blob: 6b98095d600f95f1da6a59d6e3e9cbffbccb13f7 [file] [log] [blame]
/*
* Copyright (C) 2022, STMicroelectronics - All Rights Reserved
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <drivers/st/stm32mp_ddr_test.h>
#include <lib/mmio.h>
#include <platform_def.h>
#define DDR_PATTERN 0xAAAAAAAAU
#define DDR_ANTIPATTERN 0x55555555U
/*******************************************************************************
* This function tests a simple read/write access to the DDR.
* Note that the previous content is restored after test.
* Returns 0 if success, and address value else.
******************************************************************************/
uint32_t stm32mp_ddr_test_rw_access(void)
{
uint32_t saved_value = mmio_read_32(STM32MP_DDR_BASE);
mmio_write_32(STM32MP_DDR_BASE, DDR_PATTERN);
if (mmio_read_32(STM32MP_DDR_BASE) != DDR_PATTERN) {
return (uint32_t)STM32MP_DDR_BASE;
}
mmio_write_32(STM32MP_DDR_BASE, saved_value);
return 0U;
}
/*******************************************************************************
* This function tests the DDR data bus wiring.
* This is inspired from the Data Bus Test algorithm written by Michael Barr
* in "Programming Embedded Systems in C and C++" book.
* resources.oreilly.com/examples/9781565923546/blob/master/Chapter6/
* File: memtest.c - This source code belongs to Public Domain.
* Returns 0 if success, and address value else.
******************************************************************************/
uint32_t stm32mp_ddr_test_data_bus(void)
{
uint32_t pattern;
for (pattern = 1U; pattern != 0U; pattern <<= 1U) {
mmio_write_32(STM32MP_DDR_BASE, pattern);
if (mmio_read_32(STM32MP_DDR_BASE) != pattern) {
return (uint32_t)STM32MP_DDR_BASE;
}
}
return 0;
}
/*******************************************************************************
* This function tests the DDR address bus wiring.
* This is inspired from the Data Bus Test algorithm written by Michael Barr
* in "Programming Embedded Systems in C and C++" book.
* resources.oreilly.com/examples/9781565923546/blob/master/Chapter6/
* File: memtest.c - This source code belongs to Public Domain.
* size: size in bytes of the DDR memory device.
* Returns 0 if success, and address value else.
******************************************************************************/
uint32_t stm32mp_ddr_test_addr_bus(uint64_t size)
{
uint64_t addressmask = size - 1U;
uint64_t offset;
uint64_t testoffset = 0U;
/* Write the default pattern at each of the power-of-two offsets. */
for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
offset <<= 1U) {
mmio_write_32(STM32MP_DDR_BASE + (uint32_t)offset,
DDR_PATTERN);
}
/* Check for address bits stuck high. */
mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
DDR_ANTIPATTERN);
for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
offset <<= 1U) {
if (mmio_read_32(STM32MP_DDR_BASE + (uint32_t)offset) !=
DDR_PATTERN) {
return (uint32_t)(STM32MP_DDR_BASE + offset);
}
}
mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset, DDR_PATTERN);
/* Check for address bits stuck low or shorted. */
for (testoffset = sizeof(uint32_t); (testoffset & addressmask) != 0U;
testoffset <<= 1U) {
mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
DDR_ANTIPATTERN);
if (mmio_read_32(STM32MP_DDR_BASE) != DDR_PATTERN) {
return STM32MP_DDR_BASE;
}
for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
offset <<= 1) {
if ((mmio_read_32(STM32MP_DDR_BASE +
(uint32_t)offset) != DDR_PATTERN) &&
(offset != testoffset)) {
return (uint32_t)(STM32MP_DDR_BASE + offset);
}
}
mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
DDR_PATTERN);
}
return 0U;
}
/*******************************************************************************
* This function checks the DDR size. It has to be run with Data Cache off.
* This test is run before data have been put in DDR, and is only done for
* cold boot. The DDR data can then be overwritten, and it is not useful to
* restore its content.
* Returns DDR computed size.
******************************************************************************/
uint32_t stm32mp_ddr_check_size(void)
{
uint32_t offset = sizeof(uint32_t);
mmio_write_32(STM32MP_DDR_BASE, DDR_PATTERN);
while (offset < STM32MP_DDR_MAX_SIZE) {
mmio_write_32(STM32MP_DDR_BASE + offset, DDR_ANTIPATTERN);
dsb();
if (mmio_read_32(STM32MP_DDR_BASE) != DDR_PATTERN) {
break;
}
offset <<= 1U;
}
INFO("Memory size = 0x%x (%u MB)\n", offset, offset / (1024U * 1024U));
return offset;
}