ec/google/wilco: Save and restore PS/2 data for S3

Send a command to the EC on the way into S3 suspend state telling
it to save the PS/2 data, and on resume send it a command for
restoring the PS/2 data that was previously saved.

Change-Id: Ic4b5d6d2656dbb1c476b9211b0d60c71b0cd7b32
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/29120
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/ec/google/wilco/chip.c

@@ -44,6 +44,12 @@ static void wilco_ec_post_video_init(void *unused)
 BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT,
 		      wilco_ec_post_video_init, NULL);
 
+static void wilco_ec_resume(void *unused)
+{
+	wilco_ec_send_noargs(KB_RESTORE);
+}
+BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, wilco_ec_resume, NULL);
+
 static void wilco_ec_init(struct device *dev)
 {
 	if (!dev->enabled)

src/ec/google/wilco/commands.h

@@ -26,6 +26,10 @@ enum {
 	KB_POWER_STATUS = 0x05,
 	/* Inform the EC aboout the reason host is turning off */
 	KB_POWER_OFF = 0x08,
+	/* Save PS/2 data before S3 suspend */
+	KB_SAVE = 0x2f,
+	/* Restore PS/2 data after S3 resume */
+	KB_RESTORE = 0x30,
 	/* Retrieve information about the EC */
 	KB_EC_INFO = 0x38,
 	/* Set ACPI mode on or off */

src/ec/google/wilco/smihandler.c

@@ -25,6 +25,7 @@ void wilco_ec_smi_sleep(int slp_type)
 {
 	switch (slp_type) {
 	case ACPI_S3:
+		wilco_ec_send_noargs(KB_SAVE);
 		wilco_ec_slp_en();
 		break;
 	case ACPI_S5: