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>
66 lines
1.4 KiB
C
66 lines
1.4 KiB
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 <device.h>
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#include <drivers/entropy.h>
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#include <errno.h>
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#include <init.h>
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#include <soc.h>
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#include <string.h>
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#include <zephyr.h>
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#define PRBS_STATUS ((volatile uint32_t *)DT_INST_REG_ADDR(0))
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#define PRBS_WIDTH DT_INST_REG_SIZE(0)
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#define SUBREG_SIZE_BIT 8
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static inline unsigned int prbs_read(volatile uint32_t *reg_status,
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volatile uint32_t reg_width)
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{
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uint32_t shifted_data, shift, i;
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uint32_t result = 0;
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for (i = 0; i < reg_width; ++i) {
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shifted_data = *(reg_status + i);
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shift = (reg_width - i - 1) * SUBREG_SIZE_BIT;
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result |= (shifted_data << shift);
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}
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return result;
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}
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static int entropy_prbs_get_entropy(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 = prbs_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 int entropy_prbs_init(struct device *dev)
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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_AND_API_INIT(entropy_prbs, DT_INST_LABEL(0),
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entropy_prbs_init, NULL, NULL,
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PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&entropy_prbs_api);
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