lenovo/s230u: Add Thinkpad Twist (S230U)

Created using autoport plus some manual work and copying from G505S to
account for the non-H8 EC.

This model uses the same ENE KB9012 EC as the G505S.

Tested:
- Mainboard variant with 8GB Elpida DDR3
- SeaBIOS payload
- Booting into Linux 4.9.6 with Debian/unstable installed on the
  internal HDD/SDD slot
- Native raminit
- Both native VGA init and option rom VGA init
- Basic TPM functionality (auto-detection and RNG)
- Battery status readout
- Basic ACPI functions (power button event; power-off; reboot)
- thinkpad-acpi hotkey functions
- thinkpad-acpi LED control (red thinkpad LED)
- Suspend to RAM and resume works
- Mini displayport output works

Known issues:
- Patches needed for EC battery support
  https://review.coreboot.org/#/c/18348/
  https://review.coreboot.org/#/c/18349/
- No thermal zone since temperature sensing is not H8-compatible
  and needs to be reverse engineered.

Not tested:
- msata/wwan (probably works)

Signed-off-by: Tobias Diedrich <ranma+coreboot@tdiedrich.de>
Change-Id: I52bc4515277e5c18afbb14a80a9ac788049f485c
Reviewed-on: https://review.coreboot.org/18351
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/mainboard/lenovo/s230u/ec.c b/src/mainboard/lenovo/s230u/ec.c
new file mode 100644
index 0000000000..f3e01b68be
--- /dev/null
+++ b/src/mainboard/lenovo/s230u/ec.c
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Alexandru Gagniuc <mr.nuke.me@gmail.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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include "ec.h"
+#include <ec/compal/ene932/ec.h>
+
+/* The keyboard matrix tells the EC how the keyboard is wired internally */
+static void set_keyboard_matrix_us(void)
+{
+	ec_kbc_write_cmd(0x59);
+	ec_kbc_write_ib(0xE5);
+}
+
+/* Tell EC to operate in APM mode. Events generate SMIs instead of SCIs */
+static void enter_apm_mode(void)
+{
+	ec_kbc_write_cmd(0x59);
+	ec_kbc_write_ib(0xE9);
+}
+
+void lenovo_s230u_ec_init(void)
+{
+	set_keyboard_matrix_us();
+
+	/*
+	 * The EC has a special "blinking Caps Lock LED" mode which it normally
+	 * enters when it believes the OS is not responding. It occasionally
+	 * disables battery charging when in this mode, although other
+	 * functionality is unaffected. Although the EC starts in APM mode by
+	 * default, it only leaves the "blinking Caps Lock LED" mode after
+	 * receiving the following command.
+	 */
+	enter_apm_mode();
+
+	/* Enable external USB port power. */
+	ec_mm_set_bit(0x3b, 4);
+}