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b2476490 MT |
1 | /* |
2 | * linux/include/linux/clk-provider.h | |
3 | * | |
4 | * Copyright (c) 2010-2011 Jeremy Kerr <jeremy.kerr@canonical.com> | |
5 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #ifndef __LINUX_CLK_PROVIDER_H | |
12 | #define __LINUX_CLK_PROVIDER_H | |
13 | ||
14 | #include <linux/clk.h> | |
15 | ||
16 | #ifdef CONFIG_COMMON_CLK | |
17 | ||
b2476490 MT |
18 | /* |
19 | * flags used across common struct clk. these flags should only affect the | |
20 | * top-level framework. custom flags for dealing with hardware specifics | |
21 | * belong in struct clk_foo | |
22 | */ | |
23 | #define CLK_SET_RATE_GATE BIT(0) /* must be gated across rate change */ | |
24 | #define CLK_SET_PARENT_GATE BIT(1) /* must be gated across re-parent */ | |
25 | #define CLK_SET_RATE_PARENT BIT(2) /* propagate rate change up one level */ | |
26 | #define CLK_IGNORE_UNUSED BIT(3) /* do not gate even if unused */ | |
27 | #define CLK_IS_ROOT BIT(4) /* root clk, has no parent */ | |
28 | ||
0197b3ea SK |
29 | struct clk_hw; |
30 | ||
b2476490 MT |
31 | /** |
32 | * struct clk_ops - Callback operations for hardware clocks; these are to | |
33 | * be provided by the clock implementation, and will be called by drivers | |
34 | * through the clk_* api. | |
35 | * | |
36 | * @prepare: Prepare the clock for enabling. This must not return until | |
37 | * the clock is fully prepared, and it's safe to call clk_enable. | |
38 | * This callback is intended to allow clock implementations to | |
39 | * do any initialisation that may sleep. Called with | |
40 | * prepare_lock held. | |
41 | * | |
42 | * @unprepare: Release the clock from its prepared state. This will typically | |
43 | * undo any work done in the @prepare callback. Called with | |
44 | * prepare_lock held. | |
45 | * | |
46 | * @enable: Enable the clock atomically. This must not return until the | |
47 | * clock is generating a valid clock signal, usable by consumer | |
48 | * devices. Called with enable_lock held. This function must not | |
49 | * sleep. | |
50 | * | |
51 | * @disable: Disable the clock atomically. Called with enable_lock held. | |
52 | * This function must not sleep. | |
53 | * | |
54 | * @recalc_rate Recalculate the rate of this clock, by quering hardware. The | |
55 | * parent rate is an input parameter. It is up to the caller to | |
56 | * insure that the prepare_mutex is held across this call. | |
57 | * Returns the calculated rate. Optional, but recommended - if | |
58 | * this op is not set then clock rate will be initialized to 0. | |
59 | * | |
60 | * @round_rate: Given a target rate as input, returns the closest rate actually | |
61 | * supported by the clock. | |
62 | * | |
63 | * @get_parent: Queries the hardware to determine the parent of a clock. The | |
64 | * return value is a u8 which specifies the index corresponding to | |
65 | * the parent clock. This index can be applied to either the | |
66 | * .parent_names or .parents arrays. In short, this function | |
67 | * translates the parent value read from hardware into an array | |
68 | * index. Currently only called when the clock is initialized by | |
69 | * __clk_init. This callback is mandatory for clocks with | |
70 | * multiple parents. It is optional (and unnecessary) for clocks | |
71 | * with 0 or 1 parents. | |
72 | * | |
73 | * @set_parent: Change the input source of this clock; for clocks with multiple | |
74 | * possible parents specify a new parent by passing in the index | |
75 | * as a u8 corresponding to the parent in either the .parent_names | |
76 | * or .parents arrays. This function in affect translates an | |
77 | * array index into the value programmed into the hardware. | |
78 | * Returns 0 on success, -EERROR otherwise. | |
79 | * | |
1c0035d7 SG |
80 | * @set_rate: Change the rate of this clock. The requested rate is specified |
81 | * by the second argument, which should typically be the return | |
82 | * of .round_rate call. The third argument gives the parent rate | |
83 | * which is likely helpful for most .set_rate implementation. | |
84 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
85 | * |
86 | * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow | |
87 | * implementations to split any work between atomic (enable) and sleepable | |
88 | * (prepare) contexts. If enabling a clock requires code that might sleep, | |
89 | * this must be done in clk_prepare. Clock enable code that will never be | |
90 | * called in a sleepable context may be implement in clk_enable. | |
91 | * | |
92 | * Typically, drivers will call clk_prepare when a clock may be needed later | |
93 | * (eg. when a device is opened), and clk_enable when the clock is actually | |
94 | * required (eg. from an interrupt). Note that clk_prepare MUST have been | |
95 | * called before clk_enable. | |
96 | */ | |
97 | struct clk_ops { | |
98 | int (*prepare)(struct clk_hw *hw); | |
99 | void (*unprepare)(struct clk_hw *hw); | |
100 | int (*enable)(struct clk_hw *hw); | |
101 | void (*disable)(struct clk_hw *hw); | |
102 | int (*is_enabled)(struct clk_hw *hw); | |
103 | unsigned long (*recalc_rate)(struct clk_hw *hw, | |
104 | unsigned long parent_rate); | |
105 | long (*round_rate)(struct clk_hw *hw, unsigned long, | |
106 | unsigned long *); | |
107 | int (*set_parent)(struct clk_hw *hw, u8 index); | |
108 | u8 (*get_parent)(struct clk_hw *hw); | |
1c0035d7 SG |
109 | int (*set_rate)(struct clk_hw *hw, unsigned long, |
110 | unsigned long); | |
b2476490 MT |
111 | void (*init)(struct clk_hw *hw); |
112 | }; | |
113 | ||
0197b3ea SK |
114 | /** |
115 | * struct clk_init_data - holds init data that's common to all clocks and is | |
116 | * shared between the clock provider and the common clock framework. | |
117 | * | |
118 | * @name: clock name | |
119 | * @ops: operations this clock supports | |
120 | * @parent_names: array of string names for all possible parents | |
121 | * @num_parents: number of possible parents | |
122 | * @flags: framework-level hints and quirks | |
123 | */ | |
124 | struct clk_init_data { | |
125 | const char *name; | |
126 | const struct clk_ops *ops; | |
127 | const char **parent_names; | |
128 | u8 num_parents; | |
129 | unsigned long flags; | |
130 | }; | |
131 | ||
132 | /** | |
133 | * struct clk_hw - handle for traversing from a struct clk to its corresponding | |
134 | * hardware-specific structure. struct clk_hw should be declared within struct | |
135 | * clk_foo and then referenced by the struct clk instance that uses struct | |
136 | * clk_foo's clk_ops | |
137 | * | |
138 | * @clk: pointer to the struct clk instance that points back to this struct | |
139 | * clk_hw instance | |
140 | * | |
141 | * @init: pointer to struct clk_init_data that contains the init data shared | |
142 | * with the common clock framework. | |
143 | */ | |
144 | struct clk_hw { | |
145 | struct clk *clk; | |
146 | struct clk_init_data *init; | |
147 | }; | |
148 | ||
9d9f78ed MT |
149 | /* |
150 | * DOC: Basic clock implementations common to many platforms | |
151 | * | |
152 | * Each basic clock hardware type is comprised of a structure describing the | |
153 | * clock hardware, implementations of the relevant callbacks in struct clk_ops, | |
154 | * unique flags for that hardware type, a registration function and an | |
155 | * alternative macro for static initialization | |
156 | */ | |
157 | ||
158 | /** | |
159 | * struct clk_fixed_rate - fixed-rate clock | |
160 | * @hw: handle between common and hardware-specific interfaces | |
161 | * @fixed_rate: constant frequency of clock | |
162 | */ | |
163 | struct clk_fixed_rate { | |
164 | struct clk_hw hw; | |
165 | unsigned long fixed_rate; | |
166 | u8 flags; | |
167 | }; | |
168 | ||
bffad66e | 169 | extern const struct clk_ops clk_fixed_rate_ops; |
9d9f78ed MT |
170 | struct clk *clk_register_fixed_rate(struct device *dev, const char *name, |
171 | const char *parent_name, unsigned long flags, | |
172 | unsigned long fixed_rate); | |
173 | ||
174 | /** | |
175 | * struct clk_gate - gating clock | |
176 | * | |
177 | * @hw: handle between common and hardware-specific interfaces | |
178 | * @reg: register controlling gate | |
179 | * @bit_idx: single bit controlling gate | |
180 | * @flags: hardware-specific flags | |
181 | * @lock: register lock | |
182 | * | |
183 | * Clock which can gate its output. Implements .enable & .disable | |
184 | * | |
185 | * Flags: | |
1f73f31a | 186 | * CLK_GATE_SET_TO_DISABLE - by default this clock sets the bit at bit_idx to |
9d9f78ed MT |
187 | * enable the clock. Setting this flag does the opposite: setting the bit |
188 | * disable the clock and clearing it enables the clock | |
189 | */ | |
190 | struct clk_gate { | |
191 | struct clk_hw hw; | |
192 | void __iomem *reg; | |
193 | u8 bit_idx; | |
194 | u8 flags; | |
195 | spinlock_t *lock; | |
9d9f78ed MT |
196 | }; |
197 | ||
198 | #define CLK_GATE_SET_TO_DISABLE BIT(0) | |
199 | ||
bffad66e | 200 | extern const struct clk_ops clk_gate_ops; |
9d9f78ed MT |
201 | struct clk *clk_register_gate(struct device *dev, const char *name, |
202 | const char *parent_name, unsigned long flags, | |
203 | void __iomem *reg, u8 bit_idx, | |
204 | u8 clk_gate_flags, spinlock_t *lock); | |
205 | ||
206 | /** | |
207 | * struct clk_divider - adjustable divider clock | |
208 | * | |
209 | * @hw: handle between common and hardware-specific interfaces | |
210 | * @reg: register containing the divider | |
211 | * @shift: shift to the divider bit field | |
212 | * @width: width of the divider bit field | |
213 | * @lock: register lock | |
214 | * | |
215 | * Clock with an adjustable divider affecting its output frequency. Implements | |
216 | * .recalc_rate, .set_rate and .round_rate | |
217 | * | |
218 | * Flags: | |
219 | * CLK_DIVIDER_ONE_BASED - by default the divisor is the value read from the | |
220 | * register plus one. If CLK_DIVIDER_ONE_BASED is set then the divider is | |
221 | * the raw value read from the register, with the value of zero considered | |
222 | * invalid | |
223 | * CLK_DIVIDER_POWER_OF_TWO - clock divisor is 2 raised to the value read from | |
224 | * the hardware register | |
225 | */ | |
226 | struct clk_divider { | |
227 | struct clk_hw hw; | |
228 | void __iomem *reg; | |
229 | u8 shift; | |
230 | u8 width; | |
231 | u8 flags; | |
232 | spinlock_t *lock; | |
9d9f78ed MT |
233 | }; |
234 | ||
235 | #define CLK_DIVIDER_ONE_BASED BIT(0) | |
236 | #define CLK_DIVIDER_POWER_OF_TWO BIT(1) | |
237 | ||
bffad66e | 238 | extern const struct clk_ops clk_divider_ops; |
9d9f78ed MT |
239 | struct clk *clk_register_divider(struct device *dev, const char *name, |
240 | const char *parent_name, unsigned long flags, | |
241 | void __iomem *reg, u8 shift, u8 width, | |
242 | u8 clk_divider_flags, spinlock_t *lock); | |
243 | ||
244 | /** | |
245 | * struct clk_mux - multiplexer clock | |
246 | * | |
247 | * @hw: handle between common and hardware-specific interfaces | |
248 | * @reg: register controlling multiplexer | |
249 | * @shift: shift to multiplexer bit field | |
250 | * @width: width of mutliplexer bit field | |
251 | * @num_clks: number of parent clocks | |
252 | * @lock: register lock | |
253 | * | |
254 | * Clock with multiple selectable parents. Implements .get_parent, .set_parent | |
255 | * and .recalc_rate | |
256 | * | |
257 | * Flags: | |
258 | * CLK_MUX_INDEX_ONE - register index starts at 1, not 0 | |
1f73f31a | 259 | * CLK_MUX_INDEX_BIT - register index is a single bit (power of two) |
9d9f78ed MT |
260 | */ |
261 | struct clk_mux { | |
262 | struct clk_hw hw; | |
263 | void __iomem *reg; | |
264 | u8 shift; | |
265 | u8 width; | |
266 | u8 flags; | |
267 | spinlock_t *lock; | |
268 | }; | |
269 | ||
270 | #define CLK_MUX_INDEX_ONE BIT(0) | |
271 | #define CLK_MUX_INDEX_BIT BIT(1) | |
272 | ||
bffad66e | 273 | extern const struct clk_ops clk_mux_ops; |
9d9f78ed | 274 | struct clk *clk_register_mux(struct device *dev, const char *name, |
d305fb78 | 275 | const char **parent_names, u8 num_parents, unsigned long flags, |
9d9f78ed MT |
276 | void __iomem *reg, u8 shift, u8 width, |
277 | u8 clk_mux_flags, spinlock_t *lock); | |
b2476490 | 278 | |
f0948f59 SH |
279 | /** |
280 | * struct clk_fixed_factor - fixed multiplier and divider clock | |
281 | * | |
282 | * @hw: handle between common and hardware-specific interfaces | |
283 | * @mult: multiplier | |
284 | * @div: divider | |
285 | * | |
286 | * Clock with a fixed multiplier and divider. The output frequency is the | |
287 | * parent clock rate divided by div and multiplied by mult. | |
288 | * Implements .recalc_rate, .set_rate and .round_rate | |
289 | */ | |
290 | ||
291 | struct clk_fixed_factor { | |
292 | struct clk_hw hw; | |
293 | unsigned int mult; | |
294 | unsigned int div; | |
295 | }; | |
296 | ||
297 | extern struct clk_ops clk_fixed_factor_ops; | |
298 | struct clk *clk_register_fixed_factor(struct device *dev, const char *name, | |
299 | const char *parent_name, unsigned long flags, | |
300 | unsigned int mult, unsigned int div); | |
301 | ||
b2476490 MT |
302 | /** |
303 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
304 | * @dev: device that is registering this clock | |
b2476490 | 305 | * @hw: link to hardware-specific clock data |
b2476490 MT |
306 | * |
307 | * clk_register is the primary interface for populating the clock tree with new | |
308 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
309 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
d1302a36 MT |
310 | * rest of the clock API. In the event of an error clk_register will return an |
311 | * error code; drivers must test for an error code after calling clk_register. | |
b2476490 | 312 | */ |
0197b3ea | 313 | struct clk *clk_register(struct device *dev, struct clk_hw *hw); |
b2476490 | 314 | |
1df5c939 MB |
315 | void clk_unregister(struct clk *clk); |
316 | ||
b2476490 MT |
317 | /* helper functions */ |
318 | const char *__clk_get_name(struct clk *clk); | |
319 | struct clk_hw *__clk_get_hw(struct clk *clk); | |
320 | u8 __clk_get_num_parents(struct clk *clk); | |
321 | struct clk *__clk_get_parent(struct clk *clk); | |
322 | inline int __clk_get_enable_count(struct clk *clk); | |
323 | inline int __clk_get_prepare_count(struct clk *clk); | |
324 | unsigned long __clk_get_rate(struct clk *clk); | |
325 | unsigned long __clk_get_flags(struct clk *clk); | |
326 | int __clk_is_enabled(struct clk *clk); | |
327 | struct clk *__clk_lookup(const char *name); | |
328 | ||
329 | /* | |
330 | * FIXME clock api without lock protection | |
331 | */ | |
332 | int __clk_prepare(struct clk *clk); | |
333 | void __clk_unprepare(struct clk *clk); | |
334 | void __clk_reparent(struct clk *clk, struct clk *new_parent); | |
335 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate); | |
336 | ||
337 | #endif /* CONFIG_COMMON_CLK */ | |
338 | #endif /* CLK_PROVIDER_H */ |