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_H_
9 #define _CLK_H_
10
11 #include <dm/ofnode.h>
12 #include <linux/errno.h>
13 #include <linux/types.h>
14
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_CLK is a clock provider. A provider will
24 * often implement multiple separate clocks, since the hardware it manages
25 * often has this capability. clk-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 */
31
32 struct udevice;
33
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 * @rate: The clock rate (in HZ).
44 * @flags: Flags used across common clock structure (e.g. CLK_)
45 * Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined
46 * in struct's for those devices (e.g. struct clk_mux).
47 * @id: The clock signal ID within the provider.
48 * @data: An optional data field for scenarios where a single integer ID is not
49 * sufficient. If used, it can be populated through an .of_xlate op and
50 * processed during the various clock ops.
51 *
52 * Should additional information to identify and configure any clock signal
53 * for any provider be required in the future, the struct could be expanded to
54 * either (a) add more fields to allow clock providers to store additional
55 * information, or (b) replace the id field with an opaque pointer, which the
56 * provider would dynamically allocated during its .of_xlate op, and process
57 * during is .request op. This may require the addition of an extra op to clean
58 * up the allocation.
59 */
60 struct clk {
61 struct udevice *dev;
62 long long rate; /* in HZ */
63 u32 flags;
64 int enable_count;
65 /*
66 * Written by of_xlate. In the future, we might add more fields here.
67 */
68 unsigned long id;
69 unsigned long data;
70 };
71
72 /**
73 * struct clk_bulk - A handle to (allowing control of) a bulk of clocks.
74 *
75 * Clients provide storage for the clock bulk. The content of the structure is
76 * managed solely by the clock API. A clock bulk struct is
77 * initialized by "get"ing the clock bulk struct.
78 * The clock bulk struct is passed to all other bulk clock APIs to apply
79 * the API to all the clock in the bulk struct.
80 *
81 * @clks: An array of clock handles.
82 * @count: The number of clock handles in the clks array.
83 */
84 struct clk_bulk {
85 struct clk *clks;
86 unsigned int count;
87 };
88
89 #if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK)
90 struct phandle_1_arg;
91 int clk_get_by_index_platdata(struct udevice *dev, int index,
92 struct phandle_1_arg *cells, struct clk *clk);
93
94 /**
95 * clock_get_by_index - Get/request a clock by integer index.
96 *
97 * This looks up and requests a clock. The index is relative to the client
98 * device; each device is assumed to have n clocks associated with it somehow,
99 * and this function finds and requests one of them. The mapping of client
100 * device clock indices to provider clocks may be via device-tree properties,
101 * board-provided mapping tables, or some other mechanism.
102 *
103 * @dev: The client device.
104 * @index: The index of the clock to request, within the client's list of
105 * clocks.
106 * @clock A pointer to a clock struct to initialize.
107 * @return 0 if OK, or a negative error code.
108 */
109 int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
110
111 /**
112 * clock_get_by_index_nodev - Get/request a clock by integer index
113 * without a device.
114 *
115 * This is a version of clk_get_by_index() that does not use a device.
116 *
117 * @node: The client ofnode.
118 * @index: The index of the clock to request, within the client's list of
119 * clocks.
120 * @clock A pointer to a clock struct to initialize.
121 * @return 0 if OK, or a negative error code.
122 */
123 int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
124
125 /**
126 * clock_get_bulk - Get/request all clocks of a device.
127 *
128 * This looks up and requests all clocks of the client device; each device is
129 * assumed to have n clocks associated with it somehow, and this function finds
130 * and requests all of them in a separate structure. The mapping of client
131 * device clock indices to provider clocks may be via device-tree properties,
132 * board-provided mapping tables, or some other mechanism.
133 *
134 * @dev: The client device.
135 * @bulk A pointer to a clock bulk struct to initialize.
136 * @return 0 if OK, or a negative error code.
137 */
138 int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
139
140 /**
141 * clock_get_by_name - Get/request a clock by name.
142 *
143 * This looks up and requests a clock. The name is relative to the client
144 * device; each device is assumed to have n clocks associated with it somehow,
145 * and this function finds and requests one of them. The mapping of client
146 * device clock names to provider clocks may be via device-tree properties,
147 * board-provided mapping tables, or some other mechanism.
148 *
149 * @dev: The client device.
150 * @name: The name of the clock to request, within the client's list of
151 * clocks.
152 * @clock: A pointer to a clock struct to initialize.
153 * @return 0 if OK, or a negative error code.
154 */
155 int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
156
157 /**
158 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
159 * @dev: device for clock "consumer"
160 * @id: clock consumer ID
161 *
162 * Returns a struct clk corresponding to the clock producer, or
163 * valid IS_ERR() condition containing errno. The implementation
164 * uses @dev and @id to determine the clock consumer, and thereby
165 * the clock producer. (IOW, @id may be identical strings, but
166 * clk_get may return different clock producers depending on @dev.)
167 *
168 * Drivers must assume that the clock source is not enabled.
169 *
170 * devm_clk_get should not be called from within interrupt context.
171 *
172 * The clock will automatically be freed when the device is unbound
173 * from the bus.
174 */
175 struct clk *devm_clk_get(struct udevice *dev, const char *id);
176
177 /**
178 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
179 * clock producer.
180 * @dev: device for clock "consumer"
181 * @id: clock consumer ID
182 *
183 * Behaves the same as devm_clk_get() except where there is no clock producer.
184 * In this case, instead of returning -ENOENT, the function returns NULL.
185 */
186 struct clk *devm_clk_get_optional(struct udevice *dev, const char *id);
187
188 /**
189 * clk_release_all() - Disable (turn off)/Free an array of previously
190 * requested clocks.
191 *
192 * For each clock contained in the clock array, this function will check if
193 * clock has been previously requested and then will disable and free it.
194 *
195 * @clk: A clock struct array that was previously successfully
196 * requested by clk_request/get_by_*().
197 * @count Number of clock contained in the array
198 * @return zero on success, or -ve error code.
199 */
200 int clk_release_all(struct clk *clk, int count);
201
202 /**
203 * devm_clk_put - "free" a managed clock source
204 * @dev: device used to acquire the clock
205 * @clk: clock source acquired with devm_clk_get()
206 *
207 * Note: drivers must ensure that all clk_enable calls made on this
208 * clock source are balanced by clk_disable calls prior to calling
209 * this function.
210 *
211 * clk_put should not be called from within interrupt context.
212 */
213 void devm_clk_put(struct udevice *dev, struct clk *clk);
214
215 #else
clk_get_by_index(struct udevice * dev,int index,struct clk * clk)216 static inline int clk_get_by_index(struct udevice *dev, int index,
217 struct clk *clk)
218 {
219 return -ENOSYS;
220 }
221
clk_get_bulk(struct udevice * dev,struct clk_bulk * bulk)222 static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
223 {
224 return -ENOSYS;
225 }
226
clk_get_by_name(struct udevice * dev,const char * name,struct clk * clk)227 static inline int clk_get_by_name(struct udevice *dev, const char *name,
228 struct clk *clk)
229 {
230 return -ENOSYS;
231 }
232
clk_release_all(struct clk * clk,int count)233 static inline int clk_release_all(struct clk *clk, int count)
234 {
235 return -ENOSYS;
236 }
237 #endif
238
239 #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \
240 CONFIG_IS_ENABLED(CLK)
241 /**
242 * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
243 * properties to configure clocks
244 *
245 * @dev: A device to process (the ofnode associated with this device
246 * will be processed).
247 * @stage: A integer. 0 indicates that this is called before the device
248 * is probed. 1 indicates that this is called just after the
249 * device has been probed
250 */
251 int clk_set_defaults(struct udevice *dev, int stage);
252 #else
clk_set_defaults(struct udevice * dev,int stage)253 static inline int clk_set_defaults(struct udevice *dev, int stage)
254 {
255 return 0;
256 }
257 #endif
258
259 /**
260 * clk_release_bulk() - Disable (turn off)/Free an array of previously
261 * requested clocks in a clock bulk struct.
262 *
263 * For each clock contained in the clock bulk struct, this function will check
264 * if clock has been previously requested and then will disable and free it.
265 *
266 * @clk: A clock bulk struct that was previously successfully
267 * requested by clk_get_bulk().
268 * @return zero on success, or -ve error code.
269 */
clk_release_bulk(struct clk_bulk * bulk)270 static inline int clk_release_bulk(struct clk_bulk *bulk)
271 {
272 return clk_release_all(bulk->clks, bulk->count);
273 }
274
275 /**
276 * clk_request - Request a clock by provider-specific ID.
277 *
278 * This requests a clock using a provider-specific ID. Generally, this function
279 * should not be used, since clk_get_by_index/name() provide an interface that
280 * better separates clients from intimate knowledge of clock providers.
281 * However, this function may be useful in core SoC-specific code.
282 *
283 * @dev: The clock provider device.
284 * @clock: A pointer to a clock struct to initialize. The caller must
285 * have already initialized any field in this struct which the
286 * clock provider uses to identify the clock.
287 * @return 0 if OK, or a negative error code.
288 */
289 int clk_request(struct udevice *dev, struct clk *clk);
290
291 /**
292 * clock_free - Free a previously requested clock.
293 *
294 * @clock: A clock struct that was previously successfully requested by
295 * clk_request/get_by_*().
296 * @return 0 if OK, or a negative error code.
297 */
298 int clk_free(struct clk *clk);
299
300 /**
301 * clk_get_rate() - Get current clock rate.
302 *
303 * @clk: A clock struct that was previously successfully requested by
304 * clk_request/get_by_*().
305 * @return clock rate in Hz, or -ve error code.
306 */
307 ulong clk_get_rate(struct clk *clk);
308
309 /**
310 * clk_get_parent() - Get current clock's parent.
311 *
312 * @clk: A clock struct that was previously successfully requested by
313 * clk_request/get_by_*().
314 * @return pointer to parent's struct clk, or error code passed as pointer
315 */
316 struct clk *clk_get_parent(struct clk *clk);
317
318 /**
319 * clk_get_parent_rate() - Get parent of current clock rate.
320 *
321 * @clk: A clock struct that was previously successfully requested by
322 * clk_request/get_by_*().
323 * @return clock rate in Hz, or -ve error code.
324 */
325 long long clk_get_parent_rate(struct clk *clk);
326
327 /**
328 * clk_set_rate() - Set current clock rate.
329 *
330 * @clk: A clock struct that was previously successfully requested by
331 * clk_request/get_by_*().
332 * @rate: New clock rate in Hz.
333 * @return new rate, or -ve error code.
334 */
335 ulong clk_set_rate(struct clk *clk, ulong rate);
336
337 /**
338 * clk_set_parent() - Set current clock parent.
339 *
340 * @clk: A clock struct that was previously successfully requested by
341 * clk_request/get_by_*().
342 * @parent: A clock struct that was previously successfully requested by
343 * clk_request/get_by_*().
344 * @return new rate, or -ve error code.
345 */
346 int clk_set_parent(struct clk *clk, struct clk *parent);
347
348 /**
349 * clk_enable() - Enable (turn on) a clock.
350 *
351 * @clk: A clock struct that was previously successfully requested by
352 * clk_request/get_by_*().
353 * @return zero on success, or -ve error code.
354 */
355 int clk_enable(struct clk *clk);
356
357 /**
358 * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
359 *
360 * @bulk: A clock bulk struct that was previously successfully requested
361 * by clk_get_bulk().
362 * @return zero on success, or -ve error code.
363 */
364 int clk_enable_bulk(struct clk_bulk *bulk);
365
366 /**
367 * clk_disable() - Disable (turn off) a clock.
368 *
369 * @clk: A clock struct that was previously successfully requested by
370 * clk_request/get_by_*().
371 * @return zero on success, or -ve error code.
372 */
373 int clk_disable(struct clk *clk);
374
375 /**
376 * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct.
377 *
378 * @bulk: A clock bulk struct that was previously successfully requested
379 * by clk_get_bulk().
380 * @return zero on success, or -ve error code.
381 */
382 int clk_disable_bulk(struct clk_bulk *bulk);
383
384 /**
385 * clk_is_match - check if two clk's point to the same hardware clock
386 * @p: clk compared against q
387 * @q: clk compared against p
388 *
389 * Returns true if the two struct clk pointers both point to the same hardware
390 * clock node.
391 *
392 * Returns false otherwise. Note that two NULL clks are treated as matching.
393 */
394 bool clk_is_match(const struct clk *p, const struct clk *q);
395
396 int soc_clk_dump(void);
397
398 /**
399 * clk_valid() - check if clk is valid
400 *
401 * @clk: the clock to check
402 * @return true if valid, or false
403 */
clk_valid(struct clk * clk)404 static inline bool clk_valid(struct clk *clk)
405 {
406 return clk && !!clk->dev;
407 }
408
409 /**
410 * clk_get_by_id() - Get the clock by its ID
411 *
412 * @id: The clock ID to search for
413 *
414 * @clkp: A pointer to clock struct that has been found among added clocks
415 * to UCLASS_CLK
416 * @return zero on success, or -ENOENT on error
417 */
418 int clk_get_by_id(ulong id, struct clk **clkp);
419
420 /**
421 * clk_dev_binded() - Check whether the clk has a device binded
422 *
423 * @clk A pointer to the clk
424 *
425 * @return true on binded, or false on no
426 */
427 bool clk_dev_binded(struct clk *clk);
428 #endif
429
430 #define clk_prepare_enable(clk) clk_enable(clk)
431 #define clk_disable_unprepare(clk) clk_disable(clk)
432