# STM32 entropy generator driver configuration

# Copyright (c) 2017 Erwin Rol <erwin@erwinrol.com>
# SPDX-License-Identifier: Apache-2.0

DT_COMPAT_ST_STM32_RNG := st,stm32-rng

menuconfig ENTROPY_STM32_RNG
	bool "STM32 RNG driver"
	depends on SOC_FAMILY_STM32
	select ENTROPY_HAS_DRIVER
	select USE_STM32_LL_RNG
	default $(dt_compat_enabled,$(DT_COMPAT_ST_STM32_RNG))
	help
	  This option enables the RNG processor, which is a entropy number
	  generator, based on a continuous analog noise, that provides
	  a entropy 32-bit value to the host when read. It is available for
	  F4 (except STM32F401 & STM32F411), L4, F7, H7 and G4 series.

if ENTROPY_STM32_RNG

config ENTROPY_STM32_THR_POOL_SIZE
	int "Thread-mode random number pool size"
	range ENTROPY_STM32_THR_THRESHOLD 256
	default 8
	help
	  Buffer length in bytes used to store entropy bytes generated by the
	  hardware to make them ready for thread mode consumers.
	  Please note, that size of the pool must be a power of 2.

config ENTROPY_STM32_THR_THRESHOLD
	int "Thread-mode random number pool low-water threshold"
	range 4 255
	help
	  Low water-mark threshold in bytes to trigger entropy generation for
	  thread mode consumers. As soon as the number of available bytes in the
	  buffer goes below this number hardware entropy generation will be
	  started.

config ENTROPY_STM32_ISR_POOL_SIZE
	int "ISR-mode random number pool size"
	range ENTROPY_STM32_ISR_THRESHOLD 256
	default 16
	help
	  Buffer length in bytes used to store entropy bytes generated by the
	  hardware to make them ready for ISR consumers.
	  Please note, that size of the pool must be a power of 2.

config ENTROPY_STM32_ISR_THRESHOLD
	int "ISR-mode random number pool low-water threshold"
	range 12 255
	help
	  Low water-mark threshold in bytes to trigger entropy generation for
	  ISR consumers. As soon as the number of available bytes in the
	  buffer goes below this number hardware entropy generation will be
	  started.

endif # ENTROPY_STM32_RNG