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f26c8a8e SG |
1 | /* |
2 | * Copyright (c) 2015 Google, Inc | |
3 | * Written by Simon Glass <sjg@chromium.org> | |
135aa950 | 4 | * Copyright (c) 2016, NVIDIA CORPORATION. |
f26c8a8e SG |
5 | * |
6 | * SPDX-License-Identifier: GPL-2.0+ | |
7 | */ | |
8 | ||
08d0d6f3 MS |
9 | #ifndef _CLK_H_ |
10 | #define _CLK_H_ | |
11 | ||
1221ce45 | 12 | #include <linux/errno.h> |
ad1cf785 MY |
13 | #include <linux/types.h> |
14 | ||
135aa950 SW |
15 | /** |
16 | * A clock is a hardware signal that oscillates autonomously at a specific | |
17 | * frequency and duty cycle. Most hardware modules require one or more clock | |
18 | * signal to drive their operation. Clock signals are typically generated | |
19 | * externally to the HW module consuming them, by an entity this API calls a | |
20 | * clock provider. This API provides a standard means for drivers to enable and | |
21 | * disable clocks, and to set the rate at which they oscillate. | |
22 | * | |
23 | * A driver that implements UCLASS_CLOCK is a clock provider. A provider will | |
24 | * often implement multiple separate clocks, since the hardware it manages | |
25 | * often has this capability. clock_uclass.h describes the interface which | |
26 | * clock providers must implement. | |
27 | * | |
28 | * Clock consumers/clients are the HW modules driven by the clock signals. This | |
29 | * header file describes the API used by drivers for those HW modules. | |
30 | */ | |
ad1cf785 | 31 | |
135aa950 | 32 | struct udevice; |
08d0d6f3 | 33 | |
135aa950 SW |
34 | /** |
35 | * struct clk - A handle to (allowing control of) a single clock. | |
36 | * | |
37 | * Clients provide storage for clock handles. The content of the structure is | |
38 | * managed solely by the clock API and clock drivers. A clock struct is | |
39 | * initialized by "get"ing the clock struct. The clock struct is passed to all | |
40 | * other clock APIs to identify which clock signal to operate upon. | |
41 | * | |
42 | * @dev: The device which implements the clock signal. | |
43 | * @id: The clock signal ID within the provider. | |
44 | * | |
45 | * Currently, the clock API assumes that a single integer ID is enough to | |
46 | * identify and configure any clock signal for any clock provider. If this | |
47 | * assumption becomes invalid in the future, the struct could be expanded to | |
48 | * either (a) add more fields to allow clock providers to store additional | |
49 | * information, or (b) replace the id field with an opaque pointer, which the | |
50 | * provider would dynamically allocated during its .of_xlate op, and process | |
51 | * during is .request op. This may require the addition of an extra op to clean | |
52 | * up the allocation. | |
53 | */ | |
54 | struct clk { | |
55 | struct udevice *dev; | |
56 | /* | |
57 | * Written by of_xlate. We assume a single id is enough for now. In the | |
58 | * future, we might add more fields here. | |
f26c8a8e | 59 | */ |
135aa950 | 60 | unsigned long id; |
f26c8a8e SG |
61 | }; |
62 | ||
3f96f875 | 63 | #if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK) |
0d15463c | 64 | struct phandle_1_arg; |
7423daa6 | 65 | int clk_get_by_index_platdata(struct udevice *dev, int index, |
0d15463c | 66 | struct phandle_1_arg *cells, struct clk *clk); |
7423daa6 | 67 | |
135aa950 SW |
68 | /** |
69 | * clock_get_by_index - Get/request a clock by integer index. | |
70 | * | |
71 | * This looks up and requests a clock. The index is relative to the client | |
72 | * device; each device is assumed to have n clocks associated with it somehow, | |
73 | * and this function finds and requests one of them. The mapping of client | |
74 | * device clock indices to provider clocks may be via device-tree properties, | |
75 | * board-provided mapping tables, or some other mechanism. | |
76 | * | |
77 | * @dev: The client device. | |
78 | * @index: The index of the clock to request, within the client's list of | |
79 | * clocks. | |
80 | * @clock A pointer to a clock struct to initialize. | |
81 | * @return 0 if OK, or a negative error code. | |
82 | */ | |
83 | int clk_get_by_index(struct udevice *dev, int index, struct clk *clk); | |
f26c8a8e SG |
84 | |
85 | /** | |
135aa950 | 86 | * clock_get_by_name - Get/request a clock by name. |
f26c8a8e | 87 | * |
135aa950 SW |
88 | * This looks up and requests a clock. The name is relative to the client |
89 | * device; each device is assumed to have n clocks associated with it somehow, | |
90 | * and this function finds and requests one of them. The mapping of client | |
91 | * device clock names to provider clocks may be via device-tree properties, | |
92 | * board-provided mapping tables, or some other mechanism. | |
93 | * | |
94 | * @dev: The client device. | |
95 | * @name: The name of the clock to request, within the client's list of | |
96 | * clocks. | |
97 | * @clock: A pointer to a clock struct to initialize. | |
98 | * @return 0 if OK, or a negative error code. | |
f26c8a8e | 99 | */ |
135aa950 | 100 | int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk); |
b108d8a0 PC |
101 | |
102 | /** | |
103 | * clk_release_all() - Disable (turn off)/Free an array of previously | |
104 | * requested clocks. | |
105 | * | |
106 | * For each clock contained in the clock array, this function will check if | |
107 | * clock has been previously requested and then will disable and free it. | |
108 | * | |
109 | * @clk: A clock struct array that was previously successfully | |
110 | * requested by clk_request/get_by_*(). | |
111 | * @count Number of clock contained in the array | |
112 | * @return zero on success, or -ve error code. | |
113 | */ | |
114 | int clk_release_all(struct clk *clk, int count); | |
115 | ||
021abf69 MY |
116 | #else |
117 | static inline int clk_get_by_index(struct udevice *dev, int index, | |
118 | struct clk *clk) | |
119 | { | |
120 | return -ENOSYS; | |
121 | } | |
122 | ||
123 | static inline int clk_get_by_name(struct udevice *dev, const char *name, | |
124 | struct clk *clk) | |
125 | { | |
126 | return -ENOSYS; | |
127 | } | |
b108d8a0 PC |
128 | |
129 | static inline int clk_release_all(struct clk *clk, int count) | |
130 | { | |
131 | return -ENOSYS; | |
132 | } | |
133 | ||
021abf69 | 134 | #endif |
f26c8a8e | 135 | |
f4fcba5c PT |
136 | #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \ |
137 | CONFIG_IS_ENABLED(CLK) | |
138 | /** | |
139 | * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}' | |
140 | * properties to configure clocks | |
141 | * | |
142 | * @dev: A device to process (the ofnode associated with this device | |
143 | * will be processed). | |
144 | */ | |
145 | int clk_set_defaults(struct udevice *dev); | |
146 | #else | |
147 | static inline int clk_set_defaults(struct udevice *dev) | |
148 | { | |
149 | return 0; | |
150 | } | |
151 | #endif | |
152 | ||
f26c8a8e | 153 | /** |
135aa950 | 154 | * clk_request - Request a clock by provider-specific ID. |
f26c8a8e | 155 | * |
135aa950 SW |
156 | * This requests a clock using a provider-specific ID. Generally, this function |
157 | * should not be used, since clk_get_by_index/name() provide an interface that | |
158 | * better separates clients from intimate knowledge of clock providers. | |
159 | * However, this function may be useful in core SoC-specific code. | |
160 | * | |
161 | * @dev: The clock provider device. | |
162 | * @clock: A pointer to a clock struct to initialize. The caller must | |
163 | * have already initialized any field in this struct which the | |
164 | * clock provider uses to identify the clock. | |
165 | * @return 0 if OK, or a negative error code. | |
f26c8a8e | 166 | */ |
135aa950 | 167 | int clk_request(struct udevice *dev, struct clk *clk); |
f26c8a8e | 168 | |
f0e07516 | 169 | /** |
135aa950 | 170 | * clock_free - Free a previously requested clock. |
f0e07516 | 171 | * |
135aa950 SW |
172 | * @clock: A clock struct that was previously successfully requested by |
173 | * clk_request/get_by_*(). | |
174 | * @return 0 if OK, or a negative error code. | |
f0e07516 | 175 | */ |
135aa950 | 176 | int clk_free(struct clk *clk); |
f0e07516 | 177 | |
f26c8a8e | 178 | /** |
135aa950 | 179 | * clk_get_rate() - Get current clock rate. |
f26c8a8e | 180 | * |
135aa950 SW |
181 | * @clk: A clock struct that was previously successfully requested by |
182 | * clk_request/get_by_*(). | |
183 | * @return clock rate in Hz, or -ve error code. | |
f26c8a8e | 184 | */ |
135aa950 | 185 | ulong clk_get_rate(struct clk *clk); |
f26c8a8e SG |
186 | |
187 | /** | |
135aa950 | 188 | * clk_set_rate() - Set current clock rate. |
f26c8a8e | 189 | * |
135aa950 SW |
190 | * @clk: A clock struct that was previously successfully requested by |
191 | * clk_request/get_by_*(). | |
192 | * @rate: New clock rate in Hz. | |
193 | * @return new rate, or -ve error code. | |
f26c8a8e | 194 | */ |
135aa950 | 195 | ulong clk_set_rate(struct clk *clk, ulong rate); |
f26c8a8e | 196 | |
f7d1046d PT |
197 | /** |
198 | * clk_set_parent() - Set current clock parent. | |
199 | * | |
200 | * @clk: A clock struct that was previously successfully requested by | |
201 | * clk_request/get_by_*(). | |
202 | * @parent: A clock struct that was previously successfully requested by | |
203 | * clk_request/get_by_*(). | |
204 | * @return new rate, or -ve error code. | |
205 | */ | |
206 | int clk_set_parent(struct clk *clk, struct clk *parent); | |
207 | ||
e70cc438 | 208 | /** |
135aa950 | 209 | * clk_enable() - Enable (turn on) a clock. |
e70cc438 | 210 | * |
135aa950 SW |
211 | * @clk: A clock struct that was previously successfully requested by |
212 | * clk_request/get_by_*(). | |
213 | * @return zero on success, or -ve error code. | |
214 | */ | |
215 | int clk_enable(struct clk *clk); | |
216 | ||
217 | /** | |
218 | * clk_disable() - Disable (turn off) a clock. | |
e70cc438 | 219 | * |
135aa950 SW |
220 | * @clk: A clock struct that was previously successfully requested by |
221 | * clk_request/get_by_*(). | |
222 | * @return zero on success, or -ve error code. | |
e70cc438 | 223 | */ |
135aa950 | 224 | int clk_disable(struct clk *clk); |
e70cc438 | 225 | |
135aa950 SW |
226 | int soc_clk_dump(void); |
227 | ||
228 | #endif |