drivers: entropy_mcux_caam: Add semaphore (f4c2dc54) · Commits · Wenxi XU / zephyr

drivers/entropy/entropy_mcux_caam.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -10,6 +10,7 @@
		#include <zephyr/drivers/entropy.h>
		#include <zephyr/random/rand32.h>
		#include <zephyr/init.h>
		#include <zephyr/kernel.h>

		#include "fsl_caam.h"

		@@ -21,6 +22,10 @@ static caam_job_ring_interface_t jrif0 __attribute__((__section__(".nocache")));
		static uint8_t rng_buff_pool[CONFIG_ENTRY_MCUX_CAAM_POOL_SIZE]
		__attribute__((__section__(".nocache")));


		/* This semaphore is needed to prevent race condition to static variables in the HAL driver */
		K_SEM_DEFINE(mcux_caam_sem, 1, 1)

		static int entropy_mcux_caam_get_entropy(const struct device *dev,
		uint8_t *buffer,
		uint16_t length)
		@@ -30,6 +35,8 @@ static int entropy_mcux_caam_get_entropy(const struct device *dev,
		caam_handle_t handle;
		uint16_t read_length = 0;
		uint16_t insert_idx = 0;
		int ret = 0;
		k_timeout_t sem_timeout = K_MSEC(10);

		handle.jobRing = kCAAM_JobRing0;

		@@ -41,10 +48,17 @@ static int entropy_mcux_caam_get_entropy(const struct device *dev,
		while (insert_idx < length) {
		read_length = MIN(sizeof(rng_buff_pool), (length - insert_idx));

		ret = k_sem_take(&mcux_caam_sem, sem_timeout);
		if (ret) {
		return ret;
		}

		status = CAAM_RNG_GetRandomData(
		config->base, &handle, kCAAM_RngStateHandle0,
		&rng_buff_pool[0], read_length, kCAAM_RngDataAny, NULL);

		k_sem_give(&mcux_caam_sem);

		memcpy(&buffer[insert_idx], &rng_buff_pool[0], read_length);
		insert_idx += read_length;
		}