eve_fp: tri-state pins connected to PCH during S3.

There's leakage through EC_INT when in S3 to the APs P3300_A rail.
Changing the GPIO config to be an input all EC_INT and all the SPI slave
pins during S3 removes the leakage.

Signed-off-by: Todd Broch <tbroch@chromium.org>

BRANCH=none
BUG=b:35648259
TEST=on Eve, run int_test before & after suspend/resume successfully.
Change-Id: I68e286c4770831544bea0d58ffa98185fd7ba788
Reviewed-on: https://chromium-review.googlesource.com/469527
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>

2 files changed, 32 insertions, 8 deletions

diff --git a/board/eve_fp/board.c b/board/eve_fp/board.c
index 3390dbb359..94ae0daade 100644
--- a/board/eve_fp/board.c
+++ b/board/eve_fp/board.c
@@ -10,12 +10,32 @@
 #include "host_command.h"
 #include "spi.h"
 #include "system.h"
+#include "task.h"
 #include "registers.h"
 
-#include "gpio_list.h"
-
 #define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ## args)
 
+static void ap_deferred(void)
+{
+	if (gpio_get_level(GPIO_SLP_S3_L)) {
+		/* S0 */
+		gpio_set_flags(GPIO_EC_INT_L,   GPIO_ODR_HIGH | GPIO_PULL_UP);
+		hook_notify(HOOK_CHIPSET_RESUME);
+	} else {
+		/* S3 */
+		gpio_set_flags(GPIO_EC_INT_L,   GPIO_INPUT);
+		hook_notify(HOOK_CHIPSET_SUSPEND);
+	}
+}
+DECLARE_DEFERRED(ap_deferred);
+
+void slp_event(enum gpio_signal signal)
+{
+	hook_call_deferred(&ap_deferred_data, 0);
+}
+
+#include "gpio_list.h"
+
 /* SPI devices */
 const struct spi_device_t spi_devices[] = {
 	/* Fingerprint sensor */
@@ -31,8 +51,10 @@ static void board_init(void)
 	/* Enable clocks to SPI3 module (master) */
 	STM32_RCC_APB1ENR |= STM32_RCC_PB1_SPI3;
 
-	/* we are ready for host transactions */
-	hook_notify(HOOK_CHIPSET_RESUME);
+	/* Enable interrupt on SLP_S3_L */
+	gpio_enable_interrupt(GPIO_SLP_S3_L);
+	/* enable the SPI slave interface if the PCH is up */
+	hook_call_deferred(&ap_deferred_data, 0);
 }
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
 
diff --git a/board/eve_fp/gpio.inc b/board/eve_fp/gpio.inc
index 930b35ab24..370efed4cf 100644
--- a/board/eve_fp/gpio.inc
+++ b/board/eve_fp/gpio.inc
@@ -7,16 +7,18 @@
 /* Declare symbolic names for all the GPIOs that we care about.
  * Note: Those with interrupt handlers must be declared first. */
 GPIO_INT(FPS_INT,  PIN(A, 2), GPIO_INT_RISING, fps_event)
-GPIO_INT(SPI1_NSS, PIN(A, 4), GPIO_INT_BOTH | GPIO_PULL_UP,  spi_event)
+GPIO_INT(SPI1_NSS, PIN(A, 4), GPIO_INPUT,  spi_event)
+GPIO_INT(SLP_S3_L, PIN(A, 11), GPIO_INT_BOTH, slp_event)
 
 /* Outputs */
-GPIO(EC_INT_L,   PIN(A, 1), GPIO_ODR_HIGH | GPIO_PULL_UP)
+GPIO(EC_INT_L,   PIN(A, 1), GPIO_INPUT) /* Enabled when PCH is up */
 GPIO(FP_RST_ODL, PIN(A, 3), GPIO_ODR_LOW)
 GPIO(SPI3_NSS,   PIN(A, 15), GPIO_OUT_HIGH)
 
-/* Unimplemented signals which we need to emulate for now */
+GPIO(WP_L,       PIN(B, 7), GPIO_INPUT)
+
+/* Unimplemented signals which we need to emulate */
 UNIMPLEMENTED(ENTERING_RW)
-UNIMPLEMENTED(WP_L)
 
 /* USART1: PA9/10 */
 ALTERNATE(PIN_MASK(A, 0x0600), GPIO_ALT_F7, MODULE_UART, 0)