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  * @of_xlate: Translate a client's device-tree (OF) clock specifier.
20  * @request: Request a translated clock.
21  * @rfree: Free a previously requested clock.
22  * @round_rate: Adjust a rate to the exact rate a clock can provide.
23  * @get_rate: Get current clock rate.
24  * @set_rate: Set current clock rate.
25  * @set_parent: Set current clock parent
26  * @enable: Enable a clock.
27  * @disable: Disable a clock.
28  *
29  * The individual methods are described more fully below.
30  */
31 struct clk_ops {
32 	int (*of_xlate)(struct clk *clock,
33 			struct ofnode_phandle_args *args);
34 	int (*request)(struct clk *clock);
35 	void (*rfree)(struct clk *clock);
36 	ulong (*round_rate)(struct clk *clk, ulong rate);
37 	ulong (*get_rate)(struct clk *clk);
38 	ulong (*set_rate)(struct clk *clk, ulong rate);
39 	int (*set_parent)(struct clk *clk, struct clk *parent);
40 	int (*enable)(struct clk *clk);
41 	int (*disable)(struct clk *clk);
42 };
43 
44 #if 0 /* For documentation only */
45 /**
46  * of_xlate() - Translate a client's device-tree (OF) clock specifier.
47  * @clock:	The clock struct to hold the translation result.
48  * @args:	The clock specifier values from device tree.
49  *
50  * The clock core calls this function as the first step in implementing
51  * a client's clk_get_by_*() call.
52  *
53  * If this function pointer is set to NULL, the clock core will use a
54  * default implementation, which assumes #clock-cells = <1>, and that
55  * the DT cell contains a simple integer clock ID.
56  *
57  * At present, the clock API solely supports device-tree. If this
58  * changes, other xxx_xlate() functions may be added to support those
59  * other mechanisms.
60  *
61  * Return: 0 if OK, or a negative error code.
62  */
63 int of_xlate(struct clk *clock, struct ofnode_phandle_args *args);
64 
65 /**
66  * request() - Request a translated clock.
67  * @clock:	The clock struct to request; this has been fille in by
68  *		a previoux xxx_xlate() function call, or by the caller
69  *		of clk_request().
70  *
71  * The clock core calls this function as the second step in
72  * implementing a client's clk_get_by_*() call, following a successful
73  * xxx_xlate() call, or as the only step in implementing a client's
74  * clk_request() call.
75  *
76  * Return: 0 if OK, or a negative error code.
77  */
78 int request(struct clk *clock);
79 
80 /**
81  * rfree() - Free a previously requested clock.
82  * @clock:	The clock to free.
83  *
84  * Free any resources allocated in request().
85  */
86 void rfree(struct clk *clock);
87 
88 /**
89  * round_rate() - Adjust a rate to the exact rate a clock can provide.
90  * @clk:	The clock to manipulate.
91  * @rate:	Desidered clock rate in Hz.
92  *
93  * Return: rounded rate in Hz, or -ve error code.
94  */
95 ulong round_rate(struct clk *clk, ulong rate);
96 
97 /**
98  * get_rate() - Get current clock rate.
99  * @clk:	The clock to query.
100  *
101  * Return: clock rate in Hz, or -ve error code
102  */
103 ulong get_rate(struct clk *clk);
104 
105 /**
106  * set_rate() - Set current clock rate.
107  * @clk:	The clock to manipulate.
108  * @rate:	New clock rate in Hz.
109  *
110  * Return: new rate, or -ve error code.
111  */
112 ulong set_rate(struct clk *clk, ulong rate);
113 
114 /**
115  * set_parent() - Set current clock parent
116  * @clk:        The clock to manipulate.
117  * @parent:     New clock parent.
118  *
119  * Return: zero on success, or -ve error code.
120  */
121 int set_parent(struct clk *clk, struct clk *parent);
122 
123 /**
124  * enable() - Enable a clock.
125  * @clk:	The clock to manipulate.
126  *
127  * Return: zero on success, or -ve error code.
128  */
129 int enable(struct clk *clk);
130 
131 /**
132  * disable() - Disable a clock.
133  * @clk:	The clock to manipulate.
134  *
135  * Return: zero on success, or -ve error code.
136  */
137 int disable(struct clk *clk);
138 #endif
139 
140 #endif
141