diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/power/main.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'kernel/power/main.c')
-rw-r--r-- | kernel/power/main.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c new file mode 100644 index 00000000000..7960ddf04a5 --- /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); |