lenovo/h8,thinkpads: Re-do USB Always On

Re-write the UAO handling code as it had stopped working (#171)
  (the flag was not getting read from the RTC properly in SMM)

Remove the SMM code as it's not needed (but EC flag won't be set
  upon entering S3 now)
Set the EC flags on boot the same way other flags are set
Document bitwise operators for clarity
Propagate changes to other Thinkpads
  (updated X201 to have 2 bits for the flag as it only had 1)

Per Nicola Corna's previous commits, 0x0d is set for "AC only"
  "AC only" does exhibit different behaviour - the USB port is
  turned on a few seconds after entering S3, rather than < 1 sec,
  regardless of AC status

Tested on X220

Change-Id: If812cd1ef8fb1a24d7fadbe834f574b40cbcd56a
Signed-off-by: Nathaniel Roach <nroach44@gmail.com>
Reviewed-on: https://review.coreboot.org/c/29565
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

4 files changed, 39 insertions, 50 deletions

diff --git a/src/ec/lenovo/h8/Makefile.inc b/src/ec/lenovo/h8/Makefile.inc
index e4408f1ac1..ebf6d7d7a4 100644
--- a/src/ec/lenovo/h8/Makefile.inc
+++ b/src/ec/lenovo/h8/Makefile.inc
@@ -9,6 +9,5 @@ ramstage-y += h8.c
 ramstage-y += bluetooth.c
 ramstage-y += wwan.c
 ramstage-$(CONFIG_HAVE_ACPI_TABLES) += ssdt.c
-smm-y += smm.c
 
 endif
diff --git a/src/ec/lenovo/h8/h8.c b/src/ec/lenovo/h8/h8.c
index 1f1655dc40..da216ec78f 100644
--- a/src/ec/lenovo/h8/h8.c
+++ b/src/ec/lenovo/h8/h8.c
@@ -128,6 +128,34 @@ void h8_disable_event(int event)
 
 }
 
+void h8_usb_always_on_enable(enum usb_always_on on)
+{
+	u8 val;
+
+	switch (on) {
+	case UAO_OFF:
+		val = ec_read(H8_USB_ALWAYS_ON);
+		// Clear bits 0,2,3
+		val &= ~(H8_USB_ALWAYS_ON_ENABLE | H8_USB_ALWAYS_ON_AC_ONLY);
+		ec_write(H8_USB_ALWAYS_ON, val);
+		break;
+
+	case UAO_AC_AND_BATTERY:
+		val = ec_read(H8_USB_ALWAYS_ON);
+		val |= H8_USB_ALWAYS_ON_ENABLE; // Set bit 0
+		val &= ~H8_USB_ALWAYS_ON_AC_ONLY; // Clear bits 2 and 3
+		ec_write(H8_USB_ALWAYS_ON, val);
+		break;
+
+	case UAO_AC_ONLY:
+		val = ec_read(H8_USB_ALWAYS_ON);
+		// Set bits 0,2,3
+		val |= (H8_USB_ALWAYS_ON_ENABLE | H8_USB_ALWAYS_ON_AC_ONLY);
+		ec_write(H8_USB_ALWAYS_ON, val);
+		break;
+	}
+}
+
 void h8_usb_power_enable(int onoff)
 {
 	if (onoff)
@@ -270,8 +298,10 @@ static void h8_enable(struct device *dev)
 	ec_write(0x1f, conf->eventf_enable);
 
 	ec_write(H8_FAN_CONTROL, H8_FAN_CONTROL_AUTO);
-	ec_write(H8_USB_ALWAYS_ON, ec_read(H8_USB_ALWAYS_ON) &
-			~H8_USB_ALWAYS_ON_ENABLE);
+
+	if (get_option(&val, "usb_always_on") != CB_SUCCESS)
+		val = 0;
+	h8_usb_always_on_enable(val);
 
 	if (get_option(&val, "wlan") != CB_SUCCESS)
 		val = 1;
diff --git a/src/ec/lenovo/h8/h8.h b/src/ec/lenovo/h8/h8.h
index 4ac395a098..a46ba1f5e0 100644
--- a/src/ec/lenovo/h8/h8.h
+++ b/src/ec/lenovo/h8/h8.h
@@ -19,9 +19,16 @@
 #include <stdint.h>
 #include <device/device.h>
 
+enum usb_always_on {
+	UAO_OFF = 0,
+	UAO_AC_AND_BATTERY = 1,
+	UAO_AC_ONLY = 2
+};
+
 void h8_trackpoint_enable(int on);
 void h8_wlan_enable(int on);
 void h8_set_audio_mute(int on);
+void h8_usb_always_on_enable(enum usb_always_on on);
 void h8_usb_power_enable(int on);
 void h8_enable_event(int event);
 void h8_disable_event(int event);
diff --git a/src/ec/lenovo/h8/smm.c b/src/ec/lenovo/h8/smm.c
deleted file mode 100644
index 6005c31033..0000000000
--- a/src/ec/lenovo/h8/smm.c
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2016 Nicola Corna <nicola@corna.info>
- *
- * 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/acpi/ec.h>
-#include <pc80/mc146818rtc.h>
-
-#include "h8.h"
-
-enum usb_always_on {
-	UAO_OFF = 0,
-	UAO_AC_AND_BATTERY,
-	UAO_AC_ONLY
-};
-
-void h8_usb_always_on(void)
-{
-	enum usb_always_on val;
-	u8 reg;
-
-	if (get_option(&val, "usb_always_on") != CB_SUCCESS)
-		val = UAO_OFF;
-
-	if (val == UAO_AC_AND_BATTERY) {
-		reg = ec_read(H8_USB_ALWAYS_ON);
-		reg &= ~H8_USB_ALWAYS_ON_AC_ONLY;
-		reg |= H8_USB_ALWAYS_ON_ENABLE;
-		ec_write(H8_USB_ALWAYS_ON, reg);
-	} else if (val == UAO_AC_ONLY) {
-		reg = ec_read(H8_USB_ALWAYS_ON);
-		reg |= H8_USB_ALWAYS_ON_AC_ONLY;
-		reg |= H8_USB_ALWAYS_ON_ENABLE;
-		ec_write(H8_USB_ALWAYS_ON, reg);
-		ec_set_bit(0x2, 3);
-	}
-}