zephyr/drivers/bbram/bbram_it8xxx2.c

114 lines
3.3 KiB
C

/*
* Copyright (c) 2021 Google Inc
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ite_it8xxx2_bbram
#include <errno.h>
#include <zephyr/drivers/bbram.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/util.h>
#ifndef CONFIG_BBRAM_IT8XXX2_EMUL
#include <chip_chipregs.h>
#else
/* Emulation register values */
enum bram_indices {
BRAM_IDX_VALID_FLAGS0,
BRAM_IDX_VALID_FLAGS1,
BRAM_IDX_VALID_FLAGS2,
BRAM_IDX_VALID_FLAGS3,
};
#endif
#include "it8xxx2.h"
LOG_MODULE_REGISTER(it8xxx2_bbram, CONFIG_BBRAM_LOG_LEVEL);
#define BRAM_VALID_MAGIC 0x4252414D /* "BRAM" */
#define BRAM_VALID_MAGIC_FIELD0 (BRAM_VALID_MAGIC & 0xff)
#define BRAM_VALID_MAGIC_FIELD1 ((BRAM_VALID_MAGIC >> 8) & 0xff)
#define BRAM_VALID_MAGIC_FIELD2 ((BRAM_VALID_MAGIC >> 16) & 0xff)
#define BRAM_VALID_MAGIC_FIELD3 ((BRAM_VALID_MAGIC >> 24) & 0xff)
static int bbram_it8xxx2_read(const struct device *dev, size_t offset, size_t size, uint8_t *data)
{
const struct bbram_it8xxx2_config *config = dev->config;
if (size < 1 || offset + size > config->size) {
return -EINVAL;
}
bytecpy(data, ((uint8_t *)config->base_addr + offset), size);
return 0;
}
static int bbram_it8xxx2_write(const struct device *dev, size_t offset, size_t size,
const uint8_t *data)
{
const struct bbram_it8xxx2_config *config = dev->config;
if (size < 1 || offset + size > config->size) {
return -EINVAL;
}
bytecpy(((uint8_t *)config->base_addr + offset), data, size);
return 0;
}
static int bbram_it8xxx2_size(const struct device *dev, size_t *size)
{
const struct bbram_it8xxx2_config *config = dev->config;
*size = config->size;
return 0;
}
static const struct bbram_driver_api bbram_it8xxx2_driver_api = {
.read = bbram_it8xxx2_read,
.write = bbram_it8xxx2_write,
.get_size = bbram_it8xxx2_size,
};
static int bbram_it8xxx2_init(const struct device *dev)
{
const struct bbram_it8xxx2_config *config = dev->config;
uint8_t *base_addr = (uint8_t *)config->base_addr;
uint8_t *bram_valid_flag0 = base_addr + BRAM_IDX_VALID_FLAGS0;
uint8_t *bram_valid_flag1 = base_addr + BRAM_IDX_VALID_FLAGS1;
uint8_t *bram_valid_flag2 = base_addr + BRAM_IDX_VALID_FLAGS2;
uint8_t *bram_valid_flag3 = base_addr + BRAM_IDX_VALID_FLAGS3;
int size = config->size;
if ((*bram_valid_flag0 != BRAM_VALID_MAGIC_FIELD0) ||
(*bram_valid_flag1 != BRAM_VALID_MAGIC_FIELD1) ||
(*bram_valid_flag2 != BRAM_VALID_MAGIC_FIELD2) ||
(*bram_valid_flag3 != BRAM_VALID_MAGIC_FIELD3)) {
/*
* Magic does not match, so BRAM must be uninitialized. Clear
* entire Bank0 and Bank1 BRAM, and set magic value.
*/
for (int i = 0; i < size; i++) {
*(base_addr + i) = 0;
}
*bram_valid_flag0 = BRAM_VALID_MAGIC_FIELD0;
*bram_valid_flag1 = BRAM_VALID_MAGIC_FIELD1;
*bram_valid_flag2 = BRAM_VALID_MAGIC_FIELD2;
*bram_valid_flag3 = BRAM_VALID_MAGIC_FIELD3;
}
return 0;
}
#define BBRAM_INIT(inst) \
BBRAM_IT8XXX2_DECL_CONFIG(inst); \
DEVICE_DT_INST_DEFINE(inst, bbram_it8xxx2_init, NULL, NULL, &bbram_cfg_##inst, \
PRE_KERNEL_1, CONFIG_BBRAM_INIT_PRIORITY, \
&bbram_it8xxx2_driver_api);
DT_INST_FOREACH_STATUS_OKAY(BBRAM_INIT);