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
  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_suspend(struct device *dev)
  73 {
  74         return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
  75 }
  76
  77 static int scsi_bus_freeze(struct device *dev)
  78 {
  79         return scsi_bus_suspend_common(dev, PMSG_FREEZE);
  80 }
  81
  82 static int scsi_bus_poweroff(struct device *dev)
  83 {
  84         return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
  85 }
  86
  87 #else /* CONFIG_PM_SLEEP */
  88
  89 #define scsi_bus_resume_common          NULL
  90 #define scsi_bus_suspend                NULL
  91 #define scsi_bus_freeze                 NULL
  92 #define scsi_bus_poweroff               NULL
  93
  94 #endif /* CONFIG_PM_SLEEP */
  95
  96 #ifdef CONFIG_PM_RUNTIME
  97
  98 static int scsi_runtime_suspend(struct device *dev)
  99 {
 100         int err = 0;
 101
 102         dev_dbg(dev, "scsi_runtime_suspend\n");
 103         if (scsi_is_sdev_device(dev)) {
 104                 err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
 105                 if (err == -EAGAIN)
 106                         pm_schedule_suspend(dev, jiffies_to_msecs(
 107                                 round_jiffies_up_relative(HZ/10)));
 108         }
 109
 110         /* Insert hooks here for targets, hosts, and transport classes */
 111
 112         return err;
 113 }
 114
 115 static int scsi_runtime_resume(struct device *dev)
 116 {
 117         int err = 0;
 118
 119         dev_dbg(dev, "scsi_runtime_resume\n");
 120         if (scsi_is_sdev_device(dev))
 121                 err = scsi_dev_type_resume(dev);
 122
 123         /* Insert hooks here for targets, hosts, and transport classes */
 124
 125         return err;
 126 }
 127
 128 static int scsi_runtime_idle(struct device *dev)
 129 {
 130         int err;
 131
 132         dev_dbg(dev, "scsi_runtime_idle\n");
 133
 134         /* Insert hooks here for targets, hosts, and transport classes */
 135
 136         if (scsi_is_sdev_device(dev))
 137                 err = pm_schedule_suspend(dev, 100);
 138         else
 139                 err = pm_runtime_suspend(dev);
 140         return err;
 141 }
 142
 143 int scsi_autopm_get_device(struct scsi_device *sdev)
 144 {
 145         int     err;
 146
 147         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 148         if (err < 0 && err !=-EACCES)
 149                 pm_runtime_put_sync(&sdev->sdev_gendev);
 150         else
 151                 err = 0;
 152         return err;
 153 }
 154 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 155
 156 void scsi_autopm_put_device(struct scsi_device *sdev)
 157 {
 158         pm_runtime_put_sync(&sdev->sdev_gendev);
 159 }
 160 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 161
 162 void scsi_autopm_get_target(struct scsi_target *starget)
 163 {
 164         pm_runtime_get_sync(&starget->dev);
 165 }
 166
 167 void scsi_autopm_put_target(struct scsi_target *starget)
 168 {
 169         pm_runtime_put_sync(&starget->dev);
 170 }
 171
 172 int scsi_autopm_get_host(struct Scsi_Host *shost)
 173 {
 174         int     err;
 175
 176         err = pm_runtime_get_sync(&shost->shost_gendev);
 177         if (err < 0 && err !=-EACCES)
 178                 pm_runtime_put_sync(&shost->shost_gendev);
 179         else
 180                 err = 0;
 181         return err;
 182 }
 183
 184 void scsi_autopm_put_host(struct Scsi_Host *shost)
 185 {
 186         pm_runtime_put_sync(&shost->shost_gendev);
 187 }
 188
 189 #else
 190
 191 #define scsi_runtime_suspend    NULL
 192 #define scsi_runtime_resume     NULL
 193 #define scsi_runtime_idle       NULL
 194
 195 #endif /* CONFIG_PM_RUNTIME */
 196
 197 const struct dev_pm_ops scsi_bus_pm_ops = {
 198         .suspend =              scsi_bus_suspend,
 199         .resume =               scsi_bus_resume_common,
 200         .freeze =               scsi_bus_freeze,
 201         .thaw =                 scsi_bus_resume_common,
 202         .poweroff =             scsi_bus_poweroff,
 203         .restore =              scsi_bus_resume_common,
 204         .runtime_suspend =      scsi_runtime_suspend,
 205         .runtime_resume =       scsi_runtime_resume,
 206         .runtime_idle =         scsi_runtime_idle,
 207 };