1 files changed, 269 insertions, 0 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c
new file mode 100644
index 0000000..7960ddf
--- /dev/null
+++ b/kernel/power/main.c
@@ -0,0 +1,269 @@
+/*
+ * kernel/power/main.c - PM subsystem core functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * 
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/suspend.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/pm.h>
+
+
+#include "power.h"
+
+DECLARE_MUTEX(pm_sem);
+
+struct pm_ops * pm_ops = NULL;
+suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
+
+/**
+ *	pm_set_ops - Set the global power method table. 
+ *	@ops:	Pointer to ops structure.
+ */
+
+void pm_set_ops(struct pm_ops * ops)
+{
+	down(&pm_sem);
+	pm_ops = ops;
+	up(&pm_sem);
+}
+
+
+/**
+ *	suspend_prepare - Do prep work before entering low-power state.
+ *	@state:		State we're entering.
+ *
+ *	This is common code that is called for each state that we're 
+ *	entering. Allocate a console, stop all processes, then make sure
+ *	the platform can enter the requested state.
+ */
+
+static int suspend_prepare(suspend_state_t state)
+{
+	int error = 0;
+
+	if (!pm_ops || !pm_ops->enter)
+		return -EPERM;
+
+	pm_prepare_console();
+
+	if (freeze_processes()) {
+		error = -EAGAIN;
+		goto Thaw;
+	}
+
+	if (pm_ops->prepare) {
+		if ((error = pm_ops->prepare(state)))
+			goto Thaw;
+	}
+
+	if ((error = device_suspend(PMSG_SUSPEND))) {
+		printk(KERN_ERR "Some devices failed to suspend\n");
+		goto Finish;
+	}
+	return 0;
+ Finish:
+	if (pm_ops->finish)
+		pm_ops->finish(state);
+ Thaw:
+	thaw_processes();
+	pm_restore_console();
+	return error;
+}
+
+
+static int suspend_enter(suspend_state_t state)
+{
+	int error = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	if ((error = device_power_down(PMSG_SUSPEND))) {
+		printk(KERN_ERR "Some devices failed to power down\n");
+		goto Done;
+	}
+	error = pm_ops->enter(state);
+	device_power_up();
+ Done:
+	local_irq_restore(flags);
+	return error;
+}
+
+
+/**
+ *	suspend_finish - Do final work before exiting suspend sequence.
+ *	@state:		State we're coming out of.
+ *
+ *	Call platform code to clean up, restart processes, and free the 
+ *	console that we've allocated. This is not called for suspend-to-disk.
+ */
+
+static void suspend_finish(suspend_state_t state)
+{
+	device_resume();
+	if (pm_ops && pm_ops->finish)
+		pm_ops->finish(state);
+	thaw_processes();
+	pm_restore_console();
+}
+
+
+
+
+static char * pm_states[] = {
+	[PM_SUSPEND_STANDBY]	= "standby",
+	[PM_SUSPEND_MEM]	= "mem",
+	[PM_SUSPEND_DISK]	= "disk",
+	NULL,
+};
+
+
+/**
+ *	enter_state - Do common work of entering low-power state.
+ *	@state:		pm_state structure for state we're entering.
+ *
+ *	Make sure we're the only ones trying to enter a sleep state. Fail
+ *	if someone has beat us to it, since we don't want anything weird to
+ *	happen when we wake up.
+ *	Then, do the setup for suspend, enter the state, and cleaup (after
+ *	we've woken up).
+ */
+
+static int enter_state(suspend_state_t state)
+{
+	int error;
+
+	if (down_trylock(&pm_sem))
+		return -EBUSY;
+
+	if (state == PM_SUSPEND_DISK) {
+		error = pm_suspend_disk();
+		goto Unlock;
+	}
+
+	/* Suspend is hard to get right on SMP. */
+	if (num_online_cpus() != 1) {
+		error = -EPERM;
+		goto Unlock;
+	}
+
+	pr_debug("PM: Preparing system for suspend\n");
+	if ((error = suspend_prepare(state)))
+		goto Unlock;
+
+	pr_debug("PM: Entering state.\n");
+	error = suspend_enter(state);
+
+	pr_debug("PM: Finishing up.\n");
+	suspend_finish(state);
+ Unlock:
+	up(&pm_sem);
+	return error;
+}
+
+/*
+ * This is main interface to the outside world. It needs to be
+ * called from process context.
+ */
+int software_suspend(void)
+{
+	return enter_state(PM_SUSPEND_DISK);
+}
+
+
+/**
+ *	pm_suspend - Externally visible function for suspending system.
+ *	@state:		Enumarted value of state to enter.
+ *
+ *	Determine whether or not value is within range, get state 
+ *	structure, and enter (above).
+ */
+
+int pm_suspend(suspend_state_t state)
+{
+	if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX)
+		return enter_state(state);
+	return -EINVAL;
+}
+
+
+
+decl_subsys(power,NULL,NULL);
+
+
+/**
+ *	state - control system power state.
+ *
+ *	show() returns what states are supported, which is hard-coded to
+ *	'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
+ *	'disk' (Suspend-to-Disk).
+ *
+ *	store() accepts one of those strings, translates it into the 
+ *	proper enumerated value, and initiates a suspend transition.
+ */
+
+static ssize_t state_show(struct subsystem * subsys, char * buf)
+{
+	int i;
+	char * s = buf;
+
+	for (i = 0; i < PM_SUSPEND_MAX; i++) {
+		if (pm_states[i])
+			s += sprintf(s,"%s ",pm_states[i]);
+	}
+	s += sprintf(s,"\n");
+	return (s - buf);
+}
+
+static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n)
+{
+	suspend_state_t state = PM_SUSPEND_STANDBY;
+	char ** s;
+	char *p;
+	int error;
+	int len;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
+		if (*s && !strncmp(buf, *s, len))
+			break;
+	}
+	if (*s)
+		error = enter_state(state);
+	else
+		error = -EINVAL;
+	return error ? error : n;
+}
+
+power_attr(state);
+
+static struct attribute * g[] = {
+	&state_attr.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group = {
+	.attrs = g,
+};
+
+
+static int __init pm_init(void)
+{
+	int error = subsystem_register(&power_subsys);
+	if (!error)
+		error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
+	return error;
+}
+
+core_initcall(pm_init);