90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
/*
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* Copyright (c) 2023-2024 Analog Devices, Inc.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <string.h>
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#include <zephyr/sys/util.h>
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#define DT_DRV_COMPAT adi_max32_trng
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#include <zephyr/device.h>
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#include <zephyr/drivers/entropy.h>
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#include <zephyr/drivers/clock_control/adi_max32_clock_control.h>
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#include <wrap_max32_trng.h>
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struct max32_trng_config {
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const struct device *clock;
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struct max32_perclk perclk;
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};
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static int api_get_entropy(const struct device *dev, uint8_t *buf, uint16_t len)
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{
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return MXC_TRNG_Random(buf, len);
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}
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static int api_get_entropy_isr(const struct device *dev, uint8_t *buf, uint16_t len, uint32_t flags)
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{
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int ret = 0;
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if ((flags & ENTROPY_BUSYWAIT) == 0) {
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uint32_t temp;
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uint32_t copy_len;
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uint32_t count = 0;
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while (len) {
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ret = Wrap_MXC_TRNG_RandomInt_NonBlocking(&temp);
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if (ret != 0) {
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break; /* Data not ready do not wait */
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}
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copy_len = MIN(len, 4);
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memcpy(buf, (uint8_t *)&temp, copy_len);
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len -= copy_len;
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buf += copy_len;
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count += copy_len;
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}
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/* User would like to read len bytes but in non-blocking mode
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* the function might read less, in that case return value will be
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* number of bytes read, if its 0 that means no data reads function
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* will return -ENODATA
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*/
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ret = count ? count : -ENODATA;
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} else {
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/* Allowed to busy-wait */
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ret = api_get_entropy(dev, buf, len);
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if (ret == 0) {
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ret = len; /* Data retrieved successfully. */
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}
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}
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return ret;
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}
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static const struct entropy_driver_api entropy_max32_api = {.get_entropy = api_get_entropy,
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.get_entropy_isr = api_get_entropy_isr};
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static int entropy_max32_init(const struct device *dev)
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{
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int ret;
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const struct max32_trng_config *cfg = dev->config;
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/* Enable clock */
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ret = clock_control_on(cfg->clock, (clock_control_subsys_t)&cfg->perclk);
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return ret;
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}
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static const struct max32_trng_config max32_trng_cfg = {
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.clock = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(0)),
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.perclk.bus = DT_INST_CLOCKS_CELL(0, offset),
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.perclk.bit = DT_INST_CLOCKS_CELL(0, bit),
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};
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DEVICE_DT_INST_DEFINE(0, entropy_max32_init, NULL, NULL, &max32_trng_cfg, PRE_KERNEL_1,
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CONFIG_ENTROPY_INIT_PRIORITY, &entropy_max32_api);
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