drivers: entropy: esp32: enable rng driver

for esp32c3 allowing wifi subsystem to use inside
its driver.

Signed-off-by: Felipe Neves <[email protected]>

Author: Felipe Neves

boards/riscv/esp32c3_devkitm/Kconfig.defconfig

@@ -7,6 +7,9 @@ config BOARD
 	default "esp32c3"
 	depends on BOARD_ESP32C3_DEVKITM
 
+config ENTROPY_ESP32_RNG
+	default y if ENTROPY_GENERATOR
+
 if BT
 
 config HEAP_MEM_POOL_SIZE
@@ -16,4 +19,4 @@ choice BT_HCI_BUS_TYPE
 	default BT_ESP32
 endchoice
 
-endif # BT
+endif # BT

boards/riscv/esp32c3_devkitm/esp32c3_devkitm.dts

@@ -23,3 +23,7 @@
 	status = "okay";
 	current-speed = <115200>;
 };
+
+&trng0 {
+	status = "okay";
+};

drivers/entropy/Kconfig.esp32

@@ -5,7 +5,7 @@
 
 config ENTROPY_ESP32_RNG
 	bool "ESP32 entropy number generator driver"
-	depends on SOC_ESP32
+	depends on SOC_ESP32 || SOC_ESP32C3
 	select ENTROPY_HAS_DRIVER
 	default y
 	help

drivers/entropy/entropy_esp32.c

@@ -7,18 +7,20 @@
 #define DT_DRV_COMPAT espressif_esp32_trng
 
 #include <string.h>
-#include <drivers/entropy.h>
-#include <soc/dport_reg.h>
+#include <hal/cpu_hal.h>
+#include <esp_clk.h>
 #include <soc/rtc.h>
 #include <soc/wdev_reg.h>
 #include <soc/rtc_cntl_reg.h>
 #include <soc/apb_ctrl_reg.h>
 #include <esp_system.h>
 #include <soc.h>
-#include <xtensa/core-macros.h>
+#include <drivers/entropy.h>
 
-extern int esp_clk_cpu_freq(void);
-extern int esp_clk_apb_freq(void);
+#ifdef CONFIG_SOC_ESP32
+#include <xtensa/core-macros.h>
+#include <soc/dport_reg.h>
+#endif
 
 static inline uint32_t entropy_esp32_get_u32(void)
 {
@@ -37,9 +39,10 @@ static inline uint32_t entropy_esp32_get_u32(void)
 	uint32_t ccount;
 
 	do {
-		ccount = XTHAL_GET_CCOUNT();
+		ccount = cpu_hal_get_cycle_count();
 	} while (ccount - last_ccount < cpu_to_apb_freq_ratio * 16);
 	last_ccount = ccount;
+
 	return REG_READ(WDEV_RND_REG);
 }
 

dts/riscv/espressif/esp32c3.dtsi

@@ -8,6 +8,9 @@
 / {
 	#address-cells = <1>;
 	#size-cells = <1>;
+	chosen {
+		zephyr,entropy = &trng0;
+	};
 
 	cpus {
 		#address-cells = <1>;
@@ -37,6 +40,13 @@
 			label = "UART_0";
 			status = "disabled";
 		};
+
+		trng0: trng@3ff700b0 {
+			compatible = "espressif,esp32-trng";
+			reg = <0x3FF700B0 0x4>;
+			label = "TRNG_0";
+			status = "disabled";
+		};
 	};
 
 };

soc/riscv/esp32c3/linker.ld

@@ -130,6 +130,12 @@ SECTIONS
     *libzephyr.a:log_backend_uart.*(.literal .text .literal.* .text.*)
     *liblib__libc__minimal.a:string.*(.literal .text .literal.* .text.*)
     *libgcov.a:(.literal .text .literal.* .text.*)
+
+    *libnet80211.a:( .wifi0iram  .wifi0iram.* .wifislpiram .wifislpiram.*)
+    *libpp.a:( .wifi0iram  .wifi0iram.* .wifislpiram .wifislpiram.*)
+    *libnet80211.a:( .wifirxiram  .wifirxiram.* .wifislprxiram .wifislprxiram.*)
+    *libpp.a:( .wifirxiram  .wifirxiram.* .wifislprxiram .wifislprxiram.*)
+
     . = ALIGN(4);
     _init_end = ABSOLUTE(.);
     _iram_text_end = ABSOLUTE(.);   *(.srodata)