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/export.h>
  10 #include <linux/async.h>
  11
  12 #include <scsi/scsi.h>
  13 #include <scsi/scsi_device.h>
  14 #include <scsi/scsi_driver.h>
  15 #include <scsi/scsi_host.h>
  16
  17 #include "scsi_priv.h"
  18
  19 static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
  20 {
  21         struct device_driver *drv;
  22         int err;
  23
  24         err = scsi_device_quiesce(to_scsi_device(dev));
  25         if (err == 0) {
  26                 drv = dev->driver;
  27                 if (drv && drv->suspend)
  28                         err = drv->suspend(dev, msg);
  29         }
  30         dev_dbg(dev, "scsi suspend: %d\n", err);
  31         return err;
  32 }
  33
  34 static int scsi_dev_type_resume(struct device *dev)
  35 {
  36         struct device_driver *drv;
  37         int err = 0;
  38
  39         drv = dev->driver;
  40         if (drv && drv->resume)
  41                 err = drv->resume(dev);
  42         scsi_device_resume(to_scsi_device(dev));
  43         dev_dbg(dev, "scsi resume: %d\n", err);
  44         return err;
  45 }
  46
  47 #ifdef CONFIG_PM_SLEEP
  48
  49 static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
  50 {
  51         int err = 0;
  52
  53         if (scsi_is_sdev_device(dev))
  54                 err = scsi_dev_type_suspend(dev, msg);
  55         return err;
  56 }
  57
  58 static int scsi_bus_resume_common(struct device *dev)
  59 {
  60         int err = 0;
  61
  62         if (scsi_is_sdev_device(dev))
  63                 err = scsi_dev_type_resume(dev);
  64
  65         if (err == 0) {
  66                 pm_runtime_disable(dev);
  67                 pm_runtime_set_active(dev);
  68                 pm_runtime_enable(dev);
  69         }
  70         return err;
  71 }
  72
  73 static int scsi_bus_prepare(struct device *dev)
  74 {
  75         if (scsi_is_sdev_device(dev)) {
  76                 /* sd probing uses async_schedule.  Wait until it finishes. */
  77                 async_synchronize_full();
  78
  79         } else if (scsi_is_host_device(dev)) {
  80                 /* Wait until async scanning is finished */
  81                 scsi_complete_async_scans();
  82         }
  83         return 0;
  84 }
  85
  86 static int scsi_bus_suspend(struct device *dev)
  87 {
  88         return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
  89 }
  90
  91 static int scsi_bus_freeze(struct device *dev)
  92 {
  93         return scsi_bus_suspend_common(dev, PMSG_FREEZE);
  94 }
  95
  96 static int scsi_bus_poweroff(struct device *dev)
  97 {
  98         return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
  99 }
 100
 101 #else /* CONFIG_PM_SLEEP */
 102
 103 #define scsi_bus_resume_common          NULL
 104 #define scsi_bus_prepare                NULL
 105 #define scsi_bus_suspend                NULL
 106 #define scsi_bus_freeze                 NULL
 107 #define scsi_bus_poweroff               NULL
 108
 109 #endif /* CONFIG_PM_SLEEP */
 110
 111 #ifdef CONFIG_PM_RUNTIME
 112
 113 static int scsi_runtime_suspend(struct device *dev)
 114 {
 115         int err = 0;
 116
 117         dev_dbg(dev, "scsi_runtime_suspend\n");
 118         if (scsi_is_sdev_device(dev)) {
 119                 err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
 120                 if (err == -EAGAIN)
 121                         pm_schedule_suspend(dev, jiffies_to_msecs(
 122                                 round_jiffies_up_relative(HZ/10)));
 123         }
 124
 125         /* Insert hooks here for targets, hosts, and transport classes */
 126
 127         return err;
 128 }
 129
 130 static int scsi_runtime_resume(struct device *dev)
 131 {
 132         int err = 0;
 133
 134         dev_dbg(dev, "scsi_runtime_resume\n");
 135         if (scsi_is_sdev_device(dev))
 136                 err = scsi_dev_type_resume(dev);
 137
 138         /* Insert hooks here for targets, hosts, and transport classes */
 139
 140         return err;
 141 }
 142
 143 static int scsi_runtime_idle(struct device *dev)
 144 {
 145         int err;
 146
 147         dev_dbg(dev, "scsi_runtime_idle\n");
 148
 149         /* Insert hooks here for targets, hosts, and transport classes */
 150
 151         if (scsi_is_sdev_device(dev))
 152                 err = pm_schedule_suspend(dev, 100);
 153         else
 154                 err = pm_runtime_suspend(dev);
 155         return err;
 156 }
 157
 158 int scsi_autopm_get_device(struct scsi_device *sdev)
 159 {
 160         int     err;
 161
 162         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 163         if (err < 0 && err !=-EACCES)
 164                 pm_runtime_put_sync(&sdev->sdev_gendev);
 165         else
 166                 err = 0;
 167         return err;
 168 }
 169 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 170
 171 void scsi_autopm_put_device(struct scsi_device *sdev)
 172 {
 173         pm_runtime_put_sync(&sdev->sdev_gendev);
 174 }
 175 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 176
 177 void scsi_autopm_get_target(struct scsi_target *starget)
 178 {
 179         pm_runtime_get_sync(&starget->dev);
 180 }
 181
 182 void scsi_autopm_put_target(struct scsi_target *starget)
 183 {
 184         pm_runtime_put_sync(&starget->dev);
 185 }
 186
 187 int scsi_autopm_get_host(struct Scsi_Host *shost)
 188 {
 189         int     err;
 190
 191         err = pm_runtime_get_sync(&shost->shost_gendev);
 192         if (err < 0 && err !=-EACCES)
 193                 pm_runtime_put_sync(&shost->shost_gendev);
 194         else
 195                 err = 0;
 196         return err;
 197 }
 198
 199 void scsi_autopm_put_host(struct Scsi_Host *shost)
 200 {
 201         pm_runtime_put_sync(&shost->shost_gendev);
 202 }
 203
 204 #else
 205
 206 #define scsi_runtime_suspend    NULL
 207 #define scsi_runtime_resume     NULL
 208 #define scsi_runtime_idle       NULL
 209
 210 #endif /* CONFIG_PM_RUNTIME */
 211
 212 const struct dev_pm_ops scsi_bus_pm_ops = {
 213         .prepare =              scsi_bus_prepare,
 214         .suspend =              scsi_bus_suspend,
 215         .resume =               scsi_bus_resume_common,
 216         .freeze =               scsi_bus_freeze,
 217         .thaw =                 scsi_bus_resume_common,
 218         .poweroff =             scsi_bus_poweroff,
 219         .restore =              scsi_bus_resume_common,
 220         .runtime_suspend =      scsi_runtime_suspend,
 221         .runtime_resume =       scsi_runtime_resume,
 222         .runtime_idle =         scsi_runtime_idle,
 223 };