ec/lenovo/h8: Add USB Always On

USB AO is the internal name for the dedicated charging port on
ThinkPads when in S3 or lower.

AOEN (bit 0) is internal name for enabling this feature while AOCF
(bits 2 and 3) is the configuration field. According to Peter Stuge,
AOCF can be configured in this way:

    00 => AC S3 S4 S4 USB on, battery S3 USB on, battery S4 S5 off
    11 => AC S3 S4 S4 USB on, battery S3 S4 S5 USB off
    10, 01 => equivalent to 00

This commit also adds a new configuration field in the CMOS of the
X220 and the X201 to activate this feature. It probably can be also
added to all the ThinkPads that support this functionality.

With this functionality USB devices are able to negotiate full power
from the dedicated port (usually the yellow one) even in S3.

Tested on a X201 and X220 with an Android smartphone: with this
feature enabled it shows "Charging" when connected during S3, without
it it shows "Charging slowly" (or it doesn't charge at all on the
X201).

For some reasons the "AC only" mode doesn't work, so it has been
disabled.

Change-Id: Ie1269a4357e2fbd608ad8b7b8262275914730f6e
Signed-off-by: Nicola Corna <nicola@corna.info>
Reviewed-on: https://review.coreboot.org/17252
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>

6 files changed, 14 insertions, 3 deletions

diff --git a/src/mainboard/lenovo/x201/cmos.default b/src/mainboard/lenovo/x201/cmos.default
index 50d17aefd2..9f1e31ded2 100644
--- a/src/mainboard/lenovo/x201/cmos.default
+++ b/src/mainboard/lenovo/x201/cmos.default
@@ -15,3 +15,4 @@ sticky_fn=Disable
 power_management_beeps=Enable
 low_battery_beep=Enable
 sata_mode=AHCI
+usb_always_on=Disable
diff --git a/src/mainboard/lenovo/x201/cmos.layout b/src/mainboard/lenovo/x201/cmos.layout
index 2a91eb71bb..72702328fb 100644
--- a/src/mainboard/lenovo/x201/cmos.layout
+++ b/src/mainboard/lenovo/x201/cmos.layout
@@ -70,8 +70,8 @@ entries
 419         1       e       1        power_management_beeps
 420         1       e       1        low_battery_beep
 421         1       e       9        sata_mode
-
-#422        2       r       0        unused
+422         1       e       11       usb_always_on
+#423        1       r       1        unused
 
 # coreboot config options: northbridge
 424         3       e       10       gfx_uma_size
@@ -123,6 +123,8 @@ enumerations
 10    3     128M
 10    5     96M
 10    6     160M
+11    0     Disable
+11    1     AC and battery
 
 # -----------------------------------------------------------------
 checksums
diff --git a/src/mainboard/lenovo/x201/smihandler.c b/src/mainboard/lenovo/x201/smihandler.c
index 591a52112e..f00ae0dcdc 100644
--- a/src/mainboard/lenovo/x201/smihandler.c
+++ b/src/mainboard/lenovo/x201/smihandler.c
@@ -178,6 +178,8 @@ int mainboard_smi_apmc(u8 data)
 
 void mainboard_smi_sleep(u8 slp_typ)
 {
+	h8_usb_always_on();
+
 	if (slp_typ == 3) {
 		u8 ec_wake = ec_read(0x32);
 		/* If EC wake events are enabled, enable wake on EC WAKE GPE.  */
diff --git a/src/mainboard/lenovo/x220/cmos.default b/src/mainboard/lenovo/x220/cmos.default
index 1b8e212894..91331ab22e 100644
--- a/src/mainboard/lenovo/x220/cmos.default
+++ b/src/mainboard/lenovo/x220/cmos.default
@@ -10,6 +10,7 @@ wwan=Enable
 wlan=Enable
 touchpad=Enable
 sata_mode=AHCI
+usb_always_on=Disable
 fn_ctrl_swap=Disable
 sticky_fn=Disable
 trackpoint=Enable
diff --git a/src/mainboard/lenovo/x220/cmos.layout b/src/mainboard/lenovo/x220/cmos.layout
index 143ee807cd..0f57058ca2 100644
--- a/src/mainboard/lenovo/x220/cmos.layout
+++ b/src/mainboard/lenovo/x220/cmos.layout
@@ -69,7 +69,8 @@ entries
 418         1       e       1        sticky_fn
 419         1       e       1        power_management_beeps
 421         1       e       9        sata_mode
-#422	    2	    r	    1	     unused
+422         1       e       12       usb_always_on
+#423        1       r       1        unused
 
 # coreboot config options: cpu
 424          1       e       2        hyper_threading
@@ -134,6 +135,8 @@ enumerations
 11    4	    160M
 11    5	    192M
 11    6	    224M
+12    0     Disable
+12    1     AC and battery
 
 # -----------------------------------------------------------------
 checksums
diff --git a/src/mainboard/lenovo/x220/smihandler.c b/src/mainboard/lenovo/x220/smihandler.c
index 08554c93ec..e1bb37698f 100644
--- a/src/mainboard/lenovo/x220/smihandler.c
+++ b/src/mainboard/lenovo/x220/smihandler.c
@@ -133,6 +133,8 @@ int mainboard_smi_apmc(u8 data)
 
 void mainboard_smi_sleep(u8 slp_typ)
 {
+	h8_usb_always_on();
+
 	if (slp_typ == 3) {
 		u8 ec_wake = ec_read(0x32);
 		/* If EC wake events are enabled, enable wake on EC WAKE GPE.  */