power/amd_x86: Add support for STB dumping

Skyrim supports dumping the contents of the SoCs smart-trace buffer
when triggered externally. The contents of the STB can be useful in
debugging S0i3 suspend failures. Add support for triggering an STB dump
when the SoC hangs during S0i3 entry/exit.

BRANCH=none
BUG=b:246770811
TEST=Ran on skyrim DUT

Change-Id: Ie18c6072a77f6dd306a46d7f76bd345b4f9e75a7
Signed-off-by: Robert Zieba <robertzieba@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4220248
Reviewed-by: Diana Z <dzigterman@chromium.org>

2 files changed, 92 insertions, 0 deletions

diff --git a/driver/amd_stb.c b/driver/amd_stb.c
new file mode 100644
index 0000000000..9d847bb524
--- /dev/null
+++ b/driver/amd_stb.c
@@ -0,0 +1,77 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Driver for AMD STB dump functionality */
+#include "chipset.h"
+#include "driver/amd_stb.h"
+#include "hooks.h"
+
+#ifndef CONFIG_ZTEST
+#define CPRINTS(format, args...) cprints(CC_CHIPSET, format, ##args)
+#else
+#define CPRINTS(format, args...) printk(format, ##args)
+#endif
+
+static bool stb_dump_in_progress;
+static struct {
+	/* Interrupt from EC to AP. */
+	const struct gpio_dt_spec *int_out;
+	/* Interrupt from AP to EC. */
+	const struct gpio_dt_spec *int_in;
+} stb_dump_config;
+
+void amd_stb_dump_finish(void)
+{
+	gpio_pin_set_dt(stb_dump_config.int_out, 0);
+	stb_dump_in_progress = false;
+}
+
+void amd_stb_dump_trigger(void)
+{
+	if (stb_dump_in_progress || !stb_dump_config.int_out)
+		return;
+
+	CPRINTS("Triggering STB dump");
+	stb_dump_in_progress = true;
+	gpio_pin_set_dt(stb_dump_config.int_out, 1);
+}
+
+void amd_stb_dump_init(const struct gpio_dt_spec *int_out,
+		       const struct gpio_dt_spec *int_in)
+{
+	stb_dump_config.int_out = int_out;
+	stb_dump_config.int_in = int_in;
+}
+
+static void stb_dump_interrupt_deferred(void)
+{
+	/* AP has indicated that it has finished the dump. */
+	if (!stb_dump_in_progress)
+		return;
+
+	amd_stb_dump_finish();
+	CPRINTS("STB dump finished");
+}
+DECLARE_DEFERRED(stb_dump_interrupt_deferred);
+
+bool amd_stb_dump_in_progress(void)
+{
+	return stb_dump_in_progress;
+}
+
+void amd_stb_dump_interrupt(enum gpio_signal signal)
+{
+	hook_call_deferred(&stb_dump_interrupt_deferred_data, 0);
+}
+
+#ifdef CONFIG_PLATFORM_EC_AMD_STB_DUMP_CMD
+static int command_amdstbdump(int argc, const char **argv)
+{
+	amd_stb_dump_trigger();
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(amdstbdump, command_amdstbdump, NULL,
+			"Trigger an STB dump");
+#endif
diff --git a/driver/amd_stb.h b/driver/amd_stb.h
new file mode 100644
index 0000000000..5c339c66e5
--- /dev/null
+++ b/driver/amd_stb.h
@@ -0,0 +1,15 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include <stddef.h>
+
+#include <gpio_signal.h>
+
+struct gpio_dt_spec;
+void amd_stb_dump_finish(void);
+void amd_stb_dump_init(const struct gpio_dt_spec *int_out,
+		       const struct gpio_dt_spec *int_in);
+bool amd_stb_dump_in_progress(void);
+void amd_stb_dump_interrupt(enum gpio_signal signal);
+void amd_stb_dump_trigger(void);