xref: /openbmc/linux/arch/arm/mach-omap2/sleep43xx.S (revision f220d3eb) 
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Low level suspend code for AM43XX SoCs
4 *
5 * Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
6 *	Dave Gerlach, Vaibhav Bedia
7 */
8
9#include <generated/ti-pm-asm-offsets.h>
10#include <linux/linkage.h>
11#include <linux/ti-emif-sram.h>
12#include <linux/platform_data/pm33xx.h>
13#include <asm/assembler.h>
14#include <asm/hardware/cache-l2x0.h>
15#include <asm/memory.h>
16
17#include "cm33xx.h"
18#include "common.h"
19#include "iomap.h"
20#include "omap-secure.h"
21#include "omap44xx.h"
22#include "prm33xx.h"
23#include "prcm43xx.h"
24
25/* replicated define because linux/bitops.h cannot be included in assembly */
26#define BIT(nr)			(1 << (nr))
27
28#define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED		0x00030000
29#define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE		0x0003
30#define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE		0x0002
31
32#define AM43XX_EMIF_POWEROFF_ENABLE			0x1
33#define AM43XX_EMIF_POWEROFF_DISABLE			0x0
34
35#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP		0x1
36#define AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO		0x3
37
38#define AM43XX_CM_BASE					0x44DF0000
39
40#define AM43XX_CM_REGADDR(inst, reg)                           \
41       AM33XX_L4_WK_IO_ADDRESS(AM43XX_CM_BASE + (inst) + (reg))
42
43#define AM43XX_CM_MPU_CLKSTCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
44					AM43XX_CM_MPU_MPU_CDOFFS)
45#define AM43XX_CM_MPU_MPU_CLKCTRL AM43XX_CM_REGADDR(AM43XX_CM_MPU_INST, \
46					AM43XX_CM_MPU_MPU_CLKCTRL_OFFSET)
47#define AM43XX_CM_PER_EMIF_CLKCTRL  AM43XX_CM_REGADDR(AM43XX_CM_PER_INST, \
48					AM43XX_CM_PER_EMIF_CLKCTRL_OFFSET)
49#define AM43XX_PRM_EMIF_CTRL_OFFSET			0x0030
50
51#define RTC_SECONDS_REG					0x0
52#define RTC_PMIC_REG					0x98
53#define RTC_PMIC_POWER_EN				BIT(16)
54#define RTC_PMIC_EXT_WAKEUP_STS				BIT(12)
55#define RTC_PMIC_EXT_WAKEUP_POL				BIT(4)
56#define RTC_PMIC_EXT_WAKEUP_EN				BIT(0)
57
58	.arm
59	.align 3
60
61ENTRY(am43xx_do_wfi)
62	stmfd	sp!, {r4 - r11, lr}	@ save registers on stack
63
64	/* Save wfi_flags arg to data space */
65	mov	r4, r0
66	adr	r3, am43xx_pm_ro_sram_data
67	ldr	r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
68	str	r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
69
70#ifdef CONFIG_CACHE_L2X0
71	/* Retrieve l2 cache virt address BEFORE we shut off EMIF */
72	ldr	r1, get_l2cache_base
73	blx	r1
74	mov	r8, r0
75#endif
76
77	/* Only flush cache is we know we are losing MPU context */
78	tst	r4, #WFI_FLAG_FLUSH_CACHE
79	beq	cache_skip_flush
80
81	/*
82	 * Flush all data from the L1 and L2 data cache before disabling
83	 * SCTLR.C bit.
84	 */
85	ldr	r1, kernel_flush
86	blx	r1
87
88	/*
89	 * Clear the SCTLR.C bit to prevent further data cache
90	 * allocation. Clearing SCTLR.C would make all the data accesses
91	 * strongly ordered and would not hit the cache.
92	 */
93	mrc	p15, 0, r0, c1, c0, 0
94	bic	r0, r0, #(1 << 2)	@ Disable the C bit
95	mcr	p15, 0, r0, c1, c0, 0
96	isb
97	dsb
98
99	/*
100	 * Invalidate L1 and L2 data cache.
101	 */
102	ldr	r1, kernel_flush
103	blx	r1
104
105#ifdef CONFIG_CACHE_L2X0
106	/*
107	 * Clean and invalidate the L2 cache.
108	 */
109#ifdef CONFIG_PL310_ERRATA_727915
110	mov	r0, #0x03
111	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
112	dsb
113	smc	#0
114	dsb
115#endif
116	mov	r0, r8
117	adr	r4, am43xx_pm_ro_sram_data
118	ldr	r3, [r4, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
119
120	mov	r2, r0
121	ldr	r0, [r2, #L2X0_AUX_CTRL]
122	str	r0, [r3, #AMX3_PM_L2_AUX_CTRL_VAL_OFFSET]
123	ldr	r0, [r2, #L310_PREFETCH_CTRL]
124	str	r0, [r3, #AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET]
125
126	ldr	r0, l2_val
127	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
128wait:
129	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
130	ldr	r1, l2_val
131	ands	r0, r0, r1
132	bne	wait
133#ifdef CONFIG_PL310_ERRATA_727915
134	mov	r0, #0x00
135	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
136	dsb
137	smc	#0
138	dsb
139#endif
140l2x_sync:
141	mov	r0, r8
142	mov	r2, r0
143	mov	r0, #0x0
144	str	r0, [r2, #L2X0_CACHE_SYNC]
145sync:
146	ldr	r0, [r2, #L2X0_CACHE_SYNC]
147	ands	r0, r0, #0x1
148	bne	sync
149#endif
150
151	/* Restore wfi_flags */
152	adr	r3, am43xx_pm_ro_sram_data
153	ldr	r2, [r3, #AMX3_PM_RO_SRAM_DATA_VIRT_OFFSET]
154	ldr	r4, [r2, #AMX3_PM_WFI_FLAGS_OFFSET]
155
156cache_skip_flush:
157	/*
158	 * If we are trying to enter RTC+DDR mode we must perform
159	 * a read from the rtc address space to ensure translation
160	 * presence in the TLB to avoid page table walk after DDR
161	 * is unavailable.
162	 */
163	tst	r4, #WFI_FLAG_RTC_ONLY
164	beq	skip_rtc_va_refresh
165
166	adr	r3, am43xx_pm_ro_sram_data
167	ldr	r1, [r3, #AMX3_PM_RTC_BASE_VIRT_OFFSET]
168	ldr	r0, [r1]
169
170skip_rtc_va_refresh:
171	/* Check if we want self refresh */
172	tst	r4, #WFI_FLAG_SELF_REFRESH
173	beq	emif_skip_enter_sr
174
175	adr     r9, am43xx_emif_sram_table
176
177	ldr     r3, [r9, #EMIF_PM_ENTER_SR_OFFSET]
178	blx     r3
179
180emif_skip_enter_sr:
181	/* Only necessary if PER is losing context */
182	tst	r4, #WFI_FLAG_SAVE_EMIF
183	beq	emif_skip_save
184
185	ldr     r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET]
186	blx	r3
187
188emif_skip_save:
189	/* Only can disable EMIF if we have entered self refresh */
190	tst	r4, #WFI_FLAG_SELF_REFRESH
191	beq	emif_skip_disable
192
193	/* Disable EMIF */
194	ldr	r1, am43xx_virt_emif_clkctrl
195	ldr	r2, [r1]
196	bic	r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
197	str	r2, [r1]
198
199wait_emif_disable:
200	ldr	r2, [r1]
201	mov	r3, #AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED
202	cmp	r2, r3
203	bne	wait_emif_disable
204
205emif_skip_disable:
206	tst	r4, #WFI_FLAG_RTC_ONLY
207	beq	skip_rtc_only
208
209	adr	r3, am43xx_pm_ro_sram_data
210	ldr	r1, [r3, #AMX3_PM_RTC_BASE_VIRT_OFFSET]
211
212	ldr	r0, [r1, #RTC_PMIC_REG]
213	orr	r0, r0, #RTC_PMIC_POWER_EN
214	orr	r0, r0, #RTC_PMIC_EXT_WAKEUP_STS
215	orr	r0, r0, #RTC_PMIC_EXT_WAKEUP_EN
216	orr	r0, r0, #RTC_PMIC_EXT_WAKEUP_POL
217	str	r0, [r1, #RTC_PMIC_REG]
218	ldr	r0, [r1, #RTC_PMIC_REG]
219	/* Wait for 2 seconds to lose power */
220	mov	r3, #2
221	ldr	r2, [r1, #RTC_SECONDS_REG]
222rtc_loop:
223	ldr	r0, [r1, #RTC_SECONDS_REG]
224	cmp	r0, r2
225	beq	rtc_loop
226	mov	r2, r0
227	subs	r3, r3, #1
228	bne	rtc_loop
229
230	b	re_enable_emif
231
232skip_rtc_only:
233
234	tst	r4, #WFI_FLAG_WAKE_M3
235	beq	wkup_m3_skip
236
237	/*
238	 * For the MPU WFI to be registered as an interrupt
239	 * to WKUP_M3, MPU_CLKCTRL.MODULEMODE needs to be set
240	 * to DISABLED
241	 */
242	ldr	r1, am43xx_virt_mpu_clkctrl
243	ldr	r2, [r1]
244	bic	r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE
245	str	r2, [r1]
246
247	/*
248	 * Put MPU CLKDM to SW_SLEEP
249	 */
250	ldr	r1, am43xx_virt_mpu_clkstctrl
251	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_SW_SLEEP
252	str	r2, [r1]
253
254wkup_m3_skip:
255	/*
256	 * Execute a barrier instruction to ensure that all cache,
257	 * TLB and branch predictor maintenance operations issued
258	 * have completed.
259	 */
260	dsb
261	dmb
262
263	/*
264	 * Execute a WFI instruction and wait until the
265	 * STANDBYWFI output is asserted to indicate that the
266	 * CPU is in idle and low power state. CPU can specualatively
267	 * prefetch the instructions so add NOPs after WFI. Sixteen
268	 * NOPs as per Cortex-A9 pipeline.
269	 */
270	wfi
271
272	nop
273	nop
274	nop
275	nop
276	nop
277	nop
278	nop
279	nop
280	nop
281	nop
282	nop
283	nop
284	nop
285	nop
286	nop
287	nop
288
289	/* We come here in case of an abort due to a late interrupt */
290	ldr	r1, am43xx_virt_mpu_clkstctrl
291	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
292	str	r2, [r1]
293
294	/* Set MPU_CLKCTRL.MODULEMODE back to ENABLE */
295	ldr	r1, am43xx_virt_mpu_clkctrl
296	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
297	str	r2, [r1]
298
299re_enable_emif:
300	/* Re-enable EMIF */
301	ldr	r1, am43xx_virt_emif_clkctrl
302	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
303	str	r2, [r1]
304wait_emif_enable:
305	ldr	r3, [r1]
306	cmp	r2, r3
307	bne	wait_emif_enable
308
309	tst	r4, #WFI_FLAG_FLUSH_CACHE
310	beq	cache_skip_restore
311
312	/*
313	 * Set SCTLR.C bit to allow data cache allocation
314	 */
315	mrc	p15, 0, r0, c1, c0, 0
316	orr	r0, r0, #(1 << 2)	@ Enable the C bit
317	mcr	p15, 0, r0, c1, c0, 0
318	isb
319
320cache_skip_restore:
321	/* Only necessary if PER is losing context */
322	tst	r4, #WFI_FLAG_SELF_REFRESH
323	beq	emif_skip_exit_sr_abt
324
325	adr	r9, am43xx_emif_sram_table
326	ldr	r1, [r9, #EMIF_PM_ABORT_SR_OFFSET]
327	blx	r1
328
329emif_skip_exit_sr_abt:
330	/* Let the suspend code know about the abort */
331	mov	r0, #1
332	ldmfd	sp!, {r4 - r11, pc}	@ restore regs and return
333ENDPROC(am43xx_do_wfi)
334
335	.align
336ENTRY(am43xx_resume_offset)
337	.word . - am43xx_do_wfi
338
339ENTRY(am43xx_resume_from_deep_sleep)
340	/* Set MPU CLKSTCTRL to HW AUTO so that CPUidle works properly */
341	ldr	r1, am43xx_virt_mpu_clkstctrl
342	mov	r2, #AM43XX_CM_CLKSTCTRL_CLKTRCTRL_HW_AUTO
343	str	r2, [r1]
344
345	/* For AM43xx, use EMIF power down until context is restored */
346	ldr	r2, am43xx_phys_emif_poweroff
347	mov	r1, #AM43XX_EMIF_POWEROFF_ENABLE
348	str	r1, [r2, #0x0]
349
350	/* Re-enable EMIF */
351	ldr	r1, am43xx_phys_emif_clkctrl
352	mov	r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE
353	str	r2, [r1]
354wait_emif_enable1:
355	ldr	r3, [r1]
356	cmp	r2, r3
357	bne	wait_emif_enable1
358
359	adr     r9, am43xx_emif_sram_table
360
361	ldr     r1, [r9, #EMIF_PM_RESTORE_CONTEXT_OFFSET]
362	blx     r1
363
364	ldr     r1, [r9, #EMIF_PM_EXIT_SR_OFFSET]
365	blx     r1
366
367	ldr     r2, am43xx_phys_emif_poweroff
368	mov     r1, #AM43XX_EMIF_POWEROFF_DISABLE
369	str     r1, [r2, #0x0]
370
371#ifdef CONFIG_CACHE_L2X0
372	ldr	r2, l2_cache_base
373	ldr	r0, [r2, #L2X0_CTRL]
374	and	r0, #0x0f
375	cmp	r0, #1
376	beq	skip_l2en			@ Skip if already enabled
377
378	adr	r4, am43xx_pm_ro_sram_data
379	ldr	r3, [r4, #AMX3_PM_RO_SRAM_DATA_PHYS_OFFSET]
380	ldr     r0, [r3, #AMX3_PM_L2_PREFETCH_CTRL_VAL_OFFSET]
381
382	ldr	r12, l2_smc1
383	dsb
384	smc	#0
385	dsb
386set_aux_ctrl:
387	ldr     r0, [r3, #AMX3_PM_L2_AUX_CTRL_VAL_OFFSET]
388	ldr	r12, l2_smc2
389	dsb
390	smc	#0
391	dsb
392
393	/* L2 invalidate on resume */
394	ldr	r0, l2_val
395	ldr	r2, l2_cache_base
396	str	r0, [r2, #L2X0_INV_WAY]
397wait2:
398	ldr	r0, [r2, #L2X0_INV_WAY]
399	ldr	r1, l2_val
400	ands	r0, r0, r1
401	bne	wait2
402#ifdef CONFIG_PL310_ERRATA_727915
403	mov	r0, #0x00
404	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
405	dsb
406	smc	#0
407	dsb
408#endif
409l2x_sync2:
410	ldr	r2, l2_cache_base
411	mov	r0, #0x0
412	str	r0, [r2, #L2X0_CACHE_SYNC]
413sync2:
414	ldr	r0, [r2, #L2X0_CACHE_SYNC]
415	ands	r0, r0, #0x1
416	bne	sync2
417
418	mov	r0, #0x1
419	ldr	r12, l2_smc3
420	dsb
421	smc	#0
422	dsb
423#endif
424skip_l2en:
425	/* We are back. Branch to the common CPU resume routine */
426	mov	r0, #0
427	ldr	pc, resume_addr
428ENDPROC(am43xx_resume_from_deep_sleep)
429
430/*
431 * Local variables
432 */
433	.align
434kernel_flush:
435	.word   v7_flush_dcache_all
436ddr_start:
437	.word	PAGE_OFFSET
438
439am43xx_phys_emif_poweroff:
440	.word   (AM43XX_CM_BASE + AM43XX_PRM_DEVICE_INST + \
441		 AM43XX_PRM_EMIF_CTRL_OFFSET)
442am43xx_virt_mpu_clkstctrl:
443	.word	(AM43XX_CM_MPU_CLKSTCTRL)
444am43xx_virt_mpu_clkctrl:
445	.word	(AM43XX_CM_MPU_MPU_CLKCTRL)
446am43xx_virt_emif_clkctrl:
447	.word	(AM43XX_CM_PER_EMIF_CLKCTRL)
448am43xx_phys_emif_clkctrl:
449	.word	(AM43XX_CM_BASE + AM43XX_CM_PER_INST + \
450		 AM43XX_CM_PER_EMIF_CLKCTRL_OFFSET)
451
452#ifdef CONFIG_CACHE_L2X0
453/* L2 cache related defines for AM437x */
454get_l2cache_base:
455	.word	omap4_get_l2cache_base
456l2_cache_base:
457	.word	OMAP44XX_L2CACHE_BASE
458l2_smc1:
459	.word	OMAP4_MON_L2X0_PREFETCH_INDEX
460l2_smc2:
461	.word	OMAP4_MON_L2X0_AUXCTRL_INDEX
462l2_smc3:
463	.word	OMAP4_MON_L2X0_CTRL_INDEX
464l2_val:
465	.word	0xffff
466#endif
467
468.align 3
469/* DDR related defines */
470ENTRY(am43xx_emif_sram_table)
471	.space EMIF_PM_FUNCTIONS_SIZE
472
473ENTRY(am43xx_pm_sram)
474	.word am43xx_do_wfi
475	.word am43xx_do_wfi_sz
476	.word am43xx_resume_offset
477	.word am43xx_emif_sram_table
478	.word am43xx_pm_ro_sram_data
479
480resume_addr:
481	.word   cpu_resume - PAGE_OFFSET + 0x80000000
482.align 3
483
484ENTRY(am43xx_pm_ro_sram_data)
485	.space AMX3_PM_RO_SRAM_DATA_SIZE
486
487ENTRY(am43xx_do_wfi_sz)
488	.word	. - am43xx_do_wfi
489