1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #include <common.h>
8 #include <sysreset.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <regmap.h>
12 #include <dm/device-internal.h>
13 #include <dm/lists.h>
14 #include <dm/root.h>
15 #include <linux/err.h>
16 
17 int sysreset_request(struct udevice *dev, enum sysreset_t type)
18 {
19 	struct sysreset_ops *ops = sysreset_get_ops(dev);
20 
21 	if (!ops->request)
22 		return -ENOSYS;
23 
24 	return ops->request(dev, type);
25 }
26 
27 int sysreset_walk(enum sysreset_t type)
28 {
29 	struct udevice *dev;
30 	int ret = -ENOSYS;
31 
32 	while (ret != -EINPROGRESS && type < SYSRESET_COUNT) {
33 		for (uclass_first_device(UCLASS_SYSRESET, &dev);
34 		     dev;
35 		     uclass_next_device(&dev)) {
36 			ret = sysreset_request(dev, type);
37 			if (ret == -EINPROGRESS)
38 				break;
39 		}
40 		type++;
41 	}
42 
43 	return ret;
44 }
45 
46 void sysreset_walk_halt(enum sysreset_t type)
47 {
48 	int ret;
49 
50 	ret = sysreset_walk(type);
51 
52 	/* Wait for the reset to take effect */
53 	if (ret == -EINPROGRESS)
54 		mdelay(100);
55 
56 	/* Still no reset? Give up */
57 	debug("System reset not supported on this platform\n");
58 	hang();
59 }
60 
61 /**
62  * reset_cpu() - calls sysreset_walk(SYSRESET_WARM)
63  */
64 void reset_cpu(ulong addr)
65 {
66 	sysreset_walk_halt(SYSRESET_WARM);
67 }
68 
69 
70 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
71 {
72 	sysreset_walk_halt(SYSRESET_COLD);
73 
74 	return 0;
75 }
76 
77 UCLASS_DRIVER(sysreset) = {
78 	.id		= UCLASS_SYSRESET,
79 	.name		= "sysreset",
80 };
81