diff options
Diffstat (limited to 'drivers/scsi/scsi_pm.c')
| -rw-r--r-- | drivers/scsi/scsi_pm.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c new file mode 100644 index 00000000..c4670642 --- /dev/null +++ b/drivers/scsi/scsi_pm.c @@ -0,0 +1,246 @@ +/* + * scsi_pm.c Copyright (C) 2010 Alan Stern + * + * SCSI dynamic Power Management + * Initial version: Alan Stern <stern@rowland.harvard.edu> + */ + +#include <linux/pm_runtime.h> +#include <linux/export.h> +#include <linux/async.h> + +#include <scsi/scsi.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_driver.h> +#include <scsi/scsi_host.h> + +#include "scsi_priv.h" + +static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg) +{ + struct device_driver *drv; + int err; + + err = scsi_device_quiesce(to_scsi_device(dev)); + if (err == 0) { + drv = dev->driver; + if (drv && drv->suspend) + err = drv->suspend(dev, msg); + } + dev_dbg(dev, "scsi suspend: %d\n", err); + return err; +} + +static int scsi_dev_type_resume(struct device *dev) +{ + struct device_driver *drv; + int err = 0; + + drv = dev->driver; + if (drv && drv->resume) + err = drv->resume(dev); + scsi_device_resume(to_scsi_device(dev)); + dev_dbg(dev, "scsi resume: %d\n", err); + return err; +} + +#ifdef CONFIG_PM_SLEEP + +static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg) +{ + int err = 0; + + if (scsi_is_sdev_device(dev)) { + /* + * sd is the only high-level SCSI driver to implement runtime + * PM, and sd treats runtime suspend, system suspend, and + * system hibernate identically (but not system freeze). + */ + if (pm_runtime_suspended(dev)) { + if (msg.event == PM_EVENT_SUSPEND || + msg.event == PM_EVENT_HIBERNATE) + return 0; /* already suspended */ + + /* wake up device so that FREEZE will succeed */ + pm_runtime_resume(dev); + } + err = scsi_dev_type_suspend(dev, msg); + } + return err; +} + +static int scsi_bus_resume_common(struct device *dev) +{ + int err = 0; + + if (scsi_is_sdev_device(dev)) { + /* + * Parent device may have runtime suspended as soon as + * it is woken up during the system resume. + * + * Resume it on behalf of child. + */ + pm_runtime_get_sync(dev->parent); + err = scsi_dev_type_resume(dev); + pm_runtime_put_sync(dev->parent); + } + + if (err == 0) { + pm_runtime_disable(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + } + return err; +} + +static int scsi_bus_prepare(struct device *dev) +{ + if (scsi_is_sdev_device(dev)) { + /* sd probing uses async_schedule. Wait until it finishes. */ + async_synchronize_full(); + + } else if (scsi_is_host_device(dev)) { + /* Wait until async scanning is finished */ + scsi_complete_async_scans(); + } + return 0; +} + +static int scsi_bus_suspend(struct device *dev) +{ + return scsi_bus_suspend_common(dev, PMSG_SUSPEND); +} + +static int scsi_bus_freeze(struct device *dev) +{ + return scsi_bus_suspend_common(dev, PMSG_FREEZE); +} + +static int scsi_bus_poweroff(struct device *dev) +{ + return scsi_bus_suspend_common(dev, PMSG_HIBERNATE); +} + +#else /* CONFIG_PM_SLEEP */ + +#define scsi_bus_resume_common NULL +#define scsi_bus_prepare NULL +#define scsi_bus_suspend NULL +#define scsi_bus_freeze NULL +#define scsi_bus_poweroff NULL + +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_PM_RUNTIME + +static int scsi_runtime_suspend(struct device *dev) +{ + int err = 0; + + dev_dbg(dev, "scsi_runtime_suspend\n"); + if (scsi_is_sdev_device(dev)) { + err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND); + if (err == -EAGAIN) + pm_schedule_suspend(dev, jiffies_to_msecs( + round_jiffies_up_relative(HZ/10))); + } + + /* Insert hooks here for targets, hosts, and transport classes */ + + return err; +} + +static int scsi_runtime_resume(struct device *dev) +{ + int err = 0; + + dev_dbg(dev, "scsi_runtime_resume\n"); + if (scsi_is_sdev_device(dev)) + err = scsi_dev_type_resume(dev); + + /* Insert hooks here for targets, hosts, and transport classes */ + + return err; +} + +static int scsi_runtime_idle(struct device *dev) +{ + int err; + + dev_dbg(dev, "scsi_runtime_idle\n"); + + /* Insert hooks here for targets, hosts, and transport classes */ + + if (scsi_is_sdev_device(dev)) + err = pm_schedule_suspend(dev, 100); + else + err = pm_runtime_suspend(dev); + return err; +} + +int scsi_autopm_get_device(struct scsi_device *sdev) +{ + int err; + + err = pm_runtime_get_sync(&sdev->sdev_gendev); + if (err < 0 && err !=-EACCES) + pm_runtime_put_sync(&sdev->sdev_gendev); + else + err = 0; + return err; +} +EXPORT_SYMBOL_GPL(scsi_autopm_get_device); + +void scsi_autopm_put_device(struct scsi_device *sdev) +{ + pm_runtime_put_sync(&sdev->sdev_gendev); +} +EXPORT_SYMBOL_GPL(scsi_autopm_put_device); + +void scsi_autopm_get_target(struct scsi_target *starget) +{ + pm_runtime_get_sync(&starget->dev); +} + +void scsi_autopm_put_target(struct scsi_target *starget) +{ + pm_runtime_put_sync(&starget->dev); +} + +int scsi_autopm_get_host(struct Scsi_Host *shost) +{ + int err; + + err = pm_runtime_get_sync(&shost->shost_gendev); + if (err < 0 && err !=-EACCES) + pm_runtime_put_sync(&shost->shost_gendev); + else + err = 0; + return err; +} + +void scsi_autopm_put_host(struct Scsi_Host *shost) +{ + pm_runtime_put_sync(&shost->shost_gendev); +} + +#else + +#define scsi_runtime_suspend NULL +#define scsi_runtime_resume NULL +#define scsi_runtime_idle NULL + +#endif /* CONFIG_PM_RUNTIME */ + +const struct dev_pm_ops scsi_bus_pm_ops = { + .prepare = scsi_bus_prepare, + .suspend = scsi_bus_suspend, + .resume = scsi_bus_resume_common, + .freeze = scsi_bus_freeze, + .thaw = scsi_bus_resume_common, + .poweroff = scsi_bus_poweroff, + .restore = scsi_bus_resume_common, + .runtime_suspend = scsi_runtime_suspend, + .runtime_resume = scsi_runtime_resume, + .runtime_idle = scsi_runtime_idle, +}; |