1 files changed, 269 insertions, 0 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
new file mode 100644
index 000000000000..7960ddf04a57
--- /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);