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Tom Rini83d290c2018-05-06 17:58:06 -04001/* SPDX-License-Identifier: GPL-2.0 */
Stephen Warren89c1e2d2016-06-17 09:43:58 -06002/*
3 * Copyright (c) 2016, NVIDIA CORPORATION.
Stephen Warren89c1e2d2016-06-17 09:43:58 -06004 */
5
6#ifndef _RESET_H
7#define _RESET_H
8
Jagan Tekiea9dc352019-02-28 00:26:55 +05309#include <dm/ofnode.h>
Jean-Jacques Hiblot139e4a12020-09-09 15:37:03 +053010#include <linux/err.h>
Masahiro Yamada4815db82016-09-21 11:29:01 +090011
Stephen Warren89c1e2d2016-06-17 09:43:58 -060012/**
13 * A reset is a hardware signal indicating that a HW module (or IP block, or
14 * sometimes an entire off-CPU chip) reset all of its internal state to some
15 * known-good initial state. Drivers will often reset HW modules when they
16 * begin execution to ensure that hardware correctly responds to all requests,
17 * or in response to some error condition. Reset signals are often controlled
18 * externally to the HW module being reset, by an entity this API calls a reset
19 * controller. This API provides a standard means for drivers to request that
20 * reset controllers set or clear reset signals.
21 *
22 * A driver that implements UCLASS_RESET is a reset controller or provider. A
23 * controller will often implement multiple separate reset signals, since the
24 * hardware it manages often has this capability. reset-uclass.h describes the
25 * interface which reset controllers must implement.
26 *
27 * Reset consumers/clients are the HW modules affected by reset signals. This
28 * header file describes the API used by drivers for those HW modules.
29 */
30
31struct udevice;
32
33/**
34 * struct reset_ctl - A handle to (allowing control of) a single reset signal.
35 *
36 * Clients provide storage for reset control handles. The content of the
37 * structure is managed solely by the reset API and reset drivers. A reset
38 * control struct is initialized by "get"ing the reset control struct. The
39 * reset control struct is passed to all other reset APIs to identify which
40 * reset signal to operate upon.
41 *
42 * @dev: The device which implements the reset signal.
43 * @id: The reset signal ID within the provider.
Andreas Dannenbergc72f9b72018-08-27 15:57:40 +053044 * @data: An optional data field for scenarios where a single integer ID is not
45 * sufficient. If used, it can be populated through an .of_xlate op and
46 * processed during the various reset ops.
Shawn Guof5ed7482019-03-20 15:32:38 +080047 * @polarity: An optional polarity field for drivers that support
48 * different reset polarities.
Stephen Warren89c1e2d2016-06-17 09:43:58 -060049 *
Andreas Dannenbergc72f9b72018-08-27 15:57:40 +053050 * Should additional information to identify and configure any reset signal
51 * for any provider be required in the future, the struct could be expanded to
Stephen Warren89c1e2d2016-06-17 09:43:58 -060052 * either (a) add more fields to allow reset providers to store additional
53 * information, or (b) replace the id field with an opaque pointer, which the
54 * provider would dynamically allocated during its .of_xlate op, and process
55 * during is .request op. This may require the addition of an extra op to clean
56 * up the allocation.
57 */
58struct reset_ctl {
59 struct udevice *dev;
60 /*
Andreas Dannenbergc72f9b72018-08-27 15:57:40 +053061 * Written by of_xlate. In the future, we might add more fields here.
Stephen Warren89c1e2d2016-06-17 09:43:58 -060062 */
63 unsigned long id;
Andreas Dannenbergc72f9b72018-08-27 15:57:40 +053064 unsigned long data;
Shawn Guof5ed7482019-03-20 15:32:38 +080065 unsigned long polarity;
Stephen Warren89c1e2d2016-06-17 09:43:58 -060066};
67
Neil Armstrong0c282332018-04-03 11:40:50 +020068/**
69 * struct reset_ctl_bulk - A handle to (allowing control of) a bulk of reset
70 * signals.
71 *
72 * Clients provide storage for the reset control bulk. The content of the
73 * structure is managed solely by the reset API. A reset control bulk struct is
74 * initialized by "get"ing the reset control bulk struct.
75 * The reset control bulk struct is passed to all other bulk reset APIs to apply
76 * the API to all the reset signals in the bulk struct.
77 *
78 * @resets: An array of reset signal handles handles.
79 * @count: The number of reset signal handles in the reset array.
80 */
81struct reset_ctl_bulk {
82 struct reset_ctl *resets;
83 unsigned int count;
84};
85
Ley Foon Tand99894d2018-06-14 18:45:20 +080086#if CONFIG_IS_ENABLED(DM_RESET)
Jean-Jacques Hiblot139e4a12020-09-09 15:37:03 +053087
88/**
89 * devm_reset_control_get - resource managed reset_get_by_name()
90 * @dev: device to be reset by the controller
91 * @id: reset line name
92 *
93 * Managed reset_get_by_name(). For reset controllers returned
94 * from this function, reset_free() is called automatically on driver
95 * detach.
96 *
97 * Returns a struct reset_ctl or IS_ERR() condition containing errno.
98 */
99struct reset_ctl *devm_reset_control_get(struct udevice *dev, const char *id);
100
101/**
102 * devm_reset_control_get_optional - resource managed reset_get_by_name() that
103 * can fail
104 * @dev: The client device.
105 * @id: reset line name
106 *
107 * Managed reset_get_by_name(). For reset controllers returned
108 * from this function, reset_free() is called automatically on driver
109 * detach.
110 *
111 * Returns a struct reset_ctl or a dummy reset controller if it failed.
112 */
113struct reset_ctl *devm_reset_control_get_optional(struct udevice *dev,
114 const char *id);
115
116/**
117 * devm_reset_control_get - resource managed reset_get_by_index()
118 * @dev: The client device.
119 * @index: The index of the reset signal to request, within the client's
120 * list of reset signals.
121 *
122 * Managed reset_get_by_index(). For reset controllers returned
123 * from this function, reset_free() is called automatically on driver
124 * detach.
125 *
126 * Returns a struct reset_ctl or IS_ERR() condition containing errno.
127 */
128struct reset_ctl *devm_reset_control_get_by_index(struct udevice *dev,
129 int index);
130
131/**
132 * devm_reset_bulk_get - resource managed reset_get_bulk()
133 * @dev: device to be reset by the controller
134 *
135 * Managed reset_get_bulk(). For reset controllers returned
136 * from this function, reset_free() is called automatically on driver
137 * detach.
138 *
139 * Returns a struct reset_ctl or IS_ERR() condition containing errno.
140 */
141struct reset_ctl_bulk *devm_reset_bulk_get(struct udevice *dev);
142
143/**
144 * devm_reset_bulk_get_optional - resource managed reset_get_bulk() that
145 * can fail
146 * @dev: The client device.
147 *
148 * Managed reset_get_bulk(). For reset controllers returned
149 * from this function, reset_free() is called automatically on driver
150 * detach.
151 *
152 * Returns a struct reset_ctl or NULL if it failed.
153 */
154struct reset_ctl_bulk *devm_reset_bulk_get_optional(struct udevice *dev);
155
156/**
157 * devm_reset_bulk_get_by_node - resource managed reset_get_bulk()
158 * @dev: device to be reset by the controller
159 * @node: ofnode where the "resets" property is. Usually a sub-node of
160 * the dev's node.
161 *
162 * see devm_reset_bulk_get()
163 */
164struct reset_ctl_bulk *devm_reset_bulk_get_by_node(struct udevice *dev,
165 ofnode node);
166
167/**
168 * devm_reset_bulk_get_optional_by_node - resource managed reset_get_bulk()
169 * that can fail
170 * @dev: device to be reset by the controller
171 * @node: ofnode where the "resets" property is. Usually a sub-node of
172 * the dev's node.
173 *
174 * see devm_reset_bulk_get_optional()
175 */
176struct reset_ctl_bulk *devm_reset_bulk_get_optional_by_node(struct udevice *dev,
177 ofnode node);
178
Stephen Warren89c1e2d2016-06-17 09:43:58 -0600179/**
180 * reset_get_by_index - Get/request a reset signal by integer index.
181 *
182 * This looks up and requests a reset signal. The index is relative to the
183 * client device; each device is assumed to have n reset signals associated
184 * with it somehow, and this function finds and requests one of them. The
185 * mapping of client device reset signal indices to provider reset signals may
186 * be via device-tree properties, board-provided mapping tables, or some other
187 * mechanism.
188 *
189 * @dev: The client device.
190 * @index: The index of the reset signal to request, within the client's
191 * list of reset signals.
192 * @reset_ctl A pointer to a reset control struct to initialize.
193 * @return 0 if OK, or a negative error code.
194 */
195int reset_get_by_index(struct udevice *dev, int index,
196 struct reset_ctl *reset_ctl);
197
198/**
Jagan Tekiea9dc352019-02-28 00:26:55 +0530199 * reset_get_by_index_nodev - Get/request a reset signal by integer index
200 * without a device.
201 *
202 * This is a version of reset_get_by_index() that does not use a device.
203 *
204 * @node: The client ofnode.
205 * @index: The index of the reset signal to request, within the client's
206 * list of reset signals.
207 * @reset_ctl A pointer to a reset control struct to initialize.
208 * @return 0 if OK, or a negative error code.
209 */
210int reset_get_by_index_nodev(ofnode node, int index,
211 struct reset_ctl *reset_ctl);
212
213/**
Neil Armstrong0c282332018-04-03 11:40:50 +0200214 * reset_get_bulk - Get/request all reset signals of a device.
215 *
216 * This looks up and requests all reset signals of the client device; each
217 * device is assumed to have n reset signals associated with it somehow,
218 * and this function finds and requests all of them in a separate structure.
219 * The mapping of client device reset signals indices to provider reset signals
220 * may be via device-tree properties, board-provided mapping tables, or some
221 * other mechanism.
222 *
223 * @dev: The client device.
224 * @bulk A pointer to a reset control bulk struct to initialize.
225 * @return 0 if OK, or a negative error code.
226 */
227int reset_get_bulk(struct udevice *dev, struct reset_ctl_bulk *bulk);
228
229/**
Stephen Warren89c1e2d2016-06-17 09:43:58 -0600230 * reset_get_by_name - Get/request a reset signal by name.
231 *
232 * This looks up and requests a reset signal. The name is relative to the
233 * client device; each device is assumed to have n reset signals associated
234 * with it somehow, and this function finds and requests one of them. The
235 * mapping of client device reset signal names to provider reset signal may be
236 * via device-tree properties, board-provided mapping tables, or some other
237 * mechanism.
238 *
239 * @dev: The client device.
240 * @name: The name of the reset signal to request, within the client's
241 * list of reset signals.
242 * @reset_ctl: A pointer to a reset control struct to initialize.
243 * @return 0 if OK, or a negative error code.
244 */
245int reset_get_by_name(struct udevice *dev, const char *name,
246 struct reset_ctl *reset_ctl);
247
248/**
Patrice Chotard9bd5cdf2017-07-18 11:57:05 +0200249 * reset_request - Request a reset signal.
250 *
251 * @reset_ctl: A reset control struct.
252 *
253 * @return 0 if OK, or a negative error code.
254 */
255int reset_request(struct reset_ctl *reset_ctl);
256
257/**
Stephen Warren89c1e2d2016-06-17 09:43:58 -0600258 * reset_free - Free a previously requested reset signal.
259 *
260 * @reset_ctl: A reset control struct that was previously successfully
261 * requested by reset_get_by_*().
262 * @return 0 if OK, or a negative error code.
263 */
264int reset_free(struct reset_ctl *reset_ctl);
265
266/**
267 * reset_assert - Assert a reset signal.
268 *
269 * This function will assert the specified reset signal, thus resetting the
270 * affected HW module(s). Depending on the reset controller hardware, the reset
271 * signal will either stay asserted until reset_deassert() is called, or the
272 * hardware may autonomously clear the reset signal itself.
273 *
274 * @reset_ctl: A reset control struct that was previously successfully
275 * requested by reset_get_by_*().
276 * @return 0 if OK, or a negative error code.
277 */
278int reset_assert(struct reset_ctl *reset_ctl);
279
280/**
Neil Armstrong0c282332018-04-03 11:40:50 +0200281 * reset_assert_bulk - Assert all reset signals in a reset control bulk struct.
282 *
283 * This function will assert the specified reset signals in a reset control
284 * bulk struct, thus resetting the affected HW module(s). Depending on the
285 * reset controller hardware, the reset signals will either stay asserted
286 * until reset_deassert_bulk() is called, or the hardware may autonomously
287 * clear the reset signals itself.
288 *
289 * @bulk: A reset control bulk struct that was previously successfully
290 * requested by reset_get_bulk().
291 * @return 0 if OK, or a negative error code.
292 */
293int reset_assert_bulk(struct reset_ctl_bulk *bulk);
294
295/**
Stephen Warren89c1e2d2016-06-17 09:43:58 -0600296 * reset_deassert - Deassert a reset signal.
297 *
298 * This function will deassert the specified reset signal, thus releasing the
299 * affected HW modules() from reset, and allowing them to continue normal
300 * operation.
301 *
302 * @reset_ctl: A reset control struct that was previously successfully
303 * requested by reset_get_by_*().
304 * @return 0 if OK, or a negative error code.
305 */
306int reset_deassert(struct reset_ctl *reset_ctl);
307
Patrice Chotard3b9d1bd2017-07-18 11:57:06 +0200308/**
Neil Armstrong0c282332018-04-03 11:40:50 +0200309 * reset_deassert_bulk - Deassert all reset signals in a reset control bulk
310 * struct.
311 *
312 * This function will deassert the specified reset signals in a reset control
313 * bulk struct, thus releasing the affected HW modules() from reset, and
314 * allowing them to continue normal operation.
315 *
316 * @bulk: A reset control bulk struct that was previously successfully
317 * requested by reset_get_bulk().
318 * @return 0 if OK, or a negative error code.
319 */
320int reset_deassert_bulk(struct reset_ctl_bulk *bulk);
321
322/**
Andreas Dannenberge7012e62018-08-27 15:57:39 +0530323 * rst_status - Check reset signal status.
324 *
325 * @reset_ctl: The reset signal to check.
326 * @return 0 if deasserted, positive if asserted, or a negative
327 * error code.
328 */
329int reset_status(struct reset_ctl *reset_ctl);
330
331/**
Patrice Chotard3b9d1bd2017-07-18 11:57:06 +0200332 * reset_release_all - Assert/Free an array of previously requested resets.
333 *
334 * For each reset contained in the reset array, this function will check if
335 * reset has been previously requested and then will assert and free it.
336 *
337 * @reset_ctl: A reset struct array that was previously successfully
338 * requested by reset_get_by_*().
339 * @count Number of reset contained in the array
340 * @return 0 if OK, or a negative error code.
341 */
342int reset_release_all(struct reset_ctl *reset_ctl, int count);
Neil Armstrong0c282332018-04-03 11:40:50 +0200343
344/**
345 * reset_release_bulk - Assert/Free an array of previously requested reset
346 * signals in a reset control bulk struct.
347 *
348 * For each reset contained in the reset control bulk struct, this function
349 * will check if reset has been previously requested and then will assert
350 * and free it.
351 *
352 * @bulk: A reset control bulk struct that was previously successfully
353 * requested by reset_get_bulk().
354 * @return 0 if OK, or a negative error code.
355 */
356static inline int reset_release_bulk(struct reset_ctl_bulk *bulk)
357{
358 return reset_release_all(bulk->resets, bulk->count);
359}
Jean-Jacques Hiblot139e4a12020-09-09 15:37:03 +0530360
Masahiro Yamada4815db82016-09-21 11:29:01 +0900361#else
Jean-Jacques Hiblot139e4a12020-09-09 15:37:03 +0530362static inline struct reset_ctl *devm_reset_control_get(struct udevice *dev,
363 const char *id)
364{
365 return ERR_PTR(-ENOTSUPP);
366}
367
368static inline struct reset_ctl *devm_reset_control_get_optional(struct udevice *dev,
369 const char *id)
370{
371 return NULL;
372}
373
374static inline struct reset_ctl *devm_reset_control_get_by_index(struct udevice *dev,
375 int index)
376{
377 return ERR_PTR(-ENOTSUPP);
378}
379
380static inline struct reset_ctl_bulk *devm_reset_bulk_get(struct udevice *dev)
381{
382 return ERR_PTR(-ENOTSUPP);
383}
384
385static inline struct reset_ctl_bulk *devm_reset_bulk_get_optional(struct udevice *dev)
386{
387 return NULL;
388}
389
390static inline struct reset_ctl_bulk *devm_reset_bulk_get_by_node(struct udevice *dev,
391 ofnode node)
392{
393 return ERR_PTR(-ENOTSUPP);
394}
395
396static inline struct reset_ctl_bulk *devm_reset_bulk_get_optional_by_node(struct udevice *dev,
397 ofnode node)
398{
399 return NULL;
400}
401
Masahiro Yamada4815db82016-09-21 11:29:01 +0900402static inline int reset_get_by_index(struct udevice *dev, int index,
403 struct reset_ctl *reset_ctl)
404{
405 return -ENOTSUPP;
406}
407
Neil Armstrong1dd181f2018-04-12 10:03:19 +0200408static inline int reset_get_bulk(struct udevice *dev,
409 struct reset_ctl_bulk *bulk)
Neil Armstrong0c282332018-04-03 11:40:50 +0200410{
411 return -ENOTSUPP;
412}
413
Masahiro Yamada4815db82016-09-21 11:29:01 +0900414static inline int reset_get_by_name(struct udevice *dev, const char *name,
415 struct reset_ctl *reset_ctl)
416{
417 return -ENOTSUPP;
418}
419
420static inline int reset_free(struct reset_ctl *reset_ctl)
421{
422 return 0;
423}
424
425static inline int reset_assert(struct reset_ctl *reset_ctl)
426{
427 return 0;
428}
429
Neil Armstrong0c282332018-04-03 11:40:50 +0200430static inline int reset_assert_bulk(struct reset_ctl_bulk *bulk)
431{
432 return 0;
433}
434
Masahiro Yamada4815db82016-09-21 11:29:01 +0900435static inline int reset_deassert(struct reset_ctl *reset_ctl)
436{
437 return 0;
438}
Patrice Chotard3b9d1bd2017-07-18 11:57:06 +0200439
Neil Armstrong0c282332018-04-03 11:40:50 +0200440static inline int reset_deassert_bulk(struct reset_ctl_bulk *bulk)
441{
442 return 0;
443}
444
Andreas Dannenberge7012e62018-08-27 15:57:39 +0530445static inline int reset_status(struct reset_ctl *reset_ctl)
446{
447 return -ENOTSUPP;
448}
449
Patrice Chotard3b9d1bd2017-07-18 11:57:06 +0200450static inline int reset_release_all(struct reset_ctl *reset_ctl, int count)
451{
452 return 0;
453}
454
Neil Armstrong1dd181f2018-04-12 10:03:19 +0200455static inline int reset_release_bulk(struct reset_ctl_bulk *bulk)
Neil Armstrong0c282332018-04-03 11:40:50 +0200456{
457 return 0;
458}
Masahiro Yamada4815db82016-09-21 11:29:01 +0900459#endif
460
Jagan Teki652ee272018-08-06 18:55:06 +0530461/**
462 * reset_valid() - check if reset is valid
463 *
464 * @reset_ctl: the reset to check
465 * @return TRUE if valid, or FALSE
466 */
467static inline bool reset_valid(struct reset_ctl *reset_ctl)
468{
469 return !!reset_ctl->dev;
470}
471
Stephen Warren89c1e2d2016-06-17 09:43:58 -0600472#endif