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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* AVR32 AP Power Management
*
* Copyright (C) 2008 Atmel Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/vmalloc.h>
#include <asm/cacheflush.h>
#include <asm/sysreg.h>
#include <mach/chip.h>
#include <mach/pm.h>
#include <mach/sram.h>
#include "sdramc.h"
#define SRAM_PAGE_FLAGS (SYSREG_BIT(TLBELO_D) | SYSREG_BF(SZ, 1) \
| SYSREG_BF(AP, 3) | SYSREG_BIT(G))
static unsigned long pm_sram_start;
static size_t pm_sram_size;
static struct vm_struct *pm_sram_area;
static void (*avr32_pm_enter_standby)(unsigned long sdramc_base);
static void (*avr32_pm_enter_str)(unsigned long sdramc_base);
/*
* Must be called with interrupts disabled. Exceptions will be masked
* on return (i.e. all exceptions will be "unrecoverable".)
*/
static void *avr32_pm_map_sram(void)
{
unsigned long vaddr;
unsigned long page_addr;
u32 tlbehi;
u32 mmucr;
vaddr = (unsigned long)pm_sram_area->addr;
page_addr = pm_sram_start & PAGE_MASK;
/*
* Mask exceptions and grab the first TLB entry. We won't be
* needing it while sleeping.
*/
asm volatile("ssrf %0" : : "i"(SYSREG_EM_OFFSET) : "memory");
mmucr = sysreg_read(MMUCR);
tlbehi = sysreg_read(TLBEHI);
sysreg_write(MMUCR, SYSREG_BFINS(DRP, 0, mmucr));
tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi));
tlbehi |= vaddr & PAGE_MASK;
tlbehi |= SYSREG_BIT(TLBEHI_V);
sysreg_write(TLBELO, page_addr | SRAM_PAGE_FLAGS);
sysreg_write(TLBEHI, tlbehi);
__builtin_tlbw();
return (void *)(vaddr + pm_sram_start - page_addr);
}
/*
* Must be called with interrupts disabled. Exceptions will be
* unmasked on return.
*/
static void avr32_pm_unmap_sram(void)
{
u32 mmucr;
u32 tlbehi;
u32 tlbarlo;
/* Going to update TLB entry at index 0 */
mmucr = sysreg_read(MMUCR);
tlbehi = sysreg_read(TLBEHI);
sysreg_write(MMUCR, SYSREG_BFINS(DRP, 0, mmucr));
/* Clear the "valid" bit */
tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi));
sysreg_write(TLBEHI, tlbehi);
/* Mark it as "not accessed" */
tlbarlo = sysreg_read(TLBARLO);
sysreg_write(TLBARLO, tlbarlo | 0x80000000U);
/* Update the TLB */
__builtin_tlbw();
/* Unmask exceptions */
asm volatile("csrf %0" : : "i"(SYSREG_EM_OFFSET) : "memory");
}
static int avr32_pm_valid_state(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_ON:
case PM_SUSPEND_STANDBY:
case PM_SUSPEND_MEM:
return 1;
default:
return 0;
}
}
static int avr32_pm_enter(suspend_state_t state)
{
u32 lpr_saved;
u32 evba_saved;
void *sram;
switch (state) {
case PM_SUSPEND_STANDBY:
sram = avr32_pm_map_sram();
/* Switch to in-sram exception handlers */
evba_saved = sysreg_read(EVBA);
sysreg_write(EVBA, (unsigned long)sram);
/*
* Save the LPR register so that we can re-enable
* SDRAM Low Power mode on resume.
*/
lpr_saved = sdramc_readl(LPR);
pr_debug("%s: Entering standby...\n", __func__);
avr32_pm_enter_standby(SDRAMC_BASE);
sdramc_writel(LPR, lpr_saved);
/* Switch back to regular exception handlers */
sysreg_write(EVBA, evba_saved);
avr32_pm_unmap_sram();
break;
case PM_SUSPEND_MEM:
sram = avr32_pm_map_sram();
/* Switch to in-sram exception handlers */
evba_saved = sysreg_read(EVBA);
sysreg_write(EVBA, (unsigned long)sram);
/*
* Save the LPR register so that we can re-enable
* SDRAM Low Power mode on resume.
*/
lpr_saved = sdramc_readl(LPR);
pr_debug("%s: Entering suspend-to-ram...\n", __func__);
avr32_pm_enter_str(SDRAMC_BASE);
sdramc_writel(LPR, lpr_saved);
/* Switch back to regular exception handlers */
sysreg_write(EVBA, evba_saved);
avr32_pm_unmap_sram();
break;
case PM_SUSPEND_ON:
pr_debug("%s: Entering idle...\n", __func__);
cpu_enter_idle();
break;
default:
pr_debug("%s: Invalid suspend state %d\n", __func__, state);
goto out;
}
pr_debug("%s: wakeup\n", __func__);
out:
return 0;
}
static const struct platform_suspend_ops avr32_pm_ops = {
.valid = avr32_pm_valid_state,
.enter = avr32_pm_enter,
};
static unsigned long avr32_pm_offset(void *symbol)
{
extern u8 pm_exception[];
return (unsigned long)symbol - (unsigned long)pm_exception;
}
static int __init avr32_pm_init(void)
{
extern u8 pm_exception[];
extern u8 pm_irq0[];
extern u8 pm_standby[];
extern u8 pm_suspend_to_ram[];
extern u8 pm_sram_end[];
void *dst;
/*
* To keep things simple, we depend on not needing more than a
* single page.
*/
pm_sram_size = avr32_pm_offset(pm_sram_end);
if (pm_sram_size > PAGE_SIZE)
goto err;
pm_sram_start = sram_alloc(pm_sram_size);
if (!pm_sram_start)
goto err_alloc_sram;
/* Grab a virtual area we can use later on. */
pm_sram_area = get_vm_area(pm_sram_size, VM_IOREMAP);
if (!pm_sram_area)
goto err_vm_area;
pm_sram_area->phys_addr = pm_sram_start;
local_irq_disable();
dst = avr32_pm_map_sram();
memcpy(dst, pm_exception, pm_sram_size);
flush_dcache_region(dst, pm_sram_size);
invalidate_icache_region(dst, pm_sram_size);
avr32_pm_unmap_sram();
local_irq_enable();
avr32_pm_enter_standby = dst + avr32_pm_offset(pm_standby);
avr32_pm_enter_str = dst + avr32_pm_offset(pm_suspend_to_ram);
intc_set_suspend_handler(avr32_pm_offset(pm_irq0));
suspend_set_ops(&avr32_pm_ops);
printk("AVR32 AP Power Management enabled\n");
return 0;
err_vm_area:
sram_free(pm_sram_start, pm_sram_size);
err_alloc_sram:
err:
pr_err("AVR32 Power Management initialization failed\n");
return -ENOMEM;
}
arch_initcall(avr32_pm_init);
|
