ec: Filter non-FIXED PDOs in servo_v4{p1}

Add a new config CONFIG_USB_PD_ONLY_FIXED_PDOS. If that config is
enabled, ignore non-FIXED PDOs in both the console command `ada_srccaps`
and also when selecting the preferred PDO for a voltage.

Enable CONFIG_USB_PD_ONLY_FIXED_PDOS for servo_v4 and servo_v4p1, since
they don't expose non-fixed PDO in their srccaps. Without this change,
there is a risk that the "best" PDO for a given voltage will be
non-FIXED and then that voltage just won't be supported at all.

BRANCH=none
BUG=b:178484932
TEST=added

Change-Id: I0d1187ca372120c7fe21d627e1b82b59f6334add
Signed-off-by: Jeremy Bettis <jbettis@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2809353
Tested-by: Jeremy Bettis <jbettis@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>
Reviewed-by: Keith Short <keithshort@chromium.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/test/usb_pd_pdo_fixed_test.c b/test/usb_pd_pdo_fixed_test.c
new file mode 100644
index 0000000000..ad247c3ba2
--- /dev/null
+++ b/test/usb_pd_pdo_fixed_test.c
@@ -0,0 +1,47 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Test USB common module.
+ */
+#include "test_util.h"
+#include "usb_common.h"
+
+#define PDO_FIXED_FLAGS \
+	(PDO_FIXED_DUAL_ROLE | PDO_FIXED_DATA_SWAP | PDO_FIXED_COMM_CAP)
+
+/* Test that a non-fixed PDO will never be selected by pd_find_pdo_index. */
+test_static int test_pd_find_pdo_index(void)
+{
+	const uint32_t pd_snk_pdo[] = {
+		PDO_FIXED(5000, 500, PDO_FIXED_FLAGS),
+		PDO_VAR(4750, PD_MAX_VOLTAGE_MV, PD_MAX_CURRENT_MA),
+		PDO_BATT(4750, PD_MAX_VOLTAGE_MV, PD_MAX_POWER_MW),
+		PDO_FIXED(9000, 3000, PDO_FIXED_FLAGS),
+		PDO_FIXED(12000, 3000, PDO_FIXED_FLAGS),
+		PDO_FIXED(20000, 3000, PDO_FIXED_FLAGS),
+	};
+	const int pd_snk_pdo_cnt = ARRAY_SIZE(pd_snk_pdo);
+	uint32_t pdo;
+
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 5000, &pdo), 0,
+		"%d");
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 9000, &pdo), 3,
+		"%d");
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 10000, &pdo), 3,
+		"%d");
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 12000, &pdo), 4,
+		"%d");
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 15000, &pdo), 4,
+		"%d");
+	TEST_EQ(pd_find_pdo_index(pd_snk_pdo_cnt, pd_snk_pdo, 20000, &pdo), 5,
+		"%d");
+	return EC_SUCCESS;
+}
+
+void run_test(int argc, char **argv)
+{
+	RUN_TEST(test_pd_find_pdo_index);
+
+	test_print_result();
+}