mb/google/poppy/variants/nami: Fix Elan touchscreen power off sequence

Power off does not seem to use the ACPI _OFF function, but rather the
smihandler.  Creating variant_smi_sleep function for nami to handle
the power off sequence during reboot/power off.

BUG=b:78311818
BRANCH=None
TEST=Run "poweroff" command from AP console with SMI_DEBUG enabled
     Make sure delays are consistent with spec

Change-Id: Ifeea545fe268be249793b3e508c51f5e4c1a3460
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/26724
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/poppy/smihandler.c

@@ -21,6 +21,7 @@
 #include <soc/gpio.h>
 #include <soc/smm.h>
 
+#include <baseboard/variants.h>
 #include <variant/gpio.h>
 #include <variant/ec.h>
 
@@ -29,8 +30,11 @@ void mainboard_smi_espi_handler(void)
 	chromeec_smi_process_events();
 }
 
+void __weak variant_smi_sleep(u8 slp_typ) {}
+
 void mainboard_smi_sleep(u8 slp_typ)
 {
+	variant_smi_sleep(slp_typ);
 	chromeec_smi_sleep(slp_typ, MAINBOARD_EC_S3_WAKE_EVENTS,
 			MAINBOARD_EC_S5_WAKE_EVENTS);
 }

src/mainboard/google/poppy/variants/baseboard/include/baseboard/variants.h

@@ -54,6 +54,7 @@ void variant_memory_params(struct memory_params *p);
 int variant_memory_sku(void);
 void variant_devtree_update(void);
 uint32_t variant_board_sku(void);
+void variant_smi_sleep(u8 slp_typ);
 
 struct nhlt;
 void variant_nhlt_init(struct nhlt *nhlt);

src/mainboard/google/poppy/variants/nami/Makefile.inc

@@ -35,6 +35,8 @@ ramstage-y += gpio.c
 ramstage-y += nhlt.c
 ramstage-y += mainboard.c
 
+smm-$(CONFIG_HAVE_SMI_HANDLER) += smihandler.c
+
 # Add OEM ID table
 cbfs-files-y += oem.bin
 oem.bin-file := $(call strip_quotes,$(CONFIG_OEM_BIN_FILE))

src/mainboard/google/poppy/variants/nami/smihandler.c

@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018 Google Inc.
+ *
+ * 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 <arch/acpi.h>
+#include <baseboard/variants.h>
+#include <console/console.h>
+#include <delay.h>
+#include "gpio.h"
+
+#define TOUCH_DISABLE         GPP_C3
+#define TOUCH_RESET           GPP_B3
+#define TOUCH_ENABLE          GPP_B4
+
+/*
+ * Elan touchscreen has higher delay requirements than the other
+ * devices, so using that.
+ */
+#define ELAN_STOP_OFF_DELAY   2
+#define ELAN_RESET_OFF_DELAY  2
+#define ELAN_ENABLE_OFF_DELAY 100
+
+void variant_smi_sleep(u8 slp_typ)
+{
+	if (slp_typ == ACPI_S5) {
+		/* TOUCHSCREEN_DIS# */
+		gpio_set(TOUCH_DISABLE, 0);
+		mdelay(ELAN_STOP_OFF_DELAY);
+		/* TOUCHSCREEN_RST# */
+		gpio_set(TOUCH_RESET, 0);
+		mdelay(ELAN_RESET_OFF_DELAY);
+		/* EN_PP3300_DX_TOUCHSCREEN */
+		gpio_set(TOUCH_ENABLE, 0);
+		mdelay(ELAN_ENABLE_OFF_DELAY);
+	}
+}