xref: /openbmc/u-boot/include/reset-uclass.h (revision 47cef9c8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2016, NVIDIA CORPORATION.
4  */
5 
6 #ifndef _RESET_UCLASS_H
7 #define _RESET_UCLASS_H
8 
9 /* See reset.h for background documentation. */
10 
11 #include <reset.h>
12 
13 struct ofnode_phandle_args;
14 struct udevice;
15 
16 /**
17  * struct reset_ops - The functions that a reset controller driver must
18  * implement.
19  */
20 struct reset_ops {
21 	/**
22 	 * of_xlate - Translate a client's device-tree (OF) reset specifier.
23 	 *
24 	 * The reset core calls this function as the first step in implementing
25 	 * a client's reset_get_by_*() call.
26 	 *
27 	 * If this function pointer is set to NULL, the reset core will use a
28 	 * default implementation, which assumes #reset-cells = <1>, and that
29 	 * the DT cell contains a simple integer reset signal ID.
30 	 *
31 	 * At present, the reset API solely supports device-tree. If this
32 	 * changes, other xxx_xlate() functions may be added to support those
33 	 * other mechanisms.
34 	 *
35 	 * @reset_ctl:	The reset control struct to hold the translation result.
36 	 * @args:	The reset specifier values from device tree.
37 	 * @return 0 if OK, or a negative error code.
38 	 */
39 	int (*of_xlate)(struct reset_ctl *reset_ctl,
40 			struct ofnode_phandle_args *args);
41 	/**
42 	 * request - Request a translated reset control.
43 	 *
44 	 * The reset core calls this function as the second step in
45 	 * implementing a client's reset_get_by_*() call, following a
46 	 * successful xxx_xlate() call.
47 	 *
48 	 * @reset_ctl:	The reset control struct to request; this has been
49 	 *		filled in by a previoux xxx_xlate() function call.
50 	 * @return 0 if OK, or a negative error code.
51 	 */
52 	int (*request)(struct reset_ctl *reset_ctl);
53 	/**
54 	 * free - Free a previously requested reset control.
55 	 *
56 	 * This is the implementation of the client reset_free() API.
57 	 *
58 	 * @reset_ctl:	The reset control to free.
59 	 * @return 0 if OK, or a negative error code.
60 	 */
61 	int (*free)(struct reset_ctl *reset_ctl);
62 	/**
63 	 * rst_assert - Assert a reset signal.
64 	 *
65 	 * Note: This function is named rst_assert not assert to avoid
66 	 * conflicting with global macro assert().
67 	 *
68 	 * @reset_ctl:	The reset signal to assert.
69 	 * @return 0 if OK, or a negative error code.
70 	 */
71 	int (*rst_assert)(struct reset_ctl *reset_ctl);
72 	/**
73 	 * rst_deassert - Deassert a reset signal.
74 	 *
75 	 * @reset_ctl:	The reset signal to deassert.
76 	 * @return 0 if OK, or a negative error code.
77 	 */
78 	int (*rst_deassert)(struct reset_ctl *reset_ctl);
79 	/**
80 	 * rst_status - Check reset signal status.
81 	 *
82 	 * @reset_ctl:	The reset signal to check.
83 	 * @return 0 if deasserted, positive if asserted, or a negative
84 	 *           error code.
85 	 */
86 	int (*rst_status)(struct reset_ctl *reset_ctl);
87 };
88 
89 #endif
90