[PATCH v6] platform/chrome: cros_ec: Add trace event to trace EC commands

From: Raul E Rangel
Date: Tue Apr 16 2019 - 17:03:35 EST


This is useful to see which EC commands are being executed and when.

To enable:

echo 1 > /sys/kernel/debug/tracing/events/cros_ec/enable

Example:

/* cros_ec_cmd: version: 0, command: EC_CMD_GET_VERSION */
/* cros_ec_cmd: version: 0, command: EC_CMD_GET_PROTOCOL_INFO */
/* cros_ec_cmd: version: 1, command: EC_CMD_GET_CMD_VERSIONS */
/* cros_ec_cmd: version: 1, command: EC_CMD_USB_PD_CONTROL */

Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
Reviewed-by: Ross Zwisler <zwisler@xxxxxxxxxx>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
I did not add cros_ec_commands.h as an include to cros_ec_trace.c.
It's not strictly required because the macro doesn't get evaluated until
after cros_ec_trace.h has been included. That transitively brings in
cros_ec_ommands.h. I did try it, but since cros_ec_commands.h doesn't
include linux/types.h it fails to find uint32_t. I could have included
both headers, but since they aren't required I just skipped it.

My reasoning for not putting EC_CMDS in the cros_ec_trace.h was that I
didn't want to clutter the file. I think it's visually easier to find
all the trace events without having to parse through all the
implementation details.

Changes in v6:
- Added script to generate the EC_CMDS trace symbols. They were
originally sorted by value, now they are sorted by declaration order.
There is one duplicate: EC_CMD_PORT80_LAST_BOOT and
EC_CMD_PORT80_READ. They both resolve to the same value. Not sure if
this is a bug in the cros_ec_commands.h file or not. Anyway it doesn't
hurt anything.
- Changed the example in the commit

Changes in v5:
- Rebased on upstream/master. It turns out upstream/master is missing a
lot of changes to cros_ec_commands.h.
- Replace SYM with SYMBOL in macro name.

Changes in v4:
- Use the full command name so go to definition continues to work in my
editor.

Changes in v3:
- Use a macro to avoid duplicating the ec command names.

Changes in v2:
- Changed comment style to match other cros_ec files.
- Fixed commit tag.

drivers/platform/chrome/Makefile | 5 +-
drivers/platform/chrome/cros_ec_proto.c | 4 +
drivers/platform/chrome/cros_ec_trace.c | 124 ++++++++++++++++++++++++
drivers/platform/chrome/cros_ec_trace.h | 51 ++++++++++
4 files changed, 183 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/chrome/cros_ec_trace.c
create mode 100644 drivers/platform/chrome/cros_ec_trace.h

diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 1e2f0029b597..a6c0f5438e15 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -1,5 +1,8 @@
# SPDX-License-Identifier: GPL-2.0

+# tell define_trace.h where to find the cros ec trace header
+CFLAGS_cros_ec_trace.o:= -I$(src)
+
obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o
@@ -8,7 +11,7 @@ obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
-obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
+obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o cros_ec_trace.o
obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
obj-$(CONFIG_CROS_EC_LIGHTBAR) += cros_ec_lightbar.o
obj-$(CONFIG_CROS_EC_VBC) += cros_ec_vbc.o
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 97a068dff192..3d02c8259ac6 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -10,6 +10,8 @@
#include <linux/slab.h>
#include <asm/unaligned.h>

+#include "cros_ec_trace.h"
+
#define EC_COMMAND_RETRIES 50

static int prepare_packet(struct cros_ec_device *ec_dev,
@@ -51,6 +53,8 @@ static int send_command(struct cros_ec_device *ec_dev,
int ret;
int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);

+ trace_cros_ec_cmd(msg);
+
if (ec_dev->proto_version > 2)
xfer_fxn = ec_dev->pkt_xfer;
else
diff --git a/drivers/platform/chrome/cros_ec_trace.c b/drivers/platform/chrome/cros_ec_trace.c
new file mode 100644
index 000000000000..0a76412095a9
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_trace.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+// Trace events for the ChromeOS Embedded Controller
+//
+// Copyright 2019 Google LLC.
+
+#define TRACE_SYMBOL(a) {a, #a}
+
+// Generate the list using the following script:
+// sed -n 's/^#define \(EC_CMD_[[:alnum:]_]*\)\s.*/\tTRACE_SYMBOL(\1), \\/p' include/linux/mfd/cros_ec_commands.h
+#define EC_CMDS \
+ TRACE_SYMBOL(EC_CMD_PROTO_VERSION), \
+ TRACE_SYMBOL(EC_CMD_HELLO), \
+ TRACE_SYMBOL(EC_CMD_GET_VERSION), \
+ TRACE_SYMBOL(EC_CMD_READ_TEST), \
+ TRACE_SYMBOL(EC_CMD_GET_BUILD_INFO), \
+ TRACE_SYMBOL(EC_CMD_GET_CHIP_INFO), \
+ TRACE_SYMBOL(EC_CMD_GET_BOARD_VERSION), \
+ TRACE_SYMBOL(EC_CMD_READ_MEMMAP), \
+ TRACE_SYMBOL(EC_CMD_GET_CMD_VERSIONS), \
+ TRACE_SYMBOL(EC_CMD_GET_COMMS_STATUS), \
+ TRACE_SYMBOL(EC_CMD_TEST_PROTOCOL), \
+ TRACE_SYMBOL(EC_CMD_GET_PROTOCOL_INFO), \
+ TRACE_SYMBOL(EC_CMD_GSV_PAUSE_IN_S5), \
+ TRACE_SYMBOL(EC_CMD_GET_FEATURES), \
+ TRACE_SYMBOL(EC_CMD_FLASH_INFO), \
+ TRACE_SYMBOL(EC_CMD_FLASH_READ), \
+ TRACE_SYMBOL(EC_CMD_FLASH_WRITE), \
+ TRACE_SYMBOL(EC_CMD_FLASH_ERASE), \
+ TRACE_SYMBOL(EC_CMD_FLASH_PROTECT), \
+ TRACE_SYMBOL(EC_CMD_FLASH_REGION_INFO), \
+ TRACE_SYMBOL(EC_CMD_VBNV_CONTEXT), \
+ TRACE_SYMBOL(EC_CMD_PWM_GET_FAN_TARGET_RPM), \
+ TRACE_SYMBOL(EC_CMD_PWM_SET_FAN_TARGET_RPM), \
+ TRACE_SYMBOL(EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT), \
+ TRACE_SYMBOL(EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT), \
+ TRACE_SYMBOL(EC_CMD_PWM_SET_FAN_DUTY), \
+ TRACE_SYMBOL(EC_CMD_PWM_SET_DUTY), \
+ TRACE_SYMBOL(EC_CMD_PWM_GET_DUTY), \
+ TRACE_SYMBOL(EC_CMD_LIGHTBAR_CMD), \
+ TRACE_SYMBOL(EC_CMD_LED_CONTROL), \
+ TRACE_SYMBOL(EC_CMD_VBOOT_HASH), \
+ TRACE_SYMBOL(EC_CMD_MOTION_SENSE_CMD), \
+ TRACE_SYMBOL(EC_CMD_USB_CHARGE_SET_MODE), \
+ TRACE_SYMBOL(EC_CMD_PSTORE_INFO), \
+ TRACE_SYMBOL(EC_CMD_PSTORE_READ), \
+ TRACE_SYMBOL(EC_CMD_PSTORE_WRITE), \
+ TRACE_SYMBOL(EC_CMD_RTC_GET_VALUE), \
+ TRACE_SYMBOL(EC_CMD_RTC_GET_ALARM), \
+ TRACE_SYMBOL(EC_CMD_RTC_SET_VALUE), \
+ TRACE_SYMBOL(EC_CMD_RTC_SET_ALARM), \
+ TRACE_SYMBOL(EC_CMD_PORT80_LAST_BOOT), \
+ TRACE_SYMBOL(EC_CMD_PORT80_READ), \
+ TRACE_SYMBOL(EC_CMD_THERMAL_SET_THRESHOLD), \
+ TRACE_SYMBOL(EC_CMD_THERMAL_GET_THRESHOLD), \
+ TRACE_SYMBOL(EC_CMD_THERMAL_AUTO_FAN_CTRL), \
+ TRACE_SYMBOL(EC_CMD_TMP006_GET_CALIBRATION), \
+ TRACE_SYMBOL(EC_CMD_TMP006_SET_CALIBRATION), \
+ TRACE_SYMBOL(EC_CMD_TMP006_GET_RAW), \
+ TRACE_SYMBOL(EC_CMD_MKBP_STATE), \
+ TRACE_SYMBOL(EC_CMD_MKBP_INFO), \
+ TRACE_SYMBOL(EC_CMD_MKBP_SIMULATE_KEY), \
+ TRACE_SYMBOL(EC_CMD_MKBP_SET_CONFIG), \
+ TRACE_SYMBOL(EC_CMD_MKBP_GET_CONFIG), \
+ TRACE_SYMBOL(EC_CMD_KEYSCAN_SEQ_CTRL), \
+ TRACE_SYMBOL(EC_CMD_GET_NEXT_EVENT), \
+ TRACE_SYMBOL(EC_CMD_TEMP_SENSOR_GET_INFO), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_GET_B), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_GET_SMI_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_GET_SCI_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_GET_WAKE_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_SET_SMI_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_SET_SCI_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_CLEAR), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_SET_WAKE_MASK), \
+ TRACE_SYMBOL(EC_CMD_HOST_EVENT_CLEAR_B), \
+ TRACE_SYMBOL(EC_CMD_SWITCH_ENABLE_BKLIGHT), \
+ TRACE_SYMBOL(EC_CMD_SWITCH_ENABLE_WIRELESS), \
+ TRACE_SYMBOL(EC_CMD_GPIO_SET), \
+ TRACE_SYMBOL(EC_CMD_GPIO_GET), \
+ TRACE_SYMBOL(EC_CMD_I2C_READ), \
+ TRACE_SYMBOL(EC_CMD_I2C_WRITE), \
+ TRACE_SYMBOL(EC_CMD_CHARGE_CONTROL), \
+ TRACE_SYMBOL(EC_CMD_CONSOLE_SNAPSHOT), \
+ TRACE_SYMBOL(EC_CMD_CONSOLE_READ), \
+ TRACE_SYMBOL(EC_CMD_BATTERY_CUT_OFF), \
+ TRACE_SYMBOL(EC_CMD_USB_MUX), \
+ TRACE_SYMBOL(EC_CMD_LDO_SET), \
+ TRACE_SYMBOL(EC_CMD_LDO_GET), \
+ TRACE_SYMBOL(EC_CMD_POWER_INFO), \
+ TRACE_SYMBOL(EC_CMD_I2C_PASSTHRU), \
+ TRACE_SYMBOL(EC_CMD_HANG_DETECT), \
+ TRACE_SYMBOL(EC_CMD_CHARGE_STATE), \
+ TRACE_SYMBOL(EC_CMD_CHARGE_CURRENT_LIMIT), \
+ TRACE_SYMBOL(EC_CMD_EXTERNAL_POWER_LIMIT), \
+ TRACE_SYMBOL(EC_CMD_HOST_SLEEP_EVENT), \
+ TRACE_SYMBOL(EC_CMD_SB_READ_WORD), \
+ TRACE_SYMBOL(EC_CMD_SB_WRITE_WORD), \
+ TRACE_SYMBOL(EC_CMD_SB_READ_BLOCK), \
+ TRACE_SYMBOL(EC_CMD_SB_WRITE_BLOCK), \
+ TRACE_SYMBOL(EC_CMD_BATTERY_VENDOR_PARAM), \
+ TRACE_SYMBOL(EC_CMD_CODEC_I2S), \
+ TRACE_SYMBOL(EC_CMD_REBOOT_EC), \
+ TRACE_SYMBOL(EC_CMD_GET_PANIC_INFO), \
+ TRACE_SYMBOL(EC_CMD_ACPI_READ), \
+ TRACE_SYMBOL(EC_CMD_ACPI_WRITE), \
+ TRACE_SYMBOL(EC_CMD_ACPI_QUERY_EVENT), \
+ TRACE_SYMBOL(EC_CMD_CEC_WRITE_MSG), \
+ TRACE_SYMBOL(EC_CMD_CEC_SET), \
+ TRACE_SYMBOL(EC_CMD_CEC_GET), \
+ TRACE_SYMBOL(EC_CMD_REBOOT), \
+ TRACE_SYMBOL(EC_CMD_RESEND_RESPONSE), \
+ TRACE_SYMBOL(EC_CMD_VERSION0), \
+ TRACE_SYMBOL(EC_CMD_PD_EXCHANGE_STATUS), \
+ TRACE_SYMBOL(EC_CMD_USB_PD_CONTROL), \
+ TRACE_SYMBOL(EC_CMD_USB_PD_PORTS), \
+ TRACE_SYMBOL(EC_CMD_USB_PD_POWER_INFO), \
+ TRACE_SYMBOL(EC_CMD_CHARGE_PORT_COUNT), \
+ TRACE_SYMBOL(EC_CMD_USB_PD_DISCOVERY), \
+ TRACE_SYMBOL(EC_CMD_PD_CHARGE_PORT_OVERRIDE), \
+ TRACE_SYMBOL(EC_CMD_PD_GET_LOG_ENTRY), \
+ TRACE_SYMBOL(EC_CMD_USB_PD_MUX_INFO)
+
+#define CREATE_TRACE_POINTS
+#include "cros_ec_trace.h"
diff --git a/drivers/platform/chrome/cros_ec_trace.h b/drivers/platform/chrome/cros_ec_trace.h
new file mode 100644
index 000000000000..7ae3b89c78b9
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_trace.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Trace events for the ChromeOS Embedded Controller
+ *
+ * Copyright 2019 Google LLC.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM cros_ec
+
+#if !defined(_CROS_EC_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define _CROS_EC_TRACE_H_
+
+#include <linux/types.h>
+#include <linux/mfd/cros_ec.h>
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(cros_ec_cmd_class,
+ TP_PROTO(struct cros_ec_command *cmd),
+ TP_ARGS(cmd),
+ TP_STRUCT__entry(
+ __field(uint32_t, version)
+ __field(uint32_t, command)
+ ),
+ TP_fast_assign(
+ __entry->version = cmd->version;
+ __entry->command = cmd->command;
+ ),
+ TP_printk("version: %u, command: %s", __entry->version,
+ __print_symbolic(__entry->command, EC_CMDS))
+);
+
+
+DEFINE_EVENT(cros_ec_cmd_class, cros_ec_cmd,
+ TP_PROTO(struct cros_ec_command *cmd),
+ TP_ARGS(cmd)
+);
+
+
+#endif /* _CROS_EC_TRACE_H_ */
+
+/* this part must be outside header guard */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE cros_ec_trace
+
+#include <trace/define_trace.h>
--
2.21.0.392.gf8f6787159e-goog