summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-at91/pm.c
blob: 3ba0c6c560d8ecd59ed0ca56966a9b91269074bd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
/*
 * arch/arm/mach-at91/pm.c
 * AT91 Power Management
 *
 * Copyright (C) 2005 David Brownell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/genalloc.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/parser.h>
#include <linux/suspend.h>

#include <linux/clk/at91_pmc.h>

#include <asm/cacheflush.h>
#include <asm/fncpy.h>
#include <asm/system_misc.h>
#include <asm/suspend.h>

#include "generic.h"
#include "pm.h"

/*
 * FIXME: this is needed to communicate between the pinctrl driver and
 * the PM implementation in the machine. Possibly part of the PM
 * implementation should be moved down into the pinctrl driver and get
 * called as part of the generic suspend/resume path.
 */
#ifdef CONFIG_PINCTRL_AT91
extern void at91_pinctrl_gpio_suspend(void);
extern void at91_pinctrl_gpio_resume(void);
#endif

static const match_table_t pm_modes __initconst = {
	{ AT91_PM_STANDBY, "standby" },
	{ AT91_PM_ULP0, "ulp0" },
	{ AT91_PM_ULP1, "ulp1" },
	{ AT91_PM_BACKUP, "backup" },
	{ -1, NULL },
};

static struct at91_pm_data pm_data = {
	.standby_mode = AT91_PM_STANDBY,
	.suspend_mode = AT91_PM_ULP0,
};

#define at91_ramc_read(id, field) \
	__raw_readl(pm_data.ramc[id] + field)

#define at91_ramc_write(id, field, value) \
	__raw_writel(value, pm_data.ramc[id] + field)

static int at91_pm_valid_state(suspend_state_t state)
{
	switch (state) {
		case PM_SUSPEND_ON:
		case PM_SUSPEND_STANDBY:
		case PM_SUSPEND_MEM:
			return 1;

		default:
			return 0;
	}
}

static int canary = 0xA5A5A5A5;

static struct at91_pm_bu {
	int suspended;
	unsigned long reserved;
	phys_addr_t canary;
	phys_addr_t resume;
} *pm_bu;

struct wakeup_source_info {
	unsigned int pmc_fsmr_bit;
	unsigned int shdwc_mr_bit;
	bool set_polarity;
};

static const struct wakeup_source_info ws_info[] = {
	{ .pmc_fsmr_bit = AT91_PMC_FSTT(10),	.set_polarity = true },
	{ .pmc_fsmr_bit = AT91_PMC_RTCAL,	.shdwc_mr_bit = BIT(17) },
	{ .pmc_fsmr_bit = AT91_PMC_USBAL },
	{ .pmc_fsmr_bit = AT91_PMC_SDMMC_CD },
};

static const struct of_device_id sama5d2_ws_ids[] = {
	{ .compatible = "atmel,sama5d2-gem",		.data = &ws_info[0] },
	{ .compatible = "atmel,sama5d2-rtc",		.data = &ws_info[1] },
	{ .compatible = "atmel,sama5d3-udc",		.data = &ws_info[2] },
	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
	{ .compatible = "atmel,sama5d2-sdhci",		.data = &ws_info[3] },
	{ /* sentinel */ }
};

static int at91_pm_config_ws(unsigned int pm_mode, bool set)
{
	const struct wakeup_source_info *wsi;
	const struct of_device_id *match;
	struct platform_device *pdev;
	struct device_node *np;
	unsigned int mode = 0, polarity = 0, val = 0;

	if (pm_mode != AT91_PM_ULP1)
		return 0;

	if (!pm_data.pmc || !pm_data.shdwc)
		return -EPERM;

	if (!set) {
		writel(mode, pm_data.pmc + AT91_PMC_FSMR);
		return 0;
	}

	/* SHDWC.WUIR */
	val = readl(pm_data.shdwc + 0x0c);
	mode |= (val & 0x3ff);
	polarity |= ((val >> 16) & 0x3ff);

	/* SHDWC.MR */
	val = readl(pm_data.shdwc + 0x04);

	/* Loop through defined wakeup sources. */
	for_each_matching_node_and_match(np, sama5d2_ws_ids, &match) {
		pdev = of_find_device_by_node(np);
		if (!pdev)
			continue;

		if (device_may_wakeup(&pdev->dev)) {
			wsi = match->data;

			/* Check if enabled on SHDWC. */
			if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
				goto put_device;

			mode |= wsi->pmc_fsmr_bit;
			if (wsi->set_polarity)
				polarity |= wsi->pmc_fsmr_bit;
		}

put_device:
		put_device(&pdev->dev);
	}

	if (mode) {
		writel(mode, pm_data.pmc + AT91_PMC_FSMR);
		writel(polarity, pm_data.pmc + AT91_PMC_FSPR);
	} else {
		pr_err("AT91: PM: no ULP1 wakeup sources found!");
	}

	return mode ? 0 : -EPERM;
}

/*
 * Called after processes are frozen, but before we shutdown devices.
 */
static int at91_pm_begin(suspend_state_t state)
{
	switch (state) {
	case PM_SUSPEND_MEM:
		pm_data.mode = pm_data.suspend_mode;
		break;

	case PM_SUSPEND_STANDBY:
		pm_data.mode = pm_data.standby_mode;
		break;

	default:
		pm_data.mode = -1;
	}

	return at91_pm_config_ws(pm_data.mode, true);
}

/*
 * Verify that all the clocks are correct before entering
 * slow-clock mode.
 */
static int at91_pm_verify_clocks(void)
{
	unsigned long scsr;
	int i;

	scsr = readl(pm_data.pmc + AT91_PMC_SCSR);

	/* USB must not be using PLLB */
	if ((scsr & pm_data.uhp_udp_mask) != 0) {
		pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
		return 0;
	}

	/* PCK0..PCK3 must be disabled, or configured to use clk32k */
	for (i = 0; i < 4; i++) {
		u32 css;

		if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
			continue;
		css = readl(pm_data.pmc + AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
		if (css != AT91_PMC_CSS_SLOW) {
			pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
			return 0;
		}
	}

	return 1;
}

/*
 * Call this from platform driver suspend() to see how deeply to suspend.
 * For example, some controllers (like OHCI) need one of the PLL clocks
 * in order to act as a wakeup source, and those are not available when
 * going into slow clock mode.
 *
 * REVISIT: generalize as clk_will_be_available(clk)?  Other platforms have
 * the very same problem (but not using at91 main_clk), and it'd be better
 * to add one generic API rather than lots of platform-specific ones.
 */
int at91_suspend_entering_slow_clock(void)
{
	return (pm_data.mode >= AT91_PM_ULP0);
}
EXPORT_SYMBOL(at91_suspend_entering_slow_clock);

static void (*at91_suspend_sram_fn)(struct at91_pm_data *);
extern void at91_pm_suspend_in_sram(struct at91_pm_data *pm_data);
extern u32 at91_pm_suspend_in_sram_sz;

static int at91_suspend_finish(unsigned long val)
{
	flush_cache_all();
	outer_disable();

	at91_suspend_sram_fn(&pm_data);

	return 0;
}

static void at91_pm_suspend(suspend_state_t state)
{
	if (pm_data.mode == AT91_PM_BACKUP) {
		pm_bu->suspended = 1;

		cpu_suspend(0, at91_suspend_finish);

		/* The SRAM is lost between suspend cycles */
		at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
					     &at91_pm_suspend_in_sram,
					     at91_pm_suspend_in_sram_sz);
	} else {
		at91_suspend_finish(0);
	}

	outer_resume();
}

/*
 * STANDBY mode has *all* drivers suspended; ignores irqs not marked as 'wakeup'
 * event sources; and reduces DRAM power.  But otherwise it's identical to
 * PM_SUSPEND_ON: cpu idle, and nothing fancy done with main or cpu clocks.
 *
 * AT91_PM_ULP0 is like STANDBY plus slow clock mode, so drivers must
 * suspend more deeply, the master clock switches to the clk32k and turns off
 * the main oscillator
 *
 * AT91_PM_BACKUP turns off the whole SoC after placing the DDR in self refresh
 */
static int at91_pm_enter(suspend_state_t state)
{
#ifdef CONFIG_PINCTRL_AT91
	at91_pinctrl_gpio_suspend();
#endif

	switch (state) {
	case PM_SUSPEND_MEM:
	case PM_SUSPEND_STANDBY:
		/*
		 * Ensure that clocks are in a valid state.
		 */
		if (pm_data.mode >= AT91_PM_ULP0 &&
		    !at91_pm_verify_clocks())
			goto error;

		at91_pm_suspend(state);

		break;

	case PM_SUSPEND_ON:
		cpu_do_idle();
		break;

	default:
		pr_debug("AT91: PM - bogus suspend state %d\n", state);
		goto error;
	}

error:
#ifdef CONFIG_PINCTRL_AT91
	at91_pinctrl_gpio_resume();
#endif
	return 0;
}

/*
 * Called right prior to thawing processes.
 */
static void at91_pm_end(void)
{
	at91_pm_config_ws(pm_data.mode, false);
}


static const struct platform_suspend_ops at91_pm_ops = {
	.valid	= at91_pm_valid_state,
	.begin	= at91_pm_begin,
	.enter	= at91_pm_enter,
	.end	= at91_pm_end,
};

static struct platform_device at91_cpuidle_device = {
	.name = "cpuidle-at91",
};

/*
 * The AT91RM9200 goes into self-refresh mode with this command, and will
 * terminate self-refresh automatically on the next SDRAM access.
 *
 * Self-refresh mode is exited as soon as a memory access is made, but we don't
 * know for sure when that happens. However, we need to restore the low-power
 * mode if it was enabled before going idle. Restoring low-power mode while
 * still in self-refresh is "not recommended", but seems to work.
 */
static void at91rm9200_standby(void)
{
	asm volatile(
		"b    1f\n\t"
		".align    5\n\t"
		"1:  mcr    p15, 0, %0, c7, c10, 4\n\t"
		"    str    %2, [%1, %3]\n\t"
		"    mcr    p15, 0, %0, c7, c0, 4\n\t"
		:
		: "r" (0), "r" (pm_data.ramc[0]),
		  "r" (1), "r" (AT91_MC_SDRAMC_SRR));
}

/* We manage both DDRAM/SDRAM controllers, we need more than one value to
 * remember.
 */
static void at91_ddr_standby(void)
{
	/* Those two values allow us to delay self-refresh activation
	 * to the maximum. */
	u32 lpr0, lpr1 = 0;
	u32 mdr, saved_mdr0, saved_mdr1 = 0;
	u32 saved_lpr0, saved_lpr1 = 0;

	/* LPDDR1 --> force DDR2 mode during self-refresh */
	saved_mdr0 = at91_ramc_read(0, AT91_DDRSDRC_MDR);
	if ((saved_mdr0 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
		mdr = saved_mdr0 & ~AT91_DDRSDRC_MD;
		mdr |= AT91_DDRSDRC_MD_DDR2;
		at91_ramc_write(0, AT91_DDRSDRC_MDR, mdr);
	}

	if (pm_data.ramc[1]) {
		saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
		lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
		lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
		saved_mdr1 = at91_ramc_read(1, AT91_DDRSDRC_MDR);
		if ((saved_mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
			mdr = saved_mdr1 & ~AT91_DDRSDRC_MD;
			mdr |= AT91_DDRSDRC_MD_DDR2;
			at91_ramc_write(1, AT91_DDRSDRC_MDR, mdr);
		}
	}

	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
	lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;

	/* self-refresh mode now */
	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
	if (pm_data.ramc[1])
		at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);

	cpu_do_idle();

	at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr0);
	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
	if (pm_data.ramc[1]) {
		at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr1);
		at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
	}
}

static void sama5d3_ddr_standby(void)
{
	u32 lpr0;
	u32 saved_lpr0;

	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
	lpr0 |= AT91_DDRSDRC_LPCB_POWER_DOWN;

	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);

	cpu_do_idle();

	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
}

/* We manage both DDRAM/SDRAM controllers, we need more than one value to
 * remember.
 */
static void at91sam9_sdram_standby(void)
{
	u32 lpr0, lpr1 = 0;
	u32 saved_lpr0, saved_lpr1 = 0;

	if (pm_data.ramc[1]) {
		saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
		lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
		lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
	}

	saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
	lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
	lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;

	/* self-refresh mode now */
	at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
	if (pm_data.ramc[1])
		at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);

	cpu_do_idle();

	at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
	if (pm_data.ramc[1])
		at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
}

struct ramc_info {
	void (*idle)(void);
	unsigned int memctrl;
};

static const struct ramc_info ramc_infos[] __initconst = {
	{ .idle = at91rm9200_standby, .memctrl = AT91_MEMCTRL_MC},
	{ .idle = at91sam9_sdram_standby, .memctrl = AT91_MEMCTRL_SDRAMC},
	{ .idle = at91_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
	{ .idle = sama5d3_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
};

static const struct of_device_id ramc_ids[] __initconst = {
	{ .compatible = "atmel,at91rm9200-sdramc", .data = &ramc_infos[0] },
	{ .compatible = "atmel,at91sam9260-sdramc", .data = &ramc_infos[1] },
	{ .compatible = "atmel,at91sam9g45-ddramc", .data = &ramc_infos[2] },
	{ .compatible = "atmel,sama5d3-ddramc", .data = &ramc_infos[3] },
	{ /*sentinel*/ }
};

static __init void at91_dt_ramc(void)
{
	struct device_node *np;
	const struct of_device_id *of_id;
	int idx = 0;
	void *standby = NULL;
	const struct ramc_info *ramc;

	for_each_matching_node_and_match(np, ramc_ids, &of_id) {
		pm_data.ramc[idx] = of_iomap(np, 0);
		if (!pm_data.ramc[idx])
			panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);

		ramc = of_id->data;
		if (!standby)
			standby = ramc->idle;
		pm_data.memctrl = ramc->memctrl;

		idx++;
	}

	if (!idx)
		panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));

	if (!standby) {
		pr_warn("ramc no standby function available\n");
		return;
	}

	at91_cpuidle_device.dev.platform_data = standby;
}

static void at91rm9200_idle(void)
{
	/*
	 * Disable the processor clock.  The processor will be automatically
	 * re-enabled by an interrupt or by a reset.
	 */
	writel(AT91_PMC_PCK, pm_data.pmc + AT91_PMC_SCDR);
}

static void at91sam9_idle(void)
{
	writel(AT91_PMC_PCK, pm_data.pmc + AT91_PMC_SCDR);
	cpu_do_idle();
}

static void __init at91_pm_sram_init(void)
{
	struct gen_pool *sram_pool;
	phys_addr_t sram_pbase;
	unsigned long sram_base;
	struct device_node *node;
	struct platform_device *pdev = NULL;

	for_each_compatible_node(node, NULL, "mmio-sram") {
		pdev = of_find_device_by_node(node);
		if (pdev) {
			of_node_put(node);
			break;
		}
	}

	if (!pdev) {
		pr_warn("%s: failed to find sram device!\n", __func__);
		return;
	}

	sram_pool = gen_pool_get(&pdev->dev, NULL);
	if (!sram_pool) {
		pr_warn("%s: sram pool unavailable!\n", __func__);
		goto out_put_device;
	}

	sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
	if (!sram_base) {
		pr_warn("%s: unable to alloc sram!\n", __func__);
		goto out_put_device;
	}

	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
	at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
					at91_pm_suspend_in_sram_sz, false);
	if (!at91_suspend_sram_fn) {
		pr_warn("SRAM: Could not map\n");
		goto out_put_device;
	}

	/* Copy the pm suspend handler to SRAM */
	at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
			&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
	return;

out_put_device:
	put_device(&pdev->dev);
	return;
}

static bool __init at91_is_pm_mode_active(int pm_mode)
{
	return (pm_data.standby_mode == pm_mode ||
		pm_data.suspend_mode == pm_mode);
}

static int __init at91_pm_backup_init(void)
{
	struct gen_pool *sram_pool;
	struct device_node *np;
	struct platform_device *pdev = NULL;
	int ret = -ENODEV;

	if (!at91_is_pm_mode_active(AT91_PM_BACKUP))
		return 0;

	pm_bu = NULL;

	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-sfrbu");
	if (!np) {
		pr_warn("%s: failed to find sfrbu!\n", __func__);
		return ret;
	}

	pm_data.sfrbu = of_iomap(np, 0);
	of_node_put(np);
	pm_bu = NULL;

	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
	if (!np)
		goto securam_fail_no_ref_dev;

	pdev = of_find_device_by_node(np);
	of_node_put(np);
	if (!pdev) {
		pr_warn("%s: failed to find securam device!\n", __func__);
		goto securam_fail_no_ref_dev;
	}

	sram_pool = gen_pool_get(&pdev->dev, NULL);
	if (!sram_pool) {
		pr_warn("%s: securam pool unavailable!\n", __func__);
		goto securam_fail;
	}

	pm_bu = (void *)gen_pool_alloc(sram_pool, sizeof(struct at91_pm_bu));
	if (!pm_bu) {
		pr_warn("%s: unable to alloc securam!\n", __func__);
		ret = -ENOMEM;
		goto securam_fail;
	}

	pm_bu->suspended = 0;
	pm_bu->canary = __pa_symbol(&canary);
	pm_bu->resume = __pa_symbol(cpu_resume);

	return 0;

securam_fail:
	put_device(&pdev->dev);
securam_fail_no_ref_dev:
	iounmap(pm_data.sfrbu);
	pm_data.sfrbu = NULL;
	return ret;
}

static void __init at91_pm_use_default_mode(int pm_mode)
{
	if (pm_mode != AT91_PM_ULP1 && pm_mode != AT91_PM_BACKUP)
		return;

	if (pm_data.standby_mode == pm_mode)
		pm_data.standby_mode = AT91_PM_ULP0;
	if (pm_data.suspend_mode == pm_mode)
		pm_data.suspend_mode = AT91_PM_ULP0;
}

static void __init at91_pm_modes_init(void)
{
	struct device_node *np;
	int ret;

	if (!at91_is_pm_mode_active(AT91_PM_BACKUP) &&
	    !at91_is_pm_mode_active(AT91_PM_ULP1))
		return;

	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-shdwc");
	if (!np) {
		pr_warn("%s: failed to find shdwc!\n", __func__);
		goto ulp1_default;
	}

	pm_data.shdwc = of_iomap(np, 0);
	of_node_put(np);

	ret = at91_pm_backup_init();
	if (ret) {
		if (!at91_is_pm_mode_active(AT91_PM_ULP1))
			goto unmap;
		else
			goto backup_default;
	}

	return;

unmap:
	iounmap(pm_data.shdwc);
	pm_data.shdwc = NULL;
ulp1_default:
	at91_pm_use_default_mode(AT91_PM_ULP1);
backup_default:
	at91_pm_use_default_mode(AT91_PM_BACKUP);
}

struct pmc_info {
	unsigned long uhp_udp_mask;
};

static const struct pmc_info pmc_infos[] __initconst = {
	{ .uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP },
	{ .uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP },
	{ .uhp_udp_mask = AT91SAM926x_PMC_UHP },
	{ .uhp_udp_mask = 0 },
};

static const struct of_device_id atmel_pmc_ids[] __initconst = {
	{ .compatible = "atmel,at91rm9200-pmc", .data = &pmc_infos[0] },
	{ .compatible = "atmel,at91sam9260-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,at91sam9261-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,at91sam9263-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,at91sam9g45-pmc", .data = &pmc_infos[2] },
	{ .compatible = "atmel,at91sam9n12-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,at91sam9rl-pmc", .data = &pmc_infos[3] },
	{ .compatible = "atmel,at91sam9x5-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,sama5d3-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,sama5d4-pmc", .data = &pmc_infos[1] },
	{ .compatible = "atmel,sama5d2-pmc", .data = &pmc_infos[1] },
	{ /* sentinel */ },
};

static void __init at91_pm_init(void (*pm_idle)(void))
{
	struct device_node *pmc_np;
	const struct of_device_id *of_id;
	const struct pmc_info *pmc;

	if (at91_cpuidle_device.dev.platform_data)
		platform_device_register(&at91_cpuidle_device);

	pmc_np = of_find_matching_node_and_match(NULL, atmel_pmc_ids, &of_id);
	pm_data.pmc = of_iomap(pmc_np, 0);
	if (!pm_data.pmc) {
		pr_err("AT91: PM not supported, PMC not found\n");
		return;
	}

	pmc = of_id->data;
	pm_data.uhp_udp_mask = pmc->uhp_udp_mask;

	if (pm_idle)
		arm_pm_idle = pm_idle;

	at91_pm_sram_init();

	if (at91_suspend_sram_fn) {
		suspend_set_ops(&at91_pm_ops);
		pr_info("AT91: PM: standby: %s, suspend: %s\n",
			pm_modes[pm_data.standby_mode].pattern,
			pm_modes[pm_data.suspend_mode].pattern);
	} else {
		pr_info("AT91: PM not supported, due to no SRAM allocated\n");
	}
}

void __init at91rm9200_pm_init(void)
{
	if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
		return;

	at91_dt_ramc();

	/*
	 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
	 */
	at91_ramc_write(0, AT91_MC_SDRAMC_LPR, 0);

	at91_pm_init(at91rm9200_idle);
}

void __init at91sam9_pm_init(void)
{
	if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
		return;

	at91_dt_ramc();
	at91_pm_init(at91sam9_idle);
}

void __init sama5_pm_init(void)
{
	if (!IS_ENABLED(CONFIG_SOC_SAMA5))
		return;

	at91_dt_ramc();
	at91_pm_init(NULL);
}

void __init sama5d2_pm_init(void)
{
	if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
		return;

	at91_pm_modes_init();
	sama5_pm_init();
}

static int __init at91_pm_modes_select(char *str)
{
	char *s;
	substring_t args[MAX_OPT_ARGS];
	int standby, suspend;

	if (!str)
		return 0;

	s = strsep(&str, ",");
	standby = match_token(s, pm_modes, args);
	if (standby < 0)
		return 0;

	suspend = match_token(str, pm_modes, args);
	if (suspend < 0)
		return 0;

	pm_data.standby_mode = standby;
	pm_data.suspend_mode = suspend;

	return 0;
}
early_param("atmel.pm_modes", at91_pm_modes_select);