Merge git://oss.sgi.com:8090/xfs-2.6
[linux-2.6] / arch / arm / mach-pnx4008 / pm.c
1 /*
2  * arch/arm/mach-pnx4008/pm.c
3  *
4  * Power Management driver for PNX4008
5  *
6  * Authors: Vitaly Wool, Dmitry Chigirev <source@mvista.com>
7  *
8  * 2005 (c) MontaVista Software, Inc. This file is licensed under
9  * the terms of the GNU General Public License version 2. This program
10  * is licensed "as is" without any warranty of any kind, whether express
11  * or implied.
12  */
13
14 #include <linux/pm.h>
15 #include <linux/rtc.h>
16 #include <linux/sched.h>
17 #include <linux/proc_fs.h>
18 #include <linux/pm.h>
19 #include <linux/delay.h>
20 #include <linux/clk.h>
21
22 #include <asm/io.h>
23 #include <asm/mach-types.h>
24 #include <asm/cacheflush.h>
25 #include <asm/arch/pm.h>
26 #include <asm/arch/clock.h>
27
28 #define SRAM_VA IO_ADDRESS(PNX4008_IRAM_BASE)
29
30 static void *saved_sram;
31
32 static struct clk *pll4_clk;
33
34 static inline void pnx4008_standby(void)
35 {
36         void (*pnx4008_cpu_standby_ptr) (void);
37
38         local_irq_disable();
39         local_fiq_disable();
40
41         clk_disable(pll4_clk);
42
43         /*saving portion of SRAM to be used by suspend function. */
44         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_standby_sz);
45
46         /*make sure SRAM copy gets physically written into SDRAM.
47            SDRAM will be placed into self-refresh during power down */
48         flush_cache_all();
49
50         /*copy suspend function into SRAM */
51         memcpy((void *)SRAM_VA, pnx4008_cpu_standby, pnx4008_cpu_standby_sz);
52
53         /*do suspend */
54         pnx4008_cpu_standby_ptr = (void *)SRAM_VA;
55         pnx4008_cpu_standby_ptr();
56
57         /*restoring portion of SRAM that was used by suspend function */
58         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_standby_sz);
59
60         clk_enable(pll4_clk);
61
62         local_fiq_enable();
63         local_irq_enable();
64 }
65
66 static inline void pnx4008_suspend(void)
67 {
68         void (*pnx4008_cpu_suspend_ptr) (void);
69
70         local_irq_disable();
71         local_fiq_disable();
72
73         clk_disable(pll4_clk);
74
75         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_PIN_BASE_INT));
76         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_INT_BASE_INT));
77
78         /*saving portion of SRAM to be used by suspend function. */
79         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_suspend_sz);
80
81         /*make sure SRAM copy gets physically written into SDRAM.
82            SDRAM will be placed into self-refresh during power down */
83         flush_cache_all();
84
85         /*copy suspend function into SRAM */
86         memcpy((void *)SRAM_VA, pnx4008_cpu_suspend, pnx4008_cpu_suspend_sz);
87
88         /*do suspend */
89         pnx4008_cpu_suspend_ptr = (void *)SRAM_VA;
90         pnx4008_cpu_suspend_ptr();
91
92         /*restoring portion of SRAM that was used by suspend function */
93         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_suspend_sz);
94
95         clk_enable(pll4_clk);
96
97         local_fiq_enable();
98         local_irq_enable();
99 }
100
101 static int pnx4008_pm_enter(suspend_state_t state)
102 {
103         switch (state) {
104         case PM_SUSPEND_STANDBY:
105                 pnx4008_standby();
106                 break;
107         case PM_SUSPEND_MEM:
108                 pnx4008_suspend();
109                 break;
110         case PM_SUSPEND_DISK:
111                 return -ENOTSUPP;
112         default:
113                 return -EINVAL;
114         }
115         return 0;
116 }
117
118 /*
119  * Called after processes are frozen, but before we shut down devices.
120  */
121 static int pnx4008_pm_prepare(suspend_state_t state)
122 {
123         switch (state) {
124         case PM_SUSPEND_STANDBY:
125         case PM_SUSPEND_MEM:
126                 break;
127
128         case PM_SUSPEND_DISK:
129                 return -ENOTSUPP;
130                 break;
131
132         default:
133                 return -EINVAL;
134                 break;
135         }
136         return 0;
137 }
138
139 /*
140  * Called after devices are re-setup, but before processes are thawed.
141  */
142 static int pnx4008_pm_finish(suspend_state_t state)
143 {
144         return 0;
145 }
146
147 /*
148  * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
149  */
150 static struct pm_ops pnx4008_pm_ops = {
151         .prepare = pnx4008_pm_prepare,
152         .enter = pnx4008_pm_enter,
153         .finish = pnx4008_pm_finish,
154 };
155
156 static int __init pnx4008_pm_init(void)
157 {
158         u32 sram_size_to_allocate;
159
160         pll4_clk = clk_get(0, "ck_pll4");
161         if (IS_ERR(pll4_clk)) {
162                 printk(KERN_ERR
163                        "PM Suspend cannot acquire ARM(PLL4) clock control\n");
164                 return PTR_ERR(pll4_clk);
165         }
166
167         if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
168                 sram_size_to_allocate = pnx4008_cpu_standby_sz;
169         else
170                 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
171
172         saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
173         if (!saved_sram) {
174                 printk(KERN_ERR
175                        "PM Suspend: cannot allocate memory to save portion of SRAM\n");
176                 clk_put(pll4_clk);
177                 return -ENOMEM;
178         }
179
180         pm_set_ops(&pnx4008_pm_ops);
181         return 0;
182 }
183
184 late_initcall(pnx4008_pm_init);