43 lines
966 B
C
43 lines
966 B
C
/*
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* Copyright (c) 2019 Antmicro <www.antmicro.com>
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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 litex_prbs
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#include <zephyr/device.h>
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#include <zephyr/drivers/entropy.h>
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#include <errno.h>
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#include <zephyr/init.h>
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#include <soc.h>
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#include <string.h>
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#include <zephyr/kernel.h>
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#define PRBS_STATUS DT_INST_REG_ADDR(0)
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#define PRBS_WIDTH DT_INST_REG_SIZE(0)
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static int entropy_prbs_get_entropy(const struct device *dev, uint8_t *buffer,
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uint16_t length)
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{
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while (length > 0) {
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size_t to_copy;
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uint32_t value;
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value = litex_read(PRBS_STATUS, PRBS_WIDTH);
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to_copy = MIN(length, sizeof(value));
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memcpy(buffer, &value, to_copy);
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buffer += to_copy;
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length -= to_copy;
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}
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return 0;
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}
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static const struct entropy_driver_api entropy_prbs_api = {
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.get_entropy = entropy_prbs_get_entropy
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};
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DEVICE_DT_INST_DEFINE(0, NULL, NULL, NULL, NULL, PRE_KERNEL_1,
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CONFIG_ENTROPY_INIT_PRIORITY, &entropy_prbs_api);
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