Saurabh Gorecha | 87f4737 | 2020-07-09 02:20:08 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2020, The Linux Foundation. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | */ |
| 6 | #include <stddef.h> |
Saurabh Gorecha | 87f4737 | 2020-07-09 02:20:08 +0530 | [diff] [blame] | 7 | |
| 8 | #include <lib/mmio.h> |
| 9 | |
Manish V Badarkhe | d307491 | 2020-08-17 06:44:20 +0100 | [diff] [blame^] | 10 | #include <qti_rng.h> |
Saurabh Gorecha | 87f4737 | 2020-07-09 02:20:08 +0530 | [diff] [blame] | 11 | #include <qti_rng_io.h> |
| 12 | |
| 13 | int qti_rng_get_data(uint8_t *out, uint32_t out_len) |
| 14 | { |
| 15 | uint32_t tmp_rndm = 0; |
| 16 | uint32_t bytes_left = out_len; |
| 17 | int i = 0; |
| 18 | |
| 19 | if (NULL == out || 0 == out_len) { |
| 20 | return -1; |
| 21 | } |
| 22 | |
| 23 | /* |
| 24 | * RNG HW initialized at previous boot image. |
| 25 | * RNG clocks are expected to be ON. |
| 26 | */ |
| 27 | |
| 28 | do { |
| 29 | /* There is no data to read */ |
| 30 | if ((mmio_read_32(SEC_PRNG_STATUS) & |
| 31 | SEC_PRNG_STATUS_DATA_AVAIL_BMSK) == 0) { |
| 32 | continue; |
| 33 | } |
| 34 | |
| 35 | while ((tmp_rndm = mmio_read_32(SEC_PRNG_DATA_OUT)) == 0) { |
| 36 | ; |
| 37 | } |
| 38 | |
| 39 | for (i = 0; i < 4; i++) { |
| 40 | *out = (uint8_t) (tmp_rndm >> (8 * i)); |
| 41 | |
| 42 | out++; |
| 43 | bytes_left--; |
| 44 | |
| 45 | if (bytes_left == 0) { |
| 46 | break; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | } while (bytes_left != 0); |
| 51 | |
| 52 | return 0; |
| 53 | } |