a1b77fd589
git grep -l 'u\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/u\(8\|16\|32\|64\)_t/uint\1_t/g" git grep -l 's\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/s\(8\|16\|32\|64\)_t/int\1_t/g" Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
104 lines
2.1 KiB
C
104 lines
2.1 KiB
C
/*
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* Copyright (c) 2020 Lemonbeat GmbH
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT silabs_gecko_trng
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#include <drivers/entropy.h>
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#include <string.h>
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#include "soc.h"
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#include "em_cmu.h"
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static void entropy_gecko_trng_read(uint8_t *output, size_t len)
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{
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uint32_t tmp;
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uint32_t *data = (uint32_t *) output;
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/* Read known good available data. */
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while (len >= 4) {
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*data++ = TRNG0->FIFO;
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len -= 4;
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}
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if (len > 0) {
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/* Handle the case where len is not a multiple of 4
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* and FIFO data is available.
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*/
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tmp = TRNG0->FIFO;
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memcpy(data, (const uint8_t *) &tmp, len);
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}
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}
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static int entropy_gecko_trng_get_entropy(struct device *dev, uint8_t *buffer,
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uint16_t length)
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{
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size_t count = 0;
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size_t available;
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ARG_UNUSED(dev);
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while (length) {
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available = TRNG0->FIFOLEVEL * 4;
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if (available == 0) {
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return -EINVAL;
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}
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count = SL_MIN(length, available);
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entropy_gecko_trng_read(buffer, count);
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buffer += count;
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length -= count;
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}
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return 0;
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}
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static int entropy_gecko_trng_get_entropy_isr(struct device *dev, uint8_t *buf,
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uint16_t len, uint32_t flags)
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{
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if ((flags & ENTROPY_BUSYWAIT) == 0U) {
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/* No busy wait; return whatever data is available. */
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size_t count;
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size_t available = TRNG0->FIFOLEVEL * 4;
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if (available == 0) {
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return -ENODATA;
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}
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count = SL_MIN(len, available);
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entropy_gecko_trng_read(buf, count);
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return count;
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} else {
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/* Allowed to busy-wait */
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int ret = entropy_gecko_trng_get_entropy(dev, buf, len);
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if (ret == 0) {
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/* Data retrieved successfully. */
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return len;
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}
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return ret;
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}
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}
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static int entropy_gecko_trng_init(struct device *device)
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{
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/* Enable the TRNG0 clock. */
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CMU_ClockEnable(cmuClock_TRNG0, true);
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/* Enable TRNG0. */
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TRNG0->CONTROL = TRNG_CONTROL_ENABLE;
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return 0;
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}
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static struct entropy_driver_api entropy_gecko_trng_api_funcs = {
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.get_entropy = entropy_gecko_trng_get_entropy,
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.get_entropy_isr = entropy_gecko_trng_get_entropy_isr
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};
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DEVICE_AND_API_INIT(entropy_gecko_trng, DT_INST_LABEL(0),
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entropy_gecko_trng_init, NULL, NULL,
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PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&entropy_gecko_trng_api_funcs);
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