blob: 40f57eed26c9be75fe9de95c85590cb66bc4d04e [file] [log] [blame]
/*
* Copyright (c) 2020, Google LLC. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <common/debug.h>
#include <lib/mmio.h>
#include <mt8173_def.h>
#include <plat_sip_calls.h>
#include <lib/psci/psci.h>
#include <smccc_helpers.h>
#include <wdt.h>
#define WDT_BASE (RGU_BASE + 0)
#define WDT_MODE (WDT_BASE + 0x00)
#define WDT_LENGTH (WDT_BASE + 0x04)
#define WDT_RESTART (WDT_BASE + 0x08)
#define WDT_SWRST (WDT_BASE + 0x14)
#define WDT_MODE_DUAL_MODE 0x40
#define WDT_MODE_IRQ 0x8
#define WDT_MODE_KEY 0x22000000
#define WDT_MODE_EXTEN 0x4
#define WDT_MODE_EN 0x1
#define WDT_LENGTH_KEY 0x8
#define WDT_RESTART_KEY 0x1971
#define WDT_SWRST_KEY 0x1209
#define WDT_MIN_TIMEOUT 1
#define WDT_MAX_TIMEOUT 31
enum smcwd_call {
SMCWD_INFO = 0,
SMCWD_SET_TIMEOUT = 1,
SMCWD_ENABLE = 2,
SMCWD_PET = 3,
};
static int wdt_enabled_before_suspend;
/*
* We expect the WDT registers to be correctly initialized by BL2 firmware
* (which may be board specific), so we do not reinitialize them here.
*/
void wdt_trigger_reset(void)
{
mmio_write_32(WDT_SWRST, WDT_SWRST_KEY);
}
void wdt_pet(void)
{
mmio_write_32(WDT_RESTART, WDT_RESTART_KEY);
}
int wdt_set_timeout(uint32_t timeout)
{
/* One tick here equals 512 32KHz ticks. 512 / 32000 * 125 / 2 = 1 */
uint32_t ticks = timeout * 125 / 2;
if (timeout < WDT_MIN_TIMEOUT || timeout > WDT_MAX_TIMEOUT)
return PSCI_E_INVALID_PARAMS;
mmio_write_32(WDT_LENGTH, ticks << 5 | WDT_LENGTH_KEY);
return PSCI_E_SUCCESS;
}
void wdt_set_enable(int enable)
{
if (enable)
wdt_pet();
mmio_clrsetbits_32(WDT_MODE, WDT_MODE_EN,
WDT_MODE_KEY | (enable ? WDT_MODE_EN : 0));
}
void wdt_suspend(void)
{
wdt_enabled_before_suspend = mmio_read_32(WDT_MODE) & WDT_MODE_EN;
if (wdt_enabled_before_suspend)
wdt_set_enable(0);
}
void wdt_resume(void)
{
if (wdt_enabled_before_suspend)
wdt_set_enable(1);
}
uint64_t wdt_smc_handler(uint32_t x1,
uint32_t x2,
void *handle)
{
int ret;
switch (x1) {
case SMCWD_INFO:
SMC_RET3(handle, PSCI_E_SUCCESS,
WDT_MIN_TIMEOUT, WDT_MAX_TIMEOUT);
case SMCWD_SET_TIMEOUT:
ret = wdt_set_timeout(x2);
SMC_RET1(handle, ret);
case SMCWD_ENABLE:
wdt_set_enable(x2 > 0);
SMC_RET1(handle, PSCI_E_SUCCESS);
case SMCWD_PET:
wdt_pet();
SMC_RET1(handle, PSCI_E_SUCCESS);
default:
ERROR("Unimplemented SMCWD call (%d)\n", x1);
SMC_RET1(handle, PSCI_E_NOT_SUPPORTED);
}
}