64 lines
1.4 KiB
ArmAsm
64 lines
1.4 KiB
ArmAsm
/*
|
|
* Copyright (c) 2018 Foundries.io Ltd
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#include <linker/sections.h>
|
|
#include <toolchain.h>
|
|
#include <arch/cpu.h>
|
|
|
|
/* Exports */
|
|
GTEXT(_WdogInit)
|
|
|
|
/* WDOG instance base address. */
|
|
#ifdef CONFIG_SOC_OPENISA_RV32M1_RI5CY
|
|
#define WDOG_BASE 0x4002A000 /* WDOG0 */
|
|
#else
|
|
#define WDOG_BASE 0x41026000 /* WDOG1 */
|
|
#endif
|
|
|
|
/* Register offsets. */
|
|
#define WDOG_CS_OFFSET 0x00
|
|
#define WDOG_CNT_OFFSET 0x04
|
|
#define WDOG_TOVAL_OFFSET 0x08
|
|
|
|
/* Watchdog unlock key. */
|
|
#define WDOG_CNT_UNLOCK 0xD928C520
|
|
|
|
/* TOVAL must be set when disabling watchdog after reset. */
|
|
#define WDOG_TOVAL_SET 0xFFFF
|
|
|
|
/* Disable the WDOG_CS[EN] bit. */
|
|
#define WDOG_CS_EN_DISABLED ~0x80
|
|
/* Set WDOG_CS[UPDATE] bit. */
|
|
#define WDOG_CS_UPDATE_ENABLED 0x20
|
|
|
|
/*
|
|
* Unlock and disable the watchdog, which is enabled by default.
|
|
*/
|
|
SECTION_FUNC(TEXT, _WdogInit)
|
|
/* Disable interrupts if they're on. This is timing-sensitive code. */
|
|
csrrc t0, mstatus, MSTATUS_IEN
|
|
|
|
/* Get base address. */
|
|
li t1, WDOG_BASE
|
|
|
|
/* Unlock the watchdog. */
|
|
li t2, WDOG_CNT_UNLOCK
|
|
sw t2, WDOG_CNT_OFFSET(t1)
|
|
|
|
/* Disable the watchdog. Allow updates later. */
|
|
lw t2, WDOG_CS_OFFSET(t1)
|
|
andi t2, t2, WDOG_CS_EN_DISABLED
|
|
ori t2, t2, WDOG_CS_UPDATE_ENABLED
|
|
sw t2, WDOG_CS_OFFSET(t1)
|
|
|
|
/* This must also be done per reference manual. */
|
|
li t2, WDOG_TOVAL_SET
|
|
sw t2, WDOG_TOVAL_OFFSET(t1)
|
|
|
|
/* Re-enable interrupts if they were disabled. */
|
|
csrrs x0, mstatus, t0
|
|
ret
|