| /* |
| * Copyright (c) 2018 Foundries.io Ltd |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <zephyr/linker/sections.h> |
| #include <zephyr/toolchain.h> |
| #include <zephyr/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 |
