drivers: entropy: Introduce SiWx91x entropy driver

Support for random number generator is required for most of the cryptographic operations, including support for WiFi and TLS. This driver has been tested with tests/drivers/entropy: *** Booting Zephyr OS build v3.7.0-4339-g1ec5ce05f9f8 *** Running TESTSUITE entropy_api =================================================================== START - test_entropy_get_entropy random device is 0x8217298, name is rng@45090000 0x93 0x3e 0xf1 0x68 0xd4 0x22 0xbf 0x4d 0xad PASS - test_entropy_get_entropy in 0.012 seconds =================================================================== TESTSUITE entropy_api succeeded ------ TESTSUITE SUMMARY START ------ SUITE PASS - 100.00% [entropy_api]: pass = 1, fail = 0, skip = 0 ... - PASS - [entropy_api.test_entropy_get_entropy] duration = 0.01 ... ------ TESTSUITE SUMMARY END ------ =================================================================== RunID: d1547c805699201af769cb01331efcce PROJECT EXECUTION SUCCESSFUL Co-authored-by: Tibor Laczko <[email protected]> Signed-off-by: Tibor Laczko <[email protected]> Signed-off-by: Jérôme Pouiller <[email protected]>
hjuul · Feb 11, 2025 · 938fb87 · 938fb87
1 parent 8575bc0
commit 938fb87
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diff --git a/drivers/entropy/CMakeLists.txt b/drivers/entropy/CMakeLists.txt
@@ -32,6 +32,7 @@ zephyr_library_sources_ifdef(CONFIG_ENTROPY_GECKO_TRNG      entropy_gecko_trng.c
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_NEORV32_TRNG    entropy_neorv32_trng.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_BT_HCI          entropy_bt_hci.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_GECKO_SE        entropy_gecko_se.c)
+zephyr_library_sources_ifdef(CONFIG_ENTROPY_SILABS_SIWX91X  entropy_silabs_siwx91x.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_PSA_CRYPTO_RNG  entropy_psa_crypto.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_NPCX_DRBG       entropy_npcx_drbg.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_MAX32_TRNG      entropy_max32.c)

diff --git a/drivers/entropy/Kconfig b/drivers/entropy/Kconfig
@@ -33,6 +33,7 @@ source "drivers/entropy/Kconfig.native_posix"
 source "drivers/entropy/Kconfig.rv32m1"
 source "drivers/entropy/Kconfig.litex"
 source "drivers/entropy/Kconfig.gecko"
+source "drivers/entropy/Kconfig.siwx91x"
 source "drivers/entropy/Kconfig.neorv32"
 source "drivers/entropy/Kconfig.bt_hci"
 source "drivers/entropy/Kconfig.psa_crypto"

diff --git a/drivers/entropy/Kconfig.siwx91x b/drivers/entropy/Kconfig.siwx91x
@@ -0,0 +1,11 @@
+# Copyright (c) 2024 Silicon Laboratories Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config ENTROPY_SILABS_SIWX91X
+	bool "SiWx91x RNG driver"
+	default y
+	depends on DT_HAS_SILABS_SIWX91X_RNG_ENABLED
+	select ENTROPY_HAS_DRIVER
+	help
+	 Enable hardware Random Number Generator embedded on Silicon Labs
+	 SiWx91x chips.
diff --git a/drivers/entropy/entropy_silabs_siwx91x.c b/drivers/entropy/entropy_silabs_siwx91x.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2024 Silicon Laboratories Inc.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#define DT_DRV_COMPAT silabs_siwx91x_rng
+
+#include <zephyr/drivers/entropy.h>
+
+#include "rsi_rom_rng.h"
+#include "rsi_rom_clks.h"
+
+static int siwx91x_get_entropy_isr(const struct device *dev, uint8_t *buffer,
+				   uint16_t length, uint32_t flags)
+{
+	uint32_t u32_count = length / sizeof(uint32_t);
+	uint32_t u8_count = u32_count * sizeof(uint32_t);
+	uint32_t u8_remainder = length - u8_count;
+	uint32_t swap_space;
+
+	if (!(flags & ENTROPY_BUSYWAIT)) {
+		return -ENOTSUP;
+	}
+	RSI_RNG_GetBytes((void *)dev->config, (uint32_t *)buffer, u32_count);
+	if (length % sizeof(uint32_t)) {
+		RSI_RNG_GetBytes((void *)dev->config, &swap_space, 1);
+		memcpy(buffer + u8_count, &swap_space, u8_remainder);
+	}
+
+	return 0;
+}
+
+static int siwx91x_get_entropy(const struct device *dev, uint8_t *buffer, uint16_t length)
+{
+	return siwx91x_get_entropy_isr(dev, buffer, length, ENTROPY_BUSYWAIT);
+}
+
+static int siwx91x_init(const struct device *dev)
+{
+	int ret;
+
+	ret = RSI_CLK_PeripheralClkEnable1(M4CLK, HWRNG_PCLK_ENABLE);
+	if (ret) {
+		return -EIO;
+	}
+	ret = RSI_RNG_Start((void *)dev->config, RSI_RNG_TRUE_RANDOM);
+	if (ret) {
+		return -EIO;
+	}
+	return 0;
+}
+
+static DEVICE_API(entropy, siwx91x_api) = {
+	.get_entropy = siwx91x_get_entropy,
+	.get_entropy_isr = siwx91x_get_entropy_isr,
+};
+
+#define SIWX91X_RNG_INIT(idx)                                                               \
+	DEVICE_DT_INST_DEFINE(idx, siwx91x_init, NULL, NULL, (void *)DT_INST_REG_ADDR(idx), \
+			      PRE_KERNEL_1, CONFIG_ENTROPY_INIT_PRIORITY, &siwx91x_api);
+
+DT_INST_FOREACH_STATUS_OKAY(SIWX91X_RNG_INIT)
diff --git a/dts/bindings/rng/silabs,siwx91x-rng.yaml b/dts/bindings/rng/silabs,siwx91x-rng.yaml
@@ -0,0 +1,12 @@
+# Copyright (c) 2024 Silicon Laboratories Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: Hardware Random Number Generator embedded on Silabs SiWx91x chips
+
+compatible: "silabs,siwx91x-rng"
+
+include: base.yaml
+
+properties:
+  reg:
+    required: true
diff --git a/modules/hal_silabs/wiseconnect/CMakeLists.txt b/modules/hal_silabs/wiseconnect/CMakeLists.txt
@@ -50,5 +50,9 @@ zephyr_library_sources(
   ${WISECONNECT_DIR}/components/device/silabs/si91x/mcu/core/chip/src/iPMU_prog/iPMU_dotc/rsi_system_config_917.c
 )
 
+zephyr_library_sources_ifdef(CONFIG_ENTROPY_SILABS_SIWX91X
+  ${WISECONNECT_DIR}/components/device/silabs/si91x/mcu/drivers/peripheral_drivers/src/rsi_rng.c
+)
+
 zephyr_linker_sources(ROM_SECTIONS linker/code_classification_text.ld)
 zephyr_linker_sources(RAMFUNC_SECTION linker/code_classification_ramfunc.ld)