zephyr: Test SYV682 5V_OC interrupt handling

Simulate a 5V OC condition and verify that the driver turns VBUS off.
Support status interrupt conditions and clear-on-read registers in
SYV682x emulator.

Increase line coverage of syv682x.c from 37.9% to 52.8%.

BUG=b:190519131
TEST=zmake -l DEBUG configure --test zephyr/test/drivers
BRANCH=none

Signed-off-by: Abe Levkoy <alevkoy@chromium.org>
Change-Id: I9c5b419057cf4ccb1531527a71760533240d1f47
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3059218
Reviewed-by: Jeremy Bettis <jbettis@chromium.org>

4 files changed, 92 insertions, 8 deletions

diff --git a/zephyr/emul/emul_syv682x.c b/zephyr/emul/emul_syv682x.c
index dff9df651c..3d76d10492 100644
--- a/zephyr/emul/emul_syv682x.c
+++ b/zephyr/emul/emul_syv682x.c
@@ -12,6 +12,7 @@
 #define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
 #include <logging/log.h>
 LOG_MODULE_REGISTER(syv682x);
+#include <stdint.h>
 #include <string.h>
 
 #include "emul/emul_syv682x.h"
@@ -28,6 +29,12 @@ struct syv682x_emul_data {
 	const struct syv682x_emul_cfg *cfg;
 	/** Current state of all emulated SYV682x registers */
 	uint8_t reg[EMUL_REG_COUNT];
+	/**
+	 * Current state of conditions affecting interrupt bits, as distinct
+	 * from the current values of those bits stored in reg.
+	 */
+	uint8_t status_cond;
+	uint8_t control_4_cond;
 };
 
 /** Static configuration for the emulator */
@@ -53,6 +60,15 @@ int syv682x_emul_set_reg(struct i2c_emul *emul, int reg, uint8_t val)
 	return 0;
 }
 
+void syv682x_emul_set_status(struct i2c_emul *emul, uint8_t val)
+{
+	struct syv682x_emul_data *data;
+
+	data = CONTAINER_OF(emul, struct syv682x_emul_data, emul);
+	data->status_cond = val;
+	data->reg[SYV682X_STATUS_REG] |= val;
+}
+
 int syv682x_emul_get_reg(struct i2c_emul *emul, int reg, uint8_t *val)
 {
 	struct syv682x_emul_data *data;
@@ -102,6 +118,10 @@ static int syv682x_emul_transfer(struct i2c_emul *emul, struct i2c_msg *msgs,
 		return syv682x_emul_set_reg(emul, msgs[0].buf[0],
 				msgs[0].buf[1]);
 	} else if (num_msgs == 2) {
+		int ret;
+		int reg;
+		uint8_t *buf;
+
 		if (!((msgs[0].flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE
 					&& msgs[0].len == 1
 					&& (msgs[1].flags & I2C_MSG_RW_MASK) ==
@@ -110,8 +130,27 @@ static int syv682x_emul_transfer(struct i2c_emul *emul, struct i2c_msg *msgs,
 			LOG_ERR("Unexpected read msgs");
 			return -EIO;
 		}
-		return syv682x_emul_get_reg(emul, msgs[0].buf[0],
-				&msgs[1].buf[0]);
+
+		reg = msgs[0].buf[0];
+		buf = &msgs[1].buf[0];
+		ret = syv682x_emul_get_reg(emul, reg, buf);
+
+		switch (reg) {
+		/*
+		 * These registers are clear-on-read (if the underlying
+		 * condition has cleared).
+		 */
+		case SYV682X_STATUS_REG:
+			syv682x_emul_set_reg(emul, reg, data->status_cond);
+			break;
+		case SYV682X_CONTROL_4_REG:
+			syv682x_emul_set_reg(emul, reg, data->control_4_cond);
+			break;
+		default:
+			break;
+		}
+
+		return ret;
 	} else {
 		LOG_ERR("Unexpected num_msgs");
 		return -EIO;
diff --git a/zephyr/include/emul/emul_syv682x.h b/zephyr/include/emul/emul_syv682x.h
index 9fec144aa0..aa0d8840f7 100644
--- a/zephyr/include/emul/emul_syv682x.h
+++ b/zephyr/include/emul/emul_syv682x.h
@@ -12,6 +12,7 @@
 #define __EMUL_SYV682X_H
 
 #include <drivers/i2c_emul.h>
+#include <stdint.h>
 
 /* Register info copied from syv682.h */
 
@@ -109,6 +110,15 @@
 struct i2c_emul *syv682x_emul_get(int ord);
 
 /**
+ * @brief Set the underlying interrupt conditions affecting the status register
+ *
+ * @param emul SYV682x emulator
+ * @param val  A status register value corresponding to the underlying
+ *             conditions
+ */
+void syv682x_emul_set_status(struct i2c_emul *emul, uint8_t val);
+
+/**
  * @brief Set value of a register of SYV682x
  *
  * @param emul SYV682x emulator
diff --git a/zephyr/test/drivers/CMakeLists.txt b/zephyr/test/drivers/CMakeLists.txt
index 20d9a53cec..c90b334e60 100644
--- a/zephyr/test/drivers/CMakeLists.txt
+++ b/zephyr/test/drivers/CMakeLists.txt
@@ -7,7 +7,9 @@ find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 project(drivers)
 
 # Include the local test directory for shimmed_test_tasks.h
+zephyr_include_directories("${CMAKE_CURRENT_SOURCE_DIR}")
 zephyr_include_directories("${CMAKE_CURRENT_SOURCE_DIR}/include")
+zephyr_include_directories("${PLATFORM_EC}/driver/ppc/")
 
 FILE(GLOB test_sources src/*.c)
 target_sources(app PRIVATE ${test_sources})
diff --git a/zephyr/test/drivers/src/ppc.c b/zephyr/test/drivers/src/ppc.c
index d4d067ad27..dced25c227 100644
--- a/zephyr/test/drivers/src/ppc.c
+++ b/zephyr/test/drivers/src/ppc.c
@@ -10,37 +10,70 @@
 #include "emul/emul_syv682x.h"
 
 #include "stubs.h"
+#include "syv682x.h"
+#include "timer.h"
 #include "usbc_ppc.h"
 
 #define SYV682X_ORD DT_DEP_ORD(DT_NODELABEL(syv682x_emul))
 
+static const int syv682x_port = 1;
+
 static void test_ppc_syv682x_vbus_enable(void)
 {
 	struct i2c_emul *emul = syv682x_emul_get(SYV682X_ORD);
-	const int port = 1;
 	uint8_t reg;
 
-	zassert_ok(ppc_init(port), "PPC init failed");
-
 	zassert_ok(syv682x_emul_get_reg(emul, SYV682X_CONTROL_1_REG, &reg),
 			"Reading CONTROL_1 failed");
 	zassert_equal(reg & SYV682X_CONTROL_1_PWR_ENB,
 			SYV682X_CONTROL_1_PWR_ENB, "VBUS sourcing disabled");
-	zassert_false(ppc_is_sourcing_vbus(port),
+	zassert_false(ppc_is_sourcing_vbus(syv682x_port),
 			"PPC sourcing VBUS at beginning of test");
 
-	zassert_ok(ppc_vbus_source_enable(port, true), "VBUS enable failed");
+	zassert_ok(ppc_vbus_source_enable(syv682x_port, true),
+			"VBUS enable failed");
 	zassert_ok(syv682x_emul_get_reg(emul, SYV682X_CONTROL_1_REG, &reg),
 			"Reading CONTROL_1 failed");
 	zassert_equal(reg & SYV682X_CONTROL_1_PWR_ENB, 0,
 			"VBUS sourcing disabled");
-	zassert_true(ppc_is_sourcing_vbus(port),
+	zassert_true(ppc_is_sourcing_vbus(syv682x_port),
 			"PPC is not sourcing VBUS after VBUS enabled");
 }
 
+static void test_ppc_syv682x_interrupt(void)
+{
+	struct i2c_emul *emul = syv682x_emul_get(SYV682X_ORD);
+
+	syv682x_emul_set_status(emul, SYV682X_STATUS_OC_5V);
+	syv682x_interrupt(syv682x_port);
+
+	/* An OC event less than 100 ms should not cause VBUS to turn off. */
+	msleep(50);
+	syv682x_interrupt(syv682x_port);
+	zassert_true(ppc_is_sourcing_vbus(syv682x_port),
+			"PPC is not sourcing VBUS after 50 ms OC");
+	/* But one greater than 100 ms should. */
+	msleep(60);
+	syv682x_interrupt(syv682x_port);
+	zassert_false(ppc_is_sourcing_vbus(syv682x_port),
+			"PPC is sourcing VBUS after 100 ms OC");
+
+	syv682x_emul_set_status(emul, 0x0);
+	/*
+	 * TODO(b/190519131): Organize the tests to be more hermetic and avoid
+	 * the following issue: The driver triggers overcurrent protection. If
+	 * overcurrent protection is triggered 3 times, the TC won't turn the
+	 * port back on without a detach. This could frustrate efforts to test
+	 * the TC.
+	 */
+}
+
 static void test_ppc_syv682x(void)
 {
+	zassert_ok(ppc_init(syv682x_port), "PPC init failed");
+
 	test_ppc_syv682x_vbus_enable();
+	test_ppc_syv682x_interrupt();
 }
 
 void test_suite_ppc(void)