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-rw-r--r--arch/arm/mach-lpc32xx/suspend.S151
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diff --git a/arch/arm/mach-lpc32xx/suspend.S b/arch/arm/mach-lpc32xx/suspend.S
new file mode 100644
index 000000000000..374f9f07fe48
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+++ b/arch/arm/mach-lpc32xx/suspend.S
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1/*
2 * arch/arm/mach-lpc32xx/suspend.S
3 *
4 * Original authors: Dmitry Chigirev, Vitaly Wool <source@mvista.com>
5 * Modified by Kevin Wells <kevin.wells@nxp.com>
6 *
7 * 2005 (c) MontaVista Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14#include <mach/platform.h>
15#include <mach/hardware.h>
16
17/* Using named register defines makes the code easier to follow */
18#define WORK1_REG r0
19#define WORK2_REG r1
20#define SAVED_HCLK_DIV_REG r2
21#define SAVED_HCLK_PLL_REG r3
22#define SAVED_DRAM_CLKCTRL_REG r4
23#define SAVED_PWR_CTRL_REG r5
24#define CLKPWRBASE_REG r6
25#define EMCBASE_REG r7
26
27#define LPC32XX_EMC_STATUS_OFFS 0x04
28#define LPC32XX_EMC_STATUS_BUSY 0x1
29#define LPC32XX_EMC_STATUS_SELF_RFSH 0x4
30
31#define LPC32XX_CLKPWR_PWR_CTRL_OFFS 0x44
32#define LPC32XX_CLKPWR_HCLK_DIV_OFFS 0x40
33#define LPC32XX_CLKPWR_HCLKPLL_CTRL_OFFS 0x58
34
35#define CLKPWR_PCLK_DIV_MASK 0xFFFFFE7F
36
37 .text
38
39ENTRY(lpc32xx_sys_suspend)
40 @ Save a copy of the used registers in IRAM, r0 is corrupted
41 adr r0, tmp_stack_end
42 stmfd r0!, {r3 - r7, sp, lr}
43
44 @ Load a few common register addresses
45 adr WORK1_REG, reg_bases
46 ldr CLKPWRBASE_REG, [WORK1_REG, #0]
47 ldr EMCBASE_REG, [WORK1_REG, #4]
48
49 ldr SAVED_PWR_CTRL_REG, [CLKPWRBASE_REG,\
50 #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
51 orr WORK1_REG, SAVED_PWR_CTRL_REG, #LPC32XX_CLKPWR_SDRAM_SELF_RFSH
52
53 @ Wait for SDRAM busy status to go busy and then idle
54 @ This guarantees a small windows where DRAM isn't busy
551:
56 ldr WORK2_REG, [EMCBASE_REG, #LPC32XX_EMC_STATUS_OFFS]
57 and WORK2_REG, WORK2_REG, #LPC32XX_EMC_STATUS_BUSY
58 cmp WORK2_REG, #LPC32XX_EMC_STATUS_BUSY
59 bne 1b @ Branch while idle
602:
61 ldr WORK2_REG, [EMCBASE_REG, #LPC32XX_EMC_STATUS_OFFS]
62 and WORK2_REG, WORK2_REG, #LPC32XX_EMC_STATUS_BUSY
63 cmp WORK2_REG, #LPC32XX_EMC_STATUS_BUSY
64 beq 2b @ Branch until idle
65
66 @ Setup self-refresh with support for manual exit of
67 @ self-refresh mode
68 str WORK1_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
69 orr WORK2_REG, WORK1_REG, #LPC32XX_CLKPWR_UPD_SDRAM_SELF_RFSH
70 str WORK2_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
71 str WORK1_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
72
73 @ Wait for self-refresh acknowledge, clocks to the DRAM device
74 @ will automatically stop on start of self-refresh
753:
76 ldr WORK2_REG, [EMCBASE_REG, #LPC32XX_EMC_STATUS_OFFS]
77 and WORK2_REG, WORK2_REG, #LPC32XX_EMC_STATUS_SELF_RFSH
78 cmp WORK2_REG, #LPC32XX_EMC_STATUS_SELF_RFSH
79 bne 3b @ Branch until self-refresh mode starts
80
81 @ Enter direct-run mode from run mode
82 bic WORK1_REG, WORK1_REG, #LPC32XX_CLKPWR_SELECT_RUN_MODE
83 str WORK1_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
84
85 @ Safe disable of DRAM clock in EMC block, prevents DDR sync
86 @ issues on restart
87 ldr SAVED_HCLK_DIV_REG, [CLKPWRBASE_REG,\
88 #LPC32XX_CLKPWR_HCLK_DIV_OFFS]
89 and WORK2_REG, SAVED_HCLK_DIV_REG, #CLKPWR_PCLK_DIV_MASK
90 str WORK2_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_HCLK_DIV_OFFS]
91
92 @ Save HCLK PLL state and disable HCLK PLL
93 ldr SAVED_HCLK_PLL_REG, [CLKPWRBASE_REG,\
94 #LPC32XX_CLKPWR_HCLKPLL_CTRL_OFFS]
95 bic WORK2_REG, SAVED_HCLK_PLL_REG, #LPC32XX_CLKPWR_HCLKPLL_POWER_UP
96 str WORK2_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_HCLKPLL_CTRL_OFFS]
97
98 @ Enter stop mode until an enabled event occurs
99 orr WORK1_REG, WORK1_REG, #LPC32XX_CLKPWR_STOP_MODE_CTRL
100 str WORK1_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
101 .rept 9
102 nop
103 .endr
104
105 @ Clear stop status
106 bic WORK1_REG, WORK1_REG, #LPC32XX_CLKPWR_STOP_MODE_CTRL
107
108 @ Restore original HCLK PLL value and wait for PLL lock
109 str SAVED_HCLK_PLL_REG, [CLKPWRBASE_REG,\
110 #LPC32XX_CLKPWR_HCLKPLL_CTRL_OFFS]
1114:
112 ldr WORK2_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_HCLKPLL_CTRL_OFFS]
113 and WORK2_REG, WORK2_REG, #LPC32XX_CLKPWR_HCLKPLL_PLL_STS
114 bne 4b
115
116 @ Re-enter run mode with self-refresh flag cleared, but no DRAM
117 @ update yet. DRAM is still in self-refresh
118 str SAVED_PWR_CTRL_REG, [CLKPWRBASE_REG,\
119 #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
120
121 @ Restore original DRAM clock mode to restore DRAM clocks
122 str SAVED_HCLK_DIV_REG, [CLKPWRBASE_REG,\
123 #LPC32XX_CLKPWR_HCLK_DIV_OFFS]
124
125 @ Clear self-refresh mode
126 orr WORK1_REG, SAVED_PWR_CTRL_REG,\
127 #LPC32XX_CLKPWR_UPD_SDRAM_SELF_RFSH
128 str WORK1_REG, [CLKPWRBASE_REG, #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
129 str SAVED_PWR_CTRL_REG, [CLKPWRBASE_REG,\
130 #LPC32XX_CLKPWR_PWR_CTRL_OFFS]
131
132 @ Wait for EMC to clear self-refresh mode
1335:
134 ldr WORK2_REG, [EMCBASE_REG, #LPC32XX_EMC_STATUS_OFFS]
135 and WORK2_REG, WORK2_REG, #LPC32XX_EMC_STATUS_SELF_RFSH
136 bne 5b @ Branch until self-refresh has exited
137
138 @ restore regs and return
139 adr r0, tmp_stack
140 ldmfd r0!, {r3 - r7, sp, pc}
141
142reg_bases:
143 .long IO_ADDRESS(LPC32XX_CLK_PM_BASE)
144 .long IO_ADDRESS(LPC32XX_EMC_BASE)
145
146tmp_stack:
147 .long 0, 0, 0, 0, 0, 0, 0
148tmp_stack_end:
149
150ENTRY(lpc32xx_sys_suspend_sz)
151 .word . - lpc32xx_sys_suspend