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
|
/*
* linux/arch/arm/mach-omap2/sleep.S
*
* (C) Copyright 2004
* Texas Instruments, <www.ti.com>
* Richard Woodruff <r-woodruff2@ti.com>
*
* (C) Copyright 2006 Nokia Corporation
* Fixed idle loop sleep
* Igor Stoppa <igor.stoppa@nokia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <mach/io.h>
#include <plat/omap24xx.h>
#include "sdrc.h"
/* First address of reserved address space? apparently valid for OMAP2 & 3 */
#define A_SDRC0_V (0xC0000000)
.text
/*
* Forces OMAP into idle state
*
* omap24xx_idle_loop_suspend() - This bit of code just executes the WFI
* for normal idles.
*
* Note: This code get's copied to internal SRAM at boot. When the OMAP
* wakes up it continues execution at the point it went to sleep.
*/
ENTRY(omap24xx_idle_loop_suspend)
stmfd sp!, {r0, lr} @ save registers on stack
mov r0, #0 @ clear for mcr setup
mcr p15, 0, r0, c7, c0, 4 @ wait for interrupt
ldmfd sp!, {r0, pc} @ restore regs and return
ENTRY(omap24xx_idle_loop_suspend_sz)
.word . - omap24xx_idle_loop_suspend
/*
* omap24xx_cpu_suspend() - Forces OMAP into deep sleep state by completing
* SDRC shutdown then ARM shutdown. Upon wake MPU is back on so just restore
* SDRC.
*
* Input:
* R0 : DLL ctrl value pre-Sleep
* R1 : SDRC_DLLA_CTRL
* R2 : SDRC_POWER
*
* The if the DPLL is going to AutoIdle. It seems like the DPLL may be back on
* when we get called, but the DLL probably isn't. We will wait a bit more in
* case the DPLL isn't quite there yet. The code will wait on DLL for DDR even
* if in unlocked mode.
*
* For less than 242x-ES2.2 upon wake from a sleep mode where the external
* oscillator was stopped, a timing bug exists where a non-stabilized 12MHz
* clock can pass into the PRCM can cause problems at DSP and IVA.
* To work around this the code will switch to the 32kHz source prior to sleep.
* Post sleep we will shift back to using the DPLL. Apparently,
* CM_IDLEST_CLKGEN does not reflect the full clock change so you need to wait
* 3x12MHz + 3x32kHz clocks for a full switch.
*
* The DLL load value is not kept in RETENTION or OFF. It needs to be restored
* at wake
*/
ENTRY(omap24xx_cpu_suspend)
stmfd sp!, {r0 - r12, lr} @ save registers on stack
mov r3, #0x0 @ clear for mcr call
mcr p15, 0, r3, c7, c10, 4 @ memory barrier, hope SDR/DDR finished
nop
nop
ldr r4, [r2] @ read SDRC_POWER
orr r4, r4, #0x40 @ enable self refresh on idle req
mov r5, #0x2000 @ set delay (DPLL relock + DLL relock)
str r4, [r2] @ make it so
nop
mcr p15, 0, r3, c7, c0, 4 @ wait for interrupt
nop
loop:
subs r5, r5, #0x1 @ awake, wait just a bit
bne loop
/* The DPLL has to be on before we take the DDR out of self refresh */
bic r4, r4, #0x40 @ now clear self refresh bit.
str r4, [r2] @ write to SDRC_POWER
ldr r4, A_SDRC0 @ make a clock happen
ldr r4, [r4] @ read A_SDRC0
nop @ start auto refresh only after clk ok
movs r0, r0 @ see if DDR or SDR
strne r0, [r1] @ rewrite DLLA to force DLL reload
addne r1, r1, #0x8 @ move to DLLB
strne r0, [r1] @ rewrite DLLB to force DLL reload
mov r5, #0x1000
loop2:
subs r5, r5, #0x1
bne loop2
/* resume*/
ldmfd sp!, {r0 - r12, pc} @ restore regs and return
A_SDRC0:
.word A_SDRC0_V
ENTRY(omap24xx_cpu_suspend_sz)
.word . - omap24xx_cpu_suspend
|
