kernel: tty: implement tty input using line disciplines

kernel/tty/device.c

@@ -1,6 +1,7 @@
 #include <socks/tty.h>
 #include <socks/device.h>
 #include <socks/console.h>
+#include <socks/input.h>
 #include <socks/libc/stdio.h>
 
 static struct char_device_ops tty_ops = {
@@ -8,12 +9,32 @@ static struct char_device_ops tty_ops = {
 	.write = tty_write,
 };
 
-static struct device *tty_printk_output = NULL;
+static spin_lock_t foreground_lock;
+static struct device *foreground = NULL;
+static struct device *foreground_input = NULL;
+
+static void tty_input_hook_callback(struct device *dev, struct input_event *ev, enum input_event_hook_flags *flags, void *arg)
+{
+	struct device *fg_tty = foreground;
+
+	if (!fg_tty) {
+		return;
+	}
+
+	tty_report_event(fg_tty, ev);
+	*flags = 0;
+}
+
+static struct input_event_hook foreground_input_hook = {
+	.hook_callback = tty_input_hook_callback,
+};
 
 static void tty_console_write(struct console *con, const char *s, unsigned int len)
 {
-	size_t nr_written;
-	tty_write(tty_printk_output, s, len, &nr_written, 0);
+	if (foreground) {
+		size_t nr_written;
+		tty_write(foreground, s, len, &nr_written, 0);
+	}
 }
 
 static struct console tty_console = {
@@ -30,10 +51,27 @@ struct device *tty_device_create(void)
 
 	struct tty_device *tty_dev = kmalloc(sizeof *tty_dev, VM_NORMAL);
 	if (!tty_dev) {
-		/* TODO destroy cdev */
+		object_deref(char_device_object(cdev));
 		return NULL;
 	}
 
+	kern_status_t status = ringbuffer_init(&tty_dev->tty_events, TTY_EVENT_QUEUE_SIZE * sizeof(struct input_event));
+	if (status != KERN_OK) {
+		kfree(tty_dev);
+		object_deref(char_device_object(cdev));
+		return NULL;
+	}
+
+	status = ringbuffer_init(&tty_dev->tty_input, TTY_INPUT_QUEUE_SIZE * sizeof(char));
+	if (status != KERN_OK) {
+		ringbuffer_deinit(&tty_dev->tty_events);
+		kfree(tty_dev);
+		object_deref(char_device_object(cdev));
+		return NULL;
+	}
+
+	tty_dev->tty_ldisc = tty_default_line_discipline();
+
 	cdev->c_ops = &tty_ops;
 	cdev->c_tty = tty_dev;
 
@@ -62,16 +100,47 @@ kern_status_t tty_device_register(struct device *dev, struct tty_driver *owner,
 	return object_namespace_create_link(global_namespace(), link_path, &dev->dev_base);
 }
 
-void tty_set_printk_output(struct device *tty)
+void tty_set_foreground(struct device *tty)
 {
 	bool console_init = false;
-	if (tty_printk_output) {
+	if (foreground) {
 		console_init = true;
 	}
 
-	tty_printk_output = tty;
+	foreground = tty;
 
 	if (!console_init) {
 		console_register(&tty_console);
 	}
 }
+
+kern_status_t tty_connect_foreground_input_device(struct device *input)
+{
+	struct input_device *inputdev = INPUT_DEVICE(input);
+	if (!inputdev) {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	unsigned long flags;
+	spin_lock_irqsave(&foreground_lock, &flags);
+
+	if (foreground_input) {
+		struct device *prev = foreground_input;
+		foreground_input = NULL;
+
+		device_lock(prev);
+		input_device_remove_hook(prev, &foreground_input_hook);
+		device_unlock(prev);
+		object_deref(&prev->dev_base);
+	}
+
+	object_ref(&input->dev_base);
+	foreground_input = input;
+	device_lock(input);
+	input_device_add_hook(input, &foreground_input_hook);
+	device_unlock(input);
+
+	spin_unlock_irqrestore(&foreground_lock, flags);
+
+	return KERN_OK;
+}