it8728f: Add ITE IT8728F superio early serial support.

This is the first of a series of patches to provide support
for a new mainboard, Gigabyte GA-B75M-D3V.

This patch provides early serial for the superio and has been
tested on this mainboard.  The code is based on IT8718F superio.

Change-Id: I5636199b49314166ed3b81e60b41131964dd44ff
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: http://review.coreboot.org/3794
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 71 insertions, 0 deletions

diff --git a/src/superio/ite/it8728f/early_serial.c b/src/superio/ite/it8728f/early_serial.c
new file mode 100644
index 0000000000..7fbd061ab0
--- /dev/null
+++ b/src/superio/ite/it8728f/early_serial.c
@@ -0,0 +1,71 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2006 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2013 Damien Zammit <damien@zamaudio.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "early_serial.h"
+
+/* Superio raw commands */
+static void it8728f_sio_write(device_t dev, u8 index, u8 value)
+{
+	pnp_set_logical_device(dev);
+	pnp_write_config(dev, index, value);
+}
+
+static void it8728f_enter_conf(device_t dev)
+{
+	u16 port = dev >> 8;
+
+	outb(0x87, port);
+	outb(0x01, port);
+	outb(0x55, port);
+	outb((port == 0x4e) ? 0xaa : 0x55, port);
+}
+
+static void it8728f_exit_conf(device_t dev)
+{
+	it8728f_sio_write(dev, IT8728F_CONFIG_REG_CC, 0x02);
+}
+
+/* Superio low level commands */
+void it8728f_reg_write(device_t dev, u8 index, u8 value)
+{
+	it8728f_enter_conf(dev);
+	it8728f_sio_write(dev, index, value);
+	it8728f_exit_conf(dev);
+}
+
+void it8728f_24mhz_clkin(device_t dev)
+{
+	it8728f_reg_write(dev, IT8728F_CONFIG_REG_CLOCKSEL, 0x1);
+}
+
+void it8728f_enable_serial(device_t dev, u16 iobase)
+{
+	/* (1) Enter the configuration state (MB PnP mode). */
+	it8728f_enter_conf(dev);
+
+	/* (2) Modify the data of configuration registers. */
+	pnp_set_logical_device(dev);
+	pnp_set_enable(dev, 0);
+	pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
+	pnp_set_enable(dev, 1);
+
+	/* (3) Exit the configuration state (MB PnP mode). */
+	it8728f_exit_conf(dev);
+}