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 #ifndef __SYSRESET_H
8 #define __SYSRESET_H
9 
10 enum sysreset_t {
11 	SYSRESET_WARM,	/* Reset CPU, keep GPIOs active */
12 	SYSRESET_COLD,	/* Reset CPU and GPIOs */
13 	SYSRESET_POWER,	/* Reset PMIC (remove and restore power) */
14 	SYSRESET_POWER_OFF,	/* Turn off power */
15 
16 	SYSRESET_COUNT,
17 };
18 
19 struct sysreset_ops {
20 	/**
21 	 * request() - request a sysreset of the given type
22 	 *
23 	 * Note that this function may return before the reset takes effect.
24 	 *
25 	 * @type:	Reset type to request
26 	 * @return -EINPROGRESS if the reset has been started and
27 	 *		will complete soon, -EPROTONOSUPPORT if not supported
28 	 *		by this device, 0 if the reset has already happened
29 	 *		(in which case this method will not actually return)
30 	 */
31 	int (*request)(struct udevice *dev, enum sysreset_t type);
32 	/**
33 	 * get_status() - get printable reset status information
34 	 *
35 	 * @dev:	Device to check
36 	 * @buf:	Buffer to receive the textual reset information
37 	 * @size:	Size of the passed buffer
38 	 * @return 0 if OK, -ve on error
39 	 */
40 	int (*get_status)(struct udevice *dev, char *buf, int size);
41 
42 	/**
43 	 * get_last() - get information on the last reset
44 	 *
45 	 * @dev:	Device to check
46 	 * @return last reset state (enum sysreset_t) or -ve error
47 	 */
48 	int (*get_last)(struct udevice *dev);
49 };
50 
51 #define sysreset_get_ops(dev)        ((struct sysreset_ops *)(dev)->driver->ops)
52 
53 /**
54  * sysreset_request() - request a sysreset
55  *
56  * @type:	Reset type to request
57  * @return 0 if OK, -EPROTONOSUPPORT if not supported by this device
58  */
59 int sysreset_request(struct udevice *dev, enum sysreset_t type);
60 
61 /**
62  * sysreset_get_status() - get printable reset status information
63  *
64  * @dev:	Device to check
65  * @buf:	Buffer to receive the textual reset information
66  * @size:	Size of the passed buffer
67  * @return 0 if OK, -ve on error
68  */
69 int sysreset_get_status(struct udevice *dev, char *buf, int size);
70 
71 /**
72  * sysreset_get_last() - get information on the last reset
73  *
74  * @dev:	Device to check
75  * @return last reset state (enum sysreset_t) or -ve error
76  */
77 int sysreset_get_last(struct udevice *dev);
78 
79 /**
80  * sysreset_walk() - cause a system reset
81  *
82  * This works through the available sysreset devices until it finds one that can
83  * perform a reset. If the provided sysreset type is not available, the next one
84  * will be tried.
85  *
86  * If this function fails to reset, it will display a message and halt
87  *
88  * @type:	Reset type to request
89  * @return -EINPROGRESS if a reset is in progress, -ENOSYS if not available
90  */
91 int sysreset_walk(enum sysreset_t type);
92 
93 /**
94  * sysreset_get_last_walk() - get information on the last reset
95  *
96  * This works through the available sysreset devices until it finds one that can
97  * perform a reset. If the provided sysreset type is not available, the next one
98  * will be tried.
99  *
100  * If no device prives the information, this function returns -ENOENT
101  *
102  * @return last reset state (enum sysreset_t) or -ve error
103  */
104 int sysreset_get_last_walk(void);
105 
106 /**
107  * sysreset_walk_halt() - try to reset, otherwise halt
108  *
109  * This calls sysreset_walk(). If it returns, indicating that reset is not
110  * supported, it prints a message and halts.
111  */
112 void sysreset_walk_halt(enum sysreset_t type);
113 
114 /**
115  * reset_cpu() - calls sysreset_walk(SYSRESET_WARM)
116  */
117 void reset_cpu(ulong addr);
118 
119 #endif
120