ec/lenovo/h8/acpi: Add BDC interface

* Add SSDT generator to add dynamic ACPI code.
* Implement GBDC and SBDC for thinkpad_acpi kernel module.
Required for BDC power control from userspace.

Tested on Lenovo T430:
The bluetooth module is detected and can be powercycled using network manager.

Change-Id: Ida825196650966194a883945896a038b0790fe45
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/20985
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/ec/lenovo/h8/Makefile.inc

@@ -8,6 +8,7 @@ endif
 ramstage-y += h8.c
 ramstage-y += bluetooth.c
 ramstage-y += wwan.c
+ramstage-$(CONFIG_HAVE_ACPI_TABLES) += ssdt.c
 smm-y += smm.c
 
 endif

src/ec/lenovo/h8/acpi/thinkpad.asl

@@ -153,4 +153,41 @@ Device (HKEY)
 	{
 		Return (\_SB.PCI0.LPCB.EC.GSTS)
 	}
+
+	/*
+	 * Returns the current state:
+	 *  Bit 0: BT HW present
+	 *  Bit 1: BT radio enabled
+	 *  Bit 2: BT state at resume
+	 */
+	Method (GBDC, 0)
+	{
+		If (HBDC) {
+			Store(One, Local0)
+			If(\_SB.PCI0.LPCB.EC.BTEB)
+			{
+				Or(Local0, 2, Local0)
+			}
+			/* FIXME: Implement state at resume, for now Enabled */
+			Or(Local0, 4, Local0)
+			Return (Local0)
+		} Else {
+			Return (0)
+		}
+	}
+
+	/*
+	 * Set the current state:
+	 *  Bit 1: BT radio enabled
+	 *  Bit 2: BT state at resume
+	 */
+	Method (SBDC, 1)
+	{
+		If (HBDC) {
+			ShiftRight (And(Arg0, 2), 1, Local0)
+			Store (Local0, \_SB.PCI0.LPCB.EC.BTEB)
+
+			/* FIXME: Store state at resume */
+		}
+	}
 }

src/ec/lenovo/h8/h8.c

@@ -181,9 +181,20 @@ static void h8_init(struct device *dev)
 	pc_keyboard_init(NO_AUX_DEVICE);
 }
 
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+static const char *h8_acpi_name(const struct device *dev)
+{
+	return "EC";
+}
+#endif
+
 struct device_operations h8_dev_ops = {
 #if IS_ENABLED(CONFIG_GENERATE_SMBIOS_TABLES)
 	.get_smbios_strings = h8_smbios_strings,
+#endif
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+	.acpi_fill_ssdt_generator = h8_ssdt_generator,
+	.acpi_name = h8_acpi_name,
 #endif
 	.init = h8_init,
 };

src/ec/lenovo/h8/h8.h

@@ -39,6 +39,8 @@ void h8_wwan_enable(int on);
 bool h8_wwan_nv_enable(void);
 bool h8_has_wwan(struct device *dev);
 
+void h8_ssdt_generator(struct device *dev);
+
 /* EC registers */
 #define H8_CONFIG0 0x00
 #define H8_CONFIG0_EVENTS_ENABLE	0x02

src/ec/lenovo/h8/ssdt.c

@@ -0,0 +1,51 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2017 Patrick Rudolph <siro@das-labor.org>
+ *
+ * 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 <console/console.h>
+#include <arch/acpigen.h>
+#include <string.h>
+
+#include "h8.h"
+#include "chip.h"
+
+static char *h8_dsdt_scope(struct device *dev, const char *scope)
+{
+	static char buf[DEVICE_PATH_MAX] = {};
+	const char *path = acpi_device_path(dev);
+
+	memset(buf, 0, sizeof(buf));
+	snprintf(buf, sizeof(buf) - 1, "%s.%s", path, scope);
+
+	return buf;
+}
+
+/*
+ * Generates EC SSDT.
+ */
+void h8_ssdt_generator(struct device *dev)
+{
+	if (!acpi_device_path(dev))
+		return;
+
+	printk(BIOS_INFO, "ACPI:    * H8\n");
+
+	/* Scope HKEY */
+	acpigen_write_scope(h8_dsdt_scope(dev, "HKEY"));
+
+	/* Used by thinkpad_acpi */
+	acpigen_write_name_byte("HBDC", h8_has_bdc(dev) ? ONE_OP : ZERO_OP);
+
+	acpigen_pop_len(); /* Scope HKEY */
+}