xref: /openbmc/linux/arch/arm/mach-at91/pm.c (revision 8e8e69d6)
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 
19 #include <asm/cacheflush.h>
20 #include <asm/fncpy.h>
21 #include <asm/system_misc.h>
22 #include <asm/suspend.h>
23 
24 #include "generic.h"
25 #include "pm.h"
26 
27 /*
28  * FIXME: this is needed to communicate between the pinctrl driver and
29  * the PM implementation in the machine. Possibly part of the PM
30  * implementation should be moved down into the pinctrl driver and get
31  * called as part of the generic suspend/resume path.
32  */
33 #ifdef CONFIG_PINCTRL_AT91
34 extern void at91_pinctrl_gpio_suspend(void);
35 extern void at91_pinctrl_gpio_resume(void);
36 #endif
37 
38 struct at91_soc_pm {
39 	int (*config_shdwc_ws)(void __iomem *shdwc, u32 *mode, u32 *polarity);
40 	int (*config_pmc_ws)(void __iomem *pmc, u32 mode, u32 polarity);
41 	const struct of_device_id *ws_ids;
42 	struct at91_pm_data data;
43 };
44 
45 static struct at91_soc_pm soc_pm = {
46 	.data = {
47 		.standby_mode = AT91_PM_STANDBY,
48 		.suspend_mode = AT91_PM_ULP0,
49 	},
50 };
51 
52 static const match_table_t pm_modes __initconst = {
53 	{ AT91_PM_STANDBY, "standby" },
54 	{ AT91_PM_ULP0, "ulp0" },
55 	{ AT91_PM_ULP1, "ulp1" },
56 	{ AT91_PM_BACKUP, "backup" },
57 	{ -1, NULL },
58 };
59 
60 #define at91_ramc_read(id, field) \
61 	__raw_readl(soc_pm.data.ramc[id] + field)
62 
63 #define at91_ramc_write(id, field, value) \
64 	__raw_writel(value, soc_pm.data.ramc[id] + field)
65 
66 static int at91_pm_valid_state(suspend_state_t state)
67 {
68 	switch (state) {
69 		case PM_SUSPEND_ON:
70 		case PM_SUSPEND_STANDBY:
71 		case PM_SUSPEND_MEM:
72 			return 1;
73 
74 		default:
75 			return 0;
76 	}
77 }
78 
79 static int canary = 0xA5A5A5A5;
80 
81 static struct at91_pm_bu {
82 	int suspended;
83 	unsigned long reserved;
84 	phys_addr_t canary;
85 	phys_addr_t resume;
86 } *pm_bu;
87 
88 struct wakeup_source_info {
89 	unsigned int pmc_fsmr_bit;
90 	unsigned int shdwc_mr_bit;
91 	bool set_polarity;
92 };
93 
94 static const struct wakeup_source_info ws_info[] = {
95 	{ .pmc_fsmr_bit = AT91_PMC_FSTT(10),	.set_polarity = true },
96 	{ .pmc_fsmr_bit = AT91_PMC_RTCAL,	.shdwc_mr_bit = BIT(17) },
97 	{ .pmc_fsmr_bit = AT91_PMC_USBAL },
98 	{ .pmc_fsmr_bit = AT91_PMC_SDMMC_CD },
99 	{ .pmc_fsmr_bit = AT91_PMC_RTTAL },
100 	{ .pmc_fsmr_bit = AT91_PMC_RXLP_MCE },
101 };
102 
103 static const struct of_device_id sama5d2_ws_ids[] = {
104 	{ .compatible = "atmel,sama5d2-gem",		.data = &ws_info[0] },
105 	{ .compatible = "atmel,at91rm9200-rtc",		.data = &ws_info[1] },
106 	{ .compatible = "atmel,sama5d3-udc",		.data = &ws_info[2] },
107 	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
108 	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
109 	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
110 	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
111 	{ .compatible = "atmel,sama5d2-sdhci",		.data = &ws_info[3] },
112 	{ /* sentinel */ }
113 };
114 
115 static const struct of_device_id sam9x60_ws_ids[] = {
116 	{ .compatible = "atmel,at91sam9x5-rtc",		.data = &ws_info[1] },
117 	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
118 	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
119 	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
120 	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
121 	{ .compatible = "atmel,at91sam9260-rtt",	.data = &ws_info[4] },
122 	{ .compatible = "cdns,sam9x60-macb",		.data = &ws_info[5] },
123 	{ /* sentinel */ }
124 };
125 
126 static int at91_pm_config_ws(unsigned int pm_mode, bool set)
127 {
128 	const struct wakeup_source_info *wsi;
129 	const struct of_device_id *match;
130 	struct platform_device *pdev;
131 	struct device_node *np;
132 	unsigned int mode = 0, polarity = 0, val = 0;
133 
134 	if (pm_mode != AT91_PM_ULP1)
135 		return 0;
136 
137 	if (!soc_pm.data.pmc || !soc_pm.data.shdwc || !soc_pm.ws_ids)
138 		return -EPERM;
139 
140 	if (!set) {
141 		writel(mode, soc_pm.data.pmc + AT91_PMC_FSMR);
142 		return 0;
143 	}
144 
145 	if (soc_pm.config_shdwc_ws)
146 		soc_pm.config_shdwc_ws(soc_pm.data.shdwc, &mode, &polarity);
147 
148 	/* SHDWC.MR */
149 	val = readl(soc_pm.data.shdwc + 0x04);
150 
151 	/* Loop through defined wakeup sources. */
152 	for_each_matching_node_and_match(np, soc_pm.ws_ids, &match) {
153 		pdev = of_find_device_by_node(np);
154 		if (!pdev)
155 			continue;
156 
157 		if (device_may_wakeup(&pdev->dev)) {
158 			wsi = match->data;
159 
160 			/* Check if enabled on SHDWC. */
161 			if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
162 				goto put_device;
163 
164 			mode |= wsi->pmc_fsmr_bit;
165 			if (wsi->set_polarity)
166 				polarity |= wsi->pmc_fsmr_bit;
167 		}
168 
169 put_device:
170 		put_device(&pdev->dev);
171 	}
172 
173 	if (mode) {
174 		if (soc_pm.config_pmc_ws)
175 			soc_pm.config_pmc_ws(soc_pm.data.pmc, mode, polarity);
176 	} else {
177 		pr_err("AT91: PM: no ULP1 wakeup sources found!");
178 	}
179 
180 	return mode ? 0 : -EPERM;
181 }
182 
183 static int at91_sama5d2_config_shdwc_ws(void __iomem *shdwc, u32 *mode,
184 					u32 *polarity)
185 {
186 	u32 val;
187 
188 	/* SHDWC.WUIR */
189 	val = readl(shdwc + 0x0c);
190 	*mode |= (val & 0x3ff);
191 	*polarity |= ((val >> 16) & 0x3ff);
192 
193 	return 0;
194 }
195 
196 static int at91_sama5d2_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
197 {
198 	writel(mode, pmc + AT91_PMC_FSMR);
199 	writel(polarity, pmc + AT91_PMC_FSPR);
200 
201 	return 0;
202 }
203 
204 static int at91_sam9x60_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
205 {
206 	writel(mode, pmc + AT91_PMC_FSMR);
207 
208 	return 0;
209 }
210 
211 /*
212  * Called after processes are frozen, but before we shutdown devices.
213  */
214 static int at91_pm_begin(suspend_state_t state)
215 {
216 	switch (state) {
217 	case PM_SUSPEND_MEM:
218 		soc_pm.data.mode = soc_pm.data.suspend_mode;
219 		break;
220 
221 	case PM_SUSPEND_STANDBY:
222 		soc_pm.data.mode = soc_pm.data.standby_mode;
223 		break;
224 
225 	default:
226 		soc_pm.data.mode = -1;
227 	}
228 
229 	return at91_pm_config_ws(soc_pm.data.mode, true);
230 }
231 
232 /*
233  * Verify that all the clocks are correct before entering
234  * slow-clock mode.
235  */
236 static int at91_pm_verify_clocks(void)
237 {
238 	unsigned long scsr;
239 	int i;
240 
241 	scsr = readl(soc_pm.data.pmc + AT91_PMC_SCSR);
242 
243 	/* USB must not be using PLLB */
244 	if ((scsr & soc_pm.data.uhp_udp_mask) != 0) {
245 		pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
246 		return 0;
247 	}
248 
249 	/* PCK0..PCK3 must be disabled, or configured to use clk32k */
250 	for (i = 0; i < 4; i++) {
251 		u32 css;
252 
253 		if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
254 			continue;
255 		css = readl(soc_pm.data.pmc + AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
256 		if (css != AT91_PMC_CSS_SLOW) {
257 			pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
258 			return 0;
259 		}
260 	}
261 
262 	return 1;
263 }
264 
265 /*
266  * Call this from platform driver suspend() to see how deeply to suspend.
267  * For example, some controllers (like OHCI) need one of the PLL clocks
268  * in order to act as a wakeup source, and those are not available when
269  * going into slow clock mode.
270  *
271  * REVISIT: generalize as clk_will_be_available(clk)?  Other platforms have
272  * the very same problem (but not using at91 main_clk), and it'd be better
273  * to add one generic API rather than lots of platform-specific ones.
274  */
275 int at91_suspend_entering_slow_clock(void)
276 {
277 	return (soc_pm.data.mode >= AT91_PM_ULP0);
278 }
279 EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
280 
281 static void (*at91_suspend_sram_fn)(struct at91_pm_data *);
282 extern void at91_pm_suspend_in_sram(struct at91_pm_data *pm_data);
283 extern u32 at91_pm_suspend_in_sram_sz;
284 
285 static int at91_suspend_finish(unsigned long val)
286 {
287 	flush_cache_all();
288 	outer_disable();
289 
290 	at91_suspend_sram_fn(&soc_pm.data);
291 
292 	return 0;
293 }
294 
295 static void at91_pm_suspend(suspend_state_t state)
296 {
297 	if (soc_pm.data.mode == AT91_PM_BACKUP) {
298 		pm_bu->suspended = 1;
299 
300 		cpu_suspend(0, at91_suspend_finish);
301 
302 		/* The SRAM is lost between suspend cycles */
303 		at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
304 					     &at91_pm_suspend_in_sram,
305 					     at91_pm_suspend_in_sram_sz);
306 	} else {
307 		at91_suspend_finish(0);
308 	}
309 
310 	outer_resume();
311 }
312 
313 /*
314  * STANDBY mode has *all* drivers suspended; ignores irqs not marked as 'wakeup'
315  * event sources; and reduces DRAM power.  But otherwise it's identical to
316  * PM_SUSPEND_ON: cpu idle, and nothing fancy done with main or cpu clocks.
317  *
318  * AT91_PM_ULP0 is like STANDBY plus slow clock mode, so drivers must
319  * suspend more deeply, the master clock switches to the clk32k and turns off
320  * the main oscillator
321  *
322  * AT91_PM_BACKUP turns off the whole SoC after placing the DDR in self refresh
323  */
324 static int at91_pm_enter(suspend_state_t state)
325 {
326 #ifdef CONFIG_PINCTRL_AT91
327 	at91_pinctrl_gpio_suspend();
328 #endif
329 
330 	switch (state) {
331 	case PM_SUSPEND_MEM:
332 	case PM_SUSPEND_STANDBY:
333 		/*
334 		 * Ensure that clocks are in a valid state.
335 		 */
336 		if (soc_pm.data.mode >= AT91_PM_ULP0 &&
337 		    !at91_pm_verify_clocks())
338 			goto error;
339 
340 		at91_pm_suspend(state);
341 
342 		break;
343 
344 	case PM_SUSPEND_ON:
345 		cpu_do_idle();
346 		break;
347 
348 	default:
349 		pr_debug("AT91: PM - bogus suspend state %d\n", state);
350 		goto error;
351 	}
352 
353 error:
354 #ifdef CONFIG_PINCTRL_AT91
355 	at91_pinctrl_gpio_resume();
356 #endif
357 	return 0;
358 }
359 
360 /*
361  * Called right prior to thawing processes.
362  */
363 static void at91_pm_end(void)
364 {
365 	at91_pm_config_ws(soc_pm.data.mode, false);
366 }
367 
368 
369 static const struct platform_suspend_ops at91_pm_ops = {
370 	.valid	= at91_pm_valid_state,
371 	.begin	= at91_pm_begin,
372 	.enter	= at91_pm_enter,
373 	.end	= at91_pm_end,
374 };
375 
376 static struct platform_device at91_cpuidle_device = {
377 	.name = "cpuidle-at91",
378 };
379 
380 /*
381  * The AT91RM9200 goes into self-refresh mode with this command, and will
382  * terminate self-refresh automatically on the next SDRAM access.
383  *
384  * Self-refresh mode is exited as soon as a memory access is made, but we don't
385  * know for sure when that happens. However, we need to restore the low-power
386  * mode if it was enabled before going idle. Restoring low-power mode while
387  * still in self-refresh is "not recommended", but seems to work.
388  */
389 static void at91rm9200_standby(void)
390 {
391 	asm volatile(
392 		"b    1f\n\t"
393 		".align    5\n\t"
394 		"1:  mcr    p15, 0, %0, c7, c10, 4\n\t"
395 		"    str    %2, [%1, %3]\n\t"
396 		"    mcr    p15, 0, %0, c7, c0, 4\n\t"
397 		:
398 		: "r" (0), "r" (soc_pm.data.ramc[0]),
399 		  "r" (1), "r" (AT91_MC_SDRAMC_SRR));
400 }
401 
402 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
403  * remember.
404  */
405 static void at91_ddr_standby(void)
406 {
407 	/* Those two values allow us to delay self-refresh activation
408 	 * to the maximum. */
409 	u32 lpr0, lpr1 = 0;
410 	u32 mdr, saved_mdr0, saved_mdr1 = 0;
411 	u32 saved_lpr0, saved_lpr1 = 0;
412 
413 	/* LPDDR1 --> force DDR2 mode during self-refresh */
414 	saved_mdr0 = at91_ramc_read(0, AT91_DDRSDRC_MDR);
415 	if ((saved_mdr0 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
416 		mdr = saved_mdr0 & ~AT91_DDRSDRC_MD;
417 		mdr |= AT91_DDRSDRC_MD_DDR2;
418 		at91_ramc_write(0, AT91_DDRSDRC_MDR, mdr);
419 	}
420 
421 	if (soc_pm.data.ramc[1]) {
422 		saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
423 		lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
424 		lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
425 		saved_mdr1 = at91_ramc_read(1, AT91_DDRSDRC_MDR);
426 		if ((saved_mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
427 			mdr = saved_mdr1 & ~AT91_DDRSDRC_MD;
428 			mdr |= AT91_DDRSDRC_MD_DDR2;
429 			at91_ramc_write(1, AT91_DDRSDRC_MDR, mdr);
430 		}
431 	}
432 
433 	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
434 	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
435 	lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
436 
437 	/* self-refresh mode now */
438 	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
439 	if (soc_pm.data.ramc[1])
440 		at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
441 
442 	cpu_do_idle();
443 
444 	at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr0);
445 	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
446 	if (soc_pm.data.ramc[1]) {
447 		at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr1);
448 		at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
449 	}
450 }
451 
452 static void sama5d3_ddr_standby(void)
453 {
454 	u32 lpr0;
455 	u32 saved_lpr0;
456 
457 	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
458 	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
459 	lpr0 |= AT91_DDRSDRC_LPCB_POWER_DOWN;
460 
461 	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
462 
463 	cpu_do_idle();
464 
465 	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
466 }
467 
468 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
469  * remember.
470  */
471 static void at91sam9_sdram_standby(void)
472 {
473 	u32 lpr0, lpr1 = 0;
474 	u32 saved_lpr0, saved_lpr1 = 0;
475 
476 	if (soc_pm.data.ramc[1]) {
477 		saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
478 		lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
479 		lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
480 	}
481 
482 	saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
483 	lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
484 	lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
485 
486 	/* self-refresh mode now */
487 	at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
488 	if (soc_pm.data.ramc[1])
489 		at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
490 
491 	cpu_do_idle();
492 
493 	at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
494 	if (soc_pm.data.ramc[1])
495 		at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
496 }
497 
498 struct ramc_info {
499 	void (*idle)(void);
500 	unsigned int memctrl;
501 };
502 
503 static const struct ramc_info ramc_infos[] __initconst = {
504 	{ .idle = at91rm9200_standby, .memctrl = AT91_MEMCTRL_MC},
505 	{ .idle = at91sam9_sdram_standby, .memctrl = AT91_MEMCTRL_SDRAMC},
506 	{ .idle = at91_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
507 	{ .idle = sama5d3_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
508 };
509 
510 static const struct of_device_id ramc_ids[] __initconst = {
511 	{ .compatible = "atmel,at91rm9200-sdramc", .data = &ramc_infos[0] },
512 	{ .compatible = "atmel,at91sam9260-sdramc", .data = &ramc_infos[1] },
513 	{ .compatible = "atmel,at91sam9g45-ddramc", .data = &ramc_infos[2] },
514 	{ .compatible = "atmel,sama5d3-ddramc", .data = &ramc_infos[3] },
515 	{ /*sentinel*/ }
516 };
517 
518 static __init void at91_dt_ramc(void)
519 {
520 	struct device_node *np;
521 	const struct of_device_id *of_id;
522 	int idx = 0;
523 	void *standby = NULL;
524 	const struct ramc_info *ramc;
525 
526 	for_each_matching_node_and_match(np, ramc_ids, &of_id) {
527 		soc_pm.data.ramc[idx] = of_iomap(np, 0);
528 		if (!soc_pm.data.ramc[idx])
529 			panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
530 
531 		ramc = of_id->data;
532 		if (!standby)
533 			standby = ramc->idle;
534 		soc_pm.data.memctrl = ramc->memctrl;
535 
536 		idx++;
537 	}
538 
539 	if (!idx)
540 		panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
541 
542 	if (!standby) {
543 		pr_warn("ramc no standby function available\n");
544 		return;
545 	}
546 
547 	at91_cpuidle_device.dev.platform_data = standby;
548 }
549 
550 static void at91rm9200_idle(void)
551 {
552 	/*
553 	 * Disable the processor clock.  The processor will be automatically
554 	 * re-enabled by an interrupt or by a reset.
555 	 */
556 	writel(AT91_PMC_PCK, soc_pm.data.pmc + AT91_PMC_SCDR);
557 }
558 
559 static void at91sam9x60_idle(void)
560 {
561 	cpu_do_idle();
562 }
563 
564 static void at91sam9_idle(void)
565 {
566 	writel(AT91_PMC_PCK, soc_pm.data.pmc + AT91_PMC_SCDR);
567 	cpu_do_idle();
568 }
569 
570 static void __init at91_pm_sram_init(void)
571 {
572 	struct gen_pool *sram_pool;
573 	phys_addr_t sram_pbase;
574 	unsigned long sram_base;
575 	struct device_node *node;
576 	struct platform_device *pdev = NULL;
577 
578 	for_each_compatible_node(node, NULL, "mmio-sram") {
579 		pdev = of_find_device_by_node(node);
580 		if (pdev) {
581 			of_node_put(node);
582 			break;
583 		}
584 	}
585 
586 	if (!pdev) {
587 		pr_warn("%s: failed to find sram device!\n", __func__);
588 		return;
589 	}
590 
591 	sram_pool = gen_pool_get(&pdev->dev, NULL);
592 	if (!sram_pool) {
593 		pr_warn("%s: sram pool unavailable!\n", __func__);
594 		return;
595 	}
596 
597 	sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
598 	if (!sram_base) {
599 		pr_warn("%s: unable to alloc sram!\n", __func__);
600 		return;
601 	}
602 
603 	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
604 	at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
605 					at91_pm_suspend_in_sram_sz, false);
606 	if (!at91_suspend_sram_fn) {
607 		pr_warn("SRAM: Could not map\n");
608 		return;
609 	}
610 
611 	/* Copy the pm suspend handler to SRAM */
612 	at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
613 			&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
614 }
615 
616 static bool __init at91_is_pm_mode_active(int pm_mode)
617 {
618 	return (soc_pm.data.standby_mode == pm_mode ||
619 		soc_pm.data.suspend_mode == pm_mode);
620 }
621 
622 static int __init at91_pm_backup_init(void)
623 {
624 	struct gen_pool *sram_pool;
625 	struct device_node *np;
626 	struct platform_device *pdev = NULL;
627 	int ret = -ENODEV;
628 
629 	if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
630 		return -EPERM;
631 
632 	if (!at91_is_pm_mode_active(AT91_PM_BACKUP))
633 		return 0;
634 
635 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-sfrbu");
636 	if (!np) {
637 		pr_warn("%s: failed to find sfrbu!\n", __func__);
638 		return ret;
639 	}
640 
641 	soc_pm.data.sfrbu = of_iomap(np, 0);
642 	of_node_put(np);
643 
644 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
645 	if (!np)
646 		goto securam_fail_no_ref_dev;
647 
648 	pdev = of_find_device_by_node(np);
649 	of_node_put(np);
650 	if (!pdev) {
651 		pr_warn("%s: failed to find securam device!\n", __func__);
652 		goto securam_fail_no_ref_dev;
653 	}
654 
655 	sram_pool = gen_pool_get(&pdev->dev, NULL);
656 	if (!sram_pool) {
657 		pr_warn("%s: securam pool unavailable!\n", __func__);
658 		goto securam_fail;
659 	}
660 
661 	pm_bu = (void *)gen_pool_alloc(sram_pool, sizeof(struct at91_pm_bu));
662 	if (!pm_bu) {
663 		pr_warn("%s: unable to alloc securam!\n", __func__);
664 		ret = -ENOMEM;
665 		goto securam_fail;
666 	}
667 
668 	pm_bu->suspended = 0;
669 	pm_bu->canary = __pa_symbol(&canary);
670 	pm_bu->resume = __pa_symbol(cpu_resume);
671 
672 	return 0;
673 
674 securam_fail:
675 	put_device(&pdev->dev);
676 securam_fail_no_ref_dev:
677 	iounmap(soc_pm.data.sfrbu);
678 	soc_pm.data.sfrbu = NULL;
679 	return ret;
680 }
681 
682 static void __init at91_pm_use_default_mode(int pm_mode)
683 {
684 	if (pm_mode != AT91_PM_ULP1 && pm_mode != AT91_PM_BACKUP)
685 		return;
686 
687 	if (soc_pm.data.standby_mode == pm_mode)
688 		soc_pm.data.standby_mode = AT91_PM_ULP0;
689 	if (soc_pm.data.suspend_mode == pm_mode)
690 		soc_pm.data.suspend_mode = AT91_PM_ULP0;
691 }
692 
693 static void __init at91_pm_modes_init(void)
694 {
695 	struct device_node *np;
696 	int ret;
697 
698 	if (!at91_is_pm_mode_active(AT91_PM_BACKUP) &&
699 	    !at91_is_pm_mode_active(AT91_PM_ULP1))
700 		return;
701 
702 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-shdwc");
703 	if (!np) {
704 		pr_warn("%s: failed to find shdwc!\n", __func__);
705 		goto ulp1_default;
706 	}
707 
708 	soc_pm.data.shdwc = of_iomap(np, 0);
709 	of_node_put(np);
710 
711 	ret = at91_pm_backup_init();
712 	if (ret) {
713 		if (!at91_is_pm_mode_active(AT91_PM_ULP1))
714 			goto unmap;
715 		else
716 			goto backup_default;
717 	}
718 
719 	return;
720 
721 unmap:
722 	iounmap(soc_pm.data.shdwc);
723 	soc_pm.data.shdwc = NULL;
724 ulp1_default:
725 	at91_pm_use_default_mode(AT91_PM_ULP1);
726 backup_default:
727 	at91_pm_use_default_mode(AT91_PM_BACKUP);
728 }
729 
730 struct pmc_info {
731 	unsigned long uhp_udp_mask;
732 };
733 
734 static const struct pmc_info pmc_infos[] __initconst = {
735 	{ .uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP },
736 	{ .uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP },
737 	{ .uhp_udp_mask = AT91SAM926x_PMC_UHP },
738 	{ .uhp_udp_mask = 0 },
739 };
740 
741 static const struct of_device_id atmel_pmc_ids[] __initconst = {
742 	{ .compatible = "atmel,at91rm9200-pmc", .data = &pmc_infos[0] },
743 	{ .compatible = "atmel,at91sam9260-pmc", .data = &pmc_infos[1] },
744 	{ .compatible = "atmel,at91sam9261-pmc", .data = &pmc_infos[1] },
745 	{ .compatible = "atmel,at91sam9263-pmc", .data = &pmc_infos[1] },
746 	{ .compatible = "atmel,at91sam9g45-pmc", .data = &pmc_infos[2] },
747 	{ .compatible = "atmel,at91sam9n12-pmc", .data = &pmc_infos[1] },
748 	{ .compatible = "atmel,at91sam9rl-pmc", .data = &pmc_infos[3] },
749 	{ .compatible = "atmel,at91sam9x5-pmc", .data = &pmc_infos[1] },
750 	{ .compatible = "atmel,sama5d3-pmc", .data = &pmc_infos[1] },
751 	{ .compatible = "atmel,sama5d4-pmc", .data = &pmc_infos[1] },
752 	{ .compatible = "atmel,sama5d2-pmc", .data = &pmc_infos[1] },
753 	{ /* sentinel */ },
754 };
755 
756 static void __init at91_pm_init(void (*pm_idle)(void))
757 {
758 	struct device_node *pmc_np;
759 	const struct of_device_id *of_id;
760 	const struct pmc_info *pmc;
761 
762 	if (at91_cpuidle_device.dev.platform_data)
763 		platform_device_register(&at91_cpuidle_device);
764 
765 	pmc_np = of_find_matching_node_and_match(NULL, atmel_pmc_ids, &of_id);
766 	soc_pm.data.pmc = of_iomap(pmc_np, 0);
767 	if (!soc_pm.data.pmc) {
768 		pr_err("AT91: PM not supported, PMC not found\n");
769 		return;
770 	}
771 
772 	pmc = of_id->data;
773 	soc_pm.data.uhp_udp_mask = pmc->uhp_udp_mask;
774 
775 	if (pm_idle)
776 		arm_pm_idle = pm_idle;
777 
778 	at91_pm_sram_init();
779 
780 	if (at91_suspend_sram_fn) {
781 		suspend_set_ops(&at91_pm_ops);
782 		pr_info("AT91: PM: standby: %s, suspend: %s\n",
783 			pm_modes[soc_pm.data.standby_mode].pattern,
784 			pm_modes[soc_pm.data.suspend_mode].pattern);
785 	} else {
786 		pr_info("AT91: PM not supported, due to no SRAM allocated\n");
787 	}
788 }
789 
790 void __init at91rm9200_pm_init(void)
791 {
792 	if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
793 		return;
794 
795 	at91_dt_ramc();
796 
797 	/*
798 	 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
799 	 */
800 	at91_ramc_write(0, AT91_MC_SDRAMC_LPR, 0);
801 
802 	at91_pm_init(at91rm9200_idle);
803 }
804 
805 void __init sam9x60_pm_init(void)
806 {
807 	if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
808 		return;
809 
810 	at91_pm_modes_init();
811 	at91_dt_ramc();
812 	at91_pm_init(at91sam9x60_idle);
813 
814 	soc_pm.ws_ids = sam9x60_ws_ids;
815 	soc_pm.config_pmc_ws = at91_sam9x60_config_pmc_ws;
816 }
817 
818 void __init at91sam9_pm_init(void)
819 {
820 	if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
821 		return;
822 
823 	at91_dt_ramc();
824 	at91_pm_init(at91sam9_idle);
825 }
826 
827 void __init sama5_pm_init(void)
828 {
829 	if (!IS_ENABLED(CONFIG_SOC_SAMA5))
830 		return;
831 
832 	at91_dt_ramc();
833 	at91_pm_init(NULL);
834 }
835 
836 void __init sama5d2_pm_init(void)
837 {
838 	if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
839 		return;
840 
841 	at91_pm_modes_init();
842 	sama5_pm_init();
843 
844 	soc_pm.ws_ids = sama5d2_ws_ids;
845 	soc_pm.config_shdwc_ws = at91_sama5d2_config_shdwc_ws;
846 	soc_pm.config_pmc_ws = at91_sama5d2_config_pmc_ws;
847 }
848 
849 static int __init at91_pm_modes_select(char *str)
850 {
851 	char *s;
852 	substring_t args[MAX_OPT_ARGS];
853 	int standby, suspend;
854 
855 	if (!str)
856 		return 0;
857 
858 	s = strsep(&str, ",");
859 	standby = match_token(s, pm_modes, args);
860 	if (standby < 0)
861 		return 0;
862 
863 	suspend = match_token(str, pm_modes, args);
864 	if (suspend < 0)
865 		return 0;
866 
867 	soc_pm.data.standby_mode = standby;
868 	soc_pm.data.suspend_mode = suspend;
869 
870 	return 0;
871 }
872 early_param("atmel.pm_modes", at91_pm_modes_select);
873