Merge branch 'feat/rng_support_h21' into 'master'

H21 RNG support

Closes IDF-11503

See merge request espressif/esp-idf!50061

components/bootloader_support/src/bootloader_random_esp32h21.c

@@ -0,0 +1,18 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include "sdkconfig.h"
+#include "bootloader_random.h"
+#include "hal/rng_ll.h"
+
+void bootloader_random_enable(void)
+{
+    rng_ll_enable();
+}
+
+void bootloader_random_disable(void)
+{
+    rng_ll_disable();
+}

components/hal/esp32h21/include/hal/rng_ll.h

@@ -6,26 +6,90 @@
 
 #pragma once
 
+#include <stdbool.h>
 #include <stdint.h>
 #include "soc/soc.h"
 #include "soc/lpperi_reg.h"
+#include "soc/wdev_reg.h"
+#include "soc/lpperi_struct.h"
+#include "hal/lp_clkrst_ll.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+ * @brief Read random data from RNG
+ *
+ * @return 32-bit random data
+ */
 static inline uint32_t rng_ll_read_data(void)
 {
-    return REG_READ(LPPERI_RNG_DATA_REG);
+    return REG_READ(WDEV_RND_REG);
 }
 
-/* For compatibility. */
+/**
+ * @brief Enable or disable RNG sampling.
+ *
+ * @param enable True to enable, False to disable
+ */
+static inline void rng_ll_enable_sample(bool enable)
+{
+    LPPERI.rng_cfg.rng_sample_enable = enable;
+}
+
+/**
+ * @brief Enable or disable rng xor rtc timer.
+ *
+ * @param enable True to enable, False to disable
+ */
+static inline void rng_ll_enable_rtc_timer(bool enable)
+{
+    LPPERI.rng_cfg.rtc_timer_en = enable ? 0x3 : 0x0;
+}
+
+/**
+ * @brief Enable or disable rng xor async rng timer.
+ *
+ * @param enable True to enable, False to disable
+ */
+static inline void rng_ll_enable_rng_timer(bool enable)
+{
+    LPPERI.rng_cfg.rng_timer_en = enable;
+}
+
+/**
+ * @brief Reset RNG.
+ */
+static inline void rng_ll_reset(void)
+{
+    // ESP32-H21 does not expose a dedicated RNG reset bit.
+}
+
+/**
+ * @brief Enable RNG module
+ *
+ * TODO: unify in rng_hal.c
+ */
 static inline void rng_ll_enable(void)
 {
+    _lp_clkrst_ll_enable_rng_clock(true);
+    rng_ll_enable_sample(true);
+    rng_ll_enable_rtc_timer(false);
+    rng_ll_enable_rng_timer(false);
 }
 
+/**
+ * @brief Disable RNG module
+ *
+ * TODO: unify in rng_hal.c
+ */
 static inline void rng_ll_disable(void)
 {
+    rng_ll_enable_sample(false);
+    rng_ll_enable_rtc_timer(false);
+    rng_ll_enable_rng_timer(false);
+    _lp_clkrst_ll_enable_rng_clock(false);
 }
 
 #ifdef __cplusplus

components/soc/esp32h21/include/soc/Kconfig.soc_caps.in

@@ -179,6 +179,10 @@ config SOC_SPI_EXTERNAL_NOR_FLASH_SUPPORTED
     bool
     default y
 
+config SOC_RNG_SUPPORTED
+    bool
+    default y
+
 config SOC_MODEM_CLOCK_SUPPORTED
     bool
     default y

components/soc/esp32h21/include/soc/soc_caps.h

@@ -71,7 +71,7 @@
 #define SOC_RTC_WDT_SUPPORTED           1
 #define SOC_SPI_FLASH_SUPPORTED         1
 #define SOC_SPI_EXTERNAL_NOR_FLASH_SUPPORTED    1
-// #define SOC_RNG_SUPPORTED               1    //TODO: [ESP32H21] IDF-11503
+#define SOC_RNG_SUPPORTED               1
 #define SOC_MODEM_CLOCK_SUPPORTED       1
 #define SOC_REGI2C_SUPPORTED           1
 #define SOC_PHY_SUPPORTED               1

components/soc/esp32h21/include/soc/wdev_reg.h

@@ -10,4 +10,4 @@
 #include "soc/lpperi_reg.h"
 
 /* Hardware random number generator register */
-#define WDEV_RND_REG LPPERI_RNG_DATA_REG
+#define WDEV_RND_REG LPPERI_RNG_DATA_SYNC_REG