From 0245d2254bfa26b6cfd8bbd2337fc184ae3c5f10 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sun, 11 Jun 2023 14:54:39 +0100
Subject: [PATCH] kernel: tty: support for printing newlines

---
 kernel/tty/tty.c | 72 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 54 insertions(+), 18 deletions(-)

diff --git a/kernel/tty/tty.c b/kernel/tty/tty.c
index 80191a5..ed0f952 100644
--- a/kernel/tty/tty.c
+++ b/kernel/tty/tty.c
@@ -1,12 +1,58 @@
 #include <socks/tty.h>
 #include <socks/printk.h>
 
-static void putchar(struct device *tty, int c)
+static void newline(struct device *tty)
 {
 	struct tty_device *ttydev = TTY_DEVICE(tty);
 	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
 	struct tty_driver_ops *ops = tty_driver->tty_ops;
 
+	ttydev->tty_xcur = 0;
+	ttydev->tty_ycur++;
+
+	if (ttydev->tty_ycur >= ttydev->tty_ycells) {
+		ttydev->tty_xcur = 0;
+		ttydev->tty_ycur = ttydev->tty_ycells - 1;
+
+		if (ops->tty_scroll) {
+			ops->tty_scroll(tty, TTY_SCROLL_DOWN, 1);
+		}
+	}
+
+	ops->tty_move_cursor(tty, ttydev->tty_xcur, ttydev->tty_ycur);
+}
+
+static void __putchar(struct device *tty, int c)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
+	struct tty_driver_ops *ops = tty_driver->tty_ops;
+
+	ops->tty_putc(tty, c, ttydev->tty_xcur, ttydev->tty_ycur, ttydev->tty_curattrib);
+	ttydev->tty_xcur++;
+
+	if (ttydev->tty_xcur >= ttydev->tty_xcells) {
+		ttydev->tty_xcur = 0;
+		ttydev->tty_ycur++;
+	}
+
+	if (ttydev->tty_ycur >= ttydev->tty_ycells) {
+		ttydev->tty_xcur = 0;
+		ttydev->tty_ycur = ttydev->tty_ycells - 1;
+
+		if (ops->tty_scroll) {
+			ops->tty_scroll(tty, TTY_SCROLL_DOWN, 1);
+		}
+	}
+
+	ops->tty_move_cursor(tty, ttydev->tty_xcur, ttydev->tty_ycur);
+}
+
+static void putchar(struct device *tty, int c)
+{
+	struct tty_driver *tty_driver = TTY_DRIVER(tty->dev_owner);
+	struct tty_driver_ops *ops = tty_driver->tty_ops;
+
 	if (!ops->tty_putc) {
 		return;
 	}
@@ -16,24 +62,14 @@ static void putchar(struct device *tty, int c)
 		return;
 	}
 
-	ops->tty_putc(tty, c, ttydev->tty_xcur, ttydev->tty_ycur, ttydev->tty_curattrib);
-	ttydev->tty_xcur++;
-
-	if (ttydev->tty_xcur >= ttydev->tty_xcells) {
-		ttydev->tty_xcur = 0;
-		ttydev->tty_ycur++;
+	switch (c) {
+	case '\n':
+		newline(tty);
+		break;
+	default:
+		__putchar(tty, c);
+		break;
 	}
-
-	if (ttydev->tty_ycur >= ttydev->tty_ycells) {
-		if (ops->tty_scroll) {
-			ops->tty_scroll(tty, TTY_SCROLL_DOWN, 1);
-		} else {
-			ttydev->tty_xcur = 0;
-			ttydev->tty_ycur = 0;
-		}
-	}
-
-	ops->tty_move_cursor(tty, ttydev->tty_xcur, ttydev->tty_ycur);
 }
 
 kern_status_t tty_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)