ls2k-reset.c (1133B)
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2021, Qing Zhang <zhangqing@loongson.cn> 4 * Loongson-2K1000 reset support 5 */ 6 7#include <linux/of_address.h> 8#include <linux/pm.h> 9#include <asm/reboot.h> 10 11#define PM1_STS 0x0c /* Power Management 1 Status Register */ 12#define PM1_CNT 0x14 /* Power Management 1 Control Register */ 13#define RST_CNT 0x30 /* Reset Control Register */ 14 15static void __iomem *base; 16 17static void ls2k_restart(char *command) 18{ 19 writel(0x1, base + RST_CNT); 20} 21 22static void ls2k_poweroff(void) 23{ 24 /* Clear */ 25 writel((readl(base + PM1_STS) & 0xffffffff), base + PM1_STS); 26 /* Sleep Enable | Soft Off*/ 27 writel(GENMASK(12, 10) | BIT(13), base + PM1_CNT); 28} 29 30static int ls2k_reset_init(void) 31{ 32 struct device_node *np; 33 34 np = of_find_compatible_node(NULL, NULL, "loongson,ls2k-pm"); 35 if (!np) { 36 pr_info("Failed to get PM node\n"); 37 return -ENODEV; 38 } 39 40 base = of_iomap(np, 0); 41 of_node_put(np); 42 if (!base) { 43 pr_info("Failed to map PM register base address\n"); 44 return -ENOMEM; 45 } 46 47 _machine_restart = ls2k_restart; 48 pm_power_off = ls2k_poweroff; 49 50 return 0; 51} 52 53arch_initcall(ls2k_reset_init);