drivers: entropy: sf32lb: add trng driver support

Add trng driver for sf32lb platform

Signed-off-by: Qingsong Gou <[email protected]>

Author: ck-telecom

drivers/entropy/CMakeLists.txt

@@ -37,6 +37,7 @@ zephyr_library_sources_ifdef(CONFIG_ENTROPY_PSA_CRYPTO_RNG entropy_psa_crypto.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_RENESAS_RA entropy_renesas_ra.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_RV32M1_TRNG entropy_rv32m1_trng.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_SAM_RNG entropy_sam.c)
+zephyr_library_sources_ifdef(CONFIG_ENTROPY_SF32LB entropy_sf32lb.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_SILABS_SIWX91X entropy_silabs_siwx91x.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_SMARTBOND_TRNG entropy_smartbond.c)
 zephyr_library_sources_ifdef(CONFIG_ENTROPY_STM32_RNG entropy_stm32.c)

drivers/entropy/Kconfig

@@ -43,6 +43,7 @@ source "drivers/entropy/Kconfig.psa_crypto"
 source "drivers/entropy/Kconfig.renesas_ra"
 source "drivers/entropy/Kconfig.rv32m1"
 source "drivers/entropy/Kconfig.sam"
+source "drivers/entropy/Kconfig.sf32lb"
 source "drivers/entropy/Kconfig.siwx91x"
 source "drivers/entropy/Kconfig.smartbond"
 source "drivers/entropy/Kconfig.stm32"

drivers/entropy/Kconfig.sf32lb

@@ -0,0 +1,10 @@
+# Copyright (c) 2025, Qingsong Gou <[email protected]>
+# SPDX-License-Identifier: Apache-2.0
+
+config ENTROPY_SF32LB
+	bool "SF32LB Entropy driver"
+	default y
+	depends on DT_HAS_SIFLI_SF32LB_TRNG_ENABLED
+	select ENTROPY_HAS_DRIVER
+	help
+	  Enable driver for SF32LB True Random Number Generator (TRNG).

drivers/entropy/entropy_sf32lb.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2025 Qingsong Gou <[email protected]>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#define DT_DRV_COMPAT sifli_sf32lb_trng
+
+#include <zephyr/arch/cpu.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/clock_control/sf32lb.h>
+#include <zephyr/drivers/entropy.h>
+#include <zephyr/logging/log.h>
+
+#include <register.h>
+
+LOG_MODULE_REGISTER(entropy_sf32lb, CONFIG_ENTROPY_LOG_LEVEL);
+
+#define TRNG_CTRL offsetof(TRNG_TypeDef, CTRL)
+#define TRNG_STAT offsetof(TRNG_TypeDef, STAT)
+#define TRNG_RAND offsetof(TRNG_TypeDef, RAND_NUM0)
+
+#define TRNG_RAND_NUM_MAX (8U)
+
+#define TRNG_RAND_MASK (TRNG_RAND_NUM_MAX - 1U)
+
+struct entropy_sf32lb_config {
+	uintptr_t base;
+	struct sf32lb_clock_dt_spec clock;
+};
+
+static int entropy_sf32lb_get_entropy(const struct device *dev, uint8_t *buffer, uint16_t length)
+{
+	const struct entropy_sf32lb_config *config = dev->config;
+	uint32_t buf[TRNG_RAND_NUM_MAX];
+	uint16_t bytes;
+
+	while (length) {
+		sys_set_bit(config->base + TRNG_CTRL, TRNG_CTRL_GEN_SEED_START_Pos);
+		while (!sys_test_bit(config->base + TRNG_STAT, TRNG_STAT_SEED_VALID_Pos)) {
+		}
+
+		/* Generate random data */
+		sys_set_bit(config->base + TRNG_CTRL, TRNG_CTRL_GEN_RAND_NUM_START_Pos);
+		while (!sys_test_bit(config->base + TRNG_STAT, TRNG_STAT_RAND_NUM_VALID_Pos)) {
+		}
+
+		for (uint8_t i = 0U; i < TRNG_RAND_NUM_MAX; i++) {
+			buf[i] = sys_read32(config->base + TRNG_RAND + (i * 4U));
+		}
+
+		bytes = MIN(length, sizeof(buf));
+
+		memcpy(buffer, buf, bytes);
+
+		length -= bytes;
+		buffer += bytes;
+	}
+
+	return 0;
+}
+
+static DEVICE_API(entropy, entropy_sf32lb_api) = {
+	.get_entropy = entropy_sf32lb_get_entropy,
+};
+
+static int entropy_sf32lb_init(const struct device *dev)
+{
+	const struct entropy_sf32lb_config *config = dev->config;
+
+	if (!sf32lb_clock_is_ready_dt(&config->clock)) {
+		return -ENODEV;
+	}
+
+	return sf32lb_clock_control_on_dt(&config->clock);
+}
+
+#define ENTROPY_SF32LB_DEFINE(n)                                                                   \
+	static const struct entropy_sf32lb_config entropy_sf32lb_config_##n = {                    \
+		.base = DT_INST_REG_ADDR(n),                                                       \
+		.clock = SF32LB_CLOCK_DT_INST_SPEC_GET(n),                                         \
+	};                                                                                         \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(n, entropy_sf32lb_init, NULL, NULL,                                  \
+			      &entropy_sf32lb_config_##n, PRE_KERNEL_1,                            \
+			      CONFIG_ENTROPY_INIT_PRIORITY, &entropy_sf32lb_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ENTROPY_SF32LB_DEFINE)