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| author | Giovanni Di Sirio <gdisirio@gmail.com> | 2018-10-07 07:58:29 +0000 |
|---|---|---|
| committer | Giovanni Di Sirio <gdisirio@gmail.com> | 2018-10-07 07:58:29 +0000 |
| commit | e72ef8c943b3a335fe4354e6451be99ab1346081 (patch) | |
| tree | 7f3e178fe11465c79753666492605ee34f39aaec /os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c | |
| parent | 644898df5f9771ad9308ed9abd7dee165a4b1268 (diff) | |
| download | ChibiOS-e72ef8c943b3a335fe4354e6451be99ab1346081.tar.gz ChibiOS-e72ef8c943b3a335fe4354e6451be99ab1346081.tar.bz2 ChibiOS-e72ef8c943b3a335fe4354e6451be99ab1346081.zip | |
STM32 TRNG driver, not tested yet.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@12342 110e8d01-0319-4d1e-a829-52ad28d1bb01
Diffstat (limited to 'os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c')
| -rw-r--r-- | os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c b/os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c new file mode 100644 index 000000000..ac6d39838 --- /dev/null +++ b/os/hal/ports/STM32/LLD/RNGv1/hal_trng_lld.c @@ -0,0 +1,179 @@ +/*
+ 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 TRNGD1 driver identifier.
+ */
+#if (STM32_TRNG_USE_RNG1 == TRUE) || defined(__DOXYGEN__)
+TRNGDriver TRNGD1;
+#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 STM32_TRNG_USE_RNG1 == TRUE
+ /* Driver initialization.*/
+ trngObjectInit(&TRNGD1);
+ TRNGD1.rng = RNG;
+#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 STM32_TRNG_USE_RNG1 == TRUE
+ if (&TRNGD1 == trngp) {
+ rccEnableRNG(false);
+ }
+#endif
+ }
+ /* Configures the peripheral.*/
+ trngp->rng->CR |= RNG_CR_RNGEN;
+}
+
+/**
+ * @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->rng->CR &= ~RNG_CR_RNGEN;
+
+ /* Disables the peripheral.*/
+#if STM32_TRNG_USE_RNG1 == TRUE
+ if (&TRNGD1 == trngp) {
+ rccDisableRNG();
+ }
+#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 error conditions to be cleared.*/
+ tmo = STM32_TRNG_ERROR_CLEAR_ATTEMPTS;
+ while ((tmo > 0) && ((trngp->rng->SR & (RNG_SR_CECS | RNG_SR_SECS)) != 0)) {
+ tmo--;
+ if (tmo == 0) {
+ return true;
+ }
+ }
+
+ /* Waiting for a random number in data register.*/
+ tmo = STM32_DATA_FETCH_ATTEMPTS;
+ while ((tmo > 0) && ((trngp->rng->SR & RNG_SR_DRDY) != 0)) {
+ tmo--;
+ if (tmo == 0) {
+ return true;
+ }
+ }
+
+ /* Getting the generated random number.*/
+ r = trngp->rng->DR;
+
+ /* 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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