ITE: drivers/bbram: add magic number to compare in initial

BBRAM content should be cleared when boot from cutoff. Compare magic
number to decide whether to clear entire BBRAM.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>
This commit is contained in:
Tim Lin 2021-12-24 17:33:39 +08:00 committed by Anas Nashif
commit 95ba8e3fe4
2 changed files with 49 additions and 2 deletions

View file

@ -13,6 +13,12 @@
#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 */
@ -53,7 +59,30 @@ static const struct bbram_driver_api bbram_it8xxx2_driver_api = {
static int bbram_it8xxx2_init(const struct device *dev)
{
ARG_UNUSED(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;
}

View file

@ -1,4 +1,4 @@
/*
/*
* Copyright (c) 2020 ITE Corporation. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0
*/
@ -1876,6 +1876,24 @@ struct gctrl_it8xxx2_regs {
/* bit[2] = 1: Enable global reset. */
#define IT8XXX2_GCTRL_GRST BIT(2)
/**
*
* (22xxh) Battery-backed SRAM (BRAM) registers
*
*/
#ifndef __ASSEMBLER__
/* Battery backed RAM indices. */
#define BRAM_MAGIC_FIELD_OFFSET 0xbc
enum bram_indices {
/* This field is used to indicate BRAM is valid or not. */
BRAM_IDX_VALID_FLAGS0 = BRAM_MAGIC_FIELD_OFFSET,
BRAM_IDX_VALID_FLAGS1,
BRAM_IDX_VALID_FLAGS2,
BRAM_IDX_VALID_FLAGS3
};
#endif /* !__ASSEMBLER__ */
#ifndef __ASSEMBLER__
/*
* EC2I bridge registers