43a7d26603
Replace CONFIG_ENTROPY_NAME with DT_CHOSEN_ZEPHYR_ENTROPY_LABEL. We now set zephyr,entropy in the chosen node of the device tree to the entropy device. This allows us to remove CONFIG_ENTROPY_NAME from dts_fixup.h. Also remove any other stale ENTROPY related defines in dts_fixup.h files. Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
/*
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* Copyright (c) 2016 Nordic Semiconductor ASA
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* Copyright (c) 2016 Vinayak Kariappa Chettimada
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/types.h>
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#include <drivers/entropy.h>
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#include "util.h"
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/**
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* @brief Population count: Count the number of bits set to 1
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* @details
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* TODO: Faster methods available at [1].
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* [1] http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
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*
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* @param octets Data to count over
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* @param octets_len Must not be bigger than 255/8 = 31 bytes
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*
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* @return popcnt of 'octets'
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*/
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u8_t util_ones_count_get(u8_t *octets, u8_t octets_len)
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{
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u8_t one_count = 0U;
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while (octets_len--) {
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u8_t bite;
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bite = *octets;
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while (bite) {
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bite &= (bite - 1);
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one_count++;
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}
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octets++;
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}
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return one_count;
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}
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int util_rand(void *buf, size_t len)
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{
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static struct device *dev;
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if (unlikely(!dev)) {
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/* Only one entropy device exists, so this is safe even
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* if the whole operation isn't atomic.
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*/
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dev = device_get_binding(DT_CHOSEN_ZEPHYR_ENTROPY_LABEL);
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__ASSERT((dev != NULL),
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"Device driver for %s (DT_CHOSEN_ZEPHYR_ENTROPY_LABEL) not found. "
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"Check your build configuration!",
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DT_CHOSEN_ZEPHYR_ENTROPY_LABEL);
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}
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return entropy_get_entropy(dev, (u8_t *)buf, len);
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}
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