tests: lib: tenstorrent: pgood: test pgood handling

Using emulated GPIOs, test bh_chip PGOOD fault state transitions.

The sequence is as follows:
- Setup PGOOD GPIO callbacks
- Start with PGOOD high
- Lower PGOOD and ensure that the callback sets pgood_fall_triggered = 1
- Invoke handle_pgood_event (happens in main loop outside this test) and ensure
pgood_fall_triggered is cleared, pgood_last_trip_ms was set, and a severe fault
state hasn't been entered
- Raise PGOOD and ensure pgood_rise_triggered = 1, then clear it
- Lower PGOOD again
- Invoke the handler and ensure severe fault state is entered

Signed-off-by: Petra Alexson <[email protected]>

Author: kikkiakki

tests/lib/tenstorrent/pgood/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(pgood)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

tests/lib/tenstorrent/pgood/app.overlay

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2024 Tenstorrent AI ULC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/ {
+	asic_reset {
+	       compatible = "zephyr,gpio-line";
+	       label = "Emulated ASIC reset line";
+	       gpios = <&gpio0 0 GPIO_ACTIVE_LOW>;
+	};
+
+	pgood {
+	       compatible = "zephyr,gpio-line";
+	       label = "Emulated power good indicator";
+	       gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
+	};
+
+	board_fault_led {
+	       compatible = "zephyr,gpio-line";
+	       label = "Emulated board fault LED";
+	       gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
+	};
+};

tests/lib/tenstorrent/pgood/prj.conf

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+CONFIG_ZTEST=y
+
+CONFIG_TT_BH_CHIP=y
+CONFIG_EVENTS=y
+CONFIG_TT_EVENT=y
+CONFIG_GPIO=y
+CONFIG_GPIO_EMUL=y
+
+CONFIG_JTAG=y
+CONFIG_TT_JTAG_BOOTROM=y

tests/lib/tenstorrent/pgood/src/main.c

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+/*
+ * Copyright (c) 2025 Tenstorrent AI ULC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/drivers/gpio/gpio_emul.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/ztest.h>
+
+#include <tenstorrent/bh_chip.h>
+
+static struct bh_chip test_chip = {
+	.config = {
+		.asic_reset = GPIO_DT_SPEC_GET(DT_PATH(asic_reset), gpios),
+		.pgood = GPIO_DT_SPEC_GET(DT_PATH(pgood), gpios),
+	}};
+
+const struct device *gpio_emul = DEVICE_DT_GET(DT_NODELABEL(gpio0));
+static const struct gpio_dt_spec board_fault_led =
+	GPIO_DT_SPEC_GET(DT_PATH(board_fault_led), gpios);
+
+ZTEST(pgood, test_pgood)
+{
+	/* Start with PGOOD high */
+	gpio_emul_input_set(gpio_emul, 1, 1);
+	/* Manually clear pgood_rise_triggered */
+	test_chip.data.pgood_rise_triggered = 0;
+
+	/* Wait 1ms so pgood_last_trip_ms will not be set to 0 */
+	k_msleep(1);
+
+	/* Set PGOOD low */
+	gpio_emul_input_set(gpio_emul, 1, 0);
+	/* Check that PGOOD fall was triggered */
+	zassert_true(test_chip.data.pgood_fall_triggered);
+
+	handle_pgood_event(&test_chip, board_fault_led);
+	/* Check that PGOOD fall was handled */
+	zassert_true(test_chip.data.pgood_last_trip_ms > 0);
+	zassert_false(test_chip.data.pgood_fall_triggered);
+	zassert_false(test_chip.data.pgood_severe_fault);
+
+	/* Set PGOOD high */
+	gpio_emul_input_set(gpio_emul, 1, 1);
+	/* Check that PGOOD rise was triggered */
+	zassert_true(test_chip.data.pgood_rise_triggered);
+	/* Manually clear it because bh_chip_reset_chip can't run here */
+	test_chip.data.pgood_rise_triggered = 0;
+
+	/* Set PGOOD low */
+	gpio_emul_input_set(gpio_emul, 1, 0);
+	zassert_true(test_chip.data.pgood_fall_triggered);
+
+	handle_pgood_event(&test_chip, board_fault_led);
+	/* Check that PGOOD fall was handled and severe state was entered */
+	zassert_true(test_chip.data.pgood_last_trip_ms > 0);
+	zassert_false(test_chip.data.pgood_fall_triggered);
+	zassert_true(test_chip.data.pgood_severe_fault);
+}
+
+static void before(void *arg)
+{
+	ARG_UNUSED(arg);
+
+	zassert_ok(pgood_gpio_setup(&test_chip));
+}
+
+ZTEST_SUITE(pgood, NULL, NULL, before, NULL, NULL);

tests/lib/tenstorrent/pgood/testcase.yaml

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+tests:
+  lib.tenstorrent.pgood:
+    filter: dt_compat_enabled("zephyr,gpio-emul")