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/suspend.h>
19 #include <linux/delay.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23
24 #include <asm/cacheflush.h>
25
26 #include <mach/hardware.h>
27 #include <mach/pm.h>
28 #include <mach/clock.h>
29
30 #define SRAM_VA IO_ADDRESS(PNX4008_IRAM_BASE)
31
32 static void *saved_sram;
33
34 static struct clk *pll4_clk;
35
pnx4008_standby(void)36 static inline void pnx4008_standby(void)
37 {
38 void (*pnx4008_cpu_standby_ptr) (void);
39
40 local_irq_disable();
41 local_fiq_disable();
42
43 clk_disable(pll4_clk);
44
45 /*saving portion of SRAM to be used by suspend function. */
46 memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_standby_sz);
47
48 /*make sure SRAM copy gets physically written into SDRAM.
49 SDRAM will be placed into self-refresh during power down */
50 flush_cache_all();
51
52 /*copy suspend function into SRAM */
53 memcpy((void *)SRAM_VA, pnx4008_cpu_standby, pnx4008_cpu_standby_sz);
54
55 /*do suspend */
56 pnx4008_cpu_standby_ptr = (void *)SRAM_VA;
57 pnx4008_cpu_standby_ptr();
58
59 /*restoring portion of SRAM that was used by suspend function */
60 memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_standby_sz);
61
62 clk_enable(pll4_clk);
63
64 local_fiq_enable();
65 local_irq_enable();
66 }
67
pnx4008_suspend(void)68 static inline void pnx4008_suspend(void)
69 {
70 void (*pnx4008_cpu_suspend_ptr) (void);
71
72 local_irq_disable();
73 local_fiq_disable();
74
75 clk_disable(pll4_clk);
76
77 __raw_writel(0xffffffff, START_INT_RSR_REG(SE_PIN_BASE_INT));
78 __raw_writel(0xffffffff, START_INT_RSR_REG(SE_INT_BASE_INT));
79
80 /*saving portion of SRAM to be used by suspend function. */
81 memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_suspend_sz);
82
83 /*make sure SRAM copy gets physically written into SDRAM.
84 SDRAM will be placed into self-refresh during power down */
85 flush_cache_all();
86
87 /*copy suspend function into SRAM */
88 memcpy((void *)SRAM_VA, pnx4008_cpu_suspend, pnx4008_cpu_suspend_sz);
89
90 /*do suspend */
91 pnx4008_cpu_suspend_ptr = (void *)SRAM_VA;
92 pnx4008_cpu_suspend_ptr();
93
94 /*restoring portion of SRAM that was used by suspend function */
95 memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_suspend_sz);
96
97 clk_enable(pll4_clk);
98
99 local_fiq_enable();
100 local_irq_enable();
101 }
102
pnx4008_pm_enter(suspend_state_t state)103 static int pnx4008_pm_enter(suspend_state_t state)
104 {
105 switch (state) {
106 case PM_SUSPEND_STANDBY:
107 pnx4008_standby();
108 break;
109 case PM_SUSPEND_MEM:
110 pnx4008_suspend();
111 break;
112 }
113 return 0;
114 }
115
pnx4008_pm_valid(suspend_state_t state)116 static int pnx4008_pm_valid(suspend_state_t state)
117 {
118 return (state == PM_SUSPEND_STANDBY) ||
119 (state == PM_SUSPEND_MEM);
120 }
121
122 static const struct platform_suspend_ops pnx4008_pm_ops = {
123 .enter = pnx4008_pm_enter,
124 .valid = pnx4008_pm_valid,
125 };
126
pnx4008_pm_init(void)127 static int __init pnx4008_pm_init(void)
128 {
129 u32 sram_size_to_allocate;
130
131 pll4_clk = clk_get(0, "ck_pll4");
132 if (IS_ERR(pll4_clk)) {
133 printk(KERN_ERR
134 "PM Suspend cannot acquire ARM(PLL4) clock control\n");
135 return PTR_ERR(pll4_clk);
136 }
137
138 if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
139 sram_size_to_allocate = pnx4008_cpu_standby_sz;
140 else
141 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
142
143 saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
144 if (!saved_sram) {
145 printk(KERN_ERR
146 "PM Suspend: cannot allocate memory to save portion of SRAM\n");
147 clk_put(pll4_clk);
148 return -ENOMEM;
149 }
150
151 suspend_set_ops(&pnx4008_pm_ops);
152 return 0;
153 }
154
155 late_initcall(pnx4008_pm_init);
156