aoz1380: ignore false positive over current/temp

AOZ1380 can issue an over current/temperature interrupt
when we disconnect as source or sink.  Ignoring it
recovers the issue without having to alert the USB PD
stack.  If the interrupts hits a second time, don't
ignore it.

BUG=b:147359722
BRANCH=none
TEST=connect/disconnect charger to AOZ1380 attached port

Change-Id: I2d3250de91c3607431c64c0a5eaeafa759abdcc0
Signed-off-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1984040
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2224684
Reviewed-by: Diana Z <dzigterman@chromium.org>
Tested-by: David Huang <david.huang@quanta.corp-partner.google.com>
Commit-Queue: Diana Z <dzigterman@chromium.org>

1 files changed, 49 insertions, 8 deletions

diff --git a/driver/ppc/aoz1380.c b/driver/ppc/aoz1380.c
index 708d488e94..990bd41a73 100644
--- a/driver/ppc/aoz1380.c
+++ b/driver/ppc/aoz1380.c
@@ -11,6 +11,7 @@
  * controlled PPC chips that are similar to the AOZ1380
  */
 
+#include "atomic.h"
 #include "common.h"
 #include "console.h"
 #include "driver/ppc/aoz1380.h"
@@ -27,7 +28,12 @@
 static uint32_t irq_pending; /* Bitmask of ports signaling an interrupt. */
 
 #define AOZ1380_FLAGS_SOURCE_ENABLED    BIT(0)
-static uint8_t flags[CONFIG_USB_PD_PORT_MAX_COUNT];
+#define AOZ1380_FLAGS_SINK_ENABLED      BIT(1)
+#define AOZ1380_FLAGS_INT_ON_DISCONNECT BIT(2)
+static uint32_t flags[CONFIG_USB_PD_PORT_MAX_COUNT];
+
+#define AOZ1380_SET_FLAG(port, flag) atomic_or(&flags[port], (flag))
+#define AOZ1380_CLR_FLAG(port, flag) atomic_clear(&flags[port], (flag))
 
 static int aoz1380_init(int port)
 {
@@ -41,8 +47,20 @@ static int aoz1380_vbus_sink_enable(int port, int enable)
 	int rv;
 
 	rv = tcpm_set_snk_ctrl(port, enable);
+	if (rv)
+		return rv;
+
+	/*
+	 * On enable, we want to indicate connection as a SINK.
+	 * On disable, clear SINK and that we have interrupted.
+	 */
+	if (enable)
+		AOZ1380_SET_FLAG(port, AOZ1380_FLAGS_SINK_ENABLED);
+	else
+		AOZ1380_CLR_FLAG(port, (AOZ1380_FLAGS_SINK_ENABLED |
+					AOZ1380_FLAGS_INT_ON_DISCONNECT));
 
-	return rv;
+	return EC_SUCCESS;
 }
 
 static int aoz1380_vbus_source_enable(int port, int enable)
@@ -53,12 +71,17 @@ static int aoz1380_vbus_source_enable(int port, int enable)
 	if (rv)
 		return rv;
 
+	/*
+	 * On enable, we want to indicate connection as a SOURCE.
+	 * On disable, clear SOURCE and that we have interrupted.
+	 */
 	if (enable)
-		flags[port] |= AOZ1380_FLAGS_SOURCE_ENABLED;
+		AOZ1380_SET_FLAG(port, AOZ1380_FLAGS_SOURCE_ENABLED);
 	else
-		flags[port] &= ~AOZ1380_FLAGS_SOURCE_ENABLED;
+		AOZ1380_CLR_FLAG(port, (AOZ1380_FLAGS_SOURCE_ENABLED |
+					AOZ1380_FLAGS_INT_ON_DISCONNECT));
 
-	return rv;
+	return EC_SUCCESS;
 }
 
 static int aoz1380_is_sourcing_vbus(int port)
@@ -78,14 +101,32 @@ static int aoz1380_set_vbus_source_current_limit(int port,
  * This device only has a single over current/temperature interrupt.
  * TODO(b/141939343) Determine how to clear the interrupt
  * TODO(b/142076004) Test this to verify we shut off vbus current
+ * TODO(b/147359722) Verify correct fault functionality
  */
 static void aoz1380_handle_interrupt(int port)
 {
 	/*
-	 * This is a over current/temperature condition
+	 * We can get a false positive on disconnect that we
+	 * had an over current/temperature event when we are no
+	 * longer connected as sink or source.  Ignore it if
+	 * that is the case.
 	 */
-	CPRINTS("C%d: PPC detected Vbus overcurrent/temperature!", port);
-	pd_handle_overcurrent(port);
+	if (flags[port] != 0) {
+		/*
+		 * This is a over current/temperature condition
+		 */
+		CPRINTS("C%d PPC Vbus overcurrent/temperature", port);
+		pd_handle_overcurrent(port);
+	} else {
+		/*
+		 * Just in case there is a condition that we will
+		 * continue an interrupt storm, track that we have
+		 * already been here once and will take the other
+		 * path if we do this again before setting the
+		 * sink/source as enabled or disabled again.
+		 */
+		AOZ1380_SET_FLAG(port, AOZ1380_FLAGS_INT_ON_DISCONNECT);
+	}
 }
 
 static void aoz1380_irq_deferred(void)