platform/chrome: cros_ec_proto: Add trace event to trace EC commands

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

The list of current commands is generated using the following script:

    sed -n 's/^#define \(EC_CMD_[[:alnum:]_]*\)\s.*/\tTRACE_SYMBOL(\1),\\/p' include/linux/mfd/cros_ec_commands.h

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

drivers/platform/chrome/Makefile

 # 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
@@ -9,7 +12,7 @@ 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

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

drivers/platform/chrome/cros_ec_trace.c

+// 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"

drivers/platform/chrome/cros_ec_trace.h

+/* 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>