7  * SPDX-License-Identifier: Apache-2.0
44  *  - simple rng without hardware fifo and no DMA.
45  *  - Variable delay between two consecutive random numbers
74 	      (CONFIG_ENTROPY_STM32_ISR_POOL_SIZE - 1)) == 0,
78 	      (CONFIG_ENTROPY_STM32_THR_POOL_SIZE - 1)) == 0,
110 	struct entropy_stm32_rng_dev_data *dev_data = dev->data;  in entropy_stm32_suspend()
111 	const struct entropy_stm32_rng_dev_cfg *dev_cfg = dev->config;  in entropy_stm32_suspend()
112 	RNG_TypeDef *rng = dev_data->rng;  in entropy_stm32_suspend()
128 	if (clock_control_get_rate(dev_data->clock,  in entropy_stm32_suspend()
129 			(clock_control_subsys_t) &dev_cfg->pclken[0],  in entropy_stm32_suspend()
131 		return -EIO;  in entropy_stm32_suspend()
136 	for (int i = wait_cycles; i >= 0; i--) {  in entropy_stm32_suspend()
140 	res = clock_control_off(dev_data->clock,  in entropy_stm32_suspend()
141 			(clock_control_subsys_t)&dev_cfg->pclken[0]);  in entropy_stm32_suspend()
153 	struct entropy_stm32_rng_dev_data *dev_data = dev->data;  in entropy_stm32_resume()
154 	const struct entropy_stm32_rng_dev_cfg *dev_cfg = dev->config;  in entropy_stm32_resume()
155 	RNG_TypeDef *rng = dev_data->rng;  in entropy_stm32_resume()
158 	res = clock_control_on(dev_data->clock,  in entropy_stm32_resume()
159 			(clock_control_subsys_t)&dev_cfg->pclken[0]);  in entropy_stm32_resume()
179 	 * The nist-config is direclty copied from the DTS.  in configure_rng()
183 	cur_nist_cfg = READ_BIT(rng->CR,  in configure_rng()
188 	/* For STM32U5 series, the ARDIS bit7 is considered in the nist-config */  in configure_rng()
198 		MODIFY_REG(rng->CR, cur_nist_cfg, (desired_nist_cfg | RNG_CR_CONDRST));  in configure_rng()
222 	/* Lock the RNG to prevent concurrent access */  in acquire_rng()
253 /* SOCS w/ soft-reset support: execute the reset */
269 			return -ETIMEDOUT;  in recover_seed_error()
277 /* SOCS w/o soft-reset support: flush pipeline */
287 		return -EIO;  in recover_seed_error()
296 	int retval = -EAGAIN;  in random_byte_get()
312 		retval = -EIO;  in random_byte_get()
318 			retval = -EIO;  in random_byte_get()
327 			retval = -EAGAIN;  in random_byte_get()
361 	 * RNG event will set the Cortex-M single-bit event register  in generate_from_isr()
374 			 * SEV-On-Pend feature must be enabled (enabled  in generate_from_isr()
393 		buf[--remaining_len] = byte;  in generate_from_isr()
406 	/* In non-blocking mode, return immediately if the RNG is not available */  in start_pool_filling()
409 		return -EAGAIN;  in start_pool_filling()
449 	uint32_t last  = rngp->last;  in rng_pool_get()
450 	uint32_t mask  = rngp->mask;  in rng_pool_get()
457 	first = rngp->first_alloc;  in rng_pool_get()
460 	 * The other_read_in_progress is non-zero if rngp->first_read != first,  in rng_pool_get()
461 	 * which means that lower-priority code (which was interrupted by this  in rng_pool_get()
464 	other_read_in_progress = (rngp->first_read ^ first);  in rng_pool_get()
466 	available = (last - first) & mask;  in rng_pool_get()
475 	rngp->first_alloc = (first + len) & mask;  in rng_pool_get()
478 	while (likely(len--)) {  in rng_pool_get()
479 		*dst++ = rngp->buffer[first];  in rng_pool_get()
485 	 * to signal that all allocated regions are now read and could be  in rng_pool_get()
490 		rngp->first_read = rngp->first_alloc;  in rng_pool_get()
494 	len = dst - buf;  in rng_pool_get()
495 	available = available - len;  in rng_pool_get()
496 	if (available <= rngp->threshold) {  in rng_pool_get()
514 	uint8_t first = rngp->first_read;  in rng_pool_put()
515 	uint8_t last  = rngp->last;  in rng_pool_put()
516 	uint8_t mask  = rngp->mask;  in rng_pool_put()
519 	if (((last - first) & mask) == mask) {  in rng_pool_put()
520 		return -ENOBUFS;  in rng_pool_put()
523 	rngp->buffer[last] = byte;  in rng_pool_put()
524 	rngp->last = (last + 1) & mask;  in rng_pool_put()
532 	rngp->first_alloc = 0U;  in rng_pool_init()
533 	rngp->first_read  = 0U;  in rng_pool_init()
534 	rngp->last	  = 0U;  in rng_pool_init()
535 	rngp->mask	  = size - 1;  in rng_pool_init()
536 	rngp->threshold	  = threshold;  in rng_pool_init()
575 	__ASSERT_NO_MSG(&entropy_stm32_rng_data == dev->data);  in entropy_stm32_rng_get_entropy()
592 		len -= bytes;  in entropy_stm32_rng_get_entropy()
607 	__ASSERT_NO_MSG(&entropy_stm32_rng_data == dev->data);  in entropy_stm32_rng_get_entropy_isr()
634 		/* Restore the state of the RNG lock and IRQ */  in entropy_stm32_rng_get_entropy_isr()
655 	dev_data = dev->data;  in entropy_stm32_rng_init()
656 	dev_cfg = dev->config;  in entropy_stm32_rng_init()
661 	dev_data->clock = DEVICE_DT_GET(STM32_CLOCK_CONTROL_NODE);  in entropy_stm32_rng_init()
663 	if (!device_is_ready(dev_data->clock)) {  in entropy_stm32_rng_init()
664 		return -ENODEV;  in entropy_stm32_rng_init()
667 	res = clock_control_on(dev_data->clock,  in entropy_stm32_rng_init()
668 		(clock_control_subsys_t)&dev_cfg->pclken[0]);  in entropy_stm32_rng_init()
673 		res = clock_control_configure(dev_data->clock,  in entropy_stm32_rng_init()
674 					      (clock_control_subsys_t)&dev_cfg->pclken[1],  in entropy_stm32_rng_init()
680 	k_sem_init(&dev_data->sem_lock, 1, 1);  in entropy_stm32_rng_init()
683 	k_sem_init(&dev_data->sem_sync, 0, 1);  in entropy_stm32_rng_init()
685 	k_work_init(&dev_data->filling_work, pool_filling_work_handler);  in entropy_stm32_rng_init()
687 	rng_pool_init((struct rng_pool *)(dev_data->thr),  in entropy_stm32_rng_init()
690 	rng_pool_init((struct rng_pool *)(dev_data->isr),  in entropy_stm32_rng_init()
697 	/* For multi-core MCUs, RNG configuration is automatically performed  in entropy_stm32_rng_init()
712 	struct entropy_stm32_rng_dev_data *dev_data = dev->data;  in entropy_stm32_rng_pm_action()
722 		/* Lock to Prevent concurrent access with PM */  in entropy_stm32_rng_pm_action()
733 			LL_RNG_SetHealthConfig(dev_data->rng, DT_INST_PROP(0, health_test_magic));  in entropy_stm32_rng_pm_action()
735 			if (LL_RNG_GetHealthConfig(dev_data->rng) !=  in entropy_stm32_rng_pm_action()
741 				/* Lock to Prevent concurrent access with PM */  in entropy_stm32_rng_pm_action()
759 		return -ENOTSUP;  in entropy_stm32_rng_pm_action()