From: Eddie Huang <eddie.huang@mediatek.com>
Date: Tue, 28 Apr 2015 13:40:33 +0000 (+0800)
Subject: tty: serial: 8250_mtk: Add earlycon
X-Git-Tag: v4.2-rc1~87^2~118
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2c40b57dc82de8e1337666341efe41a0fe9dd741;p=karo-tx-linux.git

tty: serial: 8250_mtk: Add earlycon

Add 8250 MTK UART driver to support earlycon device tree.
Earlycon take effect by
  add "earlycon" in kernel boot argument
  add "linux,sdtout-path" property in device tree file

Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 8eb3876563f1..4488c2bdb7ba 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -305,6 +305,19 @@ static struct platform_driver mtk8250_platform_driver = {
 };
 module_platform_driver(mtk8250_platform_driver);
 
+static int __init early_mtk8250_setup(struct earlycon_device *device,
+					const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+
+	return early_serial8250_setup(device, NULL);
+}
+
+OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
+
 MODULE_AUTHOR("Matthias Brugger");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Mediatek 8250 serial port driver");