drivers/scsi/scsi_pm.c

   1 /*
   2  *      scsi_pm.c       Copyright (C) 2010 Alan Stern
   3  *
   4  *      SCSI dynamic Power Management
   5  *              Initial version: Alan Stern <stern@rowland.harvard.edu>
   6  */
   7
   8 #include <linux/pm_runtime.h>
   9 #include <linux/async.h>
  10
  11 #include <scsi/scsi.h>
  12 #include <scsi/scsi_device.h>
  13 #include <scsi/scsi_driver.h>
  14 #include <scsi/scsi_host.h>
  15
  16 #include "scsi_priv.h"
  17
  18 static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
  19 {
  20         struct device_driver *drv;
  21         int err;
  22
  23         err = scsi_device_quiesce(to_scsi_device(dev));
  24         if (err == 0) {
  25                 drv = dev->driver;
  26                 if (drv && drv->suspend)
  27                         err = drv->suspend(dev, msg);
  28         }
  29         dev_dbg(dev, "scsi suspend: %d\n", err);
  30         return err;
  31 }
  32
  33 static int scsi_dev_type_resume(struct device *dev)
  34 {
  35         struct device_driver *drv;
  36         int err = 0;
  37
  38         drv = dev->driver;
  39         if (drv && drv->resume)
  40                 err = drv->resume(dev);
  41         scsi_device_resume(to_scsi_device(dev));
  42         dev_dbg(dev, "scsi resume: %d\n", err);
  43         return err;
  44 }
  45
  46 #ifdef CONFIG_PM_SLEEP
  47
  48 static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
  49 {
  50         int err = 0;
  51
  52         if (scsi_is_sdev_device(dev))
  53                 err = scsi_dev_type_suspend(dev, msg);
  54         return err;
  55 }
  56
  57 static int scsi_bus_resume_common(struct device *dev)
  58 {
  59         int err = 0;
  60
  61         if (scsi_is_sdev_device(dev))
  62                 err = scsi_dev_type_resume(dev);
  63
  64         if (err == 0) {
  65                 pm_runtime_disable(dev);
  66                 pm_runtime_set_active(dev);
  67                 pm_runtime_enable(dev);
  68         }
  69         return err;
  70 }
  71
  72 static int scsi_bus_prepare(struct device *dev)
  73 {
  74         if (scsi_is_sdev_device(dev)) {
  75                 /* sd probing uses async_schedule.  Wait until it finishes. */
  76                 async_synchronize_full();
  77
  78         } else if (scsi_is_host_device(dev)) {
  79                 /* Wait until async scanning is finished */
  80                 scsi_complete_async_scans();
  81         }
  82         return 0;
  83 }
  84
  85 static int scsi_bus_suspend(struct device *dev)
  86 {
  87         return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
  88 }
  89
  90 static int scsi_bus_freeze(struct device *dev)
  91 {
  92         return scsi_bus_suspend_common(dev, PMSG_FREEZE);
  93 }
  94
  95 static int scsi_bus_poweroff(struct device *dev)
  96 {
  97         return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
  98 }
  99
 100 #else /* CONFIG_PM_SLEEP */
 101
 102 #define scsi_bus_resume_common          NULL
 103 #define scsi_bus_prepare                NULL
 104 #define scsi_bus_suspend                NULL
 105 #define scsi_bus_freeze                 NULL
 106 #define scsi_bus_poweroff               NULL
 107
 108 #endif /* CONFIG_PM_SLEEP */
 109
 110 #ifdef CONFIG_PM_RUNTIME
 111
 112 static int scsi_runtime_suspend(struct device *dev)
 113 {
 114         int err = 0;
 115
 116         dev_dbg(dev, "scsi_runtime_suspend\n");
 117         if (scsi_is_sdev_device(dev)) {
 118                 err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
 119                 if (err == -EAGAIN)
 120                         pm_schedule_suspend(dev, jiffies_to_msecs(
 121                                 round_jiffies_up_relative(HZ/10)));
 122         }
 123
 124         /* Insert hooks here for targets, hosts, and transport classes */
 125
 126         return err;
 127 }
 128
 129 static int scsi_runtime_resume(struct device *dev)
 130 {
 131         int err = 0;
 132
 133         dev_dbg(dev, "scsi_runtime_resume\n");
 134         if (scsi_is_sdev_device(dev))
 135                 err = scsi_dev_type_resume(dev);
 136
 137         /* Insert hooks here for targets, hosts, and transport classes */
 138
 139         return err;
 140 }
 141
 142 static int scsi_runtime_idle(struct device *dev)
 143 {
 144         int err;
 145
 146         dev_dbg(dev, "scsi_runtime_idle\n");
 147
 148         /* Insert hooks here for targets, hosts, and transport classes */
 149
 150         if (scsi_is_sdev_device(dev))
 151                 err = pm_schedule_suspend(dev, 100);
 152         else
 153                 err = pm_runtime_suspend(dev);
 154         return err;
 155 }
 156
 157 int scsi_autopm_get_device(struct scsi_device *sdev)
 158 {
 159         int     err;
 160
 161         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 162         if (err < 0)
 163                 pm_runtime_put_sync(&sdev->sdev_gendev);
 164         else if (err > 0)
 165                 err = 0;
 166         return err;
 167 }
 168 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 169
 170 void scsi_autopm_put_device(struct scsi_device *sdev)
 171 {
 172         pm_runtime_put_sync(&sdev->sdev_gendev);
 173 }
 174 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 175
 176 void scsi_autopm_get_target(struct scsi_target *starget)
 177 {
 178         pm_runtime_get_sync(&starget->dev);
 179 }
 180
 181 void scsi_autopm_put_target(struct scsi_target *starget)
 182 {
 183         pm_runtime_put_sync(&starget->dev);
 184 }
 185
 186 int scsi_autopm_get_host(struct Scsi_Host *shost)
 187 {
 188         int     err;
 189
 190         err = pm_runtime_get_sync(&shost->shost_gendev);
 191         if (err < 0)
 192                 pm_runtime_put_sync(&shost->shost_gendev);
 193         else if (err > 0)
 194                 err = 0;
 195         return err;
 196 }
 197
 198 void scsi_autopm_put_host(struct Scsi_Host *shost)
 199 {
 200         pm_runtime_put_sync(&shost->shost_gendev);
 201 }
 202
 203 #else
 204
 205 #define scsi_runtime_suspend    NULL
 206 #define scsi_runtime_resume     NULL
 207 #define scsi_runtime_idle       NULL
 208
 209 #endif /* CONFIG_PM_RUNTIME */
 210
 211 const struct dev_pm_ops scsi_bus_pm_ops = {
 212         .prepare =              scsi_bus_prepare,
 213         .suspend =              scsi_bus_suspend,
 214         .resume =               scsi_bus_resume_common,
 215         .freeze =               scsi_bus_freeze,
 216         .thaw =                 scsi_bus_resume_common,
 217         .poweroff =             scsi_bus_poweroff,
 218         .restore =              scsi_bus_resume_common,
 219         .runtime_suspend =      scsi_runtime_suspend,
 220         .runtime_resume =       scsi_runtime_resume,
 221         .runtime_idle =         scsi_runtime_idle,
 222 };