Merge master.kernel.org:/home/rmk/linux-2.6-arm-smp
[linux-2.6] / 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 #define __KERNEL_SYSCALLS__
8
9 #include <linux/config.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/sched.h>
14 #include <linux/signal.h>
15 #include <linux/delay.h>
16 #include <linux/interrupt.h>
17
18 #include <asm/system.h>
19 #include <asm/ebus.h>
20 #include <asm/auxio.h>
21
22 #include <linux/unistd.h>
23
24 /*
25  * sysctl - toggle power-off restriction for serial console 
26  * systems in machine_power_off()
27  */
28 int scons_pwroff = 1; 
29
30 #ifdef CONFIG_PCI
31 static void __iomem *power_reg;
32
33 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
34 static int button_pressed;
35
36 static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
37 {
38         if (button_pressed == 0) {
39                 button_pressed = 1;
40                 wake_up(&powerd_wait);
41         }
42
43         /* FIXME: Check registers for status... */
44         return IRQ_HANDLED;
45 }
46 #endif /* CONFIG_PCI */
47
48 extern void machine_halt(void);
49 extern void machine_alt_power_off(void);
50 static void (*poweroff_method)(void) = machine_alt_power_off;
51
52 void machine_power_off(void)
53 {
54         if (!serial_console || scons_pwroff) {
55 #ifdef CONFIG_PCI
56                 if (power_reg) {
57                         /* Both register bits seem to have the
58                          * same effect, so until I figure out
59                          * what the difference is...
60                          */
61                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
62                 } else
63 #endif /* CONFIG_PCI */
64                         if (poweroff_method != NULL) {
65                                 poweroff_method();
66                                 /* not reached */
67                         }
68         }
69         machine_halt();
70 }
71
72 #ifdef CONFIG_PCI
73 static int powerd(void *__unused)
74 {
75         static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
76         char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
77         DECLARE_WAITQUEUE(wait, current);
78
79         daemonize("powerd");
80
81         add_wait_queue(&powerd_wait, &wait);
82 again:
83         for (;;) {
84                 set_task_state(current, TASK_INTERRUPTIBLE);
85                 if (button_pressed)
86                         break;
87                 flush_signals(current);
88                 schedule();
89         }
90         __set_current_state(TASK_RUNNING);
91         remove_wait_queue(&powerd_wait, &wait);
92
93         /* Ok, down we go... */
94         button_pressed = 0;
95         if (execve("/sbin/shutdown", argv, envp) < 0) {
96                 printk("powerd: shutdown execution failed\n");
97                 add_wait_queue(&powerd_wait, &wait);
98                 goto again;
99         }
100         return 0;
101 }
102
103 static int __init has_button_interrupt(struct linux_ebus_device *edev)
104 {
105         if (edev->irqs[0] == PCI_IRQ_NONE)
106                 return 0;
107         if (!prom_node_has_property(edev->prom_node, "button"))
108                 return 0;
109
110         return 1;
111 }
112
113 void __init power_init(void)
114 {
115         struct linux_ebus *ebus;
116         struct linux_ebus_device *edev;
117         static int invoked;
118
119         if (invoked)
120                 return;
121         invoked = 1;
122
123         for_each_ebus(ebus) {
124                 for_each_ebusdev(edev, ebus) {
125                         if (!strcmp(edev->prom_name, "power"))
126                                 goto found;
127                 }
128         }
129         return;
130
131 found:
132         power_reg = ioremap(edev->resource[0].start, 0x4);
133         printk("power: Control reg at %p ... ", power_reg);
134         poweroff_method = machine_halt;  /* able to use the standard halt */
135         if (has_button_interrupt(edev)) {
136                 if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
137                         printk("Failed to start power daemon.\n");
138                         return;
139                 }
140                 printk("powerd running.\n");
141
142                 if (request_irq(edev->irqs[0],
143                                 power_handler, SA_SHIRQ, "power", NULL) < 0)
144                         printk("power: Error, cannot register IRQ handler.\n");
145         } else {
146                 printk("not using powerd.\n");
147         }
148 }
149 #endif /* CONFIG_PCI */