diff options
Diffstat (limited to 'os/hal/ports/SAMA/LLD/RNGv1/hal_trng_lld.c')
| -rw-r--r-- | os/hal/ports/SAMA/LLD/RNGv1/hal_trng_lld.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/os/hal/ports/SAMA/LLD/RNGv1/hal_trng_lld.c b/os/hal/ports/SAMA/LLD/RNGv1/hal_trng_lld.c new file mode 100644 index 000000000..6d8fde7d6 --- /dev/null +++ b/os/hal/ports/SAMA/LLD/RNGv1/hal_trng_lld.c @@ -0,0 +1,175 @@ +/*
+ ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+/**
+ * @file hal_trng_lld.c
+ * @brief STM32 TRNG subsystem low level driver source.
+ *
+ * @addtogroup TRNG
+ * @{
+ */
+
+#include "hal.h"
+
+#if (HAL_USE_TRNG == TRUE) || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/**
+ * @brief TRNGD0 driver identifier.
+ */
+#if (SAMA_TRNG_USE_TRNG0 == TRUE) || defined(__DOXYGEN__)
+TRNGDriver TRNGD0;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+static const TRNGConfig default_cfg = {0};
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level TRNG driver initialization.
+ *
+ * @notapi
+ */
+void trng_lld_init(void) {
+
+#if SAMA_TRNG_USE_TRNG0 == TRUE
+
+#if SAMA_HAL_IS_SECURE
+ mtxConfigPeriphSecurity(MATRIX1, ID_TRNG, SECURE_PER);
+#endif /* SAMA_HAL_IS_SECURE */
+
+ /* Driver initialization.*/
+ trngObjectInit(&TRNGD0);
+ TRNGD0.trng = TRNG;
+#endif
+}
+
+/**
+ * @brief Configures and activates the TRNG peripheral.
+ *
+ * @param[in] trngp pointer to the @p TRNGDriver object
+ *
+ * @notapi
+ */
+void trng_lld_start(TRNGDriver *trngp) {
+
+ /* There is no real configuration but setting up a valid pointer anyway.*/
+ if (trngp->config == NULL) {
+ trngp->config = &default_cfg;
+ }
+
+ if (trngp->state == TRNG_STOP) {
+ /* Enables the peripheral.*/
+#if SAMA_TRNG_USE_TRNG0 == TRUE
+ if (&TRNGD0 == trngp) {
+ pmcEnableTRNG0();
+ }
+#endif
+ }
+ /* Configures the peripheral.*/
+ trngp->trng->TRNG_CR = TRNG_CR_ENABLE | TRNG_CR_KEY_PASSWD;
+}
+
+/**
+ * @brief Deactivates the TRNG peripheral.
+ *
+ * @param[in] trngp pointer to the @p TRNGDriver object
+ *
+ * @notapi
+ */
+void trng_lld_stop(TRNGDriver *trngp) {
+
+ if (trngp->state == TRNG_READY) {
+ /* Resets the peripheral.*/
+ trngp->trng->TRNG_CR = TRNG_CR_KEY_PASSWD;
+
+ /* Disables the peripheral.*/
+#if SAMA_TRNG_USE_TRNG0 == TRUE
+ if (&TRNGD0 == trngp) {
+ pmcDisableTRNG0();
+ }
+#endif
+ }
+}
+
+/**
+ * @brief True random numbers generator.
+ * @note The function is blocking and likely performs polled waiting
+ * inside the low level implementation.
+ *
+ * @param[in] trngp pointer to the @p TRNGDriver object
+ * @param[in] size size of output buffer
+ * @param[out] out output buffer
+ * @return The operation status.
+ * @retval false if a random number has been generated.
+ * @retval true if an HW error occurred.
+ *
+ * @api
+ */
+bool trng_lld_generate(TRNGDriver *trngp, size_t size, uint8_t *out) {
+
+ while (true) {
+ uint32_t r, tmo;
+ size_t i;
+
+ /* Waiting for a random number in data register.*/
+ tmo = SAMA_DATA_FETCH_ATTEMPTS;
+ while ((tmo > 0) && ((trngp->trng->TRNG_ISR & TRNG_ISR_DATRDY) == 0)) {
+ tmo--;
+ if (tmo == 0) {
+ return true;
+ }
+ }
+
+ /* Getting the generated random number.*/
+ r = trngp->trng->TRNG_ODATA;
+
+ /* Writing in the output buffer.*/
+ for (i = 0; i < sizeof (uint32_t) / sizeof (uint8_t); i++) {
+ *out++ = (uint8_t)r;
+ r = r >> 8;
+ size--;
+ if (size == 0) {
+ return false;
+ }
+ }
+ }
+}
+
+#endif /* HAL_USE_TRNG == TRUE */
+
+/** @} */
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