xref: /openbmc/linux/arch/arm/mach-at91/pm.c (revision b1a3e75e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * arch/arm/mach-at91/pm.c
4  * AT91 Power Management
5  *
6  * Copyright (C) 2005 David Brownell
7  */
8 
9 #include <linux/genalloc.h>
10 #include <linux/io.h>
11 #include <linux/of_address.h>
12 #include <linux/of.h>
13 #include <linux/of_platform.h>
14 #include <linux/parser.h>
15 #include <linux/suspend.h>
16 
17 #include <linux/clk/at91_pmc.h>
18 #include <linux/platform_data/atmel.h>
19 
20 #include <asm/cacheflush.h>
21 #include <asm/fncpy.h>
22 #include <asm/system_misc.h>
23 #include <asm/suspend.h>
24 
25 #include "generic.h"
26 #include "pm.h"
27 
28 /*
29  * FIXME: this is needed to communicate between the pinctrl driver and
30  * the PM implementation in the machine. Possibly part of the PM
31  * implementation should be moved down into the pinctrl driver and get
32  * called as part of the generic suspend/resume path.
33  */
34 #ifdef CONFIG_PINCTRL_AT91
35 extern void at91_pinctrl_gpio_suspend(void);
36 extern void at91_pinctrl_gpio_resume(void);
37 #endif
38 
39 struct at91_soc_pm {
40 	int (*config_shdwc_ws)(void __iomem *shdwc, u32 *mode, u32 *polarity);
41 	int (*config_pmc_ws)(void __iomem *pmc, u32 mode, u32 polarity);
42 	const struct of_device_id *ws_ids;
43 	struct at91_pm_data data;
44 };
45 
46 static struct at91_soc_pm soc_pm = {
47 	.data = {
48 		.standby_mode = AT91_PM_STANDBY,
49 		.suspend_mode = AT91_PM_ULP0,
50 	},
51 };
52 
53 static const match_table_t pm_modes __initconst = {
54 	{ AT91_PM_STANDBY, "standby" },
55 	{ AT91_PM_ULP0, "ulp0" },
56 	{ AT91_PM_ULP1, "ulp1" },
57 	{ AT91_PM_BACKUP, "backup" },
58 	{ -1, NULL },
59 };
60 
61 #define at91_ramc_read(id, field) \
62 	__raw_readl(soc_pm.data.ramc[id] + field)
63 
64 #define at91_ramc_write(id, field, value) \
65 	__raw_writel(value, soc_pm.data.ramc[id] + field)
66 
67 static int at91_pm_valid_state(suspend_state_t state)
68 {
69 	switch (state) {
70 		case PM_SUSPEND_ON:
71 		case PM_SUSPEND_STANDBY:
72 		case PM_SUSPEND_MEM:
73 			return 1;
74 
75 		default:
76 			return 0;
77 	}
78 }
79 
80 static int canary = 0xA5A5A5A5;
81 
82 static struct at91_pm_bu {
83 	int suspended;
84 	unsigned long reserved;
85 	phys_addr_t canary;
86 	phys_addr_t resume;
87 } *pm_bu;
88 
89 struct wakeup_source_info {
90 	unsigned int pmc_fsmr_bit;
91 	unsigned int shdwc_mr_bit;
92 	bool set_polarity;
93 };
94 
95 static const struct wakeup_source_info ws_info[] = {
96 	{ .pmc_fsmr_bit = AT91_PMC_FSTT(10),	.set_polarity = true },
97 	{ .pmc_fsmr_bit = AT91_PMC_RTCAL,	.shdwc_mr_bit = BIT(17) },
98 	{ .pmc_fsmr_bit = AT91_PMC_USBAL },
99 	{ .pmc_fsmr_bit = AT91_PMC_SDMMC_CD },
100 	{ .pmc_fsmr_bit = AT91_PMC_RTTAL },
101 	{ .pmc_fsmr_bit = AT91_PMC_RXLP_MCE },
102 };
103 
104 static const struct of_device_id sama5d2_ws_ids[] = {
105 	{ .compatible = "atmel,sama5d2-gem",		.data = &ws_info[0] },
106 	{ .compatible = "atmel,at91rm9200-rtc",		.data = &ws_info[1] },
107 	{ .compatible = "atmel,sama5d3-udc",		.data = &ws_info[2] },
108 	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
109 	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
110 	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
111 	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
112 	{ .compatible = "atmel,sama5d2-sdhci",		.data = &ws_info[3] },
113 	{ /* sentinel */ }
114 };
115 
116 static const struct of_device_id sam9x60_ws_ids[] = {
117 	{ .compatible = "atmel,at91sam9x5-rtc",		.data = &ws_info[1] },
118 	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
119 	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
120 	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
121 	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
122 	{ .compatible = "atmel,at91sam9260-rtt",	.data = &ws_info[4] },
123 	{ .compatible = "cdns,sam9x60-macb",		.data = &ws_info[5] },
124 	{ /* sentinel */ }
125 };
126 
127 static int at91_pm_config_ws(unsigned int pm_mode, bool set)
128 {
129 	const struct wakeup_source_info *wsi;
130 	const struct of_device_id *match;
131 	struct platform_device *pdev;
132 	struct device_node *np;
133 	unsigned int mode = 0, polarity = 0, val = 0;
134 
135 	if (pm_mode != AT91_PM_ULP1)
136 		return 0;
137 
138 	if (!soc_pm.data.pmc || !soc_pm.data.shdwc || !soc_pm.ws_ids)
139 		return -EPERM;
140 
141 	if (!set) {
142 		writel(mode, soc_pm.data.pmc + AT91_PMC_FSMR);
143 		return 0;
144 	}
145 
146 	if (soc_pm.config_shdwc_ws)
147 		soc_pm.config_shdwc_ws(soc_pm.data.shdwc, &mode, &polarity);
148 
149 	/* SHDWC.MR */
150 	val = readl(soc_pm.data.shdwc + 0x04);
151 
152 	/* Loop through defined wakeup sources. */
153 	for_each_matching_node_and_match(np, soc_pm.ws_ids, &match) {
154 		pdev = of_find_device_by_node(np);
155 		if (!pdev)
156 			continue;
157 
158 		if (device_may_wakeup(&pdev->dev)) {
159 			wsi = match->data;
160 
161 			/* Check if enabled on SHDWC. */
162 			if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
163 				goto put_device;
164 
165 			mode |= wsi->pmc_fsmr_bit;
166 			if (wsi->set_polarity)
167 				polarity |= wsi->pmc_fsmr_bit;
168 		}
169 
170 put_device:
171 		put_device(&pdev->dev);
172 	}
173 
174 	if (mode) {
175 		if (soc_pm.config_pmc_ws)
176 			soc_pm.config_pmc_ws(soc_pm.data.pmc, mode, polarity);
177 	} else {
178 		pr_err("AT91: PM: no ULP1 wakeup sources found!");
179 	}
180 
181 	return mode ? 0 : -EPERM;
182 }
183 
184 static int at91_sama5d2_config_shdwc_ws(void __iomem *shdwc, u32 *mode,
185 					u32 *polarity)
186 {
187 	u32 val;
188 
189 	/* SHDWC.WUIR */
190 	val = readl(shdwc + 0x0c);
191 	*mode |= (val & 0x3ff);
192 	*polarity |= ((val >> 16) & 0x3ff);
193 
194 	return 0;
195 }
196 
197 static int at91_sama5d2_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
198 {
199 	writel(mode, pmc + AT91_PMC_FSMR);
200 	writel(polarity, pmc + AT91_PMC_FSPR);
201 
202 	return 0;
203 }
204 
205 static int at91_sam9x60_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
206 {
207 	writel(mode, pmc + AT91_PMC_FSMR);
208 
209 	return 0;
210 }
211 
212 /*
213  * Called after processes are frozen, but before we shutdown devices.
214  */
215 static int at91_pm_begin(suspend_state_t state)
216 {
217 	switch (state) {
218 	case PM_SUSPEND_MEM:
219 		soc_pm.data.mode = soc_pm.data.suspend_mode;
220 		break;
221 
222 	case PM_SUSPEND_STANDBY:
223 		soc_pm.data.mode = soc_pm.data.standby_mode;
224 		break;
225 
226 	default:
227 		soc_pm.data.mode = -1;
228 	}
229 
230 	return at91_pm_config_ws(soc_pm.data.mode, true);
231 }
232 
233 /*
234  * Verify that all the clocks are correct before entering
235  * slow-clock mode.
236  */
237 static int at91_pm_verify_clocks(void)
238 {
239 	unsigned long scsr;
240 	int i;
241 
242 	scsr = readl(soc_pm.data.pmc + AT91_PMC_SCSR);
243 
244 	/* USB must not be using PLLB */
245 	if ((scsr & soc_pm.data.uhp_udp_mask) != 0) {
246 		pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
247 		return 0;
248 	}
249 
250 	/* PCK0..PCK3 must be disabled, or configured to use clk32k */
251 	for (i = 0; i < 4; i++) {
252 		u32 css;
253 
254 		if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
255 			continue;
256 		css = readl(soc_pm.data.pmc + AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
257 		if (css != AT91_PMC_CSS_SLOW) {
258 			pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
259 			return 0;
260 		}
261 	}
262 
263 	return 1;
264 }
265 
266 /*
267  * Call this from platform driver suspend() to see how deeply to suspend.
268  * For example, some controllers (like OHCI) need one of the PLL clocks
269  * in order to act as a wakeup source, and those are not available when
270  * going into slow clock mode.
271  *
272  * REVISIT: generalize as clk_will_be_available(clk)?  Other platforms have
273  * the very same problem (but not using at91 main_clk), and it'd be better
274  * to add one generic API rather than lots of platform-specific ones.
275  */
276 int at91_suspend_entering_slow_clock(void)
277 {
278 	return (soc_pm.data.mode >= AT91_PM_ULP0);
279 }
280 EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
281 
282 static void (*at91_suspend_sram_fn)(struct at91_pm_data *);
283 extern void at91_pm_suspend_in_sram(struct at91_pm_data *pm_data);
284 extern u32 at91_pm_suspend_in_sram_sz;
285 
286 static int at91_suspend_finish(unsigned long val)
287 {
288 	flush_cache_all();
289 	outer_disable();
290 
291 	at91_suspend_sram_fn(&soc_pm.data);
292 
293 	return 0;
294 }
295 
296 static void at91_pm_suspend(suspend_state_t state)
297 {
298 	if (soc_pm.data.mode == AT91_PM_BACKUP) {
299 		pm_bu->suspended = 1;
300 
301 		cpu_suspend(0, at91_suspend_finish);
302 
303 		/* The SRAM is lost between suspend cycles */
304 		at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
305 					     &at91_pm_suspend_in_sram,
306 					     at91_pm_suspend_in_sram_sz);
307 	} else {
308 		at91_suspend_finish(0);
309 	}
310 
311 	outer_resume();
312 }
313 
314 /*
315  * STANDBY mode has *all* drivers suspended; ignores irqs not marked as 'wakeup'
316  * event sources; and reduces DRAM power.  But otherwise it's identical to
317  * PM_SUSPEND_ON: cpu idle, and nothing fancy done with main or cpu clocks.
318  *
319  * AT91_PM_ULP0 is like STANDBY plus slow clock mode, so drivers must
320  * suspend more deeply, the master clock switches to the clk32k and turns off
321  * the main oscillator
322  *
323  * AT91_PM_BACKUP turns off the whole SoC after placing the DDR in self refresh
324  */
325 static int at91_pm_enter(suspend_state_t state)
326 {
327 #ifdef CONFIG_PINCTRL_AT91
328 	at91_pinctrl_gpio_suspend();
329 #endif
330 
331 	switch (state) {
332 	case PM_SUSPEND_MEM:
333 	case PM_SUSPEND_STANDBY:
334 		/*
335 		 * Ensure that clocks are in a valid state.
336 		 */
337 		if (soc_pm.data.mode >= AT91_PM_ULP0 &&
338 		    !at91_pm_verify_clocks())
339 			goto error;
340 
341 		at91_pm_suspend(state);
342 
343 		break;
344 
345 	case PM_SUSPEND_ON:
346 		cpu_do_idle();
347 		break;
348 
349 	default:
350 		pr_debug("AT91: PM - bogus suspend state %d\n", state);
351 		goto error;
352 	}
353 
354 error:
355 #ifdef CONFIG_PINCTRL_AT91
356 	at91_pinctrl_gpio_resume();
357 #endif
358 	return 0;
359 }
360 
361 /*
362  * Called right prior to thawing processes.
363  */
364 static void at91_pm_end(void)
365 {
366 	at91_pm_config_ws(soc_pm.data.mode, false);
367 }
368 
369 
370 static const struct platform_suspend_ops at91_pm_ops = {
371 	.valid	= at91_pm_valid_state,
372 	.begin	= at91_pm_begin,
373 	.enter	= at91_pm_enter,
374 	.end	= at91_pm_end,
375 };
376 
377 static struct platform_device at91_cpuidle_device = {
378 	.name = "cpuidle-at91",
379 };
380 
381 /*
382  * The AT91RM9200 goes into self-refresh mode with this command, and will
383  * terminate self-refresh automatically on the next SDRAM access.
384  *
385  * Self-refresh mode is exited as soon as a memory access is made, but we don't
386  * know for sure when that happens. However, we need to restore the low-power
387  * mode if it was enabled before going idle. Restoring low-power mode while
388  * still in self-refresh is "not recommended", but seems to work.
389  */
390 static void at91rm9200_standby(void)
391 {
392 	asm volatile(
393 		"b    1f\n\t"
394 		".align    5\n\t"
395 		"1:  mcr    p15, 0, %0, c7, c10, 4\n\t"
396 		"    str    %2, [%1, %3]\n\t"
397 		"    mcr    p15, 0, %0, c7, c0, 4\n\t"
398 		:
399 		: "r" (0), "r" (soc_pm.data.ramc[0]),
400 		  "r" (1), "r" (AT91_MC_SDRAMC_SRR));
401 }
402 
403 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
404  * remember.
405  */
406 static void at91_ddr_standby(void)
407 {
408 	/* Those two values allow us to delay self-refresh activation
409 	 * to the maximum. */
410 	u32 lpr0, lpr1 = 0;
411 	u32 mdr, saved_mdr0, saved_mdr1 = 0;
412 	u32 saved_lpr0, saved_lpr1 = 0;
413 
414 	/* LPDDR1 --> force DDR2 mode during self-refresh */
415 	saved_mdr0 = at91_ramc_read(0, AT91_DDRSDRC_MDR);
416 	if ((saved_mdr0 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
417 		mdr = saved_mdr0 & ~AT91_DDRSDRC_MD;
418 		mdr |= AT91_DDRSDRC_MD_DDR2;
419 		at91_ramc_write(0, AT91_DDRSDRC_MDR, mdr);
420 	}
421 
422 	if (soc_pm.data.ramc[1]) {
423 		saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
424 		lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
425 		lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
426 		saved_mdr1 = at91_ramc_read(1, AT91_DDRSDRC_MDR);
427 		if ((saved_mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
428 			mdr = saved_mdr1 & ~AT91_DDRSDRC_MD;
429 			mdr |= AT91_DDRSDRC_MD_DDR2;
430 			at91_ramc_write(1, AT91_DDRSDRC_MDR, mdr);
431 		}
432 	}
433 
434 	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
435 	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
436 	lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
437 
438 	/* self-refresh mode now */
439 	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
440 	if (soc_pm.data.ramc[1])
441 		at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
442 
443 	cpu_do_idle();
444 
445 	at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr0);
446 	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
447 	if (soc_pm.data.ramc[1]) {
448 		at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr1);
449 		at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
450 	}
451 }
452 
453 static void sama5d3_ddr_standby(void)
454 {
455 	u32 lpr0;
456 	u32 saved_lpr0;
457 
458 	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
459 	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
460 	lpr0 |= AT91_DDRSDRC_LPCB_POWER_DOWN;
461 
462 	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
463 
464 	cpu_do_idle();
465 
466 	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
467 }
468 
469 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
470  * remember.
471  */
472 static void at91sam9_sdram_standby(void)
473 {
474 	u32 lpr0, lpr1 = 0;
475 	u32 saved_lpr0, saved_lpr1 = 0;
476 
477 	if (soc_pm.data.ramc[1]) {
478 		saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
479 		lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
480 		lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
481 	}
482 
483 	saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
484 	lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
485 	lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
486 
487 	/* self-refresh mode now */
488 	at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
489 	if (soc_pm.data.ramc[1])
490 		at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
491 
492 	cpu_do_idle();
493 
494 	at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
495 	if (soc_pm.data.ramc[1])
496 		at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
497 }
498 
499 struct ramc_info {
500 	void (*idle)(void);
501 	unsigned int memctrl;
502 };
503 
504 static const struct ramc_info ramc_infos[] __initconst = {
505 	{ .idle = at91rm9200_standby, .memctrl = AT91_MEMCTRL_MC},
506 	{ .idle = at91sam9_sdram_standby, .memctrl = AT91_MEMCTRL_SDRAMC},
507 	{ .idle = at91_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
508 	{ .idle = sama5d3_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
509 };
510 
511 static const struct of_device_id ramc_ids[] __initconst = {
512 	{ .compatible = "atmel,at91rm9200-sdramc", .data = &ramc_infos[0] },
513 	{ .compatible = "atmel,at91sam9260-sdramc", .data = &ramc_infos[1] },
514 	{ .compatible = "atmel,at91sam9g45-ddramc", .data = &ramc_infos[2] },
515 	{ .compatible = "atmel,sama5d3-ddramc", .data = &ramc_infos[3] },
516 	{ /*sentinel*/ }
517 };
518 
519 static __init void at91_dt_ramc(void)
520 {
521 	struct device_node *np;
522 	const struct of_device_id *of_id;
523 	int idx = 0;
524 	void *standby = NULL;
525 	const struct ramc_info *ramc;
526 
527 	for_each_matching_node_and_match(np, ramc_ids, &of_id) {
528 		soc_pm.data.ramc[idx] = of_iomap(np, 0);
529 		if (!soc_pm.data.ramc[idx])
530 			panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
531 
532 		ramc = of_id->data;
533 		if (!standby)
534 			standby = ramc->idle;
535 		soc_pm.data.memctrl = ramc->memctrl;
536 
537 		idx++;
538 	}
539 
540 	if (!idx)
541 		panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
542 
543 	if (!standby) {
544 		pr_warn("ramc no standby function available\n");
545 		return;
546 	}
547 
548 	at91_cpuidle_device.dev.platform_data = standby;
549 }
550 
551 static void at91rm9200_idle(void)
552 {
553 	/*
554 	 * Disable the processor clock.  The processor will be automatically
555 	 * re-enabled by an interrupt or by a reset.
556 	 */
557 	writel(AT91_PMC_PCK, soc_pm.data.pmc + AT91_PMC_SCDR);
558 }
559 
560 static void at91sam9x60_idle(void)
561 {
562 	cpu_do_idle();
563 }
564 
565 static void at91sam9_idle(void)
566 {
567 	writel(AT91_PMC_PCK, soc_pm.data.pmc + AT91_PMC_SCDR);
568 	cpu_do_idle();
569 }
570 
571 static void __init at91_pm_sram_init(void)
572 {
573 	struct gen_pool *sram_pool;
574 	phys_addr_t sram_pbase;
575 	unsigned long sram_base;
576 	struct device_node *node;
577 	struct platform_device *pdev = NULL;
578 
579 	for_each_compatible_node(node, NULL, "mmio-sram") {
580 		pdev = of_find_device_by_node(node);
581 		if (pdev) {
582 			of_node_put(node);
583 			break;
584 		}
585 	}
586 
587 	if (!pdev) {
588 		pr_warn("%s: failed to find sram device!\n", __func__);
589 		return;
590 	}
591 
592 	sram_pool = gen_pool_get(&pdev->dev, NULL);
593 	if (!sram_pool) {
594 		pr_warn("%s: sram pool unavailable!\n", __func__);
595 		goto out_put_device;
596 	}
597 
598 	sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
599 	if (!sram_base) {
600 		pr_warn("%s: unable to alloc sram!\n", __func__);
601 		goto out_put_device;
602 	}
603 
604 	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
605 	at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
606 					at91_pm_suspend_in_sram_sz, false);
607 	if (!at91_suspend_sram_fn) {
608 		pr_warn("SRAM: Could not map\n");
609 		goto out_put_device;
610 	}
611 
612 	/* Copy the pm suspend handler to SRAM */
613 	at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
614 			&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
615 	return;
616 
617 out_put_device:
618 	put_device(&pdev->dev);
619 	return;
620 }
621 
622 static bool __init at91_is_pm_mode_active(int pm_mode)
623 {
624 	return (soc_pm.data.standby_mode == pm_mode ||
625 		soc_pm.data.suspend_mode == pm_mode);
626 }
627 
628 static int __init at91_pm_backup_init(void)
629 {
630 	struct gen_pool *sram_pool;
631 	struct device_node *np;
632 	struct platform_device *pdev = NULL;
633 	int ret = -ENODEV;
634 
635 	if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
636 		return -EPERM;
637 
638 	if (!at91_is_pm_mode_active(AT91_PM_BACKUP))
639 		return 0;
640 
641 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-sfrbu");
642 	if (!np) {
643 		pr_warn("%s: failed to find sfrbu!\n", __func__);
644 		return ret;
645 	}
646 
647 	soc_pm.data.sfrbu = of_iomap(np, 0);
648 	of_node_put(np);
649 
650 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
651 	if (!np)
652 		goto securam_fail_no_ref_dev;
653 
654 	pdev = of_find_device_by_node(np);
655 	of_node_put(np);
656 	if (!pdev) {
657 		pr_warn("%s: failed to find securam device!\n", __func__);
658 		goto securam_fail_no_ref_dev;
659 	}
660 
661 	sram_pool = gen_pool_get(&pdev->dev, NULL);
662 	if (!sram_pool) {
663 		pr_warn("%s: securam pool unavailable!\n", __func__);
664 		goto securam_fail;
665 	}
666 
667 	pm_bu = (void *)gen_pool_alloc(sram_pool, sizeof(struct at91_pm_bu));
668 	if (!pm_bu) {
669 		pr_warn("%s: unable to alloc securam!\n", __func__);
670 		ret = -ENOMEM;
671 		goto securam_fail;
672 	}
673 
674 	pm_bu->suspended = 0;
675 	pm_bu->canary = __pa_symbol(&canary);
676 	pm_bu->resume = __pa_symbol(cpu_resume);
677 
678 	return 0;
679 
680 securam_fail:
681 	put_device(&pdev->dev);
682 securam_fail_no_ref_dev:
683 	iounmap(soc_pm.data.sfrbu);
684 	soc_pm.data.sfrbu = NULL;
685 	return ret;
686 }
687 
688 static void __init at91_pm_use_default_mode(int pm_mode)
689 {
690 	if (pm_mode != AT91_PM_ULP1 && pm_mode != AT91_PM_BACKUP)
691 		return;
692 
693 	if (soc_pm.data.standby_mode == pm_mode)
694 		soc_pm.data.standby_mode = AT91_PM_ULP0;
695 	if (soc_pm.data.suspend_mode == pm_mode)
696 		soc_pm.data.suspend_mode = AT91_PM_ULP0;
697 }
698 
699 static const struct of_device_id atmel_shdwc_ids[] = {
700 	{ .compatible = "atmel,sama5d2-shdwc" },
701 	{ .compatible = "microchip,sam9x60-shdwc" },
702 	{ /* sentinel. */ }
703 };
704 
705 static void __init at91_pm_modes_init(void)
706 {
707 	struct device_node *np;
708 	int ret;
709 
710 	if (!at91_is_pm_mode_active(AT91_PM_BACKUP) &&
711 	    !at91_is_pm_mode_active(AT91_PM_ULP1))
712 		return;
713 
714 	np = of_find_matching_node(NULL, atmel_shdwc_ids);
715 	if (!np) {
716 		pr_warn("%s: failed to find shdwc!\n", __func__);
717 		goto ulp1_default;
718 	}
719 
720 	soc_pm.data.shdwc = of_iomap(np, 0);
721 	of_node_put(np);
722 
723 	ret = at91_pm_backup_init();
724 	if (ret) {
725 		if (!at91_is_pm_mode_active(AT91_PM_ULP1))
726 			goto unmap;
727 		else
728 			goto backup_default;
729 	}
730 
731 	return;
732 
733 unmap:
734 	iounmap(soc_pm.data.shdwc);
735 	soc_pm.data.shdwc = NULL;
736 ulp1_default:
737 	at91_pm_use_default_mode(AT91_PM_ULP1);
738 backup_default:
739 	at91_pm_use_default_mode(AT91_PM_BACKUP);
740 }
741 
742 struct pmc_info {
743 	unsigned long uhp_udp_mask;
744 	unsigned long mckr;
745 	unsigned long version;
746 };
747 
748 static const struct pmc_info pmc_infos[] __initconst = {
749 	{
750 		.uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP,
751 		.mckr = 0x30,
752 		.version = AT91_PMC_V1,
753 	},
754 
755 	{
756 		.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP,
757 		.mckr = 0x30,
758 		.version = AT91_PMC_V1,
759 	},
760 	{
761 		.uhp_udp_mask = AT91SAM926x_PMC_UHP,
762 		.mckr = 0x30,
763 		.version = AT91_PMC_V1,
764 	},
765 	{	.uhp_udp_mask = 0,
766 		.mckr = 0x30,
767 		.version = AT91_PMC_V1,
768 	},
769 	{
770 		.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP,
771 		.mckr = 0x28,
772 		.version = AT91_PMC_V2,
773 	},
774 };
775 
776 static const struct of_device_id atmel_pmc_ids[] __initconst = {
777 	{ .compatible = "atmel,at91rm9200-pmc", .data = &pmc_infos[0] },
778 	{ .compatible = "atmel,at91sam9260-pmc", .data = &pmc_infos[1] },
779 	{ .compatible = "atmel,at91sam9261-pmc", .data = &pmc_infos[1] },
780 	{ .compatible = "atmel,at91sam9263-pmc", .data = &pmc_infos[1] },
781 	{ .compatible = "atmel,at91sam9g45-pmc", .data = &pmc_infos[2] },
782 	{ .compatible = "atmel,at91sam9n12-pmc", .data = &pmc_infos[1] },
783 	{ .compatible = "atmel,at91sam9rl-pmc", .data = &pmc_infos[3] },
784 	{ .compatible = "atmel,at91sam9x5-pmc", .data = &pmc_infos[1] },
785 	{ .compatible = "atmel,sama5d3-pmc", .data = &pmc_infos[1] },
786 	{ .compatible = "atmel,sama5d4-pmc", .data = &pmc_infos[1] },
787 	{ .compatible = "atmel,sama5d2-pmc", .data = &pmc_infos[1] },
788 	{ .compatible = "microchip,sam9x60-pmc", .data = &pmc_infos[4] },
789 	{ /* sentinel */ },
790 };
791 
792 static void __init at91_pm_init(void (*pm_idle)(void))
793 {
794 	struct device_node *pmc_np;
795 	const struct of_device_id *of_id;
796 	const struct pmc_info *pmc;
797 
798 	if (at91_cpuidle_device.dev.platform_data)
799 		platform_device_register(&at91_cpuidle_device);
800 
801 	pmc_np = of_find_matching_node_and_match(NULL, atmel_pmc_ids, &of_id);
802 	soc_pm.data.pmc = of_iomap(pmc_np, 0);
803 	if (!soc_pm.data.pmc) {
804 		pr_err("AT91: PM not supported, PMC not found\n");
805 		return;
806 	}
807 
808 	pmc = of_id->data;
809 	soc_pm.data.uhp_udp_mask = pmc->uhp_udp_mask;
810 	soc_pm.data.pmc_mckr_offset = pmc->mckr;
811 	soc_pm.data.pmc_version = pmc->version;
812 
813 	if (pm_idle)
814 		arm_pm_idle = pm_idle;
815 
816 	at91_pm_sram_init();
817 
818 	if (at91_suspend_sram_fn) {
819 		suspend_set_ops(&at91_pm_ops);
820 		pr_info("AT91: PM: standby: %s, suspend: %s\n",
821 			pm_modes[soc_pm.data.standby_mode].pattern,
822 			pm_modes[soc_pm.data.suspend_mode].pattern);
823 	} else {
824 		pr_info("AT91: PM not supported, due to no SRAM allocated\n");
825 	}
826 }
827 
828 void __init at91rm9200_pm_init(void)
829 {
830 	if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
831 		return;
832 
833 	at91_dt_ramc();
834 
835 	/*
836 	 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
837 	 */
838 	at91_ramc_write(0, AT91_MC_SDRAMC_LPR, 0);
839 
840 	at91_pm_init(at91rm9200_idle);
841 }
842 
843 void __init sam9x60_pm_init(void)
844 {
845 	if (!IS_ENABLED(CONFIG_SOC_SAM9X60))
846 		return;
847 
848 	at91_pm_modes_init();
849 	at91_dt_ramc();
850 	at91_pm_init(at91sam9x60_idle);
851 
852 	soc_pm.ws_ids = sam9x60_ws_ids;
853 	soc_pm.config_pmc_ws = at91_sam9x60_config_pmc_ws;
854 }
855 
856 void __init at91sam9_pm_init(void)
857 {
858 	if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
859 		return;
860 
861 	at91_dt_ramc();
862 	at91_pm_init(at91sam9_idle);
863 }
864 
865 void __init sama5_pm_init(void)
866 {
867 	if (!IS_ENABLED(CONFIG_SOC_SAMA5))
868 		return;
869 
870 	at91_dt_ramc();
871 	at91_pm_init(NULL);
872 }
873 
874 void __init sama5d2_pm_init(void)
875 {
876 	if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
877 		return;
878 
879 	at91_pm_modes_init();
880 	sama5_pm_init();
881 
882 	soc_pm.ws_ids = sama5d2_ws_ids;
883 	soc_pm.config_shdwc_ws = at91_sama5d2_config_shdwc_ws;
884 	soc_pm.config_pmc_ws = at91_sama5d2_config_pmc_ws;
885 }
886 
887 static int __init at91_pm_modes_select(char *str)
888 {
889 	char *s;
890 	substring_t args[MAX_OPT_ARGS];
891 	int standby, suspend;
892 
893 	if (!str)
894 		return 0;
895 
896 	s = strsep(&str, ",");
897 	standby = match_token(s, pm_modes, args);
898 	if (standby < 0)
899 		return 0;
900 
901 	suspend = match_token(str, pm_modes, args);
902 	if (suspend < 0)
903 		return 0;
904 
905 	soc_pm.data.standby_mode = standby;
906 	soc_pm.data.suspend_mode = suspend;
907 
908 	return 0;
909 }
910 early_param("atmel.pm_modes", at91_pm_modes_select);
911