| 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 | /* |
| 54 | * sd is the only high-level SCSI driver to implement runtime |
| 55 | * PM, and sd treats runtime suspend, system suspend, and |
| 56 | * system hibernate identically (but not system freeze). |
| 57 | */ |
| 58 | if (pm_runtime_suspended(dev)) { |
| 59 | if (msg.event == PM_EVENT_SUSPEND || |
| 60 | msg.event == PM_EVENT_HIBERNATE) |
| 61 | return 0; /* already suspended */ |
| 62 | |
| 63 | /* wake up device so that FREEZE will succeed */ |
| 64 | pm_runtime_resume(dev); |
| 65 | } |
| 66 | err = scsi_dev_type_suspend(dev, msg); |
| 67 | } |
| 68 | return err; |
| 69 | } |
| 70 | |
| 71 | static int scsi_bus_resume_common(struct device *dev) |
| 72 | { |
| 73 | int err = 0; |
| 74 | |
| 75 | if (scsi_is_sdev_device(dev)) { |
| 76 | /* |
| 77 | * Parent device may have runtime suspended as soon as |
| 78 | * it is woken up during the system resume. |
| 79 | * |
| 80 | * Resume it on behalf of child. |
| 81 | */ |
| 82 | pm_runtime_get_sync(dev->parent); |
| 83 | err = scsi_dev_type_resume(dev); |
| 84 | pm_runtime_put_sync(dev->parent); |
| 85 | } |
| 86 | |
| 87 | if (err == 0) { |
| 88 | pm_runtime_disable(dev); |
| 89 | pm_runtime_set_active(dev); |
| 90 | pm_runtime_enable(dev); |
| 91 | } |
| 92 | return err; |
| 93 | } |
| 94 | |
| 95 | static int scsi_bus_suspend(struct device *dev) |
| 96 | { |
| 97 | return scsi_bus_suspend_common(dev, PMSG_SUSPEND); |
| 98 | } |
| 99 | |
| 100 | static int scsi_bus_freeze(struct device *dev) |
| 101 | { |
| 102 | return scsi_bus_suspend_common(dev, PMSG_FREEZE); |
| 103 | } |
| 104 | |
| 105 | static int scsi_bus_poweroff(struct device *dev) |
| 106 | { |
| 107 | return scsi_bus_suspend_common(dev, PMSG_HIBERNATE); |
| 108 | } |
| 109 | |
| 110 | #else /* CONFIG_PM_SLEEP */ |
| 111 | |
| 112 | #define scsi_bus_resume_common NULL |
| 113 | #define scsi_bus_suspend NULL |
| 114 | #define scsi_bus_freeze NULL |
| 115 | #define scsi_bus_poweroff NULL |
| 116 | |
| 117 | #endif /* CONFIG_PM_SLEEP */ |
| 118 | |
| 119 | #ifdef CONFIG_PM_RUNTIME |
| 120 | |
| 121 | static int scsi_runtime_suspend(struct device *dev) |
| 122 | { |
| 123 | int err = 0; |
| 124 | |
| 125 | dev_dbg(dev, "scsi_runtime_suspend\n"); |
| 126 | if (scsi_is_sdev_device(dev)) { |
| 127 | err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND); |
| 128 | if (err == -EAGAIN) |
| 129 | pm_schedule_suspend(dev, jiffies_to_msecs( |
| 130 | round_jiffies_up_relative(HZ/10))); |
| 131 | } |
| 132 | |
| 133 | /* Insert hooks here for targets, hosts, and transport classes */ |
| 134 | |
| 135 | return err; |
| 136 | } |
| 137 | |
| 138 | static int scsi_runtime_resume(struct device *dev) |
| 139 | { |
| 140 | int err = 0; |
| 141 | |
| 142 | dev_dbg(dev, "scsi_runtime_resume\n"); |
| 143 | if (scsi_is_sdev_device(dev)) |
| 144 | err = scsi_dev_type_resume(dev); |
| 145 | |
| 146 | /* Insert hooks here for targets, hosts, and transport classes */ |
| 147 | |
| 148 | return err; |
| 149 | } |
| 150 | |
| 151 | static int scsi_runtime_idle(struct device *dev) |
| 152 | { |
| 153 | int err; |
| 154 | |
| 155 | dev_dbg(dev, "scsi_runtime_idle\n"); |
| 156 | |
| 157 | /* Insert hooks here for targets, hosts, and transport classes */ |
| 158 | |
| 159 | if (scsi_is_sdev_device(dev)) |
| 160 | err = pm_schedule_suspend(dev, 100); |
| 161 | else |
| 162 | err = pm_runtime_suspend(dev); |
| 163 | return err; |
| 164 | } |
| 165 | |
| 166 | int scsi_autopm_get_device(struct scsi_device *sdev) |
| 167 | { |
| 168 | int err; |
| 169 | |
| 170 | err = pm_runtime_get_sync(&sdev->sdev_gendev); |
| 171 | if (err < 0 && err !=-EACCES) |
| 172 | pm_runtime_put_sync(&sdev->sdev_gendev); |
| 173 | else |
| 174 | err = 0; |
| 175 | return err; |
| 176 | } |
| 177 | EXPORT_SYMBOL_GPL(scsi_autopm_get_device); |
| 178 | |
| 179 | void scsi_autopm_put_device(struct scsi_device *sdev) |
| 180 | { |
| 181 | pm_runtime_put_sync(&sdev->sdev_gendev); |
| 182 | } |
| 183 | EXPORT_SYMBOL_GPL(scsi_autopm_put_device); |
| 184 | |
| 185 | void scsi_autopm_get_target(struct scsi_target *starget) |
| 186 | { |
| 187 | pm_runtime_get_sync(&starget->dev); |
| 188 | } |
| 189 | |
| 190 | void scsi_autopm_put_target(struct scsi_target *starget) |
| 191 | { |
| 192 | pm_runtime_put_sync(&starget->dev); |
| 193 | } |
| 194 | |
| 195 | int scsi_autopm_get_host(struct Scsi_Host *shost) |
| 196 | { |
| 197 | int err; |
| 198 | |
| 199 | err = pm_runtime_get_sync(&shost->shost_gendev); |
| 200 | if (err < 0 && err !=-EACCES) |
| 201 | pm_runtime_put_sync(&shost->shost_gendev); |
| 202 | else |
| 203 | err = 0; |
| 204 | return err; |
| 205 | } |
| 206 | |
| 207 | void scsi_autopm_put_host(struct Scsi_Host *shost) |
| 208 | { |
| 209 | pm_runtime_put_sync(&shost->shost_gendev); |
| 210 | } |
| 211 | |
| 212 | #else |
| 213 | |
| 214 | #define scsi_runtime_suspend NULL |
| 215 | #define scsi_runtime_resume NULL |
| 216 | #define scsi_runtime_idle NULL |
| 217 | |
| 218 | #endif /* CONFIG_PM_RUNTIME */ |
| 219 | |
| 220 | const struct dev_pm_ops scsi_bus_pm_ops = { |
| 221 | .suspend = scsi_bus_suspend, |
| 222 | .resume = scsi_bus_resume_common, |
| 223 | .freeze = scsi_bus_freeze, |
| 224 | .thaw = scsi_bus_resume_common, |
| 225 | .poweroff = scsi_bus_poweroff, |
| 226 | .restore = scsi_bus_resume_common, |
| 227 | .runtime_suspend = scsi_runtime_suspend, |
| 228 | .runtime_resume = scsi_runtime_resume, |
| 229 | .runtime_idle = scsi_runtime_idle, |
| 230 | }; |