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author | Alistair Delva <adelva@google.com> | 2021-02-16 21:01:22 +0000 |
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committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | 2021-02-16 21:01:22 +0000 |
commit | efb2826bb8160e2d8e0fcec85133a7468484f9fd (patch) | |
tree | 37a21c69306801ee7cdda5167a30896c8740155b /drivers/brcm/rng.c | |
parent | b00a71fc312c9781fa6f404dccfb55b062b2ccac (diff) | |
parent | faa476c0caaa598afa5a6109d17102db5fe35ec6 (diff) | |
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Merge branch 'aosp/upstream-master' into HEAD am: faa476c0caHEADandroid-s-beta-5android-s-beta-4android-s-beta-3android-s-beta-2android-s-beta-1mastermain-cg-testing-releaseandroid-s-beta-5android-s-beta-4
Original change: https://android-review.googlesource.com/c/platform/external/arm-trusted-firmware/+/1589611
MUST ONLY BE SUBMITTED BY AUTOMERGER
Change-Id: I3a25534ceed4f8e188510641080d8b8ed49b8f62
Diffstat (limited to 'drivers/brcm/rng.c')
-rw-r--r-- | drivers/brcm/rng.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/brcm/rng.c b/drivers/brcm/rng.c new file mode 100644 index 000000000..ee2e6561e --- /dev/null +++ b/drivers/brcm/rng.c @@ -0,0 +1,97 @@ +/* + * Copyright (c) 2017 - 2020, Broadcom + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <common/debug.h> +#include <drivers/delay_timer.h> +#include <lib/mmio.h> +#include <platform_def.h> + +#define RNG_CTRL_REG (RNG_BASE_ADDR + 0x00) +#define RNG_CTRL_MASK 0x00001FFF +#define RNG_CTRL_ENABLE 0x00000001 +#define RNG_CTRL_DISABLE 0x00000000 + +#define RNG_SOFT_RESET_REG (RNG_BASE_ADDR + 0x04) +#define RNG_SOFT_RESET_MASK 0x00000001 + +#define RNG_FIFO_DATA_REG (RNG_BASE_ADDR + 0x20) + +#define RNG_FIFO_COUNT_REG (RNG_BASE_ADDR + 0x24) +#define RNG_FIFO_COUNT_MASK 0x000000FF + +#define RNG_FIFO_WORDS_MAX 16 +#define MAX_WAIT_COUNT_50US 20000 + + +static void rng_reset(void) +{ + /* Disable RBG */ + mmio_clrbits_32(RNG_CTRL_REG, RNG_CTRL_MASK); + + /* Reset RNG and RBG */ + mmio_setbits_32(RNG_SOFT_RESET_REG, RNG_SOFT_RESET_MASK); + + /* Take all out of reset */ + mmio_clrbits_32(RNG_SOFT_RESET_REG, RNG_SOFT_RESET_MASK); +} + +static void rng_enable(void) +{ + /* Setup RNG. */ + mmio_clrsetbits_32(RNG_CTRL_REG, RNG_CTRL_MASK, RNG_CTRL_ENABLE); +} + +int rng_init(void) +{ + rng_reset(); + + rng_enable(); + + return 0; +} + +int rng_read(uint32_t *p_out, uint32_t *words_read) +{ + uint32_t available_words; + uint32_t i; + uint32_t word_processed = 0; + uint32_t wait_count = MAX_WAIT_COUNT_50US; + + if (*words_read == 0) { + ERROR("RNG Parameter: No word requested\n"); + return -1; + } + + do { + available_words = mmio_read_32(RNG_FIFO_COUNT_REG); + available_words &= RNG_FIFO_COUNT_MASK; + + if (available_words != 0) { + available_words = MIN(available_words, + *words_read - word_processed); + + for (i = 0; i < available_words; i++) + p_out[word_processed + i] = + mmio_read_32(RNG_FIFO_DATA_REG); + word_processed += available_words; + } else { + udelay(50); + } + + if (word_processed == *words_read) + break; + + } while (--wait_count); + + if (word_processed != *words_read) { + ERROR("RNG Timeout: requested %d word(s) got %d\n", + *words_read, word_processed); + *words_read = word_processed; + return -1; + } + + return 0; +} |