87 lines
2.7 KiB
C
87 lines
2.7 KiB
C
/*
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* Copyright (c) 2025 Qingsong Gou <gouqs@hotmail.com>
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT sifli_sf32lb_trng
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#include <zephyr/arch/cpu.h>
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#include <zephyr/device.h>
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#include <zephyr/drivers/clock_control/sf32lb.h>
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#include <zephyr/drivers/entropy.h>
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#include <zephyr/logging/log.h>
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#include <register.h>
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LOG_MODULE_REGISTER(entropy_sf32lb, CONFIG_ENTROPY_LOG_LEVEL);
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#define TRNG_CTRL offsetof(TRNG_TypeDef, CTRL)
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#define TRNG_STAT offsetof(TRNG_TypeDef, STAT)
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#define TRNG_RAND offsetof(TRNG_TypeDef, RAND_NUM0)
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#define TRNG_RAND_NUM_MAX (8U)
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#define TRNG_RAND_MASK (TRNG_RAND_NUM_MAX - 1U)
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struct entropy_sf32lb_config {
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uintptr_t base;
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struct sf32lb_clock_dt_spec clock;
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};
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static int entropy_sf32lb_get_entropy(const struct device *dev, uint8_t *buffer, uint16_t length)
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{
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const struct entropy_sf32lb_config *config = dev->config;
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uint32_t buf[TRNG_RAND_NUM_MAX];
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uint16_t bytes;
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while (length) {
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sys_set_bit(config->base + TRNG_CTRL, TRNG_CTRL_GEN_SEED_START_Pos);
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while (!sys_test_bit(config->base + TRNG_STAT, TRNG_STAT_SEED_VALID_Pos)) {
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}
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/* Generate random data */
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sys_set_bit(config->base + TRNG_CTRL, TRNG_CTRL_GEN_RAND_NUM_START_Pos);
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while (!sys_test_bit(config->base + TRNG_STAT, TRNG_STAT_RAND_NUM_VALID_Pos)) {
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}
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for (uint8_t i = 0U; i < TRNG_RAND_NUM_MAX; i++) {
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buf[i] = sys_read32(config->base + TRNG_RAND + (i * 4U));
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}
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bytes = MIN(length, sizeof(buf));
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memcpy(buffer, buf, bytes);
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length -= bytes;
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buffer += bytes;
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}
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return 0;
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}
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static DEVICE_API(entropy, entropy_sf32lb_api) = {
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.get_entropy = entropy_sf32lb_get_entropy,
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};
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static int entropy_sf32lb_init(const struct device *dev)
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{
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const struct entropy_sf32lb_config *config = dev->config;
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if (!sf32lb_clock_is_ready_dt(&config->clock)) {
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return -ENODEV;
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}
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return sf32lb_clock_control_on_dt(&config->clock);
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}
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#define ENTROPY_SF32LB_DEFINE(n) \
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static const struct entropy_sf32lb_config entropy_sf32lb_config_##n = { \
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.base = DT_INST_REG_ADDR(n), \
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.clock = SF32LB_CLOCK_DT_INST_SPEC_GET(n), \
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}; \
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\
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DEVICE_DT_INST_DEFINE(n, entropy_sf32lb_init, NULL, NULL, \
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&entropy_sf32lb_config_##n, PRE_KERNEL_1, \
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CONFIG_ENTROPY_INIT_PRIORITY, &entropy_sf32lb_api);
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DT_INST_FOREACH_STATUS_OKAY(ENTROPY_SF32LB_DEFINE)
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