100 lines
2.9 KiB
C
100 lines
2.9 KiB
C
/*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Copyright (c) 2025 Realtek Semiconductor Corporation, SIBG-SD7
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* Author: Elmo Lan <elmo_lan@realtek.com>
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*/
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#define DT_DRV_COMPAT realtek_rts5912_bbram
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#include <zephyr/drivers/bbram.h>
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#include <errno.h>
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#include <zephyr/sys/util.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(rts5912_bbram, CONFIG_BBRAM_LOG_LEVEL);
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struct bbram_rts5912_config {
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uintptr_t base;
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int size;
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};
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static int bbram_rts5912_get_size(const struct device *dev, size_t *size)
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{
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const struct bbram_rts5912_config *config = dev->config;
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*size = config->size;
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LOG_INF("size: 0x%08x", *size);
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return 0;
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}
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static int bbram_rts5912_read(const struct device *dev, size_t offset, size_t size, uint8_t *data)
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{
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const struct bbram_rts5912_config *config = dev->config;
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uint32_t word;
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size_t start_offset, bytes_to_read;
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if (size < 1 || offset + size > config->size) {
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LOG_ERR("Invalid params");
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return -EFAULT;
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}
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/* The bbram in RTS5912 only accepts word-access.
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* Read it as a word, then split it into bytes.
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*/
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for (int i = 0; i < size;) {
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word = *(uint32_t *)(config->base + ROUND_DOWN((offset + i), 4));
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start_offset = (offset + i) % 4;
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bytes_to_read = MIN(4 - start_offset, size - i);
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memcpy(&data[i], ((uint8_t *)&word) + start_offset, bytes_to_read);
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i += bytes_to_read;
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}
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return 0;
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}
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static int bbram_rts5912_write(const struct device *dev, size_t offset, size_t size,
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const uint8_t *data)
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{
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const struct bbram_rts5912_config *config = dev->config;
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uint32_t word;
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size_t start_offset, bytes_to_write;
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if (size < 1 || offset + size > config->size) {
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LOG_ERR("Invalid params");
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return -EFAULT;
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}
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/* The BBRAM in RTS5912 only accepts word-access. Read it as a word,
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* then modify the byte field, and finally write it back as a word
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*/
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for (int i = 0; i < size;) {
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word = *(uint32_t *)(config->base + ROUND_DOWN((offset + i), 4));
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start_offset = (offset + i) % 4;
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bytes_to_write = MIN(4 - start_offset, size - i);
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memcpy(((uint8_t *)&word) + start_offset, &data[i], bytes_to_write);
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*(uint32_t *)(config->base + ROUND_DOWN((offset + i), 4)) = word;
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i += bytes_to_write;
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}
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return 0;
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}
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static DEVICE_API(bbram, bbram_rts5912_driver_api) = {
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.get_size = bbram_rts5912_get_size,
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.read = bbram_rts5912_read,
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.write = bbram_rts5912_write,
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};
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#define BBRAM_INIT(inst) \
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static const struct bbram_rts5912_config bbram_cfg_##inst = { \
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.base = DT_INST_REG_ADDR(inst), \
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.size = DT_INST_REG_SIZE(inst), \
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}; \
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DEVICE_DT_INST_DEFINE(inst, NULL, NULL, NULL, &bbram_cfg_##inst, PRE_KERNEL_1, \
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CONFIG_BBRAM_INIT_PRIORITY, &bbram_rts5912_driver_api);
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DT_INST_FOREACH_STATUS_OKAY(BBRAM_INIT);
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