[PATCH] introduce kernel_execve
[linux-3.10.git] / arch / sparc64 / kernel / power.c
1 /* $Id: power.c,v 1.10 2001/12/11 01:57:16 davem Exp $
2  * power.c: Power management driver.
3  *
4  * Copyright (C) 1999 David S. Miller (davem@redhat.com)
5  */
6
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/sched.h>
11 #include <linux/signal.h>
12 #include <linux/delay.h>
13 #include <linux/interrupt.h>
14 #include <linux/pm.h>
15 #include <linux/syscalls.h>
16
17 #include <asm/system.h>
18 #include <asm/auxio.h>
19 #include <asm/prom.h>
20 #include <asm/of_device.h>
21 #include <asm/io.h>
22
23 #include <linux/unistd.h>
24
25 /*
26  * sysctl - toggle power-off restriction for serial console 
27  * systems in machine_power_off()
28  */
29 int scons_pwroff = 1; 
30
31 #ifdef CONFIG_PCI
32 #include <linux/pci.h>
33 static void __iomem *power_reg;
34
35 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
36 static int button_pressed;
37
38 static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
39 {
40         if (button_pressed == 0) {
41                 button_pressed = 1;
42                 wake_up(&powerd_wait);
43         }
44
45         /* FIXME: Check registers for status... */
46         return IRQ_HANDLED;
47 }
48 #endif /* CONFIG_PCI */
49
50 extern void machine_halt(void);
51 extern void machine_alt_power_off(void);
52 static void (*poweroff_method)(void) = machine_alt_power_off;
53
54 void machine_power_off(void)
55 {
56         if (!serial_console || scons_pwroff) {
57 #ifdef CONFIG_PCI
58                 if (power_reg) {
59                         /* Both register bits seem to have the
60                          * same effect, so until I figure out
61                          * what the difference is...
62                          */
63                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
64                 } else
65 #endif /* CONFIG_PCI */
66                         if (poweroff_method != NULL) {
67                                 poweroff_method();
68                                 /* not reached */
69                         }
70         }
71         machine_halt();
72 }
73
74 void (*pm_power_off)(void) = machine_power_off;
75 EXPORT_SYMBOL(pm_power_off);
76
77 #ifdef CONFIG_PCI
78 static int powerd(void *__unused)
79 {
80         static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
81         char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
82         DECLARE_WAITQUEUE(wait, current);
83
84         daemonize("powerd");
85
86         add_wait_queue(&powerd_wait, &wait);
87 again:
88         for (;;) {
89                 set_task_state(current, TASK_INTERRUPTIBLE);
90                 if (button_pressed)
91                         break;
92                 flush_signals(current);
93                 schedule();
94         }
95         __set_current_state(TASK_RUNNING);
96         remove_wait_queue(&powerd_wait, &wait);
97
98         /* Ok, down we go... */
99         button_pressed = 0;
100         if (kernel_execve("/sbin/shutdown", argv, envp) < 0) {
101                 printk("powerd: shutdown execution failed\n");
102                 add_wait_queue(&powerd_wait, &wait);
103                 goto again;
104         }
105         return 0;
106 }
107
108 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
109 {
110         if (irq == PCI_IRQ_NONE)
111                 return 0;
112         if (!of_find_property(dp, "button", NULL))
113                 return 0;
114
115         return 1;
116 }
117
118 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
119 {
120         struct resource *res = &op->resource[0];
121         unsigned int irq= op->irqs[0];
122
123         power_reg = of_ioremap(res, 0, 0x4, "power");
124
125         printk("%s: Control reg at %lx ... ",
126                op->node->name, res->start);
127
128         poweroff_method = machine_halt;  /* able to use the standard halt */
129
130         if (has_button_interrupt(irq, op->node)) {
131                 if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
132                         printk("Failed to start power daemon.\n");
133                         return 0;
134                 }
135                 printk("powerd running.\n");
136
137                 if (request_irq(irq,
138                                 power_handler, 0, "power", NULL) < 0)
139                         printk("power: Error, cannot register IRQ handler.\n");
140         } else {
141                 printk("not using powerd.\n");
142         }
143
144         return 0;
145 }
146
147 static struct of_device_id power_match[] = {
148         {
149                 .name = "power",
150         },
151         {},
152 };
153
154 static struct of_platform_driver power_driver = {
155         .name           = "power",
156         .match_table    = power_match,
157         .probe          = power_probe,
158 };
159
160 void __init power_init(void)
161 {
162         of_register_driver(&power_driver, &of_bus_type);
163         return;
164 }
165 #endif /* CONFIG_PCI */