blob: fb5e72b532b00bba9ecfe0976c440d9ea825b6c8 [file] [log] [blame]
Sekhar Noriefc1bb82009-12-17 18:29:31 +05301/*
2 * (C) Copyright 2009, Texas Instruments, Inc. http://www.ti.com/
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * version 2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
16 * MA 02111-1307 USA
17 */
18
19/* replicated define because linux/bitops.h cannot be included in assembly */
20#define BIT(nr) (1 << (nr))
21
22#include <linux/linkage.h>
23#include <asm/assembler.h>
24#include <mach/psc.h>
25#include <mach/memory.h>
26
27#include "clock.h"
28
29/* Arbitrary, hardware currently does not update PHYRDY correctly */
30#define PHYRDY_CYCLES 0x1000
31
32/* Assume 25 MHz speed for the cycle conversions since PLLs are bypassed */
33#define PLL_BYPASS_CYCLES (PLL_BYPASS_TIME * 25)
34#define PLL_RESET_CYCLES (PLL_RESET_TIME * 25)
35#define PLL_LOCK_CYCLES (PLL_LOCK_TIME * 25)
36
37#define DEEPSLEEP_SLEEPENABLE_BIT BIT(31)
38
39 .text
40/*
41 * Move DaVinci into deep sleep state
42 *
43 * Note: This code is copied to internal SRAM by PM code. When the DaVinci
44 * wakes up it continues execution at the point it went to sleep.
45 * Register Usage:
46 * r0: contains virtual base for DDR2 controller
47 * r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
48 * r2: contains PSC number for DDR2
49 * r3: contains virtual base DDR2 PLL controller
50 * r4: contains virtual address of the DEEPSLEEP register
51 */
52ENTRY(davinci_cpu_suspend)
53 stmfd sp!, {r0-r12, lr} @ save registers on stack
54
55 ldr ip, CACHE_FLUSH
56 blx ip
57
58 ldmia r0, {r0-r4}
59
60 /*
61 * Switch DDR to self-refresh mode.
62 */
63
64 /* calculate SDRCR address */
65 ldr ip, [r0, #DDR2_SDRCR_OFFSET]
66 bic ip, ip, #DDR2_SRPD_BIT
67 orr ip, ip, #DDR2_LPMODEN_BIT
68 str ip, [r0, #DDR2_SDRCR_OFFSET]
69
70 ldr ip, [r0, #DDR2_SDRCR_OFFSET]
71 orr ip, ip, #DDR2_MCLKSTOPEN_BIT
72 str ip, [r0, #DDR2_SDRCR_OFFSET]
73
74 mov ip, #PHYRDY_CYCLES
751: subs ip, ip, #0x1
76 bne 1b
77
78 /* Disable DDR2 LPSC */
79 mov r7, r0
80 mov r0, #0x2
81 bl davinci_ddr_psc_config
82 mov r0, r7
83
84 /* Disable clock to DDR PHY */
85 ldr ip, [r3, #PLLDIV1]
86 bic ip, ip, #PLLDIV_EN
87 str ip, [r3, #PLLDIV1]
88
89 /* Put the DDR PLL in bypass and power down */
90 ldr ip, [r3, #PLLCTL]
91 bic ip, ip, #PLLCTL_PLLENSRC
92 bic ip, ip, #PLLCTL_PLLEN
93 str ip, [r3, #PLLCTL]
94
95 /* Wait for PLL to switch to bypass */
96 mov ip, #PLL_BYPASS_CYCLES
972: subs ip, ip, #0x1
98 bne 2b
99
100 /* Power down the PLL */
101 ldr ip, [r3, #PLLCTL]
102 orr ip, ip, #PLLCTL_PLLPWRDN
103 str ip, [r3, #PLLCTL]
104
105 /* Go to deep sleep */
106 ldr ip, [r4]
107 orr ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
108 /* System goes to sleep beyond after this instruction */
109 str ip, [r4]
110
111 /* Wake up from sleep */
112
113 /* Clear sleep enable */
114 ldr ip, [r4]
115 bic ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
116 str ip, [r4]
117
118 /* initialize the DDR PLL controller */
119
120 /* Put PLL in reset */
121 ldr ip, [r3, #PLLCTL]
122 bic ip, ip, #PLLCTL_PLLRST
123 str ip, [r3, #PLLCTL]
124
125 /* Clear PLL power down */
126 ldr ip, [r3, #PLLCTL]
127 bic ip, ip, #PLLCTL_PLLPWRDN
128 str ip, [r3, #PLLCTL]
129
130 mov ip, #PLL_RESET_CYCLES
1313: subs ip, ip, #0x1
132 bne 3b
133
134 /* Bring PLL out of reset */
135 ldr ip, [r3, #PLLCTL]
136 orr ip, ip, #PLLCTL_PLLRST
137 str ip, [r3, #PLLCTL]
138
139 /* Wait for PLL to lock (assume prediv = 1, 25MHz OSCIN) */
140 mov ip, #PLL_LOCK_CYCLES
1414: subs ip, ip, #0x1
142 bne 4b
143
144 /* Remove PLL from bypass mode */
145 ldr ip, [r3, #PLLCTL]
146 bic ip, ip, #PLLCTL_PLLENSRC
147 orr ip, ip, #PLLCTL_PLLEN
148 str ip, [r3, #PLLCTL]
149
150 /* Start 2x clock to DDR2 */
151
152 ldr ip, [r3, #PLLDIV1]
153 orr ip, ip, #PLLDIV_EN
154 str ip, [r3, #PLLDIV1]
155
156 /* Enable VCLK */
157
158 /* Enable DDR2 LPSC */
159 mov r7, r0
160 mov r0, #0x3
161 bl davinci_ddr_psc_config
162 mov r0, r7
163
164 /* clear MCLKSTOPEN */
165
166 ldr ip, [r0, #DDR2_SDRCR_OFFSET]
167 bic ip, ip, #DDR2_MCLKSTOPEN_BIT
168 str ip, [r0, #DDR2_SDRCR_OFFSET]
169
170 ldr ip, [r0, #DDR2_SDRCR_OFFSET]
171 bic ip, ip, #DDR2_LPMODEN_BIT
172 str ip, [r0, #DDR2_SDRCR_OFFSET]
173
174 /* Restore registers and return */
175 ldmfd sp!, {r0-r12, pc}
176
177ENDPROC(davinci_cpu_suspend)
178
179/*
180 * Disables or Enables DDR2 LPSC
181 * Register Usage:
182 * r0: Enable or Disable LPSC r0 = 0x3 => Enable, r0 = 0x2 => Disable LPSC
183 * r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
184 * r2: contains PSC number for DDR2
185 */
186ENTRY(davinci_ddr_psc_config)
187 /* Set next state in mdctl for DDR2 */
188 mov r6, #MDCTL
189 add r6, r6, r2, lsl #2
190 ldr ip, [r1, r6]
191 bic ip, ip, #MDSTAT_STATE_MASK
192 orr ip, ip, r0
193 str ip, [r1, r6]
194
195 /* Enable the Power Domain Transition Command */
196 ldr ip, [r1, #PTCMD]
197 orr ip, ip, #0x1
198 str ip, [r1, #PTCMD]
199
200 /* Check for Transition Complete (PTSTAT) */
201ptstat_done:
202 ldr ip, [r1, #PTSTAT]
203 and ip, ip, #0x1
204 cmp ip, #0x0
205 bne ptstat_done
206
207 /* Check for DDR2 clock disable completion; */
208 mov r6, #MDSTAT
209 add r6, r6, r2, lsl #2
210ddr2clk_stop_done:
211 ldr ip, [r1, r6]
212 and ip, ip, #MDSTAT_STATE_MASK
213 cmp ip, r0
214 bne ddr2clk_stop_done
215
216 mov pc, lr
217ENDPROC(davinci_ddr_psc_config)
218
219CACHE_FLUSH:
220 .word arm926_flush_kern_cache_all
221
222ENTRY(davinci_cpu_suspend_sz)
223 .word . - davinci_cpu_suspend
224ENDPROC(davinci_cpu_suspend_sz)