
+{
+	kern_status_t status = driver_register(&driver->tty_base);
+	if (status != KERN_OK) {
+		return status;
+	}
+
+	unsigned long flags;
+	spin_lock_irqsave(&tty_drivers_lock, &flags);
+	queue_push_back(&tty_drivers, &driver->tty_head);
+	spin_unlock_irqrestore(&tty_drivers_lock, flags);
+
+	return KERN_OK;
+}
+
+kern_status_t tty_driver_unregister(struct tty_driver *driver)
+{
+	if (driver->tty_base.drv_major == DEV_MAJOR_INVALID) {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	unsigned long flags;
+	spin_lock_irqsave(&tty_drivers_lock, &flags);
+	queue_delete(&tty_drivers, &driver->tty_head);
+	spin_unlock_irqrestore(&tty_drivers_lock, flags);
+
+	return driver_unregister(&driver->tty_base);
+}