# Copyright (c) 2021 Nordic Semiconductor ASA
# SPDX-License-Identifier: Apache-2.0

config LOG_BACKEND_RTT
	bool "Segger J-Link RTT backend"
	depends on USE_SEGGER_RTT
	default y if !SHELL_BACKEND_RTT
	select SEGGER_RTT_CUSTOM_LOCKING
	select LOG_OUTPUT
	help
	  When enabled, backend will use RTT for logging. This backend works on a per
	  message basis. Only a whole message (terminated with a carriage return: '\r')
	  is transferred to up-buffer at once depending on available space and
	  selected mode.
	  In panic mode backend always blocks and waits until there is space
	  in up-buffer for a message and message is transferred to host.

if LOG_BACKEND_RTT

choice LOG_BACKEND_RTT_MODE
	prompt "Logger behavior"
	default LOG_BACKEND_RTT_MODE_BLOCK

config LOG_BACKEND_RTT_MODE_DROP
	bool "Drop messages that do not fit in up-buffer."
	help
	  If there is not enough space in up-buffer for a message, drop it.
	  Number of dropped messages will be logged.
	  Increase up-buffer size helps to reduce dropping of messages.

config LOG_BACKEND_RTT_MODE_BLOCK
	bool "Block until message is transferred to host."
	help
	  Waits until there is enough space in the up-buffer for a message.

config LOG_BACKEND_RTT_MODE_OVERWRITE
	bool "Overwrite messages if up-buffer full"
	help
	  If there is not enough space in up-buffer for a message overwrite
	  oldest one.

endchoice

backend = RTT
backend-str = rtt
source "subsys/logging/Kconfig.template.log_format_config"

config LOG_BACKEND_RTT_MESSAGE_SIZE
	int "Size of internal buffer for storing messages."
	range 32 256
	default 128
	depends on LOG_BACKEND_RTT_MODE_DROP
	help
	  This option defines maximum message size transferable to up-buffer.

if LOG_BACKEND_RTT_MODE_BLOCK

config LOG_BACKEND_RTT_OUTPUT_BUFFER_SIZE
	int "Size of the output buffer"
	default 16
	help
	  Buffer is used by log_output module for preparing output data (e.g.
	  string formatting).

config LOG_BACKEND_RTT_RETRY_CNT
	int "Number of retries"
	default 4
	help
	  Number of TX retries before dropping the data and assuming that
	  RTT session is inactive.

config LOG_BACKEND_RTT_RETRY_DELAY_MS
	int "Delay between TX retries in milliseconds"
	default 5
	help
	  Sleep period between TX retry attempts. During RTT session, host pulls
	  data periodically. Period starts from 1-2 milliseconds and can be
	  increased if traffic on RTT increases (also from host to device). In
	  case of heavy traffic data can be lost and it may be necessary to
	  increase delay or number of retries.

endif # LOG_BACKEND_RTT_MODE_BLOCK

config LOG_BACKEND_RTT_BUFFER
	int "Buffer number used for logger output."
	range 0 SEGGER_RTT_MAX_NUM_UP_BUFFERS
	default 0
	help
	  Select index of up-buffer used for logger output, by default it uses
	  terminal up-buffer and its settings.

config LOG_BACKEND_RTT_BUFFER_SIZE
	int "Size of reserved up-buffer for logger output."
	default 1024
	depends on LOG_BACKEND_RTT_BUFFER > 0
	help
	  Specify reserved size of up-buffer used for logger output.

# Enable processing of printk calls using log if terminal buffer is used.
# Same buffer is used by RTT console. If printk would go through RTT console
# that will lead to corruption of RTT data which is not protected against being
# interrupted by an interrupt.
config LOG_BACKEND_RTT_FORCE_PRINTK
	bool
	default y if LOG_BACKEND_RTT_BUFFER = 0 && RTT_CONSOLE
	select LOG_PRINTK

endif # LOG_BACKEND_RTT