1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2015 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  * Copyright (c) 2016, NVIDIA CORPORATION.
6  */
7 
8 #ifndef _CLK_UCLASS_H
9 #define _CLK_UCLASS_H
10 
11 /* See clk.h for background documentation. */
12 
13 #include <clk.h>
14 
15 struct ofnode_phandle_args;
16 
17 /**
18  * struct clk_ops - The functions that a clock driver must implement.
19  */
20 struct clk_ops {
21 	/**
22 	 * of_xlate - Translate a client's device-tree (OF) clock specifier.
23 	 *
24 	 * The clock core calls this function as the first step in implementing
25 	 * a client's clk_get_by_*() call.
26 	 *
27 	 * If this function pointer is set to NULL, the clock core will use a
28 	 * default implementation, which assumes #clock-cells = <1>, and that
29 	 * the DT cell contains a simple integer clock ID.
30 	 *
31 	 * At present, the clock API solely supports device-tree. If this
32 	 * changes, other xxx_xlate() functions may be added to support those
33 	 * other mechanisms.
34 	 *
35 	 * @clock:	The clock struct to hold the translation result.
36 	 * @args:	The clock specifier values from device tree.
37 	 * @return 0 if OK, or a negative error code.
38 	 */
39 	int (*of_xlate)(struct clk *clock,
40 			struct ofnode_phandle_args *args);
41 	/**
42 	 * request - Request a translated clock.
43 	 *
44 	 * The clock core calls this function as the second step in
45 	 * implementing a client's clk_get_by_*() call, following a successful
46 	 * xxx_xlate() call, or as the only step in implementing a client's
47 	 * clk_request() call.
48 	 *
49 	 * @clock:	The clock struct to request; this has been fille in by
50 	 *		a previoux xxx_xlate() function call, or by the caller
51 	 *		of clk_request().
52 	 * @return 0 if OK, or a negative error code.
53 	 */
54 	int (*request)(struct clk *clock);
55 	/**
56 	 * rfree - Free a previously requested clock.
57 	 *
58 	 * This is the implementation of the client clk_free() API.
59 	 *
60 	 * @clock:	The clock to free.
61 	 * @return 0 if OK, or a negative error code.
62 	 */
63 	int (*rfree)(struct clk *clock);
64 	/**
65 	 * round_rate() - Adjust a rate to the exact rate a clock can provide.
66 	 *
67 	 * @clk:	The clock to manipulate.
68 	 * @rate:	Desidered clock rate in Hz.
69 	 * @return rounded rate in Hz, or -ve error code.
70 	 */
71 	ulong (*round_rate)(struct clk *clk, ulong rate);
72 	/**
73 	 * get_rate() - Get current clock rate.
74 	 *
75 	 * @clk:	The clock to query.
76 	 * @return clock rate in Hz, or -ve error code
77 	 */
78 	ulong (*get_rate)(struct clk *clk);
79 	/**
80 	 * set_rate() - Set current clock rate.
81 	 *
82 	 * @clk:	The clock to manipulate.
83 	 * @rate:	New clock rate in Hz.
84 	 * @return new rate, or -ve error code.
85 	 */
86 	ulong (*set_rate)(struct clk *clk, ulong rate);
87 	/**
88 	 * set_parent() - Set current clock parent
89 	 *
90 	 * @clk:        The clock to manipulate.
91 	 * @parent:     New clock parent.
92 	 * @return zero on success, or -ve error code.
93 	 */
94 	int (*set_parent)(struct clk *clk, struct clk *parent);
95 	/**
96 	 * enable() - Enable a clock.
97 	 *
98 	 * @clk:	The clock to manipulate.
99 	 * @return zero on success, or -ve error code.
100 	 */
101 	int (*enable)(struct clk *clk);
102 	/**
103 	 * disable() - Disable a clock.
104 	 *
105 	 * @clk:	The clock to manipulate.
106 	 * @return zero on success, or -ve error code.
107 	 */
108 	int (*disable)(struct clk *clk);
109 };
110 
111 #endif
112