drivers: entropy: add Renesas SmartBond entropy generator driver

This adds driver for SmartBond TRNG peripheral that with separate
ISR an thread data pools.

Co-authored-by: Jerzy Kasenberg <[email protected]>

Signed-off-by: Ben Lauret <[email protected]>

Author: blauret

boards/arm/da1469x_dk_pro/da1469x_dk_pro.dts

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Renesas Electronics Corporation
+ * Copyright (c) 2022 Renesas Electronics Corporation and/or its affiliates
  * SPDX-License-Identifier: Apache-2.0
  */
 

drivers/entropy/CMakeLists.txt

@@ -12,6 +12,7 @@ zephyr_library_sources_ifdef(CONFIG_ENTROPY_MCUX_CAAM          entropy_mcux_caam
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_MCUX_CSS           entropy_mcux_css.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_NRF5_RNG           entropy_nrf5.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_SAM_RNG            entropy_sam.c)
+zephyr_library_sources_ifdef(CONFIG_ENTROPY_SMARTBOND_TRNG     entropy_smartbond.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_STM32_RNG          entropy_stm32.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_LITEX_RNG          entropy_litex.c)
 zephyr_library_sources_ifdef(CONFIG_FAKE_ENTROPY_NATIVE_POSIX  fake_entropy_native_posix.c)

drivers/entropy/Kconfig

@@ -27,6 +27,7 @@ source "drivers/entropy/Kconfig.stm32"
 source "drivers/entropy/Kconfig.esp32"
 source "drivers/entropy/Kconfig.nrf5"
 source "drivers/entropy/Kconfig.sam"
+source "drivers/entropy/Kconfig.smartbond"
 source "drivers/entropy/Kconfig.native_posix"
 source "drivers/entropy/Kconfig.rv32m1"
 source "drivers/entropy/Kconfig.litex"

drivers/entropy/Kconfig.smartbond

@@ -0,0 +1,53 @@
+# Smartbond TRNG configuration
+
+# Copyright (c) 2023 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+
+config ENTROPY_SMARTBOND_TRNG
+	bool "Renesas Smartbond MCU Family True Random Number Generator (TRNG) Driver"
+	default y
+	depends on DT_HAS_RENESAS_SMARTBOND_TRNG_ENABLED
+	select ENTROPY_HAS_DRIVER
+	help
+	  Enable True Random Number Generator (TRNG) driver for Renesas Smartbond MCUs.
+
+if ENTROPY_SMARTBOND_TRNG
+
+config ENTROPY_SMARTBOND_THR_POOL_SIZE
+	int "Thread-mode random number pool size"
+	range ENTROPY_SMARTBOND_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_SMARTBOND_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_SMARTBOND_ISR_POOL_SIZE
+	int "ISR-mode random number pool size"
+	range ENTROPY_SMARTBOND_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_SMARTBOND_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_SMARTBOND_TRNG