1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP powerdomain control
4  *
5  * Copyright (C) 2007-2008, 2011 Texas Instruments, Inc.
6  * Copyright (C) 2007-2011 Nokia Corporation
7  *
8  * Written by Paul Walmsley
9  * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
10  * State counting code by Tero Kristo <tero.kristo@nokia.com>
11  */
12 #undef DEBUG
13 
14 #include <linux/cpu_pm.h>
15 #include <linux/kernel.h>
16 #include <linux/types.h>
17 #include <linux/list.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/spinlock.h>
21 #include <trace/events/power.h>
22 
23 #include "cm2xxx_3xxx.h"
24 #include "prcm44xx.h"
25 #include "cm44xx.h"
26 #include "prm2xxx_3xxx.h"
27 #include "prm44xx.h"
28 
29 #include <asm/cpu.h>
30 
31 #include "powerdomain.h"
32 #include "clockdomain.h"
33 #include "voltage.h"
34 
35 #include "soc.h"
36 #include "pm.h"
37 
38 #define PWRDM_TRACE_STATES_FLAG	(1<<31)
39 
40 static void pwrdms_save_context(void);
41 static void pwrdms_restore_context(void);
42 
43 enum {
44 	PWRDM_STATE_NOW = 0,
45 	PWRDM_STATE_PREV,
46 };
47 
48 /*
49  * Types of sleep_switch used internally in omap_set_pwrdm_state()
50  * and its associated static functions
51  *
52  * XXX Better documentation is needed here
53  */
54 #define ALREADYACTIVE_SWITCH		0
55 #define FORCEWAKEUP_SWITCH		1
56 #define LOWPOWERSTATE_SWITCH		2
57 
58 /* pwrdm_list contains all registered struct powerdomains */
59 static LIST_HEAD(pwrdm_list);
60 
61 static struct pwrdm_ops *arch_pwrdm;
62 
63 /* Private functions */
64 
65 static struct powerdomain *_pwrdm_lookup(const char *name)
66 {
67 	struct powerdomain *pwrdm, *temp_pwrdm;
68 
69 	pwrdm = NULL;
70 
71 	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
72 		if (!strcmp(name, temp_pwrdm->name)) {
73 			pwrdm = temp_pwrdm;
74 			break;
75 		}
76 	}
77 
78 	return pwrdm;
79 }
80 
81 /**
82  * _pwrdm_register - register a powerdomain
83  * @pwrdm: struct powerdomain * to register
84  *
85  * Adds a powerdomain to the internal powerdomain list.  Returns
86  * -EINVAL if given a null pointer, -EEXIST if a powerdomain is
87  * already registered by the provided name, or 0 upon success.
88  */
89 static int _pwrdm_register(struct powerdomain *pwrdm)
90 {
91 	int i;
92 	struct voltagedomain *voltdm;
93 
94 	if (!pwrdm || !pwrdm->name)
95 		return -EINVAL;
96 
97 	if (cpu_is_omap44xx() &&
98 	    pwrdm->prcm_partition == OMAP4430_INVALID_PRCM_PARTITION) {
99 		pr_err("powerdomain: %s: missing OMAP4 PRCM partition ID\n",
100 		       pwrdm->name);
101 		return -EINVAL;
102 	}
103 
104 	if (_pwrdm_lookup(pwrdm->name))
105 		return -EEXIST;
106 
107 	if (arch_pwrdm && arch_pwrdm->pwrdm_has_voltdm)
108 		if (!arch_pwrdm->pwrdm_has_voltdm())
109 			goto skip_voltdm;
110 
111 	voltdm = voltdm_lookup(pwrdm->voltdm.name);
112 	if (!voltdm) {
113 		pr_err("powerdomain: %s: voltagedomain %s does not exist\n",
114 		       pwrdm->name, pwrdm->voltdm.name);
115 		return -EINVAL;
116 	}
117 	pwrdm->voltdm.ptr = voltdm;
118 	INIT_LIST_HEAD(&pwrdm->voltdm_node);
119 skip_voltdm:
120 	spin_lock_init(&pwrdm->_lock);
121 
122 	list_add(&pwrdm->node, &pwrdm_list);
123 
124 	/* Initialize the powerdomain's state counter */
125 	for (i = 0; i < PWRDM_MAX_PWRSTS; i++)
126 		pwrdm->state_counter[i] = 0;
127 
128 	pwrdm->ret_logic_off_counter = 0;
129 	for (i = 0; i < pwrdm->banks; i++)
130 		pwrdm->ret_mem_off_counter[i] = 0;
131 
132 	if (arch_pwrdm && arch_pwrdm->pwrdm_wait_transition)
133 		arch_pwrdm->pwrdm_wait_transition(pwrdm);
134 	pwrdm->state = pwrdm_read_pwrst(pwrdm);
135 	pwrdm->state_counter[pwrdm->state] = 1;
136 
137 	pr_debug("powerdomain: registered %s\n", pwrdm->name);
138 
139 	return 0;
140 }
141 
142 static void _update_logic_membank_counters(struct powerdomain *pwrdm)
143 {
144 	int i;
145 	u8 prev_logic_pwrst, prev_mem_pwrst;
146 
147 	prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
148 	if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
149 	    (prev_logic_pwrst == PWRDM_POWER_OFF))
150 		pwrdm->ret_logic_off_counter++;
151 
152 	for (i = 0; i < pwrdm->banks; i++) {
153 		prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);
154 
155 		if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
156 		    (prev_mem_pwrst == PWRDM_POWER_OFF))
157 			pwrdm->ret_mem_off_counter[i]++;
158 	}
159 }
160 
161 static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
162 {
163 
164 	int prev, next, state, trace_state = 0;
165 
166 	if (pwrdm == NULL)
167 		return -EINVAL;
168 
169 	state = pwrdm_read_pwrst(pwrdm);
170 
171 	switch (flag) {
172 	case PWRDM_STATE_NOW:
173 		prev = pwrdm->state;
174 		break;
175 	case PWRDM_STATE_PREV:
176 		prev = pwrdm_read_prev_pwrst(pwrdm);
177 		if (prev >= 0 && pwrdm->state != prev)
178 			pwrdm->state_counter[prev]++;
179 		if (prev == PWRDM_POWER_RET)
180 			_update_logic_membank_counters(pwrdm);
181 		/*
182 		 * If the power domain did not hit the desired state,
183 		 * generate a trace event with both the desired and hit states
184 		 */
185 		next = pwrdm_read_next_pwrst(pwrdm);
186 		if (next != prev) {
187 			trace_state = (PWRDM_TRACE_STATES_FLAG |
188 				       ((next & OMAP_POWERSTATE_MASK) << 8) |
189 				       ((prev & OMAP_POWERSTATE_MASK) << 0));
190 			trace_power_domain_target(pwrdm->name,
191 						  trace_state,
192 						  raw_smp_processor_id());
193 		}
194 		break;
195 	default:
196 		return -EINVAL;
197 	}
198 
199 	if (state != prev)
200 		pwrdm->state_counter[state]++;
201 
202 	pm_dbg_update_time(pwrdm, prev);
203 
204 	pwrdm->state = state;
205 
206 	return 0;
207 }
208 
209 static int _pwrdm_pre_transition_cb(struct powerdomain *pwrdm, void *unused)
210 {
211 	pwrdm_clear_all_prev_pwrst(pwrdm);
212 	_pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
213 	return 0;
214 }
215 
216 static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
217 {
218 	_pwrdm_state_switch(pwrdm, PWRDM_STATE_PREV);
219 	return 0;
220 }
221 
222 /**
223  * _pwrdm_save_clkdm_state_and_activate - prepare for power state change
224  * @pwrdm: struct powerdomain * to operate on
225  * @curr_pwrst: current power state of @pwrdm
226  * @pwrst: power state to switch to
227  *
228  * Determine whether the powerdomain needs to be turned on before
229  * attempting to switch power states.  Called by
230  * omap_set_pwrdm_state().  NOTE that if the powerdomain contains
231  * multiple clockdomains, this code assumes that the first clockdomain
232  * supports software-supervised wakeup mode - potentially a problem.
233  * Returns the power state switch mode currently in use (see the
234  * "Types of sleep_switch" comment above).
235  */
236 static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
237 					       u8 curr_pwrst, u8 pwrst)
238 {
239 	u8 sleep_switch;
240 
241 	if (curr_pwrst < PWRDM_POWER_ON) {
242 		if (curr_pwrst > pwrst &&
243 		    pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
244 		    arch_pwrdm->pwrdm_set_lowpwrstchange) {
245 			sleep_switch = LOWPOWERSTATE_SWITCH;
246 		} else {
247 			clkdm_deny_idle_nolock(pwrdm->pwrdm_clkdms[0]);
248 			sleep_switch = FORCEWAKEUP_SWITCH;
249 		}
250 	} else {
251 		sleep_switch = ALREADYACTIVE_SWITCH;
252 	}
253 
254 	return sleep_switch;
255 }
256 
257 /**
258  * _pwrdm_restore_clkdm_state - restore the clkdm hwsup state after pwrst change
259  * @pwrdm: struct powerdomain * to operate on
260  * @sleep_switch: return value from _pwrdm_save_clkdm_state_and_activate()
261  *
262  * Restore the clockdomain state perturbed by
263  * _pwrdm_save_clkdm_state_and_activate(), and call the power state
264  * bookkeeping code.  Called by omap_set_pwrdm_state().  NOTE that if
265  * the powerdomain contains multiple clockdomains, this assumes that
266  * the first associated clockdomain supports either
267  * hardware-supervised idle control in the register, or
268  * software-supervised sleep.  No return value.
269  */
270 static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
271 				       u8 sleep_switch)
272 {
273 	switch (sleep_switch) {
274 	case FORCEWAKEUP_SWITCH:
275 		clkdm_allow_idle_nolock(pwrdm->pwrdm_clkdms[0]);
276 		break;
277 	case LOWPOWERSTATE_SWITCH:
278 		if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
279 		    arch_pwrdm->pwrdm_set_lowpwrstchange)
280 			arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
281 		pwrdm_state_switch_nolock(pwrdm);
282 		break;
283 	}
284 }
285 
286 /* Public functions */
287 
288 /**
289  * pwrdm_register_platform_funcs - register powerdomain implementation fns
290  * @po: func pointers for arch specific implementations
291  *
292  * Register the list of function pointers used to implement the
293  * powerdomain functions on different OMAP SoCs.  Should be called
294  * before any other pwrdm_register*() function.  Returns -EINVAL if
295  * @po is null, -EEXIST if platform functions have already been
296  * registered, or 0 upon success.
297  */
298 int pwrdm_register_platform_funcs(struct pwrdm_ops *po)
299 {
300 	if (!po)
301 		return -EINVAL;
302 
303 	if (arch_pwrdm)
304 		return -EEXIST;
305 
306 	arch_pwrdm = po;
307 
308 	return 0;
309 }
310 
311 /**
312  * pwrdm_register_pwrdms - register SoC powerdomains
313  * @ps: pointer to an array of struct powerdomain to register
314  *
315  * Register the powerdomains available on a particular OMAP SoC.  Must
316  * be called after pwrdm_register_platform_funcs().  May be called
317  * multiple times.  Returns -EACCES if called before
318  * pwrdm_register_platform_funcs(); -EINVAL if the argument @ps is
319  * null; or 0 upon success.
320  */
321 int pwrdm_register_pwrdms(struct powerdomain **ps)
322 {
323 	struct powerdomain **p = NULL;
324 
325 	if (!arch_pwrdm)
326 		return -EEXIST;
327 
328 	if (!ps)
329 		return -EINVAL;
330 
331 	for (p = ps; *p; p++)
332 		_pwrdm_register(*p);
333 
334 	return 0;
335 }
336 
337 static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
338 {
339 	switch (cmd) {
340 	case CPU_CLUSTER_PM_ENTER:
341 		if (enable_off_mode)
342 			pwrdms_save_context();
343 		break;
344 	case CPU_CLUSTER_PM_EXIT:
345 		if (enable_off_mode)
346 			pwrdms_restore_context();
347 		break;
348 	}
349 
350 	return NOTIFY_OK;
351 }
352 
353 /**
354  * pwrdm_complete_init - set up the powerdomain layer
355  *
356  * Do whatever is necessary to initialize registered powerdomains and
357  * powerdomain code.  Currently, this programs the next power state
358  * for each powerdomain to ON.  This prevents powerdomains from
359  * unexpectedly losing context or entering high wakeup latency modes
360  * with non-power-management-enabled kernels.  Must be called after
361  * pwrdm_register_pwrdms().  Returns -EACCES if called before
362  * pwrdm_register_pwrdms(), or 0 upon success.
363  */
364 int pwrdm_complete_init(void)
365 {
366 	struct powerdomain *temp_p;
367 	static struct notifier_block nb;
368 
369 	if (list_empty(&pwrdm_list))
370 		return -EACCES;
371 
372 	list_for_each_entry(temp_p, &pwrdm_list, node)
373 		pwrdm_set_next_pwrst(temp_p, PWRDM_POWER_ON);
374 
375 	/* Only AM43XX can lose pwrdm context during rtc-ddr suspend */
376 	if (soc_is_am43xx()) {
377 		nb.notifier_call = cpu_notifier;
378 		cpu_pm_register_notifier(&nb);
379 	}
380 
381 	return 0;
382 }
383 
384 /**
385  * pwrdm_lock - acquire a Linux spinlock on a powerdomain
386  * @pwrdm: struct powerdomain * to lock
387  *
388  * Acquire the powerdomain spinlock on @pwrdm.  No return value.
389  */
390 void pwrdm_lock(struct powerdomain *pwrdm)
391 	__acquires(&pwrdm->_lock)
392 {
393 	spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags);
394 }
395 
396 /**
397  * pwrdm_unlock - release a Linux spinlock on a powerdomain
398  * @pwrdm: struct powerdomain * to unlock
399  *
400  * Release the powerdomain spinlock on @pwrdm.  No return value.
401  */
402 void pwrdm_unlock(struct powerdomain *pwrdm)
403 	__releases(&pwrdm->_lock)
404 {
405 	spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags);
406 }
407 
408 /**
409  * pwrdm_lookup - look up a powerdomain by name, return a pointer
410  * @name: name of powerdomain
411  *
412  * Find a registered powerdomain by its name @name.  Returns a pointer
413  * to the struct powerdomain if found, or NULL otherwise.
414  */
415 struct powerdomain *pwrdm_lookup(const char *name)
416 {
417 	struct powerdomain *pwrdm;
418 
419 	if (!name)
420 		return NULL;
421 
422 	pwrdm = _pwrdm_lookup(name);
423 
424 	return pwrdm;
425 }
426 
427 /**
428  * pwrdm_for_each - call function on each registered clockdomain
429  * @fn: callback function *
430  *
431  * Call the supplied function @fn for each registered powerdomain.
432  * The callback function @fn can return anything but 0 to bail out
433  * early from the iterator.  Returns the last return value of the
434  * callback function, which should be 0 for success or anything else
435  * to indicate failure; or -EINVAL if the function pointer is null.
436  */
437 int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
438 		   void *user)
439 {
440 	struct powerdomain *temp_pwrdm;
441 	int ret = 0;
442 
443 	if (!fn)
444 		return -EINVAL;
445 
446 	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
447 		ret = (*fn)(temp_pwrdm, user);
448 		if (ret)
449 			break;
450 	}
451 
452 	return ret;
453 }
454 
455 /**
456  * pwrdm_add_clkdm - add a clockdomain to a powerdomain
457  * @pwrdm: struct powerdomain * to add the clockdomain to
458  * @clkdm: struct clockdomain * to associate with a powerdomain
459  *
460  * Associate the clockdomain @clkdm with a powerdomain @pwrdm.  This
461  * enables the use of pwrdm_for_each_clkdm().  Returns -EINVAL if
462  * presented with invalid pointers; -ENOMEM if memory could not be allocated;
463  * or 0 upon success.
464  */
465 int pwrdm_add_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
466 {
467 	int i;
468 	int ret = -EINVAL;
469 
470 	if (!pwrdm || !clkdm)
471 		return -EINVAL;
472 
473 	pr_debug("powerdomain: %s: associating clockdomain %s\n",
474 		 pwrdm->name, clkdm->name);
475 
476 	for (i = 0; i < PWRDM_MAX_CLKDMS; i++) {
477 		if (!pwrdm->pwrdm_clkdms[i])
478 			break;
479 #ifdef DEBUG
480 		if (pwrdm->pwrdm_clkdms[i] == clkdm) {
481 			ret = -EINVAL;
482 			goto pac_exit;
483 		}
484 #endif
485 	}
486 
487 	if (i == PWRDM_MAX_CLKDMS) {
488 		pr_debug("powerdomain: %s: increase PWRDM_MAX_CLKDMS for clkdm %s\n",
489 			 pwrdm->name, clkdm->name);
490 		WARN_ON(1);
491 		ret = -ENOMEM;
492 		goto pac_exit;
493 	}
494 
495 	pwrdm->pwrdm_clkdms[i] = clkdm;
496 
497 	ret = 0;
498 
499 pac_exit:
500 	return ret;
501 }
502 
503 /**
504  * pwrdm_get_mem_bank_count - get number of memory banks in this powerdomain
505  * @pwrdm: struct powerdomain *
506  *
507  * Return the number of controllable memory banks in powerdomain @pwrdm,
508  * starting with 1.  Returns -EINVAL if the powerdomain pointer is null.
509  */
510 int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
511 {
512 	if (!pwrdm)
513 		return -EINVAL;
514 
515 	return pwrdm->banks;
516 }
517 
518 /**
519  * pwrdm_set_next_pwrst - set next powerdomain power state
520  * @pwrdm: struct powerdomain * to set
521  * @pwrst: one of the PWRDM_POWER_* macros
522  *
523  * Set the powerdomain @pwrdm's next power state to @pwrst.  The powerdomain
524  * may not enter this state immediately if the preconditions for this state
525  * have not been satisfied.  Returns -EINVAL if the powerdomain pointer is
526  * null or if the power state is invalid for the powerdomin, or returns 0
527  * upon success.
528  */
529 int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
530 {
531 	int ret = -EINVAL;
532 
533 	if (!pwrdm)
534 		return -EINVAL;
535 
536 	if (!(pwrdm->pwrsts & (1 << pwrst)))
537 		return -EINVAL;
538 
539 	pr_debug("powerdomain: %s: setting next powerstate to %0x\n",
540 		 pwrdm->name, pwrst);
541 
542 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
543 		/* Trace the pwrdm desired target state */
544 		trace_power_domain_target(pwrdm->name, pwrst,
545 					  raw_smp_processor_id());
546 		/* Program the pwrdm desired target state */
547 		ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
548 	}
549 
550 	return ret;
551 }
552 
553 /**
554  * pwrdm_read_next_pwrst - get next powerdomain power state
555  * @pwrdm: struct powerdomain * to get power state
556  *
557  * Return the powerdomain @pwrdm's next power state.  Returns -EINVAL
558  * if the powerdomain pointer is null or returns the next power state
559  * upon success.
560  */
561 int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
562 {
563 	int ret = -EINVAL;
564 
565 	if (!pwrdm)
566 		return -EINVAL;
567 
568 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_next_pwrst)
569 		ret = arch_pwrdm->pwrdm_read_next_pwrst(pwrdm);
570 
571 	return ret;
572 }
573 
574 /**
575  * pwrdm_read_pwrst - get current powerdomain power state
576  * @pwrdm: struct powerdomain * to get power state
577  *
578  * Return the powerdomain @pwrdm's current power state.	Returns -EINVAL
579  * if the powerdomain pointer is null or returns the current power state
580  * upon success. Note that if the power domain only supports the ON state
581  * then just return ON as the current state.
582  */
583 int pwrdm_read_pwrst(struct powerdomain *pwrdm)
584 {
585 	int ret = -EINVAL;
586 
587 	if (!pwrdm)
588 		return -EINVAL;
589 
590 	if (pwrdm->pwrsts == PWRSTS_ON)
591 		return PWRDM_POWER_ON;
592 
593 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_pwrst)
594 		ret = arch_pwrdm->pwrdm_read_pwrst(pwrdm);
595 
596 	return ret;
597 }
598 
599 /**
600  * pwrdm_read_prev_pwrst - get previous powerdomain power state
601  * @pwrdm: struct powerdomain * to get previous power state
602  *
603  * Return the powerdomain @pwrdm's previous power state.  Returns -EINVAL
604  * if the powerdomain pointer is null or returns the previous power state
605  * upon success.
606  */
607 int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
608 {
609 	int ret = -EINVAL;
610 
611 	if (!pwrdm)
612 		return -EINVAL;
613 
614 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_pwrst)
615 		ret = arch_pwrdm->pwrdm_read_prev_pwrst(pwrdm);
616 
617 	return ret;
618 }
619 
620 /**
621  * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
622  * @pwrdm: struct powerdomain * to set
623  * @pwrst: one of the PWRDM_POWER_* macros
624  *
625  * Set the next power state @pwrst that the logic portion of the
626  * powerdomain @pwrdm will enter when the powerdomain enters retention.
627  * This will be either RETENTION or OFF, if supported.  Returns
628  * -EINVAL if the powerdomain pointer is null or the target power
629  * state is not supported, or returns 0 upon success.
630  */
631 int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
632 {
633 	int ret = -EINVAL;
634 
635 	if (!pwrdm)
636 		return -EINVAL;
637 
638 	if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
639 		return -EINVAL;
640 
641 	pr_debug("powerdomain: %s: setting next logic powerstate to %0x\n",
642 		 pwrdm->name, pwrst);
643 
644 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_logic_retst)
645 		ret = arch_pwrdm->pwrdm_set_logic_retst(pwrdm, pwrst);
646 
647 	return ret;
648 }
649 
650 /**
651  * pwrdm_set_mem_onst - set memory power state while powerdomain ON
652  * @pwrdm: struct powerdomain * to set
653  * @bank: memory bank number to set (0-3)
654  * @pwrst: one of the PWRDM_POWER_* macros
655  *
656  * Set the next power state @pwrst that memory bank @bank of the
657  * powerdomain @pwrdm will enter when the powerdomain enters the ON
658  * state.  @bank will be a number from 0 to 3, and represents different
659  * types of memory, depending on the powerdomain.  Returns -EINVAL if
660  * the powerdomain pointer is null or the target power state is not
661  * supported for this memory bank, -EEXIST if the target memory
662  * bank does not exist or is not controllable, or returns 0 upon
663  * success.
664  */
665 int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
666 {
667 	int ret = -EINVAL;
668 
669 	if (!pwrdm)
670 		return -EINVAL;
671 
672 	if (pwrdm->banks < (bank + 1))
673 		return -EEXIST;
674 
675 	if (!(pwrdm->pwrsts_mem_on[bank] & (1 << pwrst)))
676 		return -EINVAL;
677 
678 	pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-ON to %0x\n",
679 		 pwrdm->name, bank, pwrst);
680 
681 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_onst)
682 		ret = arch_pwrdm->pwrdm_set_mem_onst(pwrdm, bank, pwrst);
683 
684 	return ret;
685 }
686 
687 /**
688  * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
689  * @pwrdm: struct powerdomain * to set
690  * @bank: memory bank number to set (0-3)
691  * @pwrst: one of the PWRDM_POWER_* macros
692  *
693  * Set the next power state @pwrst that memory bank @bank of the
694  * powerdomain @pwrdm will enter when the powerdomain enters the
695  * RETENTION state.  Bank will be a number from 0 to 3, and represents
696  * different types of memory, depending on the powerdomain.  @pwrst
697  * will be either RETENTION or OFF, if supported.  Returns -EINVAL if
698  * the powerdomain pointer is null or the target power state is not
699  * supported for this memory bank, -EEXIST if the target memory
700  * bank does not exist or is not controllable, or returns 0 upon
701  * success.
702  */
703 int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
704 {
705 	int ret = -EINVAL;
706 
707 	if (!pwrdm)
708 		return -EINVAL;
709 
710 	if (pwrdm->banks < (bank + 1))
711 		return -EEXIST;
712 
713 	if (!(pwrdm->pwrsts_mem_ret[bank] & (1 << pwrst)))
714 		return -EINVAL;
715 
716 	pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-RET to %0x\n",
717 		 pwrdm->name, bank, pwrst);
718 
719 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_retst)
720 		ret = arch_pwrdm->pwrdm_set_mem_retst(pwrdm, bank, pwrst);
721 
722 	return ret;
723 }
724 
725 /**
726  * pwrdm_read_logic_pwrst - get current powerdomain logic retention power state
727  * @pwrdm: struct powerdomain * to get current logic retention power state
728  *
729  * Return the power state that the logic portion of powerdomain @pwrdm
730  * will enter when the powerdomain enters retention.  Returns -EINVAL
731  * if the powerdomain pointer is null or returns the logic retention
732  * power state upon success.
733  */
734 int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
735 {
736 	int ret = -EINVAL;
737 
738 	if (!pwrdm)
739 		return -EINVAL;
740 
741 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_pwrst)
742 		ret = arch_pwrdm->pwrdm_read_logic_pwrst(pwrdm);
743 
744 	return ret;
745 }
746 
747 /**
748  * pwrdm_read_prev_logic_pwrst - get previous powerdomain logic power state
749  * @pwrdm: struct powerdomain * to get previous logic power state
750  *
751  * Return the powerdomain @pwrdm's previous logic power state.  Returns
752  * -EINVAL if the powerdomain pointer is null or returns the previous
753  * logic power state upon success.
754  */
755 int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
756 {
757 	int ret = -EINVAL;
758 
759 	if (!pwrdm)
760 		return -EINVAL;
761 
762 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_logic_pwrst)
763 		ret = arch_pwrdm->pwrdm_read_prev_logic_pwrst(pwrdm);
764 
765 	return ret;
766 }
767 
768 /**
769  * pwrdm_read_logic_retst - get next powerdomain logic power state
770  * @pwrdm: struct powerdomain * to get next logic power state
771  *
772  * Return the powerdomain pwrdm's logic power state.  Returns -EINVAL
773  * if the powerdomain pointer is null or returns the next logic
774  * power state upon success.
775  */
776 int pwrdm_read_logic_retst(struct powerdomain *pwrdm)
777 {
778 	int ret = -EINVAL;
779 
780 	if (!pwrdm)
781 		return -EINVAL;
782 
783 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_retst)
784 		ret = arch_pwrdm->pwrdm_read_logic_retst(pwrdm);
785 
786 	return ret;
787 }
788 
789 /**
790  * pwrdm_read_mem_pwrst - get current memory bank power state
791  * @pwrdm: struct powerdomain * to get current memory bank power state
792  * @bank: memory bank number (0-3)
793  *
794  * Return the powerdomain @pwrdm's current memory power state for bank
795  * @bank.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
796  * the target memory bank does not exist or is not controllable, or
797  * returns the current memory power state upon success.
798  */
799 int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
800 {
801 	int ret = -EINVAL;
802 
803 	if (!pwrdm)
804 		return ret;
805 
806 	if (pwrdm->banks < (bank + 1))
807 		return ret;
808 
809 	if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
810 		bank = 1;
811 
812 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_pwrst)
813 		ret = arch_pwrdm->pwrdm_read_mem_pwrst(pwrdm, bank);
814 
815 	return ret;
816 }
817 
818 /**
819  * pwrdm_read_prev_mem_pwrst - get previous memory bank power state
820  * @pwrdm: struct powerdomain * to get previous memory bank power state
821  * @bank: memory bank number (0-3)
822  *
823  * Return the powerdomain @pwrdm's previous memory power state for
824  * bank @bank.  Returns -EINVAL if the powerdomain pointer is null,
825  * -EEXIST if the target memory bank does not exist or is not
826  * controllable, or returns the previous memory power state upon
827  * success.
828  */
829 int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
830 {
831 	int ret = -EINVAL;
832 
833 	if (!pwrdm)
834 		return ret;
835 
836 	if (pwrdm->banks < (bank + 1))
837 		return ret;
838 
839 	if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
840 		bank = 1;
841 
842 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_mem_pwrst)
843 		ret = arch_pwrdm->pwrdm_read_prev_mem_pwrst(pwrdm, bank);
844 
845 	return ret;
846 }
847 
848 /**
849  * pwrdm_read_mem_retst - get next memory bank power state
850  * @pwrdm: struct powerdomain * to get mext memory bank power state
851  * @bank: memory bank number (0-3)
852  *
853  * Return the powerdomain pwrdm's next memory power state for bank
854  * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
855  * the target memory bank does not exist or is not controllable, or
856  * returns the next memory power state upon success.
857  */
858 int pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
859 {
860 	int ret = -EINVAL;
861 
862 	if (!pwrdm)
863 		return ret;
864 
865 	if (pwrdm->banks < (bank + 1))
866 		return ret;
867 
868 	if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_retst)
869 		ret = arch_pwrdm->pwrdm_read_mem_retst(pwrdm, bank);
870 
871 	return ret;
872 }
873 
874 /**
875  * pwrdm_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
876  * @pwrdm: struct powerdomain * to clear
877  *
878  * Clear the powerdomain's previous power state register @pwrdm.
879  * Clears the entire register, including logic and memory bank
880  * previous power states.  Returns -EINVAL if the powerdomain pointer
881  * is null, or returns 0 upon success.
882  */
883 int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
884 {
885 	int ret = -EINVAL;
886 
887 	if (!pwrdm)
888 		return ret;
889 
890 	/*
891 	 * XXX should get the powerdomain's current state here;
892 	 * warn & fail if it is not ON.
893 	 */
894 
895 	pr_debug("powerdomain: %s: clearing previous power state reg\n",
896 		 pwrdm->name);
897 
898 	if (arch_pwrdm && arch_pwrdm->pwrdm_clear_all_prev_pwrst)
899 		ret = arch_pwrdm->pwrdm_clear_all_prev_pwrst(pwrdm);
900 
901 	return ret;
902 }
903 
904 /**
905  * pwrdm_enable_hdwr_sar - enable automatic hardware SAR for a pwrdm
906  * @pwrdm: struct powerdomain *
907  *
908  * Enable automatic context save-and-restore upon power state change
909  * for some devices in the powerdomain @pwrdm.  Warning: this only
910  * affects a subset of devices in a powerdomain; check the TRM
911  * closely.  Returns -EINVAL if the powerdomain pointer is null or if
912  * the powerdomain does not support automatic save-and-restore, or
913  * returns 0 upon success.
914  */
915 int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm)
916 {
917 	int ret = -EINVAL;
918 
919 	if (!pwrdm)
920 		return ret;
921 
922 	if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
923 		return ret;
924 
925 	pr_debug("powerdomain: %s: setting SAVEANDRESTORE bit\n", pwrdm->name);
926 
927 	if (arch_pwrdm && arch_pwrdm->pwrdm_enable_hdwr_sar)
928 		ret = arch_pwrdm->pwrdm_enable_hdwr_sar(pwrdm);
929 
930 	return ret;
931 }
932 
933 /**
934  * pwrdm_disable_hdwr_sar - disable automatic hardware SAR for a pwrdm
935  * @pwrdm: struct powerdomain *
936  *
937  * Disable automatic context save-and-restore upon power state change
938  * for some devices in the powerdomain @pwrdm.  Warning: this only
939  * affects a subset of devices in a powerdomain; check the TRM
940  * closely.  Returns -EINVAL if the powerdomain pointer is null or if
941  * the powerdomain does not support automatic save-and-restore, or
942  * returns 0 upon success.
943  */
944 int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm)
945 {
946 	int ret = -EINVAL;
947 
948 	if (!pwrdm)
949 		return ret;
950 
951 	if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
952 		return ret;
953 
954 	pr_debug("powerdomain: %s: clearing SAVEANDRESTORE bit\n", pwrdm->name);
955 
956 	if (arch_pwrdm && arch_pwrdm->pwrdm_disable_hdwr_sar)
957 		ret = arch_pwrdm->pwrdm_disable_hdwr_sar(pwrdm);
958 
959 	return ret;
960 }
961 
962 /**
963  * pwrdm_has_hdwr_sar - test whether powerdomain supports hardware SAR
964  * @pwrdm: struct powerdomain *
965  *
966  * Returns 1 if powerdomain @pwrdm supports hardware save-and-restore
967  * for some devices, or 0 if it does not.
968  */
969 bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
970 {
971 	return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
972 }
973 
974 int pwrdm_state_switch_nolock(struct powerdomain *pwrdm)
975 {
976 	int ret;
977 
978 	if (!pwrdm || !arch_pwrdm)
979 		return -EINVAL;
980 
981 	ret = arch_pwrdm->pwrdm_wait_transition(pwrdm);
982 	if (!ret)
983 		ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
984 
985 	return ret;
986 }
987 
988 int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm)
989 {
990 	int ret;
991 
992 	pwrdm_lock(pwrdm);
993 	ret = pwrdm_state_switch_nolock(pwrdm);
994 	pwrdm_unlock(pwrdm);
995 
996 	return ret;
997 }
998 
999 int pwrdm_pre_transition(struct powerdomain *pwrdm)
1000 {
1001 	if (pwrdm)
1002 		_pwrdm_pre_transition_cb(pwrdm, NULL);
1003 	else
1004 		pwrdm_for_each(_pwrdm_pre_transition_cb, NULL);
1005 
1006 	return 0;
1007 }
1008 
1009 int pwrdm_post_transition(struct powerdomain *pwrdm)
1010 {
1011 	if (pwrdm)
1012 		_pwrdm_post_transition_cb(pwrdm, NULL);
1013 	else
1014 		pwrdm_for_each(_pwrdm_post_transition_cb, NULL);
1015 
1016 	return 0;
1017 }
1018 
1019 /**
1020  * pwrdm_get_valid_lp_state() - Find best match deep power state
1021  * @pwrdm:	power domain for which we want to find best match
1022  * @is_logic_state: Are we looking for logic state match here? Should
1023  *		    be one of PWRDM_xxx macro values
1024  * @req_state:	requested power state
1025  *
1026  * Returns: closest match for requested power state. default fallback
1027  * is RET for logic state and ON for power state.
1028  *
1029  * This does a search from the power domain data looking for the
1030  * closest valid power domain state that the hardware can achieve.
1031  * PRCM definitions for PWRSTCTRL allows us to program whatever
1032  * configuration we'd like, and PRCM will actually attempt such
1033  * a transition, however if the powerdomain does not actually support it,
1034  * we endup with a hung system. The valid power domain states are already
1035  * available in our powerdomain data files. So this function tries to do
1036  * the following:
1037  * a) find if we have an exact match to the request - no issues.
1038  * b) else find if a deeper power state is possible.
1039  * c) failing which, it tries to find closest higher power state for the
1040  * request.
1041  */
1042 u8 pwrdm_get_valid_lp_state(struct powerdomain *pwrdm,
1043 			    bool is_logic_state, u8 req_state)
1044 {
1045 	u8 pwrdm_states = is_logic_state ? pwrdm->pwrsts_logic_ret :
1046 			pwrdm->pwrsts;
1047 	/* For logic, ret is highest and others, ON is highest */
1048 	u8 default_pwrst = is_logic_state ? PWRDM_POWER_RET : PWRDM_POWER_ON;
1049 	u8 new_pwrst;
1050 	bool found;
1051 
1052 	/* If it is already supported, nothing to search */
1053 	if (pwrdm_states & BIT(req_state))
1054 		return req_state;
1055 
1056 	if (!req_state)
1057 		goto up_search;
1058 
1059 	/*
1060 	 * So, we dont have a exact match
1061 	 * Can we get a deeper power state match?
1062 	 */
1063 	new_pwrst = req_state - 1;
1064 	found = true;
1065 	while (!(pwrdm_states & BIT(new_pwrst))) {
1066 		/* No match even at OFF? Not available */
1067 		if (new_pwrst == PWRDM_POWER_OFF) {
1068 			found = false;
1069 			break;
1070 		}
1071 		new_pwrst--;
1072 	}
1073 
1074 	if (found)
1075 		goto done;
1076 
1077 up_search:
1078 	/* OK, no deeper ones, can we get a higher match? */
1079 	new_pwrst = req_state + 1;
1080 	while (!(pwrdm_states & BIT(new_pwrst))) {
1081 		if (new_pwrst > PWRDM_POWER_ON) {
1082 			WARN(1, "powerdomain: %s: Fix max powerstate to ON\n",
1083 			     pwrdm->name);
1084 			return PWRDM_POWER_ON;
1085 		}
1086 
1087 		if (new_pwrst == default_pwrst)
1088 			break;
1089 		new_pwrst++;
1090 	}
1091 done:
1092 	return new_pwrst;
1093 }
1094 
1095 /**
1096  * omap_set_pwrdm_state - change a powerdomain's current power state
1097  * @pwrdm: struct powerdomain * to change the power state of
1098  * @pwrst: power state to change to
1099  *
1100  * Change the current hardware power state of the powerdomain
1101  * represented by @pwrdm to the power state represented by @pwrst.
1102  * Returns -EINVAL if @pwrdm is null or invalid or if the
1103  * powerdomain's current power state could not be read, or returns 0
1104  * upon success or if @pwrdm does not support @pwrst or any
1105  * lower-power state.  XXX Should not return 0 if the @pwrdm does not
1106  * support @pwrst or any lower-power state: this should be an error.
1107  */
1108 int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
1109 {
1110 	u8 next_pwrst, sleep_switch;
1111 	int curr_pwrst;
1112 	int ret = 0;
1113 
1114 	if (!pwrdm || IS_ERR(pwrdm))
1115 		return -EINVAL;
1116 
1117 	while (!(pwrdm->pwrsts & (1 << pwrst))) {
1118 		if (pwrst == PWRDM_POWER_OFF)
1119 			return ret;
1120 		pwrst--;
1121 	}
1122 
1123 	pwrdm_lock(pwrdm);
1124 
1125 	curr_pwrst = pwrdm_read_pwrst(pwrdm);
1126 	if (curr_pwrst < 0) {
1127 		ret = -EINVAL;
1128 		goto osps_out;
1129 	}
1130 
1131 	next_pwrst = pwrdm_read_next_pwrst(pwrdm);
1132 	if (curr_pwrst == pwrst && next_pwrst == pwrst)
1133 		goto osps_out;
1134 
1135 	sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
1136 							    pwrst);
1137 
1138 	ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
1139 	if (ret)
1140 		pr_err("%s: unable to set power state of powerdomain: %s\n",
1141 		       __func__, pwrdm->name);
1142 
1143 	_pwrdm_restore_clkdm_state(pwrdm, sleep_switch);
1144 
1145 osps_out:
1146 	pwrdm_unlock(pwrdm);
1147 
1148 	return ret;
1149 }
1150 
1151 /**
1152  * pwrdm_save_context - save powerdomain registers
1153  *
1154  * Register state is going to be lost due to a suspend or hibernate
1155  * event. Save the powerdomain registers.
1156  */
1157 static int pwrdm_save_context(struct powerdomain *pwrdm, void *unused)
1158 {
1159 	if (arch_pwrdm && arch_pwrdm->pwrdm_save_context)
1160 		arch_pwrdm->pwrdm_save_context(pwrdm);
1161 	return 0;
1162 }
1163 
1164 /**
1165  * pwrdm_save_context - restore powerdomain registers
1166  *
1167  * Restore powerdomain control registers after a suspend or resume
1168  * event.
1169  */
1170 static int pwrdm_restore_context(struct powerdomain *pwrdm, void *unused)
1171 {
1172 	if (arch_pwrdm && arch_pwrdm->pwrdm_restore_context)
1173 		arch_pwrdm->pwrdm_restore_context(pwrdm);
1174 	return 0;
1175 }
1176 
1177 static void pwrdms_save_context(void)
1178 {
1179 	pwrdm_for_each(pwrdm_save_context, NULL);
1180 }
1181 
1182 static void pwrdms_restore_context(void)
1183 {
1184 	pwrdm_for_each(pwrdm_restore_context, NULL);
1185 }
1186