1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * linux/arch/arm/plat-omap/dmtimer.c
4  *
5  * OMAP Dual-Mode Timers
6  *
7  * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
8  * Tarun Kanti DebBarma <tarun.kanti@ti.com>
9  * Thara Gopinath <thara@ti.com>
10  *
11  * dmtimer adaptation to platform_driver.
12  *
13  * Copyright (C) 2005 Nokia Corporation
14  * OMAP2 support by Juha Yrjola
15  * API improvements and OMAP2 clock framework support by Timo Teras
16  *
17  * Copyright (C) 2009 Texas Instruments
18  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
19  */
20 
21 #include <linux/clk.h>
22 #include <linux/clk-provider.h>
23 #include <linux/cpu_pm.h>
24 #include <linux/module.h>
25 #include <linux/io.h>
26 #include <linux/device.h>
27 #include <linux/err.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/platform_device.h>
32 #include <linux/platform_data/dmtimer-omap.h>
33 
34 #include <clocksource/timer-ti-dm.h>
35 
36 static u32 omap_reserved_systimers;
37 static LIST_HEAD(omap_timer_list);
38 static DEFINE_SPINLOCK(dm_timer_lock);
39 
40 enum {
41 	REQUEST_ANY = 0,
42 	REQUEST_BY_ID,
43 	REQUEST_BY_CAP,
44 	REQUEST_BY_NODE,
45 };
46 
47 /**
48  * omap_dm_timer_read_reg - read timer registers in posted and non-posted mode
49  * @timer:      timer pointer over which read operation to perform
50  * @reg:        lowest byte holds the register offset
51  *
52  * The posted mode bit is encoded in reg. Note that in posted mode write
53  * pending bit must be checked. Otherwise a read of a non completed write
54  * will produce an error.
55  */
56 static inline u32 omap_dm_timer_read_reg(struct omap_dm_timer *timer, u32 reg)
57 {
58 	WARN_ON((reg & 0xff) < _OMAP_TIMER_WAKEUP_EN_OFFSET);
59 	return __omap_dm_timer_read(timer, reg, timer->posted);
60 }
61 
62 /**
63  * omap_dm_timer_write_reg - write timer registers in posted and non-posted mode
64  * @timer:      timer pointer over which write operation is to perform
65  * @reg:        lowest byte holds the register offset
66  * @value:      data to write into the register
67  *
68  * The posted mode bit is encoded in reg. Note that in posted mode the write
69  * pending bit must be checked. Otherwise a write on a register which has a
70  * pending write will be lost.
71  */
72 static void omap_dm_timer_write_reg(struct omap_dm_timer *timer, u32 reg,
73 						u32 value)
74 {
75 	WARN_ON((reg & 0xff) < _OMAP_TIMER_WAKEUP_EN_OFFSET);
76 	__omap_dm_timer_write(timer, reg, value, timer->posted);
77 }
78 
79 static void omap_timer_restore_context(struct omap_dm_timer *timer)
80 {
81 	omap_dm_timer_write_reg(timer, OMAP_TIMER_WAKEUP_EN_REG,
82 				timer->context.twer);
83 	omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG,
84 				timer->context.tcrr);
85 	omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG,
86 				timer->context.tldr);
87 	omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG,
88 				timer->context.tmar);
89 	omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG,
90 				timer->context.tsicr);
91 	writel_relaxed(timer->context.tier, timer->irq_ena);
92 	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG,
93 				timer->context.tclr);
94 }
95 
96 static void omap_timer_save_context(struct omap_dm_timer *timer)
97 {
98 	timer->context.tclr =
99 			omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
100 	timer->context.twer =
101 			omap_dm_timer_read_reg(timer, OMAP_TIMER_WAKEUP_EN_REG);
102 	timer->context.tldr =
103 			omap_dm_timer_read_reg(timer, OMAP_TIMER_LOAD_REG);
104 	timer->context.tmar =
105 			omap_dm_timer_read_reg(timer, OMAP_TIMER_MATCH_REG);
106 	timer->context.tier = readl_relaxed(timer->irq_ena);
107 	timer->context.tsicr =
108 			omap_dm_timer_read_reg(timer, OMAP_TIMER_IF_CTRL_REG);
109 }
110 
111 static int omap_timer_context_notifier(struct notifier_block *nb,
112 				       unsigned long cmd, void *v)
113 {
114 	struct omap_dm_timer *timer;
115 
116 	timer = container_of(nb, struct omap_dm_timer, nb);
117 
118 	switch (cmd) {
119 	case CPU_CLUSTER_PM_ENTER:
120 		if ((timer->capability & OMAP_TIMER_ALWON) ||
121 		    !atomic_read(&timer->enabled))
122 			break;
123 		omap_timer_save_context(timer);
124 		break;
125 	case CPU_CLUSTER_PM_ENTER_FAILED:
126 	case CPU_CLUSTER_PM_EXIT:
127 		if ((timer->capability & OMAP_TIMER_ALWON) ||
128 		    !atomic_read(&timer->enabled))
129 			break;
130 		omap_timer_restore_context(timer);
131 		break;
132 	}
133 
134 	return NOTIFY_OK;
135 }
136 
137 static int omap_dm_timer_reset(struct omap_dm_timer *timer)
138 {
139 	u32 l, timeout = 100000;
140 
141 	if (timer->revision != 1)
142 		return -EINVAL;
143 
144 	omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG, 0x06);
145 
146 	do {
147 		l = __omap_dm_timer_read(timer,
148 					 OMAP_TIMER_V1_SYS_STAT_OFFSET, 0);
149 	} while (!l && timeout--);
150 
151 	if (!timeout) {
152 		dev_err(&timer->pdev->dev, "Timer failed to reset\n");
153 		return -ETIMEDOUT;
154 	}
155 
156 	/* Configure timer for smart-idle mode */
157 	l = __omap_dm_timer_read(timer, OMAP_TIMER_OCP_CFG_OFFSET, 0);
158 	l |= 0x2 << 0x3;
159 	__omap_dm_timer_write(timer, OMAP_TIMER_OCP_CFG_OFFSET, l, 0);
160 
161 	timer->posted = 0;
162 
163 	return 0;
164 }
165 
166 static int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
167 {
168 	int ret;
169 	const char *parent_name;
170 	struct clk *parent;
171 	struct dmtimer_platform_data *pdata;
172 
173 	if (unlikely(!timer) || IS_ERR(timer->fclk))
174 		return -EINVAL;
175 
176 	switch (source) {
177 	case OMAP_TIMER_SRC_SYS_CLK:
178 		parent_name = "timer_sys_ck";
179 		break;
180 	case OMAP_TIMER_SRC_32_KHZ:
181 		parent_name = "timer_32k_ck";
182 		break;
183 	case OMAP_TIMER_SRC_EXT_CLK:
184 		parent_name = "timer_ext_ck";
185 		break;
186 	default:
187 		return -EINVAL;
188 	}
189 
190 	pdata = timer->pdev->dev.platform_data;
191 
192 	/*
193 	 * FIXME: Used for OMAP1 devices only because they do not currently
194 	 * use the clock framework to set the parent clock. To be removed
195 	 * once OMAP1 migrated to using clock framework for dmtimers
196 	 */
197 	if (pdata && pdata->set_timer_src)
198 		return pdata->set_timer_src(timer->pdev, source);
199 
200 #if defined(CONFIG_COMMON_CLK)
201 	/* Check if the clock has configurable parents */
202 	if (clk_hw_get_num_parents(__clk_get_hw(timer->fclk)) < 2)
203 		return 0;
204 #endif
205 
206 	parent = clk_get(&timer->pdev->dev, parent_name);
207 	if (IS_ERR(parent)) {
208 		pr_err("%s: %s not found\n", __func__, parent_name);
209 		return -EINVAL;
210 	}
211 
212 	ret = clk_set_parent(timer->fclk, parent);
213 	if (ret < 0)
214 		pr_err("%s: failed to set %s as parent\n", __func__,
215 			parent_name);
216 
217 	clk_put(parent);
218 
219 	return ret;
220 }
221 
222 static void omap_dm_timer_enable(struct omap_dm_timer *timer)
223 {
224 	pm_runtime_get_sync(&timer->pdev->dev);
225 }
226 
227 static void omap_dm_timer_disable(struct omap_dm_timer *timer)
228 {
229 	pm_runtime_put_sync(&timer->pdev->dev);
230 }
231 
232 static int omap_dm_timer_prepare(struct omap_dm_timer *timer)
233 {
234 	int rc;
235 
236 	/*
237 	 * FIXME: OMAP1 devices do not use the clock framework for dmtimers so
238 	 * do not call clk_get() for these devices.
239 	 */
240 	if (!(timer->capability & OMAP_TIMER_NEEDS_RESET)) {
241 		timer->fclk = clk_get(&timer->pdev->dev, "fck");
242 		if (WARN_ON_ONCE(IS_ERR(timer->fclk))) {
243 			dev_err(&timer->pdev->dev, ": No fclk handle.\n");
244 			return -EINVAL;
245 		}
246 	}
247 
248 	omap_dm_timer_enable(timer);
249 
250 	if (timer->capability & OMAP_TIMER_NEEDS_RESET) {
251 		rc = omap_dm_timer_reset(timer);
252 		if (rc) {
253 			omap_dm_timer_disable(timer);
254 			return rc;
255 		}
256 	}
257 
258 	__omap_dm_timer_enable_posted(timer);
259 	omap_dm_timer_disable(timer);
260 
261 	return 0;
262 }
263 
264 static inline u32 omap_dm_timer_reserved_systimer(int id)
265 {
266 	return (omap_reserved_systimers & (1 << (id - 1))) ? 1 : 0;
267 }
268 
269 int omap_dm_timer_reserve_systimer(int id)
270 {
271 	if (omap_dm_timer_reserved_systimer(id))
272 		return -ENODEV;
273 
274 	omap_reserved_systimers |= (1 << (id - 1));
275 
276 	return 0;
277 }
278 
279 static struct omap_dm_timer *_omap_dm_timer_request(int req_type, void *data)
280 {
281 	struct omap_dm_timer *timer = NULL, *t;
282 	struct device_node *np = NULL;
283 	unsigned long flags;
284 	u32 cap = 0;
285 	int id = 0;
286 
287 	switch (req_type) {
288 	case REQUEST_BY_ID:
289 		id = *(int *)data;
290 		break;
291 	case REQUEST_BY_CAP:
292 		cap = *(u32 *)data;
293 		break;
294 	case REQUEST_BY_NODE:
295 		np = (struct device_node *)data;
296 		break;
297 	default:
298 		/* REQUEST_ANY */
299 		break;
300 	}
301 
302 	spin_lock_irqsave(&dm_timer_lock, flags);
303 	list_for_each_entry(t, &omap_timer_list, node) {
304 		if (t->reserved)
305 			continue;
306 
307 		switch (req_type) {
308 		case REQUEST_BY_ID:
309 			if (id == t->pdev->id) {
310 				timer = t;
311 				timer->reserved = 1;
312 				goto found;
313 			}
314 			break;
315 		case REQUEST_BY_CAP:
316 			if (cap == (t->capability & cap)) {
317 				/*
318 				 * If timer is not NULL, we have already found
319 				 * one timer. But it was not an exact match
320 				 * because it had more capabilities than what
321 				 * was required. Therefore, unreserve the last
322 				 * timer found and see if this one is a better
323 				 * match.
324 				 */
325 				if (timer)
326 					timer->reserved = 0;
327 				timer = t;
328 				timer->reserved = 1;
329 
330 				/* Exit loop early if we find an exact match */
331 				if (t->capability == cap)
332 					goto found;
333 			}
334 			break;
335 		case REQUEST_BY_NODE:
336 			if (np == t->pdev->dev.of_node) {
337 				timer = t;
338 				timer->reserved = 1;
339 				goto found;
340 			}
341 			break;
342 		default:
343 			/* REQUEST_ANY */
344 			timer = t;
345 			timer->reserved = 1;
346 			goto found;
347 		}
348 	}
349 found:
350 	spin_unlock_irqrestore(&dm_timer_lock, flags);
351 
352 	if (timer && omap_dm_timer_prepare(timer)) {
353 		timer->reserved = 0;
354 		timer = NULL;
355 	}
356 
357 	if (!timer)
358 		pr_debug("%s: timer request failed!\n", __func__);
359 
360 	return timer;
361 }
362 
363 static struct omap_dm_timer *omap_dm_timer_request(void)
364 {
365 	return _omap_dm_timer_request(REQUEST_ANY, NULL);
366 }
367 
368 static struct omap_dm_timer *omap_dm_timer_request_specific(int id)
369 {
370 	/* Requesting timer by ID is not supported when device tree is used */
371 	if (of_have_populated_dt()) {
372 		pr_warn("%s: Please use omap_dm_timer_request_by_node()\n",
373 			__func__);
374 		return NULL;
375 	}
376 
377 	return _omap_dm_timer_request(REQUEST_BY_ID, &id);
378 }
379 
380 /**
381  * omap_dm_timer_request_by_cap - Request a timer by capability
382  * @cap:	Bit mask of capabilities to match
383  *
384  * Find a timer based upon capabilities bit mask. Callers of this function
385  * should use the definitions found in the plat/dmtimer.h file under the
386  * comment "timer capabilities used in hwmod database". Returns pointer to
387  * timer handle on success and a NULL pointer on failure.
388  */
389 struct omap_dm_timer *omap_dm_timer_request_by_cap(u32 cap)
390 {
391 	return _omap_dm_timer_request(REQUEST_BY_CAP, &cap);
392 }
393 
394 /**
395  * omap_dm_timer_request_by_node - Request a timer by device-tree node
396  * @np:		Pointer to device-tree timer node
397  *
398  * Request a timer based upon a device node pointer. Returns pointer to
399  * timer handle on success and a NULL pointer on failure.
400  */
401 static struct omap_dm_timer *omap_dm_timer_request_by_node(struct device_node *np)
402 {
403 	if (!np)
404 		return NULL;
405 
406 	return _omap_dm_timer_request(REQUEST_BY_NODE, np);
407 }
408 
409 static int omap_dm_timer_free(struct omap_dm_timer *timer)
410 {
411 	if (unlikely(!timer))
412 		return -EINVAL;
413 
414 	clk_put(timer->fclk);
415 
416 	WARN_ON(!timer->reserved);
417 	timer->reserved = 0;
418 	return 0;
419 }
420 
421 int omap_dm_timer_get_irq(struct omap_dm_timer *timer)
422 {
423 	if (timer)
424 		return timer->irq;
425 	return -EINVAL;
426 }
427 
428 #if defined(CONFIG_ARCH_OMAP1)
429 #include <mach/hardware.h>
430 
431 static struct clk *omap_dm_timer_get_fclk(struct omap_dm_timer *timer)
432 {
433 	return NULL;
434 }
435 
436 /**
437  * omap_dm_timer_modify_idlect_mask - Check if any running timers use ARMXOR
438  * @inputmask: current value of idlect mask
439  */
440 __u32 omap_dm_timer_modify_idlect_mask(__u32 inputmask)
441 {
442 	int i = 0;
443 	struct omap_dm_timer *timer = NULL;
444 	unsigned long flags;
445 
446 	/* If ARMXOR cannot be idled this function call is unnecessary */
447 	if (!(inputmask & (1 << 1)))
448 		return inputmask;
449 
450 	/* If any active timer is using ARMXOR return modified mask */
451 	spin_lock_irqsave(&dm_timer_lock, flags);
452 	list_for_each_entry(timer, &omap_timer_list, node) {
453 		u32 l;
454 
455 		l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
456 		if (l & OMAP_TIMER_CTRL_ST) {
457 			if (((omap_readl(MOD_CONF_CTRL_1) >> (i * 2)) & 0x03) == 0)
458 				inputmask &= ~(1 << 1);
459 			else
460 				inputmask &= ~(1 << 2);
461 		}
462 		i++;
463 	}
464 	spin_unlock_irqrestore(&dm_timer_lock, flags);
465 
466 	return inputmask;
467 }
468 
469 #else
470 
471 static struct clk *omap_dm_timer_get_fclk(struct omap_dm_timer *timer)
472 {
473 	if (timer && !IS_ERR(timer->fclk))
474 		return timer->fclk;
475 	return NULL;
476 }
477 
478 __u32 omap_dm_timer_modify_idlect_mask(__u32 inputmask)
479 {
480 	BUG();
481 
482 	return 0;
483 }
484 
485 #endif
486 
487 int omap_dm_timer_trigger(struct omap_dm_timer *timer)
488 {
489 	if (unlikely(!timer || !atomic_read(&timer->enabled))) {
490 		pr_err("%s: timer not available or enabled.\n", __func__);
491 		return -EINVAL;
492 	}
493 
494 	omap_dm_timer_write_reg(timer, OMAP_TIMER_TRIGGER_REG, 0);
495 	return 0;
496 }
497 
498 static int omap_dm_timer_start(struct omap_dm_timer *timer)
499 {
500 	u32 l;
501 
502 	if (unlikely(!timer))
503 		return -EINVAL;
504 
505 	omap_dm_timer_enable(timer);
506 
507 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
508 	if (!(l & OMAP_TIMER_CTRL_ST)) {
509 		l |= OMAP_TIMER_CTRL_ST;
510 		omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
511 	}
512 
513 	return 0;
514 }
515 
516 static int omap_dm_timer_stop(struct omap_dm_timer *timer)
517 {
518 	unsigned long rate = 0;
519 
520 	if (unlikely(!timer))
521 		return -EINVAL;
522 
523 	if (!(timer->capability & OMAP_TIMER_NEEDS_RESET))
524 		rate = clk_get_rate(timer->fclk);
525 
526 	__omap_dm_timer_stop(timer, timer->posted, rate);
527 
528 	omap_dm_timer_disable(timer);
529 	return 0;
530 }
531 
532 static int omap_dm_timer_set_load(struct omap_dm_timer *timer,
533 				  unsigned int load)
534 {
535 	if (unlikely(!timer))
536 		return -EINVAL;
537 
538 	omap_dm_timer_enable(timer);
539 	omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG, load);
540 
541 	omap_dm_timer_disable(timer);
542 	return 0;
543 }
544 
545 static int omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable,
546 				   unsigned int match)
547 {
548 	u32 l;
549 
550 	if (unlikely(!timer))
551 		return -EINVAL;
552 
553 	omap_dm_timer_enable(timer);
554 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
555 	if (enable)
556 		l |= OMAP_TIMER_CTRL_CE;
557 	else
558 		l &= ~OMAP_TIMER_CTRL_CE;
559 	omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG, match);
560 	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
561 
562 	omap_dm_timer_disable(timer);
563 	return 0;
564 }
565 
566 static int omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on,
567 				 int toggle, int trigger, int autoreload)
568 {
569 	u32 l;
570 
571 	if (unlikely(!timer))
572 		return -EINVAL;
573 
574 	omap_dm_timer_enable(timer);
575 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
576 	l &= ~(OMAP_TIMER_CTRL_GPOCFG | OMAP_TIMER_CTRL_SCPWM |
577 	       OMAP_TIMER_CTRL_PT | (0x03 << 10) | OMAP_TIMER_CTRL_AR);
578 	if (def_on)
579 		l |= OMAP_TIMER_CTRL_SCPWM;
580 	if (toggle)
581 		l |= OMAP_TIMER_CTRL_PT;
582 	l |= trigger << 10;
583 	if (autoreload)
584 		l |= OMAP_TIMER_CTRL_AR;
585 	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
586 
587 	omap_dm_timer_disable(timer);
588 	return 0;
589 }
590 
591 static int omap_dm_timer_get_pwm_status(struct omap_dm_timer *timer)
592 {
593 	u32 l;
594 
595 	if (unlikely(!timer))
596 		return -EINVAL;
597 
598 	omap_dm_timer_enable(timer);
599 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
600 	omap_dm_timer_disable(timer);
601 
602 	return l;
603 }
604 
605 static int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer,
606 					int prescaler)
607 {
608 	u32 l;
609 
610 	if (unlikely(!timer) || prescaler < -1 || prescaler > 7)
611 		return -EINVAL;
612 
613 	omap_dm_timer_enable(timer);
614 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
615 	l &= ~(OMAP_TIMER_CTRL_PRE | (0x07 << 2));
616 	if (prescaler >= 0) {
617 		l |= OMAP_TIMER_CTRL_PRE;
618 		l |= prescaler << 2;
619 	}
620 	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
621 
622 	omap_dm_timer_disable(timer);
623 	return 0;
624 }
625 
626 static int omap_dm_timer_set_int_enable(struct omap_dm_timer *timer,
627 					unsigned int value)
628 {
629 	if (unlikely(!timer))
630 		return -EINVAL;
631 
632 	omap_dm_timer_enable(timer);
633 	__omap_dm_timer_int_enable(timer, value);
634 
635 	omap_dm_timer_disable(timer);
636 	return 0;
637 }
638 
639 /**
640  * omap_dm_timer_set_int_disable - disable timer interrupts
641  * @timer:	pointer to timer handle
642  * @mask:	bit mask of interrupts to be disabled
643  *
644  * Disables the specified timer interrupts for a timer.
645  */
646 static int omap_dm_timer_set_int_disable(struct omap_dm_timer *timer, u32 mask)
647 {
648 	u32 l = mask;
649 
650 	if (unlikely(!timer))
651 		return -EINVAL;
652 
653 	omap_dm_timer_enable(timer);
654 
655 	if (timer->revision == 1)
656 		l = readl_relaxed(timer->irq_ena) & ~mask;
657 
658 	writel_relaxed(l, timer->irq_dis);
659 	l = omap_dm_timer_read_reg(timer, OMAP_TIMER_WAKEUP_EN_REG) & ~mask;
660 	omap_dm_timer_write_reg(timer, OMAP_TIMER_WAKEUP_EN_REG, l);
661 
662 	omap_dm_timer_disable(timer);
663 	return 0;
664 }
665 
666 static unsigned int omap_dm_timer_read_status(struct omap_dm_timer *timer)
667 {
668 	unsigned int l;
669 
670 	if (unlikely(!timer || !atomic_read(&timer->enabled))) {
671 		pr_err("%s: timer not available or enabled.\n", __func__);
672 		return 0;
673 	}
674 
675 	l = readl_relaxed(timer->irq_stat);
676 
677 	return l;
678 }
679 
680 static int omap_dm_timer_write_status(struct omap_dm_timer *timer, unsigned int value)
681 {
682 	if (unlikely(!timer || !atomic_read(&timer->enabled)))
683 		return -EINVAL;
684 
685 	__omap_dm_timer_write_status(timer, value);
686 
687 	return 0;
688 }
689 
690 static unsigned int omap_dm_timer_read_counter(struct omap_dm_timer *timer)
691 {
692 	if (unlikely(!timer || !atomic_read(&timer->enabled))) {
693 		pr_err("%s: timer not iavailable or enabled.\n", __func__);
694 		return 0;
695 	}
696 
697 	return __omap_dm_timer_read_counter(timer, timer->posted);
698 }
699 
700 static int omap_dm_timer_write_counter(struct omap_dm_timer *timer, unsigned int value)
701 {
702 	if (unlikely(!timer || !atomic_read(&timer->enabled))) {
703 		pr_err("%s: timer not available or enabled.\n", __func__);
704 		return -EINVAL;
705 	}
706 
707 	omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG, value);
708 
709 	/* Save the context */
710 	timer->context.tcrr = value;
711 	return 0;
712 }
713 
714 int omap_dm_timers_active(void)
715 {
716 	struct omap_dm_timer *timer;
717 
718 	list_for_each_entry(timer, &omap_timer_list, node) {
719 		if (!timer->reserved)
720 			continue;
721 
722 		if (omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG) &
723 		    OMAP_TIMER_CTRL_ST) {
724 			return 1;
725 		}
726 	}
727 	return 0;
728 }
729 
730 static int __maybe_unused omap_dm_timer_runtime_suspend(struct device *dev)
731 {
732 	struct omap_dm_timer *timer = dev_get_drvdata(dev);
733 
734 	atomic_set(&timer->enabled, 0);
735 
736 	if (timer->capability & OMAP_TIMER_ALWON || !timer->func_base)
737 		return 0;
738 
739 	omap_timer_save_context(timer);
740 
741 	return 0;
742 }
743 
744 static int __maybe_unused omap_dm_timer_runtime_resume(struct device *dev)
745 {
746 	struct omap_dm_timer *timer = dev_get_drvdata(dev);
747 
748 	if (!(timer->capability & OMAP_TIMER_ALWON) && timer->func_base)
749 		omap_timer_restore_context(timer);
750 
751 	atomic_set(&timer->enabled, 1);
752 
753 	return 0;
754 }
755 
756 static const struct dev_pm_ops omap_dm_timer_pm_ops = {
757 	SET_RUNTIME_PM_OPS(omap_dm_timer_runtime_suspend,
758 			   omap_dm_timer_runtime_resume, NULL)
759 };
760 
761 static const struct of_device_id omap_timer_match[];
762 
763 /**
764  * omap_dm_timer_probe - probe function called for every registered device
765  * @pdev:	pointer to current timer platform device
766  *
767  * Called by driver framework at the end of device registration for all
768  * timer devices.
769  */
770 static int omap_dm_timer_probe(struct platform_device *pdev)
771 {
772 	unsigned long flags;
773 	struct omap_dm_timer *timer;
774 	struct device *dev = &pdev->dev;
775 	const struct dmtimer_platform_data *pdata;
776 	int ret;
777 
778 	pdata = of_device_get_match_data(dev);
779 	if (!pdata)
780 		pdata = dev_get_platdata(dev);
781 	else
782 		dev->platform_data = (void *)pdata;
783 
784 	if (!pdata) {
785 		dev_err(dev, "%s: no platform data.\n", __func__);
786 		return -ENODEV;
787 	}
788 
789 	timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
790 	if (!timer)
791 		return  -ENOMEM;
792 
793 	timer->irq = platform_get_irq(pdev, 0);
794 	if (timer->irq < 0)
795 		return timer->irq;
796 
797 	timer->fclk = ERR_PTR(-ENODEV);
798 	timer->io_base = devm_platform_ioremap_resource(pdev, 0);
799 	if (IS_ERR(timer->io_base))
800 		return PTR_ERR(timer->io_base);
801 
802 	platform_set_drvdata(pdev, timer);
803 
804 	if (dev->of_node) {
805 		if (of_find_property(dev->of_node, "ti,timer-alwon", NULL))
806 			timer->capability |= OMAP_TIMER_ALWON;
807 		if (of_find_property(dev->of_node, "ti,timer-dsp", NULL))
808 			timer->capability |= OMAP_TIMER_HAS_DSP_IRQ;
809 		if (of_find_property(dev->of_node, "ti,timer-pwm", NULL))
810 			timer->capability |= OMAP_TIMER_HAS_PWM;
811 		if (of_find_property(dev->of_node, "ti,timer-secure", NULL))
812 			timer->capability |= OMAP_TIMER_SECURE;
813 	} else {
814 		timer->id = pdev->id;
815 		timer->capability = pdata->timer_capability;
816 		timer->reserved = omap_dm_timer_reserved_systimer(timer->id);
817 	}
818 
819 	if (!(timer->capability & OMAP_TIMER_ALWON)) {
820 		timer->nb.notifier_call = omap_timer_context_notifier;
821 		cpu_pm_register_notifier(&timer->nb);
822 	}
823 
824 	if (pdata)
825 		timer->errata = pdata->timer_errata;
826 
827 	timer->pdev = pdev;
828 
829 	pm_runtime_enable(dev);
830 
831 	if (!timer->reserved) {
832 		ret = pm_runtime_get_sync(dev);
833 		if (ret < 0) {
834 			dev_err(dev, "%s: pm_runtime_get_sync failed!\n",
835 				__func__);
836 			goto err_get_sync;
837 		}
838 		__omap_dm_timer_init_regs(timer);
839 		pm_runtime_put(dev);
840 	}
841 
842 	/* add the timer element to the list */
843 	spin_lock_irqsave(&dm_timer_lock, flags);
844 	list_add_tail(&timer->node, &omap_timer_list);
845 	spin_unlock_irqrestore(&dm_timer_lock, flags);
846 
847 	dev_dbg(dev, "Device Probed.\n");
848 
849 	return 0;
850 
851 err_get_sync:
852 	pm_runtime_put_noidle(dev);
853 	pm_runtime_disable(dev);
854 	return ret;
855 }
856 
857 /**
858  * omap_dm_timer_remove - cleanup a registered timer device
859  * @pdev:	pointer to current timer platform device
860  *
861  * Called by driver framework whenever a timer device is unregistered.
862  * In addition to freeing platform resources it also deletes the timer
863  * entry from the local list.
864  */
865 static int omap_dm_timer_remove(struct platform_device *pdev)
866 {
867 	struct omap_dm_timer *timer;
868 	unsigned long flags;
869 	int ret = -EINVAL;
870 
871 	spin_lock_irqsave(&dm_timer_lock, flags);
872 	list_for_each_entry(timer, &omap_timer_list, node)
873 		if (!strcmp(dev_name(&timer->pdev->dev),
874 			    dev_name(&pdev->dev))) {
875 			if (!(timer->capability & OMAP_TIMER_ALWON))
876 				cpu_pm_unregister_notifier(&timer->nb);
877 			list_del(&timer->node);
878 			ret = 0;
879 			break;
880 		}
881 	spin_unlock_irqrestore(&dm_timer_lock, flags);
882 
883 	pm_runtime_disable(&pdev->dev);
884 
885 	return ret;
886 }
887 
888 static const struct omap_dm_timer_ops dmtimer_ops = {
889 	.request_by_node = omap_dm_timer_request_by_node,
890 	.request_specific = omap_dm_timer_request_specific,
891 	.request = omap_dm_timer_request,
892 	.set_source = omap_dm_timer_set_source,
893 	.get_irq = omap_dm_timer_get_irq,
894 	.set_int_enable = omap_dm_timer_set_int_enable,
895 	.set_int_disable = omap_dm_timer_set_int_disable,
896 	.free = omap_dm_timer_free,
897 	.enable = omap_dm_timer_enable,
898 	.disable = omap_dm_timer_disable,
899 	.get_fclk = omap_dm_timer_get_fclk,
900 	.start = omap_dm_timer_start,
901 	.stop = omap_dm_timer_stop,
902 	.set_load = omap_dm_timer_set_load,
903 	.set_match = omap_dm_timer_set_match,
904 	.set_pwm = omap_dm_timer_set_pwm,
905 	.get_pwm_status = omap_dm_timer_get_pwm_status,
906 	.set_prescaler = omap_dm_timer_set_prescaler,
907 	.read_counter = omap_dm_timer_read_counter,
908 	.write_counter = omap_dm_timer_write_counter,
909 	.read_status = omap_dm_timer_read_status,
910 	.write_status = omap_dm_timer_write_status,
911 };
912 
913 static const struct dmtimer_platform_data omap3plus_pdata = {
914 	.timer_errata = OMAP_TIMER_ERRATA_I103_I767,
915 	.timer_ops = &dmtimer_ops,
916 };
917 
918 static const struct of_device_id omap_timer_match[] = {
919 	{
920 		.compatible = "ti,omap2420-timer",
921 	},
922 	{
923 		.compatible = "ti,omap3430-timer",
924 		.data = &omap3plus_pdata,
925 	},
926 	{
927 		.compatible = "ti,omap4430-timer",
928 		.data = &omap3plus_pdata,
929 	},
930 	{
931 		.compatible = "ti,omap5430-timer",
932 		.data = &omap3plus_pdata,
933 	},
934 	{
935 		.compatible = "ti,am335x-timer",
936 		.data = &omap3plus_pdata,
937 	},
938 	{
939 		.compatible = "ti,am335x-timer-1ms",
940 		.data = &omap3plus_pdata,
941 	},
942 	{
943 		.compatible = "ti,dm816-timer",
944 		.data = &omap3plus_pdata,
945 	},
946 	{},
947 };
948 MODULE_DEVICE_TABLE(of, omap_timer_match);
949 
950 static struct platform_driver omap_dm_timer_driver = {
951 	.probe  = omap_dm_timer_probe,
952 	.remove = omap_dm_timer_remove,
953 	.driver = {
954 		.name   = "omap_timer",
955 		.of_match_table = of_match_ptr(omap_timer_match),
956 		.pm = &omap_dm_timer_pm_ops,
957 	},
958 };
959 
960 module_platform_driver(omap_dm_timer_driver);
961 
962 MODULE_DESCRIPTION("OMAP Dual-Mode Timer Driver");
963 MODULE_LICENSE("GPL");
964 MODULE_AUTHOR("Texas Instruments Inc");
965