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);
54