ec/lenovo/h8: Add BDC detection support

* Add support for detecting BDC.
* Allows to turn off power to BDC if no card is installed.
* Should fix https://ticket.coreboot.org/issues/99 .

Add the following devicetree values:
* has_bdc_detection
 Set to one to indicate that the following register are sane.
* bdc_gpio_num
 SB GPIO num to read.
* bdc_gpio_lvl
 SB GPIO level for card to be present (usually zero).

Don't enable BDC power if no card is detected.
As there are no devicetree values yet, the new code doesn't
have any effect.

Change-Id: I506de2eca4b820e6d82de6b2c48a5440462e1db5
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/19809
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>

src/ec/lenovo/h8/Makefile.inc

@@ -6,6 +6,7 @@ ramstage-y += panic.c
 endif
 
 ramstage-y += h8.c
+ramstage-y += bluetooth.c
 smm-y += smm.c
 
 endif

src/ec/lenovo/h8/bluetooth.c

@@ -0,0 +1,69 @@
+/*
+ * 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 <southbridge/intel/common/gpio.h>
+#include <console/console.h>
+#include <device/device.h>
+#include <ec/acpi/ec.h>
+#include <option.h>
+
+#include "h8.h"
+#include "chip.h"
+
+/*
+ * Controls BDC (Bluetooth daughter card) power.
+ */
+void h8_bluetooth_enable(int on)
+{
+	if (on)
+		ec_set_bit(0x3a, 4);
+	else
+		ec_clr_bit(0x3a, 4);
+}
+
+/*
+ * Detect BDC on supported MBs.
+ */
+bool h8_has_bdc(struct device *dev)
+{
+	struct ec_lenovo_h8_config *conf = dev->chip_info;
+
+	if (!conf->has_bdc_detection) {
+		printk(BIOS_INFO, "H8: BDC detection not implemented. "
+				  "Assuming BDC installed\n");
+		return true;
+	}
+
+	if (get_gpio(conf->bdc_gpio_num) == conf->bdc_gpio_lvl) {
+		printk(BIOS_INFO, "H8: BDC installed\n");
+		return true;
+	}
+
+	printk(BIOS_INFO, "H8: BDC not installed\n");
+	return false;
+}
+
+/*
+ * Return BDC NVRAM setting.
+ */
+bool h8_bluetooth_nv_enable(void)
+{
+	u8 val;
+
+	if (get_option(&val, "bluetooth") != CB_SUCCESS)
+		return true;
+
+	return val;
+}

src/ec/lenovo/h8/chip.h

@@ -46,6 +46,10 @@ struct ec_lenovo_h8_config {
 	u8 has_keyboard_backlight;
 	u8 has_power_management_beeps;
 	u8 has_uwb;
+	u8 has_bdc_detection;
+
+	u8 bdc_gpio_num;
+	u8 bdc_gpio_lvl;
 };
 
 #endif /* EC_LENOVO_H8EC_CHIP_H */

src/ec/lenovo/h8/h8.c

@@ -28,14 +28,6 @@
 #include "h8.h"
 #include "chip.h"
 
-static void h8_bluetooth_enable(int on)
-{
-	if (on)
-		ec_set_bit(0x3a, 4);
-	else
-		ec_clr_bit(0x3a, 4);
-}
-
 void h8_trackpoint_enable(int on)
 {
 	ec_write(H8_TRACKPOINT_CTRL,
@@ -288,8 +280,7 @@ static void h8_enable(struct device *dev)
 	if (get_option(&val, "volume") == CB_SUCCESS && !acpi_is_wakeup_s3())
 		ec_write(H8_VOLUME_CONTROL, val);
 
-	if (get_option(&val, "bluetooth") != CB_SUCCESS)
-		val = 1;
+	val = h8_has_bdc(dev) && h8_bluetooth_nv_enable();
 	h8_bluetooth_enable(val);
 
 	if (get_option(&val, "wwan") != CB_SUCCESS)

src/ec/lenovo/h8/h8.h

@@ -17,6 +17,7 @@
 #define EC_LENOVO_H8_H
 
 #include <stdint.h>
+#include <device/device.h>
 
 void h8_trackpoint_enable(int on);
 void h8_wlan_enable(int on);
@@ -30,6 +31,10 @@ void h8_usb_always_on(void);
 
 void h8_mainboard_init_dock (void);
 
+void h8_bluetooth_enable(int on);
+bool h8_bluetooth_nv_enable(void);
+bool h8_has_bdc(struct device *dev);
+
 /* EC registers */
 #define H8_CONFIG0 0x00
 #define H8_CONFIG0_EVENTS_ENABLE	0x02