2 * linux/include/linux/clk-provider.h
4 * Copyright (c) 2010-2011 Jeremy Kerr <jeremy.kerr@canonical.com>
5 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
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.
11 #ifndef __LINUX_CLK_PROVIDER_H
12 #define __LINUX_CLK_PROVIDER_H
14 #include <linux/clk.h>
16 #ifdef CONFIG_COMMON_CLK
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
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 #define CLK_IS_BASIC BIT(5) /* Basic clk, can't do a to_clk_foo() */
33 * struct clk_ops - Callback operations for hardware clocks; these are to
34 * be provided by the clock implementation, and will be called by drivers
35 * through the clk_* api.
37 * @prepare: Prepare the clock for enabling. This must not return until
38 * the clock is fully prepared, and it's safe to call clk_enable.
39 * This callback is intended to allow clock implementations to
40 * do any initialisation that may sleep. Called with
43 * @unprepare: Release the clock from its prepared state. This will typically
44 * undo any work done in the @prepare callback. Called with
47 * @enable: Enable the clock atomically. This must not return until the
48 * clock is generating a valid clock signal, usable by consumer
49 * devices. Called with enable_lock held. This function must not
52 * @disable: Disable the clock atomically. Called with enable_lock held.
53 * This function must not sleep.
55 * @recalc_rate Recalculate the rate of this clock, by quering hardware. The
56 * parent rate is an input parameter. It is up to the caller to
57 * insure that the prepare_mutex is held across this call.
58 * Returns the calculated rate. Optional, but recommended - if
59 * this op is not set then clock rate will be initialized to 0.
61 * @round_rate: Given a target rate as input, returns the closest rate actually
62 * supported by the clock.
64 * @get_parent: Queries the hardware to determine the parent of a clock. The
65 * return value is a u8 which specifies the index corresponding to
66 * the parent clock. This index can be applied to either the
67 * .parent_names or .parents arrays. In short, this function
68 * translates the parent value read from hardware into an array
69 * index. Currently only called when the clock is initialized by
70 * __clk_init. This callback is mandatory for clocks with
71 * multiple parents. It is optional (and unnecessary) for clocks
72 * with 0 or 1 parents.
74 * @set_parent: Change the input source of this clock; for clocks with multiple
75 * possible parents specify a new parent by passing in the index
76 * as a u8 corresponding to the parent in either the .parent_names
77 * or .parents arrays. This function in affect translates an
78 * array index into the value programmed into the hardware.
79 * Returns 0 on success, -EERROR otherwise.
81 * @set_rate: Change the rate of this clock. The requested rate is specified
82 * by the second argument, which should typically be the return
83 * of .round_rate call. The third argument gives the parent rate
84 * which is likely helpful for most .set_rate implementation.
85 * Returns 0 on success, -EERROR otherwise.
87 * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow
88 * implementations to split any work between atomic (enable) and sleepable
89 * (prepare) contexts. If enabling a clock requires code that might sleep,
90 * this must be done in clk_prepare. Clock enable code that will never be
91 * called in a sleepable context may be implement in clk_enable.
93 * Typically, drivers will call clk_prepare when a clock may be needed later
94 * (eg. when a device is opened), and clk_enable when the clock is actually
95 * required (eg. from an interrupt). Note that clk_prepare MUST have been
96 * called before clk_enable.
99 int (*prepare
)(struct clk_hw
*hw
);
100 void (*unprepare
)(struct clk_hw
*hw
);
101 int (*enable
)(struct clk_hw
*hw
);
102 void (*disable
)(struct clk_hw
*hw
);
103 int (*is_enabled
)(struct clk_hw
*hw
);
104 unsigned long (*recalc_rate
)(struct clk_hw
*hw
,
105 unsigned long parent_rate
);
106 long (*round_rate
)(struct clk_hw
*hw
, unsigned long,
108 int (*set_parent
)(struct clk_hw
*hw
, u8 index
);
109 u8 (*get_parent
)(struct clk_hw
*hw
);
110 int (*set_rate
)(struct clk_hw
*hw
, unsigned long,
112 void (*init
)(struct clk_hw
*hw
);
116 * struct clk_init_data - holds init data that's common to all clocks and is
117 * shared between the clock provider and the common clock framework.
120 * @ops: operations this clock supports
121 * @parent_names: array of string names for all possible parents
122 * @num_parents: number of possible parents
123 * @flags: framework-level hints and quirks
125 struct clk_init_data
{
127 const struct clk_ops
*ops
;
128 const char **parent_names
;
134 * struct clk_hw - handle for traversing from a struct clk to its corresponding
135 * hardware-specific structure. struct clk_hw should be declared within struct
136 * clk_foo and then referenced by the struct clk instance that uses struct
139 * @clk: pointer to the struct clk instance that points back to this struct
142 * @init: pointer to struct clk_init_data that contains the init data shared
143 * with the common clock framework.
147 const struct clk_init_data
*init
;
151 * DOC: Basic clock implementations common to many platforms
153 * Each basic clock hardware type is comprised of a structure describing the
154 * clock hardware, implementations of the relevant callbacks in struct clk_ops,
155 * unique flags for that hardware type, a registration function and an
156 * alternative macro for static initialization
160 * struct clk_fixed_rate - fixed-rate clock
161 * @hw: handle between common and hardware-specific interfaces
162 * @fixed_rate: constant frequency of clock
164 struct clk_fixed_rate
{
166 unsigned long fixed_rate
;
170 extern const struct clk_ops clk_fixed_rate_ops
;
171 struct clk
*clk_register_fixed_rate(struct device
*dev
, const char *name
,
172 const char *parent_name
, unsigned long flags
,
173 unsigned long fixed_rate
);
175 void of_fixed_clk_setup(struct device_node
*np
);
178 * struct clk_gate - gating clock
180 * @hw: handle between common and hardware-specific interfaces
181 * @reg: register controlling gate
182 * @bit_idx: single bit controlling gate
183 * @flags: hardware-specific flags
184 * @lock: register lock
186 * Clock which can gate its output. Implements .enable & .disable
189 * CLK_GATE_SET_TO_DISABLE - by default this clock sets the bit at bit_idx to
190 * enable the clock. Setting this flag does the opposite: setting the bit
191 * disable the clock and clearing it enables the clock
201 #define CLK_GATE_SET_TO_DISABLE BIT(0)
203 extern const struct clk_ops clk_gate_ops
;
204 struct clk
*clk_register_gate(struct device
*dev
, const char *name
,
205 const char *parent_name
, unsigned long flags
,
206 void __iomem
*reg
, u8 bit_idx
,
207 u8 clk_gate_flags
, spinlock_t
*lock
);
209 struct clk_div_table
{
215 * struct clk_divider - adjustable divider clock
217 * @hw: handle between common and hardware-specific interfaces
218 * @reg: register containing the divider
219 * @shift: shift to the divider bit field
220 * @width: width of the divider bit field
221 * @table: array of value/divider pairs, last entry should have div = 0
222 * @lock: register lock
224 * Clock with an adjustable divider affecting its output frequency. Implements
225 * .recalc_rate, .set_rate and .round_rate
228 * CLK_DIVIDER_ONE_BASED - by default the divisor is the value read from the
229 * register plus one. If CLK_DIVIDER_ONE_BASED is set then the divider is
230 * the raw value read from the register, with the value of zero considered
232 * CLK_DIVIDER_POWER_OF_TWO - clock divisor is 2 raised to the value read from
233 * the hardware register
241 const struct clk_div_table
*table
;
245 #define CLK_DIVIDER_ONE_BASED BIT(0)
246 #define CLK_DIVIDER_POWER_OF_TWO BIT(1)
248 extern const struct clk_ops clk_divider_ops
;
249 struct clk
*clk_register_divider(struct device
*dev
, const char *name
,
250 const char *parent_name
, unsigned long flags
,
251 void __iomem
*reg
, u8 shift
, u8 width
,
252 u8 clk_divider_flags
, spinlock_t
*lock
);
253 struct clk
*clk_register_divider_table(struct device
*dev
, const char *name
,
254 const char *parent_name
, unsigned long flags
,
255 void __iomem
*reg
, u8 shift
, u8 width
,
256 u8 clk_divider_flags
, const struct clk_div_table
*table
,
260 * struct clk_mux - multiplexer clock
262 * @hw: handle between common and hardware-specific interfaces
263 * @reg: register controlling multiplexer
264 * @shift: shift to multiplexer bit field
265 * @width: width of mutliplexer bit field
266 * @num_clks: number of parent clocks
267 * @lock: register lock
269 * Clock with multiple selectable parents. Implements .get_parent, .set_parent
273 * CLK_MUX_INDEX_ONE - register index starts at 1, not 0
274 * CLK_MUX_INDEX_BIT - register index is a single bit (power of two)
285 #define CLK_MUX_INDEX_ONE BIT(0)
286 #define CLK_MUX_INDEX_BIT BIT(1)
288 extern const struct clk_ops clk_mux_ops
;
289 struct clk
*clk_register_mux(struct device
*dev
, const char *name
,
290 const char **parent_names
, u8 num_parents
, unsigned long flags
,
291 void __iomem
*reg
, u8 shift
, u8 width
,
292 u8 clk_mux_flags
, spinlock_t
*lock
);
295 * struct clk_fixed_factor - fixed multiplier and divider clock
297 * @hw: handle between common and hardware-specific interfaces
301 * Clock with a fixed multiplier and divider. The output frequency is the
302 * parent clock rate divided by div and multiplied by mult.
303 * Implements .recalc_rate, .set_rate and .round_rate
306 struct clk_fixed_factor
{
312 extern struct clk_ops clk_fixed_factor_ops
;
313 struct clk
*clk_register_fixed_factor(struct device
*dev
, const char *name
,
314 const char *parent_name
, unsigned long flags
,
315 unsigned int mult
, unsigned int div
);
318 * clk_register - allocate a new clock, register it and return an opaque cookie
319 * @dev: device that is registering this clock
320 * @hw: link to hardware-specific clock data
322 * clk_register is the primary interface for populating the clock tree with new
323 * clock nodes. It returns a pointer to the newly allocated struct clk which
324 * cannot be dereferenced by driver code but may be used in conjuction with the
325 * rest of the clock API. In the event of an error clk_register will return an
326 * error code; drivers must test for an error code after calling clk_register.
328 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
);
330 void clk_unregister(struct clk
*clk
);
332 /* helper functions */
333 const char *__clk_get_name(struct clk
*clk
);
334 struct clk_hw
*__clk_get_hw(struct clk
*clk
);
335 u8
__clk_get_num_parents(struct clk
*clk
);
336 struct clk
*__clk_get_parent(struct clk
*clk
);
337 inline int __clk_get_enable_count(struct clk
*clk
);
338 inline int __clk_get_prepare_count(struct clk
*clk
);
339 unsigned long __clk_get_rate(struct clk
*clk
);
340 unsigned long __clk_get_flags(struct clk
*clk
);
341 int __clk_is_enabled(struct clk
*clk
);
342 struct clk
*__clk_lookup(const char *name
);
345 * FIXME clock api without lock protection
347 int __clk_prepare(struct clk
*clk
);
348 void __clk_unprepare(struct clk
*clk
);
349 void __clk_reparent(struct clk
*clk
, struct clk
*new_parent
);
350 unsigned long __clk_round_rate(struct clk
*clk
, unsigned long rate
);
354 typedef void (*of_clk_init_cb_t
)(struct device_node
*);
356 int of_clk_add_provider(struct device_node
*np
,
357 struct clk
*(*clk_src_get
)(struct of_phandle_args
*args
,
360 void of_clk_del_provider(struct device_node
*np
);
361 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
363 const char *of_clk_get_parent_name(struct device_node
*np
, int index
);
364 void of_clk_init(const struct of_device_id
*matches
);
366 #endif /* CONFIG_COMMON_CLK */
367 #endif /* CLK_PROVIDER_H */