xref: /openbmc/u-boot/include/reset-uclass.h (revision 72719d2f)
1 /*
2  * Copyright (c) 2016, NVIDIA CORPORATION.
3  *
4  * SPDX-License-Identifier: GPL-2.0
5  */
6 
7 #ifndef _RESET_UCLASS_H
8 #define _RESET_UCLASS_H
9 
10 /* See reset.h for background documentation. */
11 
12 #include <reset.h>
13 
14 struct ofnode_phandle_args;
15 struct udevice;
16 
17 /**
18  * struct reset_ops - The functions that a reset controller driver must
19  * implement.
20  */
21 struct reset_ops {
22 	/**
23 	 * of_xlate - Translate a client's device-tree (OF) reset specifier.
24 	 *
25 	 * The reset core calls this function as the first step in implementing
26 	 * a client's reset_get_by_*() call.
27 	 *
28 	 * If this function pointer is set to NULL, the reset core will use a
29 	 * default implementation, which assumes #reset-cells = <1>, and that
30 	 * the DT cell contains a simple integer reset signal ID.
31 	 *
32 	 * At present, the reset API solely supports device-tree. If this
33 	 * changes, other xxx_xlate() functions may be added to support those
34 	 * other mechanisms.
35 	 *
36 	 * @reset_ctl:	The reset control struct to hold the translation result.
37 	 * @args:	The reset specifier values from device tree.
38 	 * @return 0 if OK, or a negative error code.
39 	 */
40 	int (*of_xlate)(struct reset_ctl *reset_ctl,
41 			struct ofnode_phandle_args *args);
42 	/**
43 	 * request - Request a translated reset control.
44 	 *
45 	 * The reset core calls this function as the second step in
46 	 * implementing a client's reset_get_by_*() call, following a
47 	 * successful xxx_xlate() call.
48 	 *
49 	 * @reset_ctl:	The reset control struct to request; this has been
50 	 *		filled in by a previoux xxx_xlate() function call.
51 	 * @return 0 if OK, or a negative error code.
52 	 */
53 	int (*request)(struct reset_ctl *reset_ctl);
54 	/**
55 	 * free - Free a previously requested reset control.
56 	 *
57 	 * This is the implementation of the client reset_free() API.
58 	 *
59 	 * @reset_ctl:	The reset control to free.
60 	 * @return 0 if OK, or a negative error code.
61 	 */
62 	int (*free)(struct reset_ctl *reset_ctl);
63 	/**
64 	 * rst_assert - Assert a reset signal.
65 	 *
66 	 * Note: This function is named rst_assert not assert to avoid
67 	 * conflicting with global macro assert().
68 	 *
69 	 * @reset_ctl:	The reset signal to assert.
70 	 * @return 0 if OK, or a negative error code.
71 	 */
72 	int (*rst_assert)(struct reset_ctl *reset_ctl);
73 	/**
74 	 * rst_deassert - Deassert a reset signal.
75 	 *
76 	 * @reset_ctl:	The reset signal to deassert.
77 	 * @return 0 if OK, or a negative error code.
78 	 */
79 	int (*rst_deassert)(struct reset_ctl *reset_ctl);
80 };
81 
82 #endif
83