diff options
Diffstat (limited to 'drivers/base/power/main.c')
-rw-r--r-- | drivers/base/power/main.c | 344 |
1 files changed, 340 insertions, 4 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index eb9f38d..0ab4ab2 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -20,19 +20,24 @@ */ #include <linux/device.h> +#include <linux/kallsyms.h> #include <linux/mutex.h> +#include <linux/pm.h> +#include <linux/resume-trace.h> +#include "../base.h" #include "power.h" LIST_HEAD(dpm_active); -LIST_HEAD(dpm_off); -LIST_HEAD(dpm_off_irq); +static LIST_HEAD(dpm_off); +static LIST_HEAD(dpm_off_irq); -DEFINE_MUTEX(dpm_mtx); -DEFINE_MUTEX(dpm_list_mtx); +static DEFINE_MUTEX(dpm_mtx); +static DEFINE_MUTEX(dpm_list_mtx); int (*platform_enable_wakeup)(struct device *dev, int is_on); + int device_pm_add(struct device *dev) { int error; @@ -61,3 +66,334 @@ void device_pm_remove(struct device *dev) } +/*------------------------- Resume routines -------------------------*/ + +/** + * resume_device - Restore state for one device. + * @dev: Device. + * + */ + +static int resume_device(struct device * dev) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + down(&dev->sem); + + if (dev->bus && dev->bus->resume) { + dev_dbg(dev,"resuming\n"); + error = dev->bus->resume(dev); + } + + if (!error && dev->type && dev->type->resume) { + dev_dbg(dev,"resuming\n"); + error = dev->type->resume(dev); + } + + if (!error && dev->class && dev->class->resume) { + dev_dbg(dev,"class resume\n"); + error = dev->class->resume(dev); + } + + up(&dev->sem); + + TRACE_RESUME(error); + return error; +} + + +static int resume_device_early(struct device * dev) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + if (dev->bus && dev->bus->resume_early) { + dev_dbg(dev,"EARLY resume\n"); + error = dev->bus->resume_early(dev); + } + TRACE_RESUME(error); + return error; +} + +/* + * Resume the devices that have either not gone through + * the late suspend, or that did go through it but also + * went through the early resume + */ +static void dpm_resume(void) +{ + mutex_lock(&dpm_list_mtx); + while(!list_empty(&dpm_off)) { + struct list_head * entry = dpm_off.next; + struct device * dev = to_device(entry); + + get_device(dev); + list_move_tail(entry, &dpm_active); + + mutex_unlock(&dpm_list_mtx); + resume_device(dev); + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); +} + + +/** + * device_resume - Restore state of each device in system. + * + * Walk the dpm_off list, remove each entry, resume the device, + * then add it to the dpm_active list. + */ + +void device_resume(void) +{ + might_sleep(); + mutex_lock(&dpm_mtx); + dpm_resume(); + mutex_unlock(&dpm_mtx); +} + +EXPORT_SYMBOL_GPL(device_resume); + + +/** + * dpm_power_up - Power on some devices. + * + * Walk the dpm_off_irq list and power each device up. This + * is used for devices that required they be powered down with + * interrupts disabled. As devices are powered on, they are moved + * to the dpm_active list. + * + * Interrupts must be disabled when calling this. + */ + +static void dpm_power_up(void) +{ + while(!list_empty(&dpm_off_irq)) { + struct list_head * entry = dpm_off_irq.next; + struct device * dev = to_device(entry); + + list_move_tail(entry, &dpm_off); + resume_device_early(dev); + } +} + + +/** + * device_power_up - Turn on all devices that need special attention. + * + * Power on system devices then devices that required we shut them down + * with interrupts disabled. + * Called with interrupts disabled. + */ + +void device_power_up(void) +{ + sysdev_resume(); + dpm_power_up(); +} + +EXPORT_SYMBOL_GPL(device_power_up); + + +/*------------------------- Suspend routines -------------------------*/ + +/* + * The entries in the dpm_active list are in a depth first order, simply + * because children are guaranteed to be discovered after parents, and + * are inserted at the back of the list on discovery. + * + * All list on the suspend path are done in reverse order, so we operate + * on the leaves of the device tree (or forests, depending on how you want + * to look at it ;) first. As nodes are removed from the back of the list, + * they are inserted into the front of their destintation lists. + * + * Things are the reverse on the resume path - iterations are done in + * forward order, and nodes are inserted at the back of their destination + * lists. This way, the ancestors will be accessed before their descendents. + */ + +static inline char *suspend_verb(u32 event) +{ + switch (event) { + case PM_EVENT_SUSPEND: return "suspend"; + case PM_EVENT_FREEZE: return "freeze"; + case PM_EVENT_PRETHAW: return "prethaw"; + default: return "(unknown suspend event)"; + } +} + + +static void +suspend_device_dbg(struct device *dev, pm_message_t state, char *info) +{ + dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event), + ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ? + ", may wakeup" : ""); +} + +/** + * suspend_device - Save state of one device. + * @dev: Device. + * @state: Power state device is entering. + */ + +static int suspend_device(struct device * dev, pm_message_t state) +{ + int error = 0; + + down(&dev->sem); + if (dev->power.power_state.event) { + dev_dbg(dev, "PM: suspend %d-->%d\n", + dev->power.power_state.event, state.event); + } + + if (dev->class && dev->class->suspend) { + suspend_device_dbg(dev, state, "class "); + error = dev->class->suspend(dev, state); + suspend_report_result(dev->class->suspend, error); + } + + if (!error && dev->type && dev->type->suspend) { + suspend_device_dbg(dev, state, "type "); + error = dev->type->suspend(dev, state); + suspend_report_result(dev->type->suspend, error); + } + + if (!error && dev->bus && dev->bus->suspend) { + suspend_device_dbg(dev, state, ""); + error = dev->bus->suspend(dev, state); + suspend_report_result(dev->bus->suspend, error); + } + up(&dev->sem); + return error; +} + + +/* + * This is called with interrupts off, only a single CPU + * running. We can't acquire a mutex or semaphore (and we don't + * need the protection) + */ +static int suspend_device_late(struct device *dev, pm_message_t state) +{ + int error = 0; + + if (dev->bus && dev->bus->suspend_late) { + suspend_device_dbg(dev, state, "LATE "); + error = dev->bus->suspend_late(dev, state); + suspend_report_result(dev->bus->suspend_late, error); + } + return error; +} + +/** + * device_suspend - Save state and stop all devices in system. + * @state: Power state to put each device in. + * + * Walk the dpm_active list, call ->suspend() for each device, and move + * it to the dpm_off list. + * + * (For historical reasons, if it returns -EAGAIN, that used to mean + * that the device would be called again with interrupts disabled. + * These days, we use the "suspend_late()" callback for that, so we + * print a warning and consider it an error). + * + * If we get a different error, try and back out. + * + * If we hit a failure with any of the devices, call device_resume() + * above to bring the suspended devices back to life. + * + */ + +int device_suspend(pm_message_t state) +{ + int error = 0; + + might_sleep(); + mutex_lock(&dpm_mtx); + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_active) && error == 0) { + struct list_head * entry = dpm_active.prev; + struct device * dev = to_device(entry); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = suspend_device(dev, state); + + mutex_lock(&dpm_list_mtx); + + /* Check if the device got removed */ + if (!list_empty(&dev->power.entry)) { + /* Move it to the dpm_off list */ + if (!error) + list_move(&dev->power.entry, &dpm_off); + } + if (error) + printk(KERN_ERR "Could not suspend device %s: " + "error %d%s\n", + kobject_name(&dev->kobj), error, + error == -EAGAIN ? " (please convert to suspend_late)" : ""); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + if (error) + dpm_resume(); + + mutex_unlock(&dpm_mtx); + return error; +} + +EXPORT_SYMBOL_GPL(device_suspend); + +/** + * device_power_down - Shut down special devices. + * @state: Power state to enter. + * + * Walk the dpm_off_irq list, calling ->power_down() for each device that + * couldn't power down the device with interrupts enabled. When we're + * done, power down system devices. + */ + +int device_power_down(pm_message_t state) +{ + int error = 0; + struct device * dev; + + while (!list_empty(&dpm_off)) { + struct list_head * entry = dpm_off.prev; + + dev = to_device(entry); + error = suspend_device_late(dev, state); + if (error) + goto Error; + list_move(&dev->power.entry, &dpm_off_irq); + } + + error = sysdev_suspend(state); + Done: + return error; + Error: + printk(KERN_ERR "Could not power down device %s: " + "error %d\n", kobject_name(&dev->kobj), error); + dpm_power_up(); + goto Done; +} + +EXPORT_SYMBOL_GPL(device_power_down); + +void __suspend_report_result(const char *function, void *fn, int ret) +{ + if (ret) { + printk(KERN_ERR "%s(): ", function); + print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn); + printk("%d\n", ret); + } +} +EXPORT_SYMBOL_GPL(__suspend_report_result); |