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 15 static void __iomem *base; 16 17 static void ls2k_restart(char *command) 18 { 19 writel(0x1, base + RST_CNT); 20 } 21 22 static 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 30 static 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 53 arch_initcall(ls2k_reset_init); 54