summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/sleep-tegra20.S
blob: 9a89f30d53ca172d31e9ded2878fbba21b1c2575 (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
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
 * Copyright (c) 2011, Google, Inc.
 *
 * Author: Colin Cross <ccross@android.com>
 *         Gary King <gking@nvidia.com>
 */

#include <linux/linkage.h>

#include <soc/tegra/flowctrl.h>

#include <asm/assembler.h>
#include <asm/proc-fns.h>
#include <asm/cp15.h>
#include <asm/cache.h>

#include "irammap.h"
#include "reset.h"
#include "sleep.h"

#define EMC_CFG				0xc
#define EMC_ADR_CFG			0x10
#define EMC_NOP				0xdc
#define EMC_SELF_REF			0xe0
#define EMC_REQ_CTRL			0x2b0
#define EMC_EMC_STATUS			0x2b4

#define CLK_RESET_CCLK_BURST		0x20
#define CLK_RESET_CCLK_DIVIDER		0x24
#define CLK_RESET_SCLK_BURST		0x28
#define CLK_RESET_SCLK_DIVIDER		0x2c
#define CLK_RESET_PLLC_BASE		0x80
#define CLK_RESET_PLLM_BASE		0x90
#define CLK_RESET_PLLP_BASE		0xa0

#define APB_MISC_XM2CFGCPADCTRL		0x8c8
#define APB_MISC_XM2CFGDPADCTRL		0x8cc
#define APB_MISC_XM2CLKCFGPADCTRL	0x8d0
#define APB_MISC_XM2COMPPADCTRL		0x8d4
#define APB_MISC_XM2VTTGENPADCTRL	0x8d8
#define APB_MISC_XM2CFGCPADCTRL2	0x8e4
#define APB_MISC_XM2CFGDPADCTRL2	0x8e8

#define __tegra20_cpu1_resettable_status_offset \
	(__tegra_cpu_reset_handler_data_offset + RESET_DATA(RESETTABLE_STATUS))

.macro pll_enable, rd, r_car_base, pll_base
	ldr	\rd, [\r_car_base, #\pll_base]
	tst	\rd, #(1 << 30)
	orreq	\rd, \rd, #(1 << 30)
	streq	\rd, [\r_car_base, #\pll_base]
.endm

.macro emc_device_mask, rd, base
	ldr	\rd, [\base, #EMC_ADR_CFG]
	tst	\rd, #(0x3 << 24)
	moveq	\rd, #(0x1 << 8)		@ just 1 device
	movne	\rd, #(0x3 << 8)		@ 2 devices
.endm

#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
/*
 * tegra20_hotplug_shutdown(void)
 *
 * puts the current cpu in reset
 * should never return
 */
ENTRY(tegra20_hotplug_shutdown)
	/* Put this CPU down */
	cpu_id	r0
	bl	tegra20_cpu_shutdown
	ret	lr			@ should never get here
ENDPROC(tegra20_hotplug_shutdown)

/*
 * tegra20_cpu_shutdown(int cpu)
 *
 * r0 is cpu to reset
 *
 * puts the specified CPU in wait-for-event mode on the flow controller
 * and puts the CPU in reset
 * can be called on the current cpu or another cpu
 * if called on the current cpu, does not return
 * MUST NOT BE CALLED FOR CPU 0.
 *
 * corrupts r0-r3, r12
 */
ENTRY(tegra20_cpu_shutdown)
	cmp	r0, #0
	reteq	lr			@ must not be called for CPU 0
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_RESETTABLE
	strb	r12, [r1, r2]

	cpu_to_halt_reg r1, r0
	ldr	r3, =TEGRA_FLOW_CTRL_VIRT
	mov	r2, #FLOW_CTRL_WAITEVENT | FLOW_CTRL_JTAG_RESUME
	str	r2, [r3, r1]		@ put flow controller in wait event mode
	ldr	r2, [r3, r1]
	isb
	dsb
	movw	r1, 0x1011
	mov	r1, r1, lsl r0
	ldr	r3, =TEGRA_CLK_RESET_VIRT
	str	r1, [r3, #0x340]	@ put slave CPU in reset
	isb
	dsb
	cpu_id	r3
	cmp	r3, r0
	beq	.
	ret	lr
ENDPROC(tegra20_cpu_shutdown)
#endif

#ifdef CONFIG_PM_SLEEP
/*
 * tegra_pen_lock
 *
 * spinlock implementation with no atomic test-and-set and no coherence
 * using Peterson's algorithm on strongly-ordered registers
 * used to synchronize a cpu waking up from wfi with entering lp2 on idle
 *
 * The reference link of Peterson's algorithm:
 * http://en.wikipedia.org/wiki/Peterson's_algorithm
 *
 * SCRATCH37 = r1 = !turn (inverted from Peterson's algorithm)
 * on cpu 0:
 * r2 = flag[0] (in SCRATCH38)
 * r3 = flag[1] (in SCRATCH39)
 * on cpu1:
 * r2 = flag[1] (in SCRATCH39)
 * r3 = flag[0] (in SCRATCH38)
 *
 * must be called with MMU on
 * corrupts r0-r3, r12
 */
ENTRY(tegra_pen_lock)
	mov32	r3, TEGRA_PMC_VIRT
	cpu_id	r0
	add	r1, r3, #PMC_SCRATCH37
	cmp	r0, #0
	addeq	r2, r3, #PMC_SCRATCH38
	addeq	r3, r3, #PMC_SCRATCH39
	addne	r2, r3, #PMC_SCRATCH39
	addne	r3, r3, #PMC_SCRATCH38

	mov	r12, #1
	str	r12, [r2]		@ flag[cpu] = 1
	dsb
	str	r12, [r1]		@ !turn = cpu
1:	dsb
	ldr	r12, [r3]
	cmp	r12, #1			@ flag[!cpu] == 1?
	ldreq	r12, [r1]
	cmpeq	r12, r0			@ !turn == cpu?
	beq	1b			@ while !turn == cpu && flag[!cpu] == 1

	ret	lr			@ locked
ENDPROC(tegra_pen_lock)

ENTRY(tegra_pen_unlock)
	dsb
	mov32	r3, TEGRA_PMC_VIRT
	cpu_id	r0
	cmp	r0, #0
	addeq	r2, r3, #PMC_SCRATCH38
	addne	r2, r3, #PMC_SCRATCH39
	mov	r12, #0
	str	r12, [r2]
	ret     lr
ENDPROC(tegra_pen_unlock)

/*
 * tegra20_cpu_clear_resettable(void)
 *
 * Called to clear the "resettable soon" flag in IRAM variable when
 * it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_clear_resettable)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_NOT_RESETTABLE
	strb	r12, [r1, r2]
	ret	lr
ENDPROC(tegra20_cpu_clear_resettable)

/*
 * tegra20_cpu_set_resettable_soon(void)
 *
 * Called to set the "resettable soon" flag in IRAM variable when
 * it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_set_resettable_soon)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_RESETTABLE_SOON
	strb	r12, [r1, r2]
	ret	lr
ENDPROC(tegra20_cpu_set_resettable_soon)

/*
 * tegra20_cpu_is_resettable_soon(void)
 *
 * Returns true if the "resettable soon" flag in IRAM variable has been
 * set because it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_is_resettable_soon)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	ldrb	r12, [r1, r2]
	cmp	r12, #CPU_RESETTABLE_SOON
	moveq	r0, #1
	movne	r0, #0
	ret	lr
ENDPROC(tegra20_cpu_is_resettable_soon)

/*
 * tegra20_sleep_core_finish(unsigned long v2p)
 *
 * Enters suspend in LP0 or LP1 by turning off the mmu and jumping to
 * tegra20_tear_down_core in IRAM
 */
ENTRY(tegra20_sleep_core_finish)
	mov     r4, r0
	/* Flush, disable the L1 data cache and exit SMP */
	mov     r0, #TEGRA_FLUSH_CACHE_ALL
	bl	tegra_disable_clean_inv_dcache
	mov     r0, r4

	mov32	r3, tegra_shut_off_mmu
	add	r3, r3, r0

	mov32	r0, tegra20_tear_down_core
	mov32	r1, tegra20_iram_start
	sub	r0, r0, r1
	mov32	r1, TEGRA_IRAM_LPx_RESUME_AREA
	add	r0, r0, r1

	ret	r3
ENDPROC(tegra20_sleep_core_finish)

/*
 * tegra20_sleep_cpu_secondary_finish(unsigned long v2p)
 *
 * Enters WFI on secondary CPU by exiting coherency.
 */
ENTRY(tegra20_sleep_cpu_secondary_finish)
	stmfd	sp!, {r4-r11, lr}

	mrc	p15, 0, r11, c1, c0, 1  @ save actlr before exiting coherency

	/* Flush and disable the L1 data cache */
	mov	r0, #TEGRA_FLUSH_CACHE_LOUIS
	bl	tegra_disable_clean_inv_dcache

	mov32	r0, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r4, =__tegra20_cpu1_resettable_status_offset
	mov	r3, #CPU_RESETTABLE
	strb	r3, [r0, r4]

	bl	tegra_cpu_do_idle

	/*
	 * cpu may be reset while in wfi, which will return through
	 * tegra_resume to cpu_resume
	 * or interrupt may wake wfi, which will return here
	 * cpu state is unchanged - MMU is on, cache is on, coherency
	 * is off, and the data cache is off
	 *
	 * r11 contains the original actlr
	 */

	bl	tegra_pen_lock

	mov32	r0, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r4, =__tegra20_cpu1_resettable_status_offset
	mov	r3, #CPU_NOT_RESETTABLE
	strb	r3, [r0, r4]

	bl	tegra_pen_unlock

	/* Re-enable the data cache */
	mrc	p15, 0, r10, c1, c0, 0
	orr	r10, r10, #CR_C
	mcr	p15, 0, r10, c1, c0, 0
	isb

	mcr	p15, 0, r11, c1, c0, 1	@ reenable coherency

	/* Invalidate the TLBs & BTAC */
	mov	r1, #0
	mcr	p15, 0, r1, c8, c3, 0	@ invalidate shared TLBs
	mcr	p15, 0, r1, c7, c1, 6	@ invalidate shared BTAC
	dsb
	isb

	/* the cpu was running with coherency disabled,
	 * caches may be out of date */
	bl	v7_flush_kern_cache_louis

	ldmfd	sp!, {r4 - r11, pc}
ENDPROC(tegra20_sleep_cpu_secondary_finish)

/*
 * tegra20_tear_down_cpu
 *
 * Switches the CPU cluster to PLL-P and enters sleep.
 */
ENTRY(tegra20_tear_down_cpu)
	bl	tegra_switch_cpu_to_pllp
	b	tegra20_enter_sleep
ENDPROC(tegra20_tear_down_cpu)

/* START OF ROUTINES COPIED TO IRAM */
	.align L1_CACHE_SHIFT
	.globl tegra20_iram_start
tegra20_iram_start:

/*
 * tegra20_lp1_reset
 *
 * reset vector for LP1 restore; copied into IRAM during suspend.
 * Brings the system back up to a safe staring point (SDRAM out of
 * self-refresh, PLLC, PLLM and PLLP reenabled, CPU running on PLLP,
 * system clock running on the same PLL that it suspended at), and
 * jumps to tegra_resume to restore virtual addressing and PLLX.
 * The physical address of tegra_resume expected to be stored in
 * PMC_SCRATCH41.
 *
 * NOTE: THIS *MUST* BE RELOCATED TO TEGRA_IRAM_LPx_RESUME_AREA.
 */
ENTRY(tegra20_lp1_reset)
	/*
	 * The CPU and system bus are running at 32KHz and executing from
	 * IRAM when this code is executed; immediately switch to CLKM and
	 * enable PLLM, PLLP, PLLC.
	 */
	mov32	r0, TEGRA_CLK_RESET_BASE

	mov	r1, #(1 << 28)
	str	r1, [r0, #CLK_RESET_SCLK_BURST]
	str	r1, [r0, #CLK_RESET_CCLK_BURST]
	mov	r1, #0
	str	r1, [r0, #CLK_RESET_CCLK_DIVIDER]
	str	r1, [r0, #CLK_RESET_SCLK_DIVIDER]

	pll_enable r1, r0, CLK_RESET_PLLM_BASE
	pll_enable r1, r0, CLK_RESET_PLLP_BASE
	pll_enable r1, r0, CLK_RESET_PLLC_BASE

	adr	r2, tegra20_sdram_pad_address
	adr	r4, tegra20_sdram_pad_save
	mov	r5, #0

	ldr	r6, tegra20_sdram_pad_size
padload:
	ldr	r7, [r2, r5]		@ r7 is the addr in the pad_address

	ldr	r1, [r4, r5]
	str	r1, [r7]		@ restore the value in pad_save

	add	r5, r5, #4
	cmp	r6, r5
	bne	padload

padload_done:
	/* 255uS delay for PLL stabilization */
	mov32	r7, TEGRA_TMRUS_BASE
	ldr	r1, [r7]
	add	r1, r1, #0xff
	wait_until r1, r7, r9

	adr	r4, tegra20_sclk_save
	ldr	r4, [r4]
	str	r4, [r0, #CLK_RESET_SCLK_BURST]
	mov32	r4, ((1 << 28) | (4))	@ burst policy is PLLP
	str	r4, [r0, #CLK_RESET_CCLK_BURST]

	mov32	r0, TEGRA_EMC_BASE
	ldr	r1, [r0, #EMC_CFG]
	bic	r1, r1, #(1 << 31)	@ disable DRAM_CLK_STOP
	str	r1, [r0, #EMC_CFG]

	mov	r1, #0
	str	r1, [r0, #EMC_SELF_REF]	@ take DRAM out of self refresh
	mov	r1, #1
	str	r1, [r0, #EMC_NOP]
	str	r1, [r0, #EMC_NOP]

	emc_device_mask r1, r0

exit_selfrefresh_loop:
	ldr	r2, [r0, #EMC_EMC_STATUS]
	ands	r2, r2, r1
	bne	exit_selfrefresh_loop

	mov	r1, #0			@ unstall all transactions
	str	r1, [r0, #EMC_REQ_CTRL]

	mov32	r0, TEGRA_PMC_BASE
	ldr	r0, [r0, #PMC_SCRATCH41]
	ret	r0			@ jump to tegra_resume
ENDPROC(tegra20_lp1_reset)

/*
 * tegra20_tear_down_core
 *
 * copied into and executed from IRAM
 * puts memory in self-refresh for LP0 and LP1
 */
tegra20_tear_down_core:
	bl	tegra20_sdram_self_refresh
	bl	tegra20_switch_cpu_to_clk32k
	b	tegra20_enter_sleep

/*
 * tegra20_switch_cpu_to_clk32k
 *
 * In LP0 and LP1 all PLLs will be turned off. Switch the CPU and system clock
 * to the 32KHz clock.
 */
tegra20_switch_cpu_to_clk32k:
	/*
	 * start by switching to CLKM to safely disable PLLs, then switch to
	 * CLKS.
	 */
	mov	r0, #(1 << 28)
	str	r0, [r5, #CLK_RESET_SCLK_BURST]
	str	r0, [r5, #CLK_RESET_CCLK_BURST]
	mov	r0, #0
	str	r0, [r5, #CLK_RESET_CCLK_DIVIDER]
	str	r0, [r5, #CLK_RESET_SCLK_DIVIDER]

	/* 2uS delay delay between changing SCLK and disabling PLLs */
	mov32	r7, TEGRA_TMRUS_BASE
	ldr	r1, [r7]
	add	r1, r1, #2
	wait_until r1, r7, r9

	/* disable PLLM, PLLP and PLLC */
	ldr	r0, [r5, #CLK_RESET_PLLM_BASE]
	bic	r0, r0, #(1 << 30)
	str	r0, [r5, #CLK_RESET_PLLM_BASE]
	ldr	r0, [r5, #CLK_RESET_PLLP_BASE]
	bic	r0, r0, #(1 << 30)
	str	r0, [r5, #CLK_RESET_PLLP_BASE]
	ldr	r0, [r5, #CLK_RESET_PLLC_BASE]
	bic	r0, r0, #(1 << 30)
	str	r0, [r5, #CLK_RESET_PLLC_BASE]

	/* switch to CLKS */
	mov	r0, #0	/* brust policy = 32KHz */
	str	r0, [r5, #CLK_RESET_SCLK_BURST]

	ret	lr

/*
 * tegra20_enter_sleep
 *
 * uses flow controller to enter sleep state
 * executes from IRAM with SDRAM in selfrefresh when target state is LP0 or LP1
 * executes from SDRAM with target state is LP2
 */
tegra20_enter_sleep:
	mov32   r6, TEGRA_FLOW_CTRL_BASE

	mov     r0, #FLOW_CTRL_WAIT_FOR_INTERRUPT
	orr	r0, r0, #FLOW_CTRL_HALT_CPU_IRQ | FLOW_CTRL_HALT_CPU_FIQ
	cpu_id	r1
	cpu_to_halt_reg r1, r1
	str	r0, [r6, r1]
	dsb
	ldr	r0, [r6, r1] /* memory barrier */

halted:
	dsb
	wfe	/* CPU should be power gated here */
	isb
	b	halted

/*
 * tegra20_sdram_self_refresh
 *
 * called with MMU off and caches disabled
 * puts sdram in self refresh
 * must be executed from IRAM
 */
tegra20_sdram_self_refresh:
	mov32	r1, TEGRA_EMC_BASE	@ r1 reserved for emc base addr

	mov	r2, #3
	str	r2, [r1, #EMC_REQ_CTRL]	@ stall incoming DRAM requests

emcidle:
	ldr	r2, [r1, #EMC_EMC_STATUS]
	tst	r2, #4
	beq	emcidle

	mov	r2, #1
	str	r2, [r1, #EMC_SELF_REF]

	emc_device_mask r2, r1

emcself:
	ldr	r3, [r1, #EMC_EMC_STATUS]
	and	r3, r3, r2
	cmp	r3, r2
	bne	emcself			@ loop until DDR in self-refresh

	adr	r2, tegra20_sdram_pad_address
	adr	r3, tegra20_sdram_pad_safe
	adr	r4, tegra20_sdram_pad_save
	mov	r5, #0

	ldr	r6, tegra20_sdram_pad_size
padsave:
	ldr	r0, [r2, r5]		@ r0 is the addr in the pad_address

	ldr	r1, [r0]
	str	r1, [r4, r5]		@ save the content of the addr

	ldr	r1, [r3, r5]
	str	r1, [r0]		@ set the save val to the addr

	add	r5, r5, #4
	cmp	r6, r5
	bne	padsave
padsave_done:

	mov32	r5, TEGRA_CLK_RESET_BASE
	ldr	r0, [r5, #CLK_RESET_SCLK_BURST]
	adr	r2, tegra20_sclk_save
	str	r0, [r2]
	dsb
	ret	lr

tegra20_sdram_pad_address:
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CLKCFGPADCTRL
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2COMPPADCTRL
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2VTTGENPADCTRL
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL2
	.word	TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGDPADCTRL2

tegra20_sdram_pad_size:
	.word	tegra20_sdram_pad_size - tegra20_sdram_pad_address

tegra20_sdram_pad_safe:
	.word	0x8
	.word	0x8
	.word	0x0
	.word	0x8
	.word	0x5500
	.word	0x08080040
	.word	0x0

tegra20_sclk_save:
	.word	0x0

tegra20_sdram_pad_save:
	.rept (tegra20_sdram_pad_size - tegra20_sdram_pad_address) / 4
	.long	0
	.endr

	.ltorg
/* dummy symbol for end of IRAM */
	.align L1_CACHE_SHIFT
	.globl tegra20_iram_end
tegra20_iram_end:
	b	.
#endif