lazor: Fix turning switchcap off when sysjump to RW

The polarity of the enable pins of DA9313 and LN9310 are different.
DA9313 is active-high while LN9310 is active-low. For power saving,
the enable pin of LN9310 has an external pull-up; so EC should
configure it open-drain.

The existing code causes an issue that the switchcap is turned off
when sysjump to RW. We should configure the enable pin properly.

DA9313 is GPIO-controlled without needing any configuration. So the
default setting in gpio.inc should favors DA9313, i.e. GPIO_OUT_LOW;
otherwise, DA9313 may turn on unexpectedly.

In the board init, should not set the level; otherwise, it will
override its level and shutdown the switchcap when sysjump to RW.

LN9313 is similar but a bit tricky. As the gpio.inc configures it
GPIO_OUT_LOW. When sysjump to RW, will output push-pull a short
period of time. As it outputs LOW, should be fine.

The GPIO changes like:
 (1) EC boots from RO -> high-Z
 (2) GPIO init according to gpio.inc -> push-pull LOW
 (3) This function configures it -> open-drain HIGH
 (4) Power sequence turns on the switchcap -> open-drain LOW
 (5) EC sysjumps to RW
 (6) GPIO init according to gpio.inc -> push-pull LOW
 (7) This function configures it -> open-drain LOW

BRANCH=None
BUG=b:163867792, b:151393598
TEST=Tested on Lazor: when sysjump to RW, switchcap not off.

Change-Id: Iec8ea7e16f525fa431230546d712c3e081fdab5c
Signed-off-by: Wai-Hong Tam <waihong@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2391830
Reviewed-by: Stephen Boyd <swboyd@chromium.org>

1 files changed, 36 insertions, 6 deletions

diff --git a/board/lazor/board.c b/board/lazor/board.c
index 2d0672331b..5de16d4fd9 100644
--- a/board/lazor/board.c
+++ b/board/lazor/board.c
@@ -260,11 +260,37 @@ static void board_switchcap_init(void)
 		gpio_set_flags(GPIO_SWITCHCAP_PG_INT_L, GPIO_INT_FALLING);
 		gpio_enable_interrupt(GPIO_SWITCHCAP_PG_INT_L);
 
-		/* Configure LN9310 enable, open-drain, active low */
-		gpio_set_flags(GPIO_SWITCHCAP_ON_L, GPIO_ODR_HIGH);
+		/*
+		 * Configure LN9310 enable, open-drain output. Don't set the
+		 * level here; otherwise, it will override its value and
+		 * shutdown the switchcap when sysjump to RW.
+		 *
+		 * Note that the gpio.inc configures it GPIO_OUT_LOW. When
+		 * sysjump to RW, will output push-pull a short period of
+		 * time. As it outputs LOW, should be fine.
+		 *
+		 * This GPIO changes like:
+		 * (1) EC boots from RO -> high-Z
+		 * (2) GPIO init according to gpio.inc -> push-pull LOW
+		 * (3) This function configures it -> open-drain HIGH
+		 * (4) Power sequence turns on the switchcap -> open-drain LOW
+		 * (5) EC sysjumps to RW
+		 * (6) GPIO init according to gpio.inc -> push-pull LOW
+		 * (7) This function configures it -> open-drain LOW
+		 */
+		gpio_set_flags(GPIO_SWITCHCAP_ON_L,
+			       GPIO_OUTPUT | GPIO_OPEN_DRAIN);
 
-		/* Init the switchcap driver */
-		ln9310_init();
+		/* Only configure the switchcap if not sysjump */
+		if (!system_jumped_late()) {
+			/*
+			 * Deassert the enable pin (set it HIGH), so the
+			 * switchcap won't be enabled after the switchcap is
+			 * configured from standby mode to switching mode.
+			 */
+			gpio_set_level(GPIO_SWITCHCAP_ON_L, 1);
+			ln9310_init();
+		}
 	} else {
 		CPRINTS("Use switchcap: DA9313");
 
@@ -274,8 +300,12 @@ static void board_switchcap_init(void)
 		 */
 		gpio_set_flags(GPIO_DA9313_GPIO0, GPIO_INPUT | GPIO_PULL_DOWN);
 
-		/* Configure DA9313 enable, push-pull, active high */
-		gpio_set_flags(GPIO_SWITCHCAP_ON, GPIO_OUT_LOW);
+		/*
+		 * Configure DA9313 enable, push-pull output. Don't set the
+		 * level here; otherwise, it will override its value and
+		 * shutdown the switchcap when sysjump to RW.
+		 */
+		gpio_set_flags(GPIO_SWITCHCAP_ON, GPIO_OUTPUT);
 	}
 }