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Alan Sterndb5bd1e2010-06-17 10:36:49 -04001/*
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>
Paul Gortmaker09703662011-05-27 09:37:25 -04009#include <linux/export.h>
Alan Sternfea6d602012-02-17 16:25:08 -050010#include <linux/async.h>
Alan Sterndb5bd1e2010-06-17 10:36:49 -040011
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
19static 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
34static 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
49static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
50{
51 int err = 0;
52
Lin Ming28640512011-12-05 09:20:25 +080053 if (scsi_is_sdev_device(dev)) {
54 /*
55 * sd is the only high-level SCSI driver to implement runtime
56 * PM, and sd treats runtime suspend, system suspend, and
57 * system hibernate identically (but not system freeze).
58 */
59 if (pm_runtime_suspended(dev)) {
60 if (msg.event == PM_EVENT_SUSPEND ||
61 msg.event == PM_EVENT_HIBERNATE)
62 return 0; /* already suspended */
63
64 /* wake up device so that FREEZE will succeed */
65 pm_runtime_resume(dev);
66 }
Alan Sterndb5bd1e2010-06-17 10:36:49 -040067 err = scsi_dev_type_suspend(dev, msg);
Lin Ming28640512011-12-05 09:20:25 +080068 }
Alan Sterndb5bd1e2010-06-17 10:36:49 -040069 return err;
70}
71
72static int scsi_bus_resume_common(struct device *dev)
73{
74 int err = 0;
75
Lin Ming28fd00d2011-12-22 14:50:47 +080076 if (scsi_is_sdev_device(dev)) {
77 /*
78 * Parent device may have runtime suspended as soon as
79 * it is woken up during the system resume.
80 *
81 * Resume it on behalf of child.
82 */
83 pm_runtime_get_sync(dev->parent);
Alan Sterndb5bd1e2010-06-17 10:36:49 -040084 err = scsi_dev_type_resume(dev);
Lin Ming28fd00d2011-12-22 14:50:47 +080085 pm_runtime_put_sync(dev->parent);
86 }
Alan Sternbc4f2402010-06-17 10:41:42 -040087
88 if (err == 0) {
89 pm_runtime_disable(dev);
90 pm_runtime_set_active(dev);
91 pm_runtime_enable(dev);
92 }
Alan Sterndb5bd1e2010-06-17 10:36:49 -040093 return err;
94}
95
Alan Sternfea6d602012-02-17 16:25:08 -050096static int scsi_bus_prepare(struct device *dev)
97{
98 if (scsi_is_sdev_device(dev)) {
99 /* sd probing uses async_schedule. Wait until it finishes. */
100 async_synchronize_full();
101
102 } else if (scsi_is_host_device(dev)) {
103 /* Wait until async scanning is finished */
104 scsi_complete_async_scans();
105 }
106 return 0;
107}
108
Alan Sterndb5bd1e2010-06-17 10:36:49 -0400109static int scsi_bus_suspend(struct device *dev)
110{
111 return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
112}
113
114static int scsi_bus_freeze(struct device *dev)
115{
116 return scsi_bus_suspend_common(dev, PMSG_FREEZE);
117}
118
119static int scsi_bus_poweroff(struct device *dev)
120{
121 return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
122}
123
124#else /* CONFIG_PM_SLEEP */
125
126#define scsi_bus_resume_common NULL
Alan Sternfea6d602012-02-17 16:25:08 -0500127#define scsi_bus_prepare NULL
Alan Sterndb5bd1e2010-06-17 10:36:49 -0400128#define scsi_bus_suspend NULL
129#define scsi_bus_freeze NULL
130#define scsi_bus_poweroff NULL
131
132#endif /* CONFIG_PM_SLEEP */
133
Alan Sternbc4f2402010-06-17 10:41:42 -0400134#ifdef CONFIG_PM_RUNTIME
135
136static int scsi_runtime_suspend(struct device *dev)
137{
138 int err = 0;
139
140 dev_dbg(dev, "scsi_runtime_suspend\n");
141 if (scsi_is_sdev_device(dev)) {
142 err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
143 if (err == -EAGAIN)
144 pm_schedule_suspend(dev, jiffies_to_msecs(
145 round_jiffies_up_relative(HZ/10)));
146 }
147
148 /* Insert hooks here for targets, hosts, and transport classes */
149
150 return err;
151}
152
153static int scsi_runtime_resume(struct device *dev)
154{
155 int err = 0;
156
157 dev_dbg(dev, "scsi_runtime_resume\n");
158 if (scsi_is_sdev_device(dev))
159 err = scsi_dev_type_resume(dev);
160
161 /* Insert hooks here for targets, hosts, and transport classes */
162
163 return err;
164}
165
166static int scsi_runtime_idle(struct device *dev)
167{
168 int err;
169
170 dev_dbg(dev, "scsi_runtime_idle\n");
171
172 /* Insert hooks here for targets, hosts, and transport classes */
173
174 if (scsi_is_sdev_device(dev))
175 err = pm_schedule_suspend(dev, 100);
176 else
177 err = pm_runtime_suspend(dev);
178 return err;
179}
180
181int scsi_autopm_get_device(struct scsi_device *sdev)
182{
183 int err;
184
185 err = pm_runtime_get_sync(&sdev->sdev_gendev);
Rafael J. Wysocki632e2702011-07-01 22:29:15 +0200186 if (err < 0 && err !=-EACCES)
Alan Sternbc4f2402010-06-17 10:41:42 -0400187 pm_runtime_put_sync(&sdev->sdev_gendev);
Rafael J. Wysocki632e2702011-07-01 22:29:15 +0200188 else
Alan Sternbc4f2402010-06-17 10:41:42 -0400189 err = 0;
190 return err;
191}
192EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
193
194void scsi_autopm_put_device(struct scsi_device *sdev)
195{
196 pm_runtime_put_sync(&sdev->sdev_gendev);
197}
198EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
199
200void scsi_autopm_get_target(struct scsi_target *starget)
201{
202 pm_runtime_get_sync(&starget->dev);
203}
204
205void scsi_autopm_put_target(struct scsi_target *starget)
206{
207 pm_runtime_put_sync(&starget->dev);
208}
209
210int scsi_autopm_get_host(struct Scsi_Host *shost)
211{
212 int err;
213
214 err = pm_runtime_get_sync(&shost->shost_gendev);
Rafael J. Wysocki632e2702011-07-01 22:29:15 +0200215 if (err < 0 && err !=-EACCES)
Alan Sternbc4f2402010-06-17 10:41:42 -0400216 pm_runtime_put_sync(&shost->shost_gendev);
Rafael J. Wysocki632e2702011-07-01 22:29:15 +0200217 else
Alan Sternbc4f2402010-06-17 10:41:42 -0400218 err = 0;
219 return err;
220}
221
222void scsi_autopm_put_host(struct Scsi_Host *shost)
223{
224 pm_runtime_put_sync(&shost->shost_gendev);
225}
226
227#else
228
229#define scsi_runtime_suspend NULL
230#define scsi_runtime_resume NULL
231#define scsi_runtime_idle NULL
232
233#endif /* CONFIG_PM_RUNTIME */
234
Alan Sterndb5bd1e2010-06-17 10:36:49 -0400235const struct dev_pm_ops scsi_bus_pm_ops = {
Alan Sternfea6d602012-02-17 16:25:08 -0500236 .prepare = scsi_bus_prepare,
Alan Sterndb5bd1e2010-06-17 10:36:49 -0400237 .suspend = scsi_bus_suspend,
238 .resume = scsi_bus_resume_common,
239 .freeze = scsi_bus_freeze,
240 .thaw = scsi_bus_resume_common,
241 .poweroff = scsi_bus_poweroff,
242 .restore = scsi_bus_resume_common,
Alan Sternbc4f2402010-06-17 10:41:42 -0400243 .runtime_suspend = scsi_runtime_suspend,
244 .runtime_resume = scsi_runtime_resume,
245 .runtime_idle = scsi_runtime_idle,
Alan Sterndb5bd1e2010-06-17 10:36:49 -0400246};