Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[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         }
111         return 0;
112 }
113
114 static int pnx4008_pm_valid(suspend_state_t state)
115 {
116         return (state == PM_SUSPEND_STANDBY) ||
117                (state == PM_SUSPEND_MEM);
118 }
119
120 static struct pm_ops pnx4008_pm_ops = {
121         .enter = pnx4008_pm_enter,
122         .valid = pnx4008_pm_valid,
123 };
124
125 static int __init pnx4008_pm_init(void)
126 {
127         u32 sram_size_to_allocate;
128
129         pll4_clk = clk_get(0, "ck_pll4");
130         if (IS_ERR(pll4_clk)) {
131                 printk(KERN_ERR
132                        "PM Suspend cannot acquire ARM(PLL4) clock control\n");
133                 return PTR_ERR(pll4_clk);
134         }
135
136         if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
137                 sram_size_to_allocate = pnx4008_cpu_standby_sz;
138         else
139                 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
140
141         saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
142         if (!saved_sram) {
143                 printk(KERN_ERR
144                        "PM Suspend: cannot allocate memory to save portion of SRAM\n");
145                 clk_put(pll4_clk);
146                 return -ENOMEM;
147         }
148
149         pm_set_ops(&pnx4008_pm_ops);
150         return 0;
151 }
152
153 late_initcall(pnx4008_pm_init);