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