servo_v4p1: Handle ioexpanders irq in a deferred function call

Performing i2c transfers from interrupt context seems to reset
the device. Handling the interrupt in a deferred function gets
around the problem.

BRANCH=none
BUG=b:146793000
TEST=make -j buildall

Signed-off-by: Sam Hurst <shurst@google.com>
Change-Id: I7d4609670f5d9826de12f87f5543f231de875df5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2270695
Reviewed-by: Wai-Hong Tam <waihong@google.com>

3 files changed, 49 insertions, 30 deletions

diff --git a/board/servo_v4p1/board.c b/board/servo_v4p1/board.c
index 8ee4e6f158..3572285dfb 100644
--- a/board/servo_v4p1/board.c
+++ b/board/servo_v4p1/board.c
@@ -58,36 +58,7 @@ static void vbus1_evt(enum gpio_signal signal)
 
 static void tca_evt(enum gpio_signal signal)
 {
-	uint8_t fault;
-
-	fault = read_faults();
-
-	if (!(fault & USERVO_FAULT_L))
-		ccprintf("FAULT: Microservo USB A port load switch\n");
-
-	if (!(fault & USB3_A0_FAULT_L))
-		ccprintf("FAULT: USB3 A0 port load switch\n");
-
-	if (!(fault & USB3_A1_FAULT_L))
-		ccprintf("FAULT: USB3 A1 port load switch\n");
-
-	if (!(fault & USB_DUTCHG_FLT_ODL))
-		ccprintf("FAULT: Overcurrent on Charger or DUB CC/SBU lines\n");
-
-	if (!(fault & PP3300_DP_FAULT_L))
-		ccprintf("FAULT: Overcurrent on DisplayPort\n");
-
-	if (!(fault & DAC_BUF1_LATCH_FAULT_L)) {
-		ccprintf("FAULT: CC1 drive circuitry has exceeded thermal ");
-		ccprintf("limits or exceeded current limits. Power ");
-		ccprintf("off DAC0 to clear the fault\n");
-	}
-
-	if (!(fault & DAC_BUF1_LATCH_FAULT_L)) {
-		ccprintf("FAULT: CC2 drive circuitry has exceeded thermal ");
-		ccprintf("limits or exceeded current limits. Power ");
-		ccprintf("off DAC1 to clear the fault\n");
-	}
+	irq_ioexpanders();
 }
 
 static volatile uint64_t hpd_prev_ts;
diff --git a/board/servo_v4p1/ioexpanders.c b/board/servo_v4p1/ioexpanders.c
index ac0f616b8a..6617a8d30e 100644
--- a/board/servo_v4p1/ioexpanders.c
+++ b/board/servo_v4p1/ioexpanders.c
@@ -3,6 +3,7 @@
  * found in the LICENSE file.
  */
 
+#include "hooks.h"
 #include "i2c.h"
 #include "ioexpanders.h"
 #include "tca6416a.h"
@@ -126,6 +127,47 @@ int init_ioexpanders(void)
 	return EC_SUCCESS;
 }
 
+static void ioexpanders_irq(void)
+{
+	int fault;
+
+	fault = read_faults();
+
+	if (!(fault & USERVO_FAULT_L))
+		ccprintf("FAULT: Microservo USB A port load switch\n");
+
+	if (!(fault & USB3_A0_FAULT_L))
+		ccprintf("FAULT: USB3 A0 port load switch\n");
+
+	if (!(fault & USB3_A1_FAULT_L))
+		ccprintf("FAULT: USB3 A1 port load switch\n");
+
+	if (!(fault & USB_DUTCHG_FLT_ODL))
+		ccprintf("FAULT: Overcurrent on Charger or DUB CC/SBU lines\n");
+
+	if (!(fault & PP3300_DP_FAULT_L))
+		ccprintf("FAULT: Overcurrent on DisplayPort\n");
+
+	if (!(fault & DAC_BUF1_LATCH_FAULT_L)) {
+		ccprintf("FAULT: CC1 drive circuitry has exceeded thermal ");
+		ccprintf("limits or exceeded current limits. Power ");
+		ccprintf("off DAC0 to clear the fault\n");
+	}
+
+	if (!(fault & DAC_BUF1_LATCH_FAULT_L)) {
+		ccprintf("FAULT: CC2 drive circuitry has exceeded thermal ");
+		ccprintf("limits or exceeded current limits. Power ");
+		ccprintf("off DAC1 to clear the fault\n");
+	}
+}
+DECLARE_DEFERRED(ioexpanders_irq);
+
+int irq_ioexpanders(void)
+{
+	hook_call_deferred(&ioexpanders_irq_data, 0);
+	return 0;
+}
+
 inline int sbu_uart_sel(int en)
 {
 	return tca6416a_write_bit(1, TCA6416A_OUT_PORT_0, 0, en);
diff --git a/board/servo_v4p1/ioexpanders.h b/board/servo_v4p1/ioexpanders.h
index 7d96448e2f..d444a6fca3 100644
--- a/board/servo_v4p1/ioexpanders.h
+++ b/board/servo_v4p1/ioexpanders.h
@@ -16,6 +16,12 @@ enum uservo_fastboot_mux_sel_t {
  */
 int init_ioexpanders(void);
 
+/*
+ * Calls the Ioexpanders Deferred handler for interrupts
+ * Should be called from the ioexpanders IRQ handler
+ */
+int irq_ioexpanders(void);
+
 /**
  * SBU Crosspoint select
  *