xref: /openbmc/linux/arch/arm/mach-imx/suspend-imx6.S (revision b830f94f) 
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 2014 Freescale Semiconductor, Inc.
4 */
5
6#include <linux/linkage.h>
7#include <asm/assembler.h>
8#include <asm/asm-offsets.h>
9#include <asm/hardware/cache-l2x0.h>
10#include "hardware.h"
11
12/*
13 * ==================== low level suspend ====================
14 *
15 * Better to follow below rules to use ARM registers:
16 * r0: pm_info structure address;
17 * r1 ~ r4: for saving pm_info members;
18 * r5 ~ r10: free registers;
19 * r11: io base address.
20 *
21 * suspend ocram space layout:
22 * ======================== high address ======================
23 *                              .
24 *                              .
25 *                              .
26 *                              ^
27 *                              ^
28 *                              ^
29 *                      imx6_suspend code
30 *              PM_INFO structure(imx6_cpu_pm_info)
31 * ======================== low address =======================
32 */
33
34/*
35 * Below offsets are based on struct imx6_cpu_pm_info
36 * which defined in arch/arm/mach-imx/pm-imx6q.c, this
37 * structure contains necessary pm info for low level
38 * suspend related code.
39 */
40#define PM_INFO_PBASE_OFFSET			0x0
41#define PM_INFO_RESUME_ADDR_OFFSET		0x4
42#define PM_INFO_DDR_TYPE_OFFSET			0x8
43#define PM_INFO_PM_INFO_SIZE_OFFSET		0xC
44#define PM_INFO_MX6Q_MMDC_P_OFFSET		0x10
45#define PM_INFO_MX6Q_MMDC_V_OFFSET		0x14
46#define PM_INFO_MX6Q_SRC_P_OFFSET		0x18
47#define PM_INFO_MX6Q_SRC_V_OFFSET		0x1C
48#define PM_INFO_MX6Q_IOMUXC_P_OFFSET		0x20
49#define PM_INFO_MX6Q_IOMUXC_V_OFFSET		0x24
50#define PM_INFO_MX6Q_CCM_P_OFFSET		0x28
51#define PM_INFO_MX6Q_CCM_V_OFFSET		0x2C
52#define PM_INFO_MX6Q_GPC_P_OFFSET		0x30
53#define PM_INFO_MX6Q_GPC_V_OFFSET		0x34
54#define PM_INFO_MX6Q_L2_P_OFFSET		0x38
55#define PM_INFO_MX6Q_L2_V_OFFSET		0x3C
56#define PM_INFO_MMDC_IO_NUM_OFFSET		0x40
57#define PM_INFO_MMDC_IO_VAL_OFFSET		0x44
58
59#define MX6Q_SRC_GPR1	0x20
60#define MX6Q_SRC_GPR2	0x24
61#define MX6Q_MMDC_MAPSR	0x404
62#define MX6Q_MMDC_MPDGCTRL0	0x83c
63#define MX6Q_GPC_IMR1	0x08
64#define MX6Q_GPC_IMR2	0x0c
65#define MX6Q_GPC_IMR3	0x10
66#define MX6Q_GPC_IMR4	0x14
67#define MX6Q_CCM_CCR	0x0
68
69	.align 3
70
71	.macro  sync_l2_cache
72
73	/* sync L2 cache to drain L2's buffers to DRAM. */
74#ifdef CONFIG_CACHE_L2X0
75	ldr	r11, [r0, #PM_INFO_MX6Q_L2_V_OFFSET]
76	teq	r11, #0
77	beq	6f
78	mov	r6, #0x0
79	str	r6, [r11, #L2X0_CACHE_SYNC]
801:
81	ldr	r6, [r11, #L2X0_CACHE_SYNC]
82	ands	r6, r6, #0x1
83	bne	1b
846:
85#endif
86
87	.endm
88
89	.macro	resume_mmdc
90
91	/* restore MMDC IO */
92	cmp	r5, #0x0
93	ldreq	r11, [r0, #PM_INFO_MX6Q_IOMUXC_V_OFFSET]
94	ldrne	r11, [r0, #PM_INFO_MX6Q_IOMUXC_P_OFFSET]
95
96	ldr	r6, [r0, #PM_INFO_MMDC_IO_NUM_OFFSET]
97	ldr	r7, =PM_INFO_MMDC_IO_VAL_OFFSET
98	add	r7, r7, r0
991:
100	ldr	r8, [r7], #0x4
101	ldr	r9, [r7], #0x4
102	str	r9, [r11, r8]
103	subs	r6, r6, #0x1
104	bne	1b
105
106	cmp	r5, #0x0
107	ldreq	r11, [r0, #PM_INFO_MX6Q_MMDC_V_OFFSET]
108	ldrne	r11, [r0, #PM_INFO_MX6Q_MMDC_P_OFFSET]
109
110	cmp	r3, #IMX_DDR_TYPE_LPDDR2
111	bne	4f
112
113	/* reset read FIFO, RST_RD_FIFO */
114	ldr	r7, =MX6Q_MMDC_MPDGCTRL0
115	ldr	r6, [r11, r7]
116	orr     r6, r6, #(1 << 31)
117	str	r6, [r11, r7]
1182:
119	ldr	r6, [r11, r7]
120	ands	r6, r6, #(1 << 31)
121	bne	2b
122
123	/* reset FIFO a second time */
124	ldr	r6, [r11, r7]
125	orr     r6, r6, #(1 << 31)
126	str	r6, [r11, r7]
1273:
128	ldr	r6, [r11, r7]
129	ands	r6, r6, #(1 << 31)
130	bne	3b
1314:
132	/* let DDR out of self-refresh */
133	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
134	bic	r7, r7, #(1 << 21)
135	str	r7, [r11, #MX6Q_MMDC_MAPSR]
1365:
137	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
138	ands	r7, r7, #(1 << 25)
139	bne	5b
140
141	/* enable DDR auto power saving */
142	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
143	bic	r7, r7, #0x1
144	str	r7, [r11, #MX6Q_MMDC_MAPSR]
145
146	.endm
147
148ENTRY(imx6_suspend)
149	ldr	r1, [r0, #PM_INFO_PBASE_OFFSET]
150	ldr	r2, [r0, #PM_INFO_RESUME_ADDR_OFFSET]
151	ldr	r3, [r0, #PM_INFO_DDR_TYPE_OFFSET]
152	ldr	r4, [r0, #PM_INFO_PM_INFO_SIZE_OFFSET]
153
154	/*
155	 * counting the resume address in iram
156	 * to set it in SRC register.
157	 */
158	ldr	r6, =imx6_suspend
159	ldr	r7, =resume
160	sub	r7, r7, r6
161	add	r8, r1, r4
162	add	r9, r8, r7
163
164	/*
165	 * make sure TLB contain the addr we want,
166	 * as we will access them after MMDC IO floated.
167	 */
168
169	ldr	r11, [r0, #PM_INFO_MX6Q_CCM_V_OFFSET]
170	ldr	r6, [r11, #0x0]
171	ldr	r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
172	ldr	r6, [r11, #0x0]
173	ldr	r11, [r0, #PM_INFO_MX6Q_IOMUXC_V_OFFSET]
174	ldr	r6, [r11, #0x0]
175
176	/* use r11 to store the IO address */
177	ldr	r11, [r0, #PM_INFO_MX6Q_SRC_V_OFFSET]
178	/* store physical resume addr and pm_info address. */
179	str	r9, [r11, #MX6Q_SRC_GPR1]
180	str	r1, [r11, #MX6Q_SRC_GPR2]
181
182	/* need to sync L2 cache before DSM. */
183	sync_l2_cache
184
185	ldr	r11, [r0, #PM_INFO_MX6Q_MMDC_V_OFFSET]
186	/*
187	 * put DDR explicitly into self-refresh and
188	 * disable automatic power savings.
189	 */
190	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
191	orr	r7, r7, #0x1
192	str	r7, [r11, #MX6Q_MMDC_MAPSR]
193
194	/* make the DDR explicitly enter self-refresh. */
195	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
196	orr	r7, r7, #(1 << 21)
197	str	r7, [r11, #MX6Q_MMDC_MAPSR]
198
199poll_dvfs_set:
200	ldr	r7, [r11, #MX6Q_MMDC_MAPSR]
201	ands	r7, r7, #(1 << 25)
202	beq	poll_dvfs_set
203
204	ldr	r11, [r0, #PM_INFO_MX6Q_IOMUXC_V_OFFSET]
205	ldr	r6, =0x0
206	ldr	r7, [r0, #PM_INFO_MMDC_IO_NUM_OFFSET]
207	ldr	r8, =PM_INFO_MMDC_IO_VAL_OFFSET
208	add	r8, r8, r0
209	/* LPDDR2's last 3 IOs need special setting */
210	cmp	r3, #IMX_DDR_TYPE_LPDDR2
211	subeq	r7, r7, #0x3
212set_mmdc_io_lpm:
213	ldr	r9, [r8], #0x8
214	str	r6, [r11, r9]
215	subs	r7, r7, #0x1
216	bne	set_mmdc_io_lpm
217
218	cmp 	r3, #IMX_DDR_TYPE_LPDDR2
219	bne	set_mmdc_io_lpm_done
220	ldr	r6, =0x1000
221	ldr	r9, [r8], #0x8
222	str	r6, [r11, r9]
223	ldr	r9, [r8], #0x8
224	str	r6, [r11, r9]
225	ldr	r6, =0x80000
226	ldr	r9, [r8]
227	str	r6, [r11, r9]
228set_mmdc_io_lpm_done:
229
230	/*
231	 * mask all GPC interrupts before
232	 * enabling the RBC counters to
233	 * avoid the counter starting too
234	 * early if an interupt is already
235	 * pending.
236	 */
237	ldr	r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
238	ldr	r6, [r11, #MX6Q_GPC_IMR1]
239	ldr	r7, [r11, #MX6Q_GPC_IMR2]
240	ldr	r8, [r11, #MX6Q_GPC_IMR3]
241	ldr	r9, [r11, #MX6Q_GPC_IMR4]
242
243	ldr	r10, =0xffffffff
244	str	r10, [r11, #MX6Q_GPC_IMR1]
245	str	r10, [r11, #MX6Q_GPC_IMR2]
246	str	r10, [r11, #MX6Q_GPC_IMR3]
247	str	r10, [r11, #MX6Q_GPC_IMR4]
248
249	/*
250	 * enable the RBC bypass counter here
251	 * to hold off the interrupts. RBC counter
252	 * = 32 (1ms), Minimum RBC delay should be
253	 * 400us for the analog LDOs to power down.
254	 */
255	ldr	r11, [r0, #PM_INFO_MX6Q_CCM_V_OFFSET]
256	ldr	r10, [r11, #MX6Q_CCM_CCR]
257	bic	r10, r10, #(0x3f << 21)
258	orr	r10, r10, #(0x20 << 21)
259	str	r10, [r11, #MX6Q_CCM_CCR]
260
261	/* enable the counter. */
262	ldr	r10, [r11, #MX6Q_CCM_CCR]
263	orr	r10, r10, #(0x1 << 27)
264	str	r10, [r11, #MX6Q_CCM_CCR]
265
266	/* unmask all the GPC interrupts. */
267	ldr	r11, [r0, #PM_INFO_MX6Q_GPC_V_OFFSET]
268	str	r6, [r11, #MX6Q_GPC_IMR1]
269	str	r7, [r11, #MX6Q_GPC_IMR2]
270	str	r8, [r11, #MX6Q_GPC_IMR3]
271	str	r9, [r11, #MX6Q_GPC_IMR4]
272
273	/*
274	 * now delay for a short while (3usec)
275	 * ARM is at 1GHz at this point
276	 * so a short loop should be enough.
277	 * this delay is required to ensure that
278	 * the RBC counter can start counting in
279	 * case an interrupt is already pending
280	 * or in case an interrupt arrives just
281	 * as ARM is about to assert DSM_request.
282	 */
283	ldr	r6, =2000
284rbc_loop:
285	subs	r6, r6, #0x1
286	bne	rbc_loop
287
288	/* Zzz, enter stop mode */
289	wfi
290	nop
291	nop
292	nop
293	nop
294
295	/*
296	 * run to here means there is pending
297	 * wakeup source, system should auto
298	 * resume, we need to restore MMDC IO first
299	 */
300	mov	r5, #0x0
301	resume_mmdc
302
303	/* return to suspend finish */
304	ret	lr
305
306resume:
307	/* invalidate L1 I-cache first */
308	mov     r6, #0x0
309	mcr     p15, 0, r6, c7, c5, 0
310	mcr     p15, 0, r6, c7, c5, 6
311	/* enable the Icache and branch prediction */
312	mov     r6, #0x1800
313	mcr     p15, 0, r6, c1, c0, 0
314	isb
315
316	/* get physical resume address from pm_info. */
317	ldr	lr, [r0, #PM_INFO_RESUME_ADDR_OFFSET]
318	/* clear core0's entry and parameter */
319	ldr	r11, [r0, #PM_INFO_MX6Q_SRC_P_OFFSET]
320	mov	r7, #0x0
321	str	r7, [r11, #MX6Q_SRC_GPR1]
322	str	r7, [r11, #MX6Q_SRC_GPR2]
323
324	ldr	r3, [r0, #PM_INFO_DDR_TYPE_OFFSET]
325	mov	r5, #0x1
326	resume_mmdc
327
328	ret	lr
329ENDPROC(imx6_suspend)
330
331/*
332 * The following code must assume it is running from physical address
333 * where absolute virtual addresses to the data section have to be
334 * turned into relative ones.
335 */
336
337ENTRY(v7_cpu_resume)
338	bl	v7_invalidate_l1
339#ifdef CONFIG_CACHE_L2X0
340	bl	l2c310_early_resume
341#endif
342	b	cpu_resume
343ENDPROC(v7_cpu_resume)
344