zephyr/drivers/bbram/bbram_it8xxx2.c

100 lines
3.2 KiB
C

/*
* Copyright (c) 2021 Google Inc
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ite_it8xxx2_bbram
#include <drivers/bbram.h>
#include <errno.h>
#include <sys/util.h>
#include <logging/log.h>
LOG_MODULE_REGISTER(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)
/** Device config */
struct bbram_it8xxx2_config {
/** BBRAM base address */
uintptr_t base_addr;
/** BBRAM size (Unit:bytes) */
int size;
};
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 -EFAULT;
}
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 -EFAULT;
}
bytecpy(((uint8_t *)config->base_addr + offset), data, size);
return 0;
}
static const struct bbram_driver_api bbram_it8xxx2_driver_api = {
.read = bbram_it8xxx2_read,
.write = bbram_it8xxx2_write,
};
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;
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 BRAM, and set magic value.
*/
for (int i = 0; i < BRAM_IDX_VALID_FLAGS0; 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) \
static const struct bbram_it8xxx2_config bbram_cfg_##inst = { \
.base_addr = DT_INST_REG_ADDR(inst), \
.size = DT_INST_REG_SIZE(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);