diff options
Diffstat (limited to 'arch/arm/mach-lpc32xx/suspend.S')
-rw-r--r-- | arch/arm/mach-lpc32xx/suspend.S | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/arm/mach-lpc32xx/suspend.S b/arch/arm/mach-lpc32xx/suspend.S new file mode 100644 index 000000000000..374f9f07fe48 --- /dev/null +++ b/arch/arm/mach-lpc32xx/suspend.S | |||
@@ -0,0 +1,151 @@ | |||
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 | |||
39 | ENTRY(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 | ||
55 | 1: | ||
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 | ||
60 | 2: | ||
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 | ||
75 | 3: | ||
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] | ||
111 | 4: | ||
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 | ||
133 | 5: | ||
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 | |||
142 | reg_bases: | ||
143 | .long IO_ADDRESS(LPC32XX_CLK_PM_BASE) | ||
144 | .long IO_ADDRESS(LPC32XX_EMC_BASE) | ||
145 | |||
146 | tmp_stack: | ||
147 | .long 0, 0, 0, 0, 0, 0, 0 | ||
148 | tmp_stack_end: | ||
149 | |||
150 | ENTRY(lpc32xx_sys_suspend_sz) | ||
151 | .word . - lpc32xx_sys_suspend | ||