1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Copyright (c) 2017 Intel Corporation 4 */ 5#include <common.h> 6#include <dm.h> 7#include <log.h> 8#include <wdt.h> 9#include <div64.h> 10#include <asm/scu.h> 11 12/* Hardware timeout in seconds */ 13#define WDT_PRETIMEOUT 15 14#define WDT_TIMEOUT_MIN (1 + WDT_PRETIMEOUT) 15#define WDT_TIMEOUT_MAX 170 16 17/* 18 * Note, firmware chooses 90 seconds as a default timeout for watchdog on 19 * Intel Tangier SoC. It means that without handling it in the running code 20 * the reboot will happen. 21 */ 22 23enum { 24 SCU_WATCHDOG_START = 0, 25 SCU_WATCHDOG_STOP = 1, 26 SCU_WATCHDOG_KEEPALIVE = 2, 27 SCU_WATCHDOG_SET_ACTION_ON_TIMEOUT = 3, 28}; 29 30static int tangier_wdt_reset(struct udevice *dev) 31{ 32 scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_KEEPALIVE); 33 return 0; 34} 35 36static int tangier_wdt_stop(struct udevice *dev) 37{ 38 return scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_STOP); 39} 40 41static int tangier_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) 42{ 43 u32 timeout_sec; 44 int in_size; 45 struct ipc_wd_start { 46 u32 pretimeout; 47 u32 timeout; 48 } ipc_wd_start; 49 50 /* Calculate timeout in seconds and restrict to min and max value */ 51 do_div(timeout_ms, 1000); 52 timeout_sec = clamp_t(u32, timeout_ms, WDT_TIMEOUT_MIN, WDT_TIMEOUT_MAX); 53 54 /* Update values in the IPC request */ 55 ipc_wd_start.pretimeout = timeout_sec - WDT_PRETIMEOUT; 56 ipc_wd_start.timeout = timeout_sec; 57 58 /* 59 * SCU expects the input size for watchdog IPC 60 * to be based on 4 bytes 61 */ 62 in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4); 63 64 scu_ipc_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_START, 65 (u32 *)&ipc_wd_start, in_size, NULL, 0); 66 67 return 0; 68} 69 70static const struct wdt_ops tangier_wdt_ops = { 71 .reset = tangier_wdt_reset, 72 .start = tangier_wdt_start, 73 .stop = tangier_wdt_stop, 74}; 75 76static const struct udevice_id tangier_wdt_ids[] = { 77 { .compatible = "intel,tangier-wdt" }, 78 { /* sentinel */ } 79}; 80 81static int tangier_wdt_probe(struct udevice *dev) 82{ 83 debug("%s: Probing wdt%u\n", __func__, dev_seq(dev)); 84 return 0; 85} 86 87U_BOOT_DRIVER(wdt_tangier) = { 88 .name = "wdt_tangier", 89 .id = UCLASS_WDT, 90 .of_match = tangier_wdt_ids, 91 .ops = &tangier_wdt_ops, 92 .probe = tangier_wdt_probe, 93}; 94