1/* 2 * Copyright (C) 2013 Broadcom Corporation 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License as 6 * published by the Free Software Foundation version 2. 7 * 8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 9 * kind, whether express or implied; without even the implied warranty 10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14#include <linux/of_address.h> 15#include <asm/io.h> 16 17#include "kona.h" 18 19static void __iomem *watchdog_base; 20 21void bcm_kona_setup_restart(void) 22{ 23 struct device_node *np_wdog; 24 25 /* 26 * The assumption is that whoever calls bcm_kona_setup_restart() 27 * also needs a Kona Watchdog Timer entry in Device Tree, i.e. we 28 * report an error if the DT entry is missing. 29 */ 30 np_wdog = of_find_compatible_node(NULL, NULL, "brcm,kona-wdt"); 31 if (!np_wdog) { 32 pr_err("brcm,kona-wdt not found in DT, reboot disabled\n"); 33 return; 34 } 35 watchdog_base = of_iomap(np_wdog, 0); 36 WARN(!watchdog_base, "failed to map watchdog base"); 37 of_node_put(np_wdog); 38} 39 40#define SECWDOG_OFFSET 0x00000000 41#define SECWDOG_RESERVED_MASK 0xE2000000 42#define SECWDOG_WD_LOAD_FLAG_MASK 0x10000000 43#define SECWDOG_EN_MASK 0x08000000 44#define SECWDOG_SRSTEN_MASK 0x04000000 45#define SECWDOG_CLKS_SHIFT 20 46#define SECWDOG_LOCK_SHIFT 0 47 48void bcm_kona_restart(enum reboot_mode mode, const char *cmd) 49{ 50 uint32_t val; 51 52 if (!watchdog_base) 53 panic("Watchdog not mapped. Reboot failed.\n"); 54 55 /* Enable watchdog2 with very short timeout. */ 56 val = readl(watchdog_base + SECWDOG_OFFSET); 57 val &= SECWDOG_RESERVED_MASK | SECWDOG_WD_LOAD_FLAG_MASK; 58 val |= SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK | 59 (0x8 << SECWDOG_CLKS_SHIFT) | 60 (0x8 << SECWDOG_LOCK_SHIFT); 61 writel(val, watchdog_base + SECWDOG_OFFSET); 62 63 while (1) 64 ; 65} 66