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1/*
2 * arch/arm/mach-at91/pm.c
3 * AT91 Power Management
4 *
5 * Copyright (C) 2005 David Brownell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/gpio.h>
14#include <linux/suspend.h>
15#include <linux/sched.h>
16#include <linux/proc_fs.h>
17#include <linux/genalloc.h>
18#include <linux/interrupt.h>
19#include <linux/sysfs.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/of_platform.h>
23#include <linux/of_address.h>
24#include <linux/platform_device.h>
25#include <linux/io.h>
26#include <linux/clk/at91_pmc.h>
27
28#include <asm/irq.h>
29#include <linux/atomic.h>
30#include <asm/mach/time.h>
31#include <asm/mach/irq.h>
32#include <asm/fncpy.h>
33#include <asm/cacheflush.h>
34#include <asm/system_misc.h>
35
36#include "generic.h"
37#include "pm.h"
38
39static void __iomem *pmc;
40
41/*
42 * FIXME: this is needed to communicate between the pinctrl driver and
43 * the PM implementation in the machine. Possibly part of the PM
44 * implementation should be moved down into the pinctrl driver and get
45 * called as part of the generic suspend/resume path.
46 */
47#ifdef CONFIG_PINCTRL_AT91
48extern void at91_pinctrl_gpio_suspend(void);
49extern void at91_pinctrl_gpio_resume(void);
50#endif
51
52static struct {
53 unsigned long uhp_udp_mask;
54 int memctrl;
55} at91_pm_data;
56
57void __iomem *at91_ramc_base[2];
58
59static int at91_pm_valid_state(suspend_state_t state)
60{
61 switch (state) {
62 case PM_SUSPEND_ON:
63 case PM_SUSPEND_STANDBY:
64 case PM_SUSPEND_MEM:
65 return 1;
66
67 default:
68 return 0;
69 }
70}
71
72
73static suspend_state_t target_state;
74
75/*
76 * Called after processes are frozen, but before we shutdown devices.
77 */
78static int at91_pm_begin(suspend_state_t state)
79{
80 target_state = state;
81 return 0;
82}
83
84/*
85 * Verify that all the clocks are correct before entering
86 * slow-clock mode.
87 */
88static int at91_pm_verify_clocks(void)
89{
90 unsigned long scsr;
91 int i;
92
93 scsr = readl(pmc + AT91_PMC_SCSR);
94
95 /* USB must not be using PLLB */
96 if ((scsr & at91_pm_data.uhp_udp_mask) != 0) {
97 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
98 return 0;
99 }
100
101 /* PCK0..PCK3 must be disabled, or configured to use clk32k */
102 for (i = 0; i < 4; i++) {
103 u32 css;
104
105 if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
106 continue;
107 css = readl(pmc + AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
108 if (css != AT91_PMC_CSS_SLOW) {
109 pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
110 return 0;
111 }
112 }
113
114 return 1;
115}
116
117/*
118 * Call this from platform driver suspend() to see how deeply to suspend.
119 * For example, some controllers (like OHCI) need one of the PLL clocks
120 * in order to act as a wakeup source, and those are not available when
121 * going into slow clock mode.
122 *
123 * REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
124 * the very same problem (but not using at91 main_clk), and it'd be better
125 * to add one generic API rather than lots of platform-specific ones.
126 */
127int at91_suspend_entering_slow_clock(void)
128{
129 return (target_state == PM_SUSPEND_MEM);
130}
131EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
132
133static void (*at91_suspend_sram_fn)(void __iomem *pmc, void __iomem *ramc0,
134 void __iomem *ramc1, int memctrl);
135
136extern void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *ramc0,
137 void __iomem *ramc1, int memctrl);
138extern u32 at91_pm_suspend_in_sram_sz;
139
140static void at91_pm_suspend(suspend_state_t state)
141{
142 unsigned int pm_data = at91_pm_data.memctrl;
143
144 pm_data |= (state == PM_SUSPEND_MEM) ?
145 AT91_PM_MODE(AT91_PM_SLOW_CLOCK) : 0;
146
147 flush_cache_all();
148 outer_disable();
149
150 at91_suspend_sram_fn(pmc, at91_ramc_base[0],
151 at91_ramc_base[1], pm_data);
152
153 outer_resume();
154}
155
156static int at91_pm_enter(suspend_state_t state)
157{
158#ifdef CONFIG_PINCTRL_AT91
159 at91_pinctrl_gpio_suspend();
160#endif
161 switch (state) {
162 /*
163 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
164 * drivers must suspend more deeply, the master clock switches
165 * to the clk32k and turns off the main oscillator
166 */
167 case PM_SUSPEND_MEM:
168 /*
169 * Ensure that clocks are in a valid state.
170 */
171 if (!at91_pm_verify_clocks())
172 goto error;
173
174 at91_pm_suspend(state);
175
176 break;
177
178 /*
179 * STANDBY mode has *all* drivers suspended; ignores irqs not
180 * marked as 'wakeup' event sources; and reduces DRAM power.
181 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
182 * nothing fancy done with main or cpu clocks.
183 */
184 case PM_SUSPEND_STANDBY:
185 at91_pm_suspend(state);
186 break;
187
188 case PM_SUSPEND_ON:
189 cpu_do_idle();
190 break;
191
192 default:
193 pr_debug("AT91: PM - bogus suspend state %d\n", state);
194 goto error;
195 }
196
197error:
198 target_state = PM_SUSPEND_ON;
199
200#ifdef CONFIG_PINCTRL_AT91
201 at91_pinctrl_gpio_resume();
202#endif
203 return 0;
204}
205
206/*
207 * Called right prior to thawing processes.
208 */
209static void at91_pm_end(void)
210{
211 target_state = PM_SUSPEND_ON;
212}
213
214
215static const struct platform_suspend_ops at91_pm_ops = {
216 .valid = at91_pm_valid_state,
217 .begin = at91_pm_begin,
218 .enter = at91_pm_enter,
219 .end = at91_pm_end,
220};
221
222static struct platform_device at91_cpuidle_device = {
223 .name = "cpuidle-at91",
224};
225
226static void at91_pm_set_standby(void (*at91_standby)(void))
227{
228 if (at91_standby)
229 at91_cpuidle_device.dev.platform_data = at91_standby;
230}
231
232/*
233 * The AT91RM9200 goes into self-refresh mode with this command, and will
234 * terminate self-refresh automatically on the next SDRAM access.
235 *
236 * Self-refresh mode is exited as soon as a memory access is made, but we don't
237 * know for sure when that happens. However, we need to restore the low-power
238 * mode if it was enabled before going idle. Restoring low-power mode while
239 * still in self-refresh is "not recommended", but seems to work.
240 */
241static void at91rm9200_standby(void)
242{
243 u32 lpr = at91_ramc_read(0, AT91_MC_SDRAMC_LPR);
244
245 asm volatile(
246 "b 1f\n\t"
247 ".align 5\n\t"
248 "1: mcr p15, 0, %0, c7, c10, 4\n\t"
249 " str %0, [%1, %2]\n\t"
250 " str %3, [%1, %4]\n\t"
251 " mcr p15, 0, %0, c7, c0, 4\n\t"
252 " str %5, [%1, %2]"
253 :
254 : "r" (0), "r" (at91_ramc_base[0]), "r" (AT91_MC_SDRAMC_LPR),
255 "r" (1), "r" (AT91_MC_SDRAMC_SRR),
256 "r" (lpr));
257}
258
259/* We manage both DDRAM/SDRAM controllers, we need more than one value to
260 * remember.
261 */
262static void at91_ddr_standby(void)
263{
264 /* Those two values allow us to delay self-refresh activation
265 * to the maximum. */
266 u32 lpr0, lpr1 = 0;
267 u32 saved_lpr0, saved_lpr1 = 0;
268
269 if (at91_ramc_base[1]) {
270 saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
271 lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
272 lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
273 }
274
275 saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
276 lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
277 lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
278
279 /* self-refresh mode now */
280 at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
281 if (at91_ramc_base[1])
282 at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
283
284 cpu_do_idle();
285
286 at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
287 if (at91_ramc_base[1])
288 at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
289}
290
291/* We manage both DDRAM/SDRAM controllers, we need more than one value to
292 * remember.
293 */
294static void at91sam9_sdram_standby(void)
295{
296 u32 lpr0, lpr1 = 0;
297 u32 saved_lpr0, saved_lpr1 = 0;
298
299 if (at91_ramc_base[1]) {
300 saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
301 lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
302 lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
303 }
304
305 saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
306 lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
307 lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
308
309 /* self-refresh mode now */
310 at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
311 if (at91_ramc_base[1])
312 at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
313
314 cpu_do_idle();
315
316 at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
317 if (at91_ramc_base[1])
318 at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
319}
320
321static const struct of_device_id const ramc_ids[] __initconst = {
322 { .compatible = "atmel,at91rm9200-sdramc", .data = at91rm9200_standby },
323 { .compatible = "atmel,at91sam9260-sdramc", .data = at91sam9_sdram_standby },
324 { .compatible = "atmel,at91sam9g45-ddramc", .data = at91_ddr_standby },
325 { .compatible = "atmel,sama5d3-ddramc", .data = at91_ddr_standby },
326 { /*sentinel*/ }
327};
328
329static __init void at91_dt_ramc(void)
330{
331 struct device_node *np;
332 const struct of_device_id *of_id;
333 int idx = 0;
334 const void *standby = NULL;
335
336 for_each_matching_node_and_match(np, ramc_ids, &of_id) {
337 at91_ramc_base[idx] = of_iomap(np, 0);
338 if (!at91_ramc_base[idx])
339 panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
340
341 if (!standby)
342 standby = of_id->data;
343
344 idx++;
345 }
346
347 if (!idx)
348 panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
349
350 if (!standby) {
351 pr_warn("ramc no standby function available\n");
352 return;
353 }
354
355 at91_pm_set_standby(standby);
356}
357
358void at91rm9200_idle(void)
359{
360 /*
361 * Disable the processor clock. The processor will be automatically
362 * re-enabled by an interrupt or by a reset.
363 */
364 writel(AT91_PMC_PCK, pmc + AT91_PMC_SCDR);
365}
366
367void at91sam9_idle(void)
368{
369 writel(AT91_PMC_PCK, pmc + AT91_PMC_SCDR);
370 cpu_do_idle();
371}
372
373static void __init at91_pm_sram_init(void)
374{
375 struct gen_pool *sram_pool;
376 phys_addr_t sram_pbase;
377 unsigned long sram_base;
378 struct device_node *node;
379 struct platform_device *pdev = NULL;
380
381 for_each_compatible_node(node, NULL, "mmio-sram") {
382 pdev = of_find_device_by_node(node);
383 if (pdev) {
384 of_node_put(node);
385 break;
386 }
387 }
388
389 if (!pdev) {
390 pr_warn("%s: failed to find sram device!\n", __func__);
391 return;
392 }
393
394 sram_pool = gen_pool_get(&pdev->dev, NULL);
395 if (!sram_pool) {
396 pr_warn("%s: sram pool unavailable!\n", __func__);
397 return;
398 }
399
400 sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
401 if (!sram_base) {
402 pr_warn("%s: unable to alloc sram!\n", __func__);
403 return;
404 }
405
406 sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
407 at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
408 at91_pm_suspend_in_sram_sz, false);
409 if (!at91_suspend_sram_fn) {
410 pr_warn("SRAM: Could not map\n");
411 return;
412 }
413
414 /* Copy the pm suspend handler to SRAM */
415 at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
416 &at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
417}
418
419static const struct of_device_id atmel_pmc_ids[] __initconst = {
420 { .compatible = "atmel,at91rm9200-pmc" },
421 { .compatible = "atmel,at91sam9260-pmc" },
422 { .compatible = "atmel,at91sam9g45-pmc" },
423 { .compatible = "atmel,at91sam9n12-pmc" },
424 { .compatible = "atmel,at91sam9x5-pmc" },
425 { .compatible = "atmel,sama5d3-pmc" },
426 { .compatible = "atmel,sama5d2-pmc" },
427 { /* sentinel */ },
428};
429
430static void __init at91_pm_init(void (*pm_idle)(void))
431{
432 struct device_node *pmc_np;
433
434 if (at91_cpuidle_device.dev.platform_data)
435 platform_device_register(&at91_cpuidle_device);
436
437 pmc_np = of_find_matching_node(NULL, atmel_pmc_ids);
438 pmc = of_iomap(pmc_np, 0);
439 if (!pmc) {
440 pr_err("AT91: PM not supported, PMC not found\n");
441 return;
442 }
443
444 if (pm_idle)
445 arm_pm_idle = pm_idle;
446
447 at91_pm_sram_init();
448
449 if (at91_suspend_sram_fn)
450 suspend_set_ops(&at91_pm_ops);
451 else
452 pr_info("AT91: PM not supported, due to no SRAM allocated\n");
453}
454
455void __init at91rm9200_pm_init(void)
456{
457 at91_dt_ramc();
458
459 /*
460 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
461 */
462 at91_ramc_write(0, AT91_MC_SDRAMC_LPR, 0);
463
464 at91_pm_data.uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP;
465 at91_pm_data.memctrl = AT91_MEMCTRL_MC;
466
467 at91_pm_init(at91rm9200_idle);
468}
469
470void __init at91sam9260_pm_init(void)
471{
472 at91_dt_ramc();
473 at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;
474 at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
475 at91_pm_init(at91sam9_idle);
476}
477
478void __init at91sam9g45_pm_init(void)
479{
480 at91_dt_ramc();
481 at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP;
482 at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
483 at91_pm_init(at91sam9_idle);
484}
485
486void __init at91sam9x5_pm_init(void)
487{
488 at91_dt_ramc();
489 at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
490 at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
491 at91_pm_init(at91sam9_idle);
492}
493
494void __init sama5_pm_init(void)
495{
496 at91_dt_ramc();
497 at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
498 at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
499 at91_pm_init(NULL);
500}
1/*
2 * arch/arm/mach-at91/pm.c
3 * AT91 Power Management
4 *
5 * Copyright (C) 2005 David Brownell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/gpio.h>
14#include <linux/suspend.h>
15#include <linux/sched.h>
16#include <linux/proc_fs.h>
17#include <linux/interrupt.h>
18#include <linux/sysfs.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/io.h>
22#include <linux/clk/at91_pmc.h>
23
24#include <asm/irq.h>
25#include <linux/atomic.h>
26#include <asm/mach/time.h>
27#include <asm/mach/irq.h>
28
29#include <mach/cpu.h>
30#include <mach/hardware.h>
31
32#include "at91_aic.h"
33#include "generic.h"
34#include "pm.h"
35
36/*
37 * Show the reason for the previous system reset.
38 */
39
40#include "at91_rstc.h"
41#include "at91_shdwc.h"
42
43static void (*at91_pm_standby)(void);
44
45static void __init show_reset_status(void)
46{
47 static char reset[] __initdata = "reset";
48
49 static char general[] __initdata = "general";
50 static char wakeup[] __initdata = "wakeup";
51 static char watchdog[] __initdata = "watchdog";
52 static char software[] __initdata = "software";
53 static char user[] __initdata = "user";
54 static char unknown[] __initdata = "unknown";
55
56 static char signal[] __initdata = "signal";
57 static char rtc[] __initdata = "rtc";
58 static char rtt[] __initdata = "rtt";
59 static char restore[] __initdata = "power-restored";
60
61 char *reason, *r2 = reset;
62 u32 reset_type, wake_type;
63
64 if (!at91_shdwc_base || !at91_rstc_base)
65 return;
66
67 reset_type = at91_rstc_read(AT91_RSTC_SR) & AT91_RSTC_RSTTYP;
68 wake_type = at91_shdwc_read(AT91_SHDW_SR);
69
70 switch (reset_type) {
71 case AT91_RSTC_RSTTYP_GENERAL:
72 reason = general;
73 break;
74 case AT91_RSTC_RSTTYP_WAKEUP:
75 /* board-specific code enabled the wakeup sources */
76 reason = wakeup;
77
78 /* "wakeup signal" */
79 if (wake_type & AT91_SHDW_WAKEUP0)
80 r2 = signal;
81 else {
82 r2 = reason;
83 if (wake_type & AT91_SHDW_RTTWK) /* rtt wakeup */
84 reason = rtt;
85 else if (wake_type & AT91_SHDW_RTCWK) /* rtc wakeup */
86 reason = rtc;
87 else if (wake_type == 0) /* power-restored wakeup */
88 reason = restore;
89 else /* unknown wakeup */
90 reason = unknown;
91 }
92 break;
93 case AT91_RSTC_RSTTYP_WATCHDOG:
94 reason = watchdog;
95 break;
96 case AT91_RSTC_RSTTYP_SOFTWARE:
97 reason = software;
98 break;
99 case AT91_RSTC_RSTTYP_USER:
100 reason = user;
101 break;
102 default:
103 reason = unknown;
104 break;
105 }
106 pr_info("AT91: Starting after %s %s\n", reason, r2);
107}
108
109static int at91_pm_valid_state(suspend_state_t state)
110{
111 switch (state) {
112 case PM_SUSPEND_ON:
113 case PM_SUSPEND_STANDBY:
114 case PM_SUSPEND_MEM:
115 return 1;
116
117 default:
118 return 0;
119 }
120}
121
122
123static suspend_state_t target_state;
124
125/*
126 * Called after processes are frozen, but before we shutdown devices.
127 */
128static int at91_pm_begin(suspend_state_t state)
129{
130 target_state = state;
131 return 0;
132}
133
134/*
135 * Verify that all the clocks are correct before entering
136 * slow-clock mode.
137 */
138static int at91_pm_verify_clocks(void)
139{
140 unsigned long scsr;
141 int i;
142
143 scsr = at91_pmc_read(AT91_PMC_SCSR);
144
145 /* USB must not be using PLLB */
146 if (cpu_is_at91rm9200()) {
147 if ((scsr & (AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP)) != 0) {
148 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
149 return 0;
150 }
151 } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263()
152 || cpu_is_at91sam9g20() || cpu_is_at91sam9g10()) {
153 if ((scsr & (AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP)) != 0) {
154 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
155 return 0;
156 }
157 }
158
159 /* PCK0..PCK3 must be disabled, or configured to use clk32k */
160 for (i = 0; i < 4; i++) {
161 u32 css;
162
163 if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
164 continue;
165
166 css = at91_pmc_read(AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
167 if (css != AT91_PMC_CSS_SLOW) {
168 pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
169 return 0;
170 }
171 }
172
173 return 1;
174}
175
176/*
177 * Call this from platform driver suspend() to see how deeply to suspend.
178 * For example, some controllers (like OHCI) need one of the PLL clocks
179 * in order to act as a wakeup source, and those are not available when
180 * going into slow clock mode.
181 *
182 * REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
183 * the very same problem (but not using at91 main_clk), and it'd be better
184 * to add one generic API rather than lots of platform-specific ones.
185 */
186int at91_suspend_entering_slow_clock(void)
187{
188 return (target_state == PM_SUSPEND_MEM);
189}
190EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
191
192
193static void (*slow_clock)(void __iomem *pmc, void __iomem *ramc0,
194 void __iomem *ramc1, int memctrl);
195
196#ifdef CONFIG_AT91_SLOW_CLOCK
197extern void at91_slow_clock(void __iomem *pmc, void __iomem *ramc0,
198 void __iomem *ramc1, int memctrl);
199extern u32 at91_slow_clock_sz;
200#endif
201
202static int at91_pm_enter(suspend_state_t state)
203{
204 if (of_have_populated_dt())
205 at91_pinctrl_gpio_suspend();
206 else
207 at91_gpio_suspend();
208 at91_irq_suspend();
209
210 pr_debug("AT91: PM - wake mask %08x, pm state %d\n",
211 /* remember all the always-wake irqs */
212 (at91_pmc_read(AT91_PMC_PCSR)
213 | (1 << AT91_ID_FIQ)
214 | (1 << AT91_ID_SYS)
215 | (at91_get_extern_irq()))
216 & at91_aic_read(AT91_AIC_IMR),
217 state);
218
219 switch (state) {
220 /*
221 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
222 * drivers must suspend more deeply: only the master clock
223 * controller may be using the main oscillator.
224 */
225 case PM_SUSPEND_MEM:
226 /*
227 * Ensure that clocks are in a valid state.
228 */
229 if (!at91_pm_verify_clocks())
230 goto error;
231
232 /*
233 * Enter slow clock mode by switching over to clk32k and
234 * turning off the main oscillator; reverse on wakeup.
235 */
236 if (slow_clock) {
237 int memctrl = AT91_MEMCTRL_SDRAMC;
238
239 if (cpu_is_at91rm9200())
240 memctrl = AT91_MEMCTRL_MC;
241 else if (cpu_is_at91sam9g45())
242 memctrl = AT91_MEMCTRL_DDRSDR;
243#ifdef CONFIG_AT91_SLOW_CLOCK
244 /* copy slow_clock handler to SRAM, and call it */
245 memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
246#endif
247 slow_clock(at91_pmc_base, at91_ramc_base[0],
248 at91_ramc_base[1], memctrl);
249 break;
250 } else {
251 pr_info("AT91: PM - no slow clock mode enabled ...\n");
252 /* FALLTHROUGH leaving master clock alone */
253 }
254
255 /*
256 * STANDBY mode has *all* drivers suspended; ignores irqs not
257 * marked as 'wakeup' event sources; and reduces DRAM power.
258 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
259 * nothing fancy done with main or cpu clocks.
260 */
261 case PM_SUSPEND_STANDBY:
262 /*
263 * NOTE: the Wait-for-Interrupt instruction needs to be
264 * in icache so no SDRAM accesses are needed until the
265 * wakeup IRQ occurs and self-refresh is terminated.
266 * For ARM 926 based chips, this requirement is weaker
267 * as at91sam9 can access a RAM in self-refresh mode.
268 */
269 if (at91_pm_standby)
270 at91_pm_standby();
271 break;
272
273 case PM_SUSPEND_ON:
274 cpu_do_idle();
275 break;
276
277 default:
278 pr_debug("AT91: PM - bogus suspend state %d\n", state);
279 goto error;
280 }
281
282 pr_debug("AT91: PM - wakeup %08x\n",
283 at91_aic_read(AT91_AIC_IPR) & at91_aic_read(AT91_AIC_IMR));
284
285error:
286 target_state = PM_SUSPEND_ON;
287 at91_irq_resume();
288 if (of_have_populated_dt())
289 at91_pinctrl_gpio_resume();
290 else
291 at91_gpio_resume();
292 return 0;
293}
294
295/*
296 * Called right prior to thawing processes.
297 */
298static void at91_pm_end(void)
299{
300 target_state = PM_SUSPEND_ON;
301}
302
303
304static const struct platform_suspend_ops at91_pm_ops = {
305 .valid = at91_pm_valid_state,
306 .begin = at91_pm_begin,
307 .enter = at91_pm_enter,
308 .end = at91_pm_end,
309};
310
311static struct platform_device at91_cpuidle_device = {
312 .name = "cpuidle-at91",
313};
314
315void at91_pm_set_standby(void (*at91_standby)(void))
316{
317 if (at91_standby) {
318 at91_cpuidle_device.dev.platform_data = at91_standby;
319 at91_pm_standby = at91_standby;
320 }
321}
322
323static int __init at91_pm_init(void)
324{
325#ifdef CONFIG_AT91_SLOW_CLOCK
326 slow_clock = (void *) (AT91_IO_VIRT_BASE - at91_slow_clock_sz);
327#endif
328
329 pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
330
331 /* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh. */
332 if (cpu_is_at91rm9200())
333 at91_ramc_write(0, AT91RM9200_SDRAMC_LPR, 0);
334
335 if (at91_cpuidle_device.dev.platform_data)
336 platform_device_register(&at91_cpuidle_device);
337
338 suspend_set_ops(&at91_pm_ops);
339
340 show_reset_status();
341 return 0;
342}
343arch_initcall(at91_pm_init);