zephyr test: PD charger integration test skeleton

The initial outline for an integration test: Emulate attaching a PD
charger. Verify that PD negotiation completes and starts charging at the
negotiated power.

BUG=b:209907297
TEST=zmake configure --test zephyr/test/drivers
BRANCH=none

Change-Id: I47fdec548a6625a850ea4578353e572e5130ed55
Signed-off-by: Abe Levkoy <alevkoy@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3359842
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>

1 files changed, 66 insertions, 0 deletions

diff --git a/zephyr/test/drivers/src/integration_usb.c b/zephyr/test/drivers/src/integration_usb.c
index 854f286c77..5a236a0df1 100644
--- a/zephyr/test/drivers/src/integration_usb.c
+++ b/zephyr/test/drivers/src/integration_usb.c
@@ -91,11 +91,77 @@ static void test_attach_compliant_charger(void)
 	/* TODO: Also check voltage, current, etc. */
 }
 
+static void test_attach_pd_charger(void)
+{
+	const struct emul *tcpci_emul =
+		emul_get_binding(DT_LABEL(TCPCI_EMUL_LABEL));
+	struct i2c_emul *i2c_emul;
+	uint16_t battery_status;
+	struct tcpci_src_emul_data my_charger;
+	const struct device *gpio_dev =
+		DEVICE_DT_GET(DT_GPIO_CTLR(GPIO_AC_OK_PATH, gpios));
+
+	/*
+	 * TODO(b/209907297): Implement the steps of the test beyond USB default
+	 * charging.
+	 */
+
+	/* 1. Configure source PDOs of partner (probably fixed source 5V 3A
+	 * and fixed source 20V 3A). Currently, the partner emulator only
+	 * supports the default USB power PDO.
+	 */
+
+	/* Attach emulated charger. This will send Source Capabilities. */
+	zassert_ok(gpio_emul_input_set(gpio_dev, GPIO_AC_OK_PIN, 1), NULL);
+	tcpci_src_emul_init(&my_charger);
+	zassert_ok(tcpci_src_emul_connect_to_tcpci(&my_charger, tcpci_emul),
+		   NULL);
+
+	/* Wait for current ramp. */
+	k_sleep(K_SECONDS(10));
+
+	/* Verify battery charging. */
+	i2c_emul = sbat_emul_get_ptr(BATTERY_ORD);
+	zassert_ok(sbat_emul_get_word_val(i2c_emul, SB_BATTERY_STATUS,
+					  &battery_status),
+		   NULL);
+	zassert_equal(battery_status & STATUS_DISCHARGING, 0,
+		      "Battery is discharging: %d", battery_status);
+
+	/*
+	 * 2. Check charging current and voltage (should be 5V, default USB
+	 * current); make sure that reports from battery and PD host commands
+	 * match; check that host command reports no active PDO.
+	 */
+
+	/*
+	 * 3. Wait for SenderResponseTimeout. Expect TCPM to send Request.
+	 * We could verify that the Request references the expected PDO, but
+	 * the voltage/current/PDO checks at the end of the test should all be
+	 * wrong if the requested PDO was wrong here.
+	 */
+
+	/*
+	 * 4. Send Accept and PS_RDY from partner with appropriate delay between
+	 * them. Emulate supplying VBUS at the requested voltage/current before
+	 * PS_RDY.
+	 */
+
+	/*
+	 * 5. Check the charging voltage and current. Cross-check the PD state,
+	 * the battery/charger state, and the active PDO as reported by the PD
+	 * state.
+	 */
+}
+
 void test_suite_integration_usb(void)
 {
 	ztest_test_suite(integration_usb,
 			 ztest_user_unit_test_setup_teardown(
 				 test_attach_compliant_charger, init_tcpm,
+				 remove_emulated_devices),
+			 ztest_user_unit_test_setup_teardown(
+				 test_attach_pd_charger, init_tcpm,
 				 remove_emulated_devices));
 	ztest_run_test_suite(integration_usb);
 }