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Diffstat (limited to '')
-rw-r--r-- | plat/qti/common/src/qti_rng.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/plat/qti/common/src/qti_rng.c b/plat/qti/common/src/qti_rng.c new file mode 100644 index 0000000..f63f3b8 --- /dev/null +++ b/plat/qti/common/src/qti_rng.c @@ -0,0 +1,53 @@ +/* + * Copyright (c) 2020, The Linux Foundation. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#include <stddef.h> + +#include <lib/mmio.h> + +#include <qti_rng.h> +#include <qti_rng_io.h> + +int qti_rng_get_data(uint8_t *out, uint32_t out_len) +{ + uint32_t tmp_rndm = 0; + uint32_t bytes_left = out_len; + int i = 0; + + if (NULL == out || 0 == out_len) { + return -1; + } + + /* + * RNG HW initialized at previous boot image. + * RNG clocks are expected to be ON. + */ + + do { + /* There is no data to read */ + if ((mmio_read_32(SEC_PRNG_STATUS) & + SEC_PRNG_STATUS_DATA_AVAIL_BMSK) == 0) { + continue; + } + + while ((tmp_rndm = mmio_read_32(SEC_PRNG_DATA_OUT)) == 0) { + ; + } + + for (i = 0; i < 4; i++) { + *out = (uint8_t) (tmp_rndm >> (8 * i)); + + out++; + bytes_left--; + + if (bytes_left == 0) { + break; + } + } + + } while (bytes_left != 0); + + return 0; +} |